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ARTICLE
Year : 1969  |  Volume : 17  |  Issue : 5  |  Page : 171-200

Dr. E. V. Srinivasan Oration- Primary keratomycosis


Bangalore Medical College and Minto Ophthalmic Hospital, Bangalore, India

Date of Web Publication11-Jan-2008

Correspondence Address:
S Puttanna
Bangalore Medical College and Minto Ophthalmic Hospital, Bangalore
India
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Source of Support: None, Conflict of Interest: None


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How to cite this article:
Puttanna S. Dr. E. V. Srinivasan Oration- Primary keratomycosis. Indian J Ophthalmol 1969;17:171-200

How to cite this URL:
Puttanna S. Dr. E. V. Srinivasan Oration- Primary keratomycosis. Indian J Ophthalmol [serial online] 1969 [cited 2020 Jun 4];17:171-200. Available from: http://www.ijo.in/text.asp?1969/17/5/171/38540

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Table 1

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President, fellow members of the All-India Ophthalmological Society, ladies and gentlemen,

I deem it a great honour to deliver Dr. E. Srinivasan's Oration today and I am highly thankful to the Scientific Body of the All-India Ophthalmologi­cal Society for having chosen me to deliver the oration, this year. Dr. E. Srinivasan was a pillar of strength to our Society and was instrumental in the organization of our Society and was one of its founder-members. He was an eminent ophthalmic surgeon and was a constant member at each annual conference, easily recognisable by his colourful turbans. His efforts elevated the status of our Society and steered it from its infancy to its pre­sent stature. I had the privilege of knowing him towards the end of his active and busy life. He was inter­ested in several phases of ophthalmo­logy, including detachment surgery. His name has been associated with dystrophies of the cornea and finds a place in Duke Elder's Text Book. He led a busy life, took active part in scientific discussions and his comments were sharp, critical based on his long and rich experience. He served the profession honestly and truthfully and breathed his last just after finishing an operation for detachment of the Retina.

I have selected `Primary Keratomy­cosis' as the subject of this oration as I have been interested in this field for the past 10 years. Corneal ulcers are of every day occurrence and the com­munities working in farms, quaries and mining areas, are the major suf­ferers of corneal blindness in our country. Corneal ulcers pose a chal­lenging problem to the ophthalmo­logists, as their etiology is of varied origin and their course unpredictable, prognosis uncertain, a specific therapy being still a confused issue, as effec­tive specific antifungal broad-spectrum agents are not still available. Corneal ulcers occur more frequently in elderly debilitated, arteriosclerotic and anaemic persons. They occur among the lower classes exposed to injury and prone to neglect the infection. They occur es­pecially during harvest season and by the time the patient seeks medical aid, the ulcers are much advanced and may recover without perforation but with opacities of varying density or end in perforation and its sequalae leading to blindness.

From January 1967 to December 1967, there were 301 cases of corneal ulcers admitted as inpatients to the Minto Ophthalmic Hospital. [Table - 1] shows the maximum incidence to be in the months of June, July, Septem­ber and October of 1967. It also in­dicates the absolute age and sex inci­dence.

I confine myself to the mycotic as­pect of the corneal ulcer which is com­ing more into light for the past decade, specially, after the advent of anti-biotics and corticosteroids, which are often used indiscriminately.

According to Kronfeld [52] "our defen­ces against the fungi are still meager and confusing." The known antifungal agents like nystatin and amphotericin B have been tried in some cases with va­riable results." This means that we are still short of broad-spectrum anti­fungal agents.


  Incidence of Fungal Infections Top


Since the report of Leber's [53] (1870) on fungus keratitis, more than 30 species of saprophytic fungi have been identified as the causative agents of primary exogenous keratomycosis. A review of the literature for the past 13 years shows a definite increase of fungal infections all over the World (Mikami and Stemmermann [66] ; Chick and Conant [23] ). Haggerty and Zimmermann [44] ) reported a fifteenfold statis­tical increase (1:77) in fungal infections of the eye since the introduction of Cortico-steroids from the incident rate of 1:11329 of previous years. A similar report is by Thygeson, Hogan and Kimura [89] ).

Surveys reveal that fungi are found in various parts of the human body with incidence as high, as 80 per cent on tongue (Benham and Hopkins [13] )-, 63.6 per cent in ear canals (Haley [16] ); and 49 per cent in tonsillar crypts (Bernard, Race and Guy [14] ). Seligmann [80] and Vogel, Michael and Timpe [95] have reported the systemic dissemination of fungus infection, after systemic corti­sone therapy. Conant, Smith, Baker, Callaway and Martin [25] stated that My­cotic Keratitis was mainly due to po­tentially pathogenic fungi.

As regards corneal infections, the literature is full of clinical case reports since Leber's [53] in 1879 [2],[6],[9],[16],[26] .

As regards Indian authors Sreenivas Rao and Ramakrishna [84] have reported 13 cases of fungal infection out of 40 cases (33%) of corneal ulcers in his series from Mangalore and Agarwal and Khosla [2] 6 cases isolating Candida Albicans and Aspurg. fumigatus in 2 cases of each and Fusarium and Can­dida krusic in 1 each. We [77] have been able to diagnose 34 cases within 10 years.

It is to be noted that in quite a num­ber of studies of un-inflamed eyes fungi have been cultured. [Table - 2] gives an indication of the wide varia­tions in the results obtained by differ­ent authors.

[Table - 2],[Table - 3],[Table - 4],[Table - 5],[Table - 6] show frequency of positive cultures from healthy eyes and the reported sites of infection by foreign authors.

Variations in frequency do occur on geographical variations and climatic conditions as in sporotrichum (Mc­Grath and Singer [61] ). Penicillium pre­dominates in temperate climates and can exist at a lower optimum tempera­ture and Aspergillus thrives in tropics and requires higher optimum tempera­ture but less moisture. Of Fazaka's [32] 258 positive cultures, 71 were of the penicillium species. There appears to be a seasonal variation in the inci­dence of fungi, the maximum incidence being in the relatively cool and humid months (Sreenivasa Rao et al [84] ). Thus, ecological differences are responsible for variation in fungal flora of differ­ent regions and in our series the max­imum number of fungal infections were due to the Aspergillus species. Of course, each genus includes a diver­sity of organisms, different species vary in pathogenicity and within each spe­cies there may be different strains which likewise vary, thus complicat­ing the therapeutic approach. Ham­meke and Ellis [46] report that the inci­dence of positive cultures below the age of 16 years is lower (4.8 per cent), as compared with adults (10.3 percent). Thus elderly individuals are more prone for fungal infections.

A number of studies indicate that indiscriminate use of antibiotics and corticosteroids potentiate fungal infec­tions of the eye or enhance the patho­genicity, though they may not be the actual cause of the infestation by fungi. Antibiotics and corticosteroids have been variously implicated sepa­rately or in combination for this potentiation. [1],[5],[8],48],[64],[69],[90],[94] .

Even so, a primary fungus keratitis is possible as shown by our own expe­rimental studies in which we success­fully produced fungal keratitis in rab­bits' cornea by aspergillus fumigatus, penicillium and caphalo-sporium spe­cies. (Puttana [74] ). We have also re­ported primary aspergillus after the instillation of herbal juices used as na­tive medicines for the eyes. (Puttana [76] ). Other authors who have reported pri­mary type of mycotic keratitis are Balkrishnan [8] and Drault-Toufesco [30] . Wilson, Sexton and Ahern [96] have re­ported corneal ulcer from mycotic af­fection of the skin due o philophore verrucosa.

Non-pathogenic fungi can be con­verted into pathogenic ones in the pre­sence of mixed infection, as shown ex­perimentally by Agarwal and Khosla [2] or in the presence of cortico-steroids­ (Ley [54]

In vitro experiments also have prov­ed the unholy effects of indiscriminate use of antibiotics and corticosteroids [30],[55],[81],[92] Tanaka [85] has shown, in vitro, the inhibiting effect of chlortetracy­clin on C. Albicans in higher concen­tration (0.25 per cent) and a stimulat­ing effect in a concentration of less than 0.01 per cent.

There is also evidence to show that there has been an increased incidence of systemic fungal infections, along with the ophthalmic, after antibiotic or steroid therapy [55],[81],[93]

It can be concluded that corticoste­roids and antibiotics used indiscrimi­nately or the presence of other non­pathogenic or pathogenic microorga­nisms can convert a non-pathogenic fungus into a pathogenic one or in­crease the virulence of pathogenic fungi.

The synergistic effects of these thera­peutic preparations or of mixed infec­tions on fungal infections have been attributed variously to different rea­sons, e.g. the growth and/or the viru­lence of the pathogens may be directly altered or the protective action of the normal flora is interfered with, or the host cell permeability is altered, per­mitting the pathogen to become more readily established. (Huppert, Mc­Pherson and Cazin [49] ).

Steroids either in combination with antibiotics or without them are freely prescribed not only by ophthalmolo­gists but also by general practitioners and non-ophthalmic specialists. The abuse of corticosteroids has done more harm than good as in herpetic keratitis and has hastened the progression of the superficial diseases of the cornea to perforation and made the opportunistic fungi like cephalosporium, penicillium and fusarium species to become patho­genic.

Secondly the suppressive, anti-in­flammatory effect of corticosteroids may delay the clinical diagnosis of a possible fungal infection which is part­ly made from the antibiotic resistant characters of fungal infections.


  Fungi and their Classification Top


Fungi have no chlorophyll in them and are unable to synthesize carbohydrates from the carbon dioxide of the air and hence are heterotrophic, i.e., they depend on prepared food mate­rials supplied to them. They are either parasitic or saprophytic in habit. Re­serve carbhydrates in fungi is glyco­gen. They reproduce by means of spe­cialized cells called spores which on a suitable substrate germinate, producing one or more filamentous processess called germ tubes. These elongate into filaments and each filament is called a hypha. (See diagram)

These hyphae branch, rebranch and intertwine to form a network called mycelium. The mycelium seen above the surface of the medium is aerial mycelium and that below the surface for food collecting is called the vege­tative mycelium. The aerial myce­lium is reproductive in function and bears spores.

At first, the hyphae are like tubes without any partitions (non-septate). When they divide into chains of cells separated by transverse walls (septa) they are called septate-hyphae. In some fungi, the hyphae remain non­septate, wherein the protoplasm flows freely uninterrupted through the hol­low tubes or cells which contain many nuclei. They are cenositic, i.e., capable of living apart from their host.

It is necessary to be familiar with the following terms while talking of spores of yeasts and fungi.

Spores = Reproductive elements of one of the lower organisms.

Exospores or conidia = Nonsexual spores arising from the end of the hy­phae (conidiophores) by budding. These can be micro-(small) or macro­(large).

Conidiophore = The specialised branch of the mycelium which bears conidia

Endospores or gonidia = Sexual spores formed in the interior of spe­cial hyphae (sporangia).

Zoospores = Endospores that are free and provided with locomotive fla­gelle. Their cases are known as zoo­sporangia.

Zygospores = Spores formed by a conjugation between two special hy­phae which bear morphologically identical cells and do not show sexual differentiation.

Oospores = spores formed by the conjugation of two sexually differen­tiated elements.

Chlamydospores = Spores enclosed by two envelopes, the whole forming the reproductive organ.

Sporangiophore = The thread-like stalk which bears at its tip the sporan­gium of molds.

Sporangium = The encysted struc­ture containing the spores. When it ruptures the spores are scattered about.

Perithecium = A cup or flask-shaped envelope enclosing the fructification of certain fungi and molds.

The classification is based on (1) type of colony, (2) presence or absence of mycelium, (3) type of mycelium, (4) methods of spore development, (5) characteristics of the spores - shape and size of spores.

Fungi are broadly grouped into

I. Pseudomycetes (False fungi)

a) Schizomycetes (bacteria)

b) Myxomycetes or slimy molds (non-pathogenic)

II. Eumycetes (true fungi)

(a) Phycomycetes

b) Basidomycetes

c) Ascomycetes

d) Deuteromycetes or fungi imperfecta.

The distinguishing characteristics of the different eumycetes are tabulated in [Table - 8].

Asexual spores on which the classi­fication of fungi imperfecti is based, are of two major types:

(a) Conidiospores : produced by a specialised hypha (conidiophore) aris­ing from septate hyphae and mycelium.

(b) Thallospores : formed by the thallus or congregation of ovoid or round-cells, which represent the simpl­est form of plant-life (e.g. sea-weeds and algae) are allied to the mycelium of molds. They arise by budding as cells from the parent cells. Sometimes the spores remain encased in a thick­wall and form a resting or hybernating stage (chlamydospores). Sometimes the segmentation of the daughter cells re­sult in rectangular or pillow-shaped spores, and assume a septate appearance and are therefore called pseudo­hyphae (Arthrospores).

From a clinician's point of view, it will suffice to divide fungi into molds and yeast groups. Molds present dry cotton-wooly growths seen on aging foods and have a net work of myce­lium. In tissues, molds grow as hy­phae beneath the surface and spores are rarely seen unless they reach the surface, where they can fruit off.

Yeasts are round or ovoid-celled or­ganisms and reproduce by budding, as daughter cells. A number of pathoge­nic fungi are dimorphic, i.e., they re­semble molds when growing as sapro­phytes and assume an yeast form when leading a parasitic life in animal tis­sues. Some of the yeast-like fungi may form fragile hyphae-like chains called pseudo-hyphae. Fungi and their spores are found everywhere and their num­ber of species run into thousands. Of these, about 50 are pathogenic to man.

True yeasts remain in the Yeast form at both room temperature (20° C) and incubator (body 37°C). They produce no mycelium and reproduce by bud­ding.

Candida species produce soft yeast-­like colonies at room and incubator temperatures. The aerial portion is yeast and the vegetative portion con­tains elongated buds remaining at­tached to the parent cell which on re­peated division produce a chain of at­tached cells somewhat constricted at their point of division but resembling hyphae-pseudo-hyphae. This colony is not a true yeast but is yeast-like.

Mode of entry : Fungi gain entry into the eye in the following manner.

i. Exogenous by direct invasion of the external eye as in fungal conjunc­tivitis, fungal keratitis, fungal infection of the lacrimal passages. Infection may extend to deeper tissues, e.g., various strains of aspergillus, candida, nocar­dia, cephalosporium, actinomyces etc.,

ii. After instillation of herbal drops as a part of native treatment, or through indiscriminate use of antibio­tics and cortico-steroids.

iii. Extension from infected neigh­bouring structures as in fungal derma­titis, nasopharyngitis, sinusitis.

iv. Lack of personal hygiene spe­cially in women suffering from fungal vaginitis and allied fungal disorders.

v. May gain entry into the inner eye by perforating wounds or during operation or postoperatively causing fungus endophthalmitis.

vi. Haemotogenous spread often missed specially when they are from an ocult source.


  Factors Favouring Mycotic Infections of the Cornea Top


There is evidence to show that even non-pathogenic species under certain conditions assume pathogenic character and proliferate on, and penetrate into tissues producing necrosis. This is specially seen in patients with low re­sistance as in debilitated individuals, diabetis, leukaemia and cancer.

The contributing role of corticoste­roids and antibiotics have already been commented upon. This is due to the fact that the normal balance that ex­ists between bacteria and fungi have been disturbed and the opportunistic fungi gain the upper hand and proli­ferate readily and rapidly under such favourable conditions. So prolonged therapy with antibiotics and cortico­steroids favour fungal infections of the eye.

Any minor trauma of the cornea favours such invasion, because mycotic infections never occur spontaneously upon an intact healthy cornea. Hence trivial injuries to the cornea, especially in the fields caused by a cow's tail while milking, twigs, thorns, inflores­ence of paddy or ragi or jola and other field crops or dusty grains which may contain these fungal elements can well be the cause of mycotic infections of the cornea.

Women suffering from fungal vagi­nitis may inadvertently infect their eyes due to lack of personal cleanli­ness. An investigation of fungal flora of female reproductive tract by Dr. A. P. Rao showed that 8 % among the pregnant group and 4% among the non-pregnant group had no symptoms of vaginitis or cervicites, yet showed positive cultures for fungi and the fungi isolated in their study is shown in [Table - 9]. Hence it is worth our while to investigate the fungal flora of female reproductive tract in case of hypopyon ulcers.

Diagnosis of mycotic ulcers of the cornea : Diagnosis of fungus infection of the cornea presents a problem spe­cially in the initial phase. The diag­nostic failure is due to the difficulty of identification by the common me­thods used for isolation and staining technique, by the slow growth of fungi on culture media and by the absence of pathogenic features to differentiate them from more common bacterial and viral infections. If the diagnosis is de­layed or incorrect, the treatment of the ulcer with antibiotics, steroids or both in combination favours the rapid proliferation of the organism resulting in perforation and loss of the eye. Hence the importance of early and cor­rect diagnosis. Proper laboratory technique for isolation and the sensi­tivity tests will help in the selection of proper anti-fungal agents to combat the infection.

In most cases, a history of trauma with vegetable matter, branches and twigs, etc., or instillation or herbal drops or injury with cow's tail or fall­ing of saw dust should make one sus­pect the ulcer to be of mycotic origin. Previous treatment with antibiotics and steroids may also be helpful in diag­nosis.

A mycotic ulcer presents as a whit­ish, yellowish or greyish slightly raised plaque or an ulcer with circumscribed edges, surrounded by infiltrative zone associated with hypopyon and runs a slow chronic course. A recalcitrant hypopyon ulcer uncontrolled by the usual antibiotics, should arouse suspi­cion of the possibility of mycotic in­fection.

Many species of fungi produce pig­ment especially on primary isolation and some strains are strong pigment producers and retain this ability under all circumstances. Hence, a pigmented corneal ulcer is presumably of mycotic origin.

Clinically, a fungal ulcer starts as a fluffy white spot with satellitic lesions which coalsce, soon breaking into a shallow ulcer with a surrounding in­filtrate and hypopyon soon follows. Distinct branching lines radiating from the margin of the ulcer are seen in the corneal stroma and these precede the satellite lesions. The extension of these hyphate margins beyond the edge of the ulcer helps to differentiate it from the bacterial ulcer which possesses a shaggy necrotic margin which under­mines the ulcer. The entire lesion ap­pears elevated well above the surround­ing cornea. The ulcer soon extends both in area as well as in depth. Inflam­matory signs are proportionately mild and the tension does not rise inspite of massive hypopyon showing that iris and ciliary body are severely involved. The administration of steroids may re­sult in sloughing of the cornea, soon ending in perforation with subsequent loss of the eye. Like bacterial infection, the fungal hyphae may be held back by the resistant Descemet's membrane for a time as they proliferate along the cleavage plane between the stroma and the membrane but unlike bacteria the hyphal elements can penetrate an in­tact Descemet's membrane and thus gain entry into the inner eye.

Slit lamp examination may help in diagnosing the mycotic ulcer. Folds in Descemet's membrane may be seen with flare in the anterior chamber. A white plaque at the endothelial level is suggestive of mycotic origin.

Hypopyon ulcer occurring in a far­mer with a history of trauma by a cow's tail or a twig or cornstalk or inflores­cence of rice, ragi or jola or of instil­lation of any herbal drops, should raise suspicion of fungus origin as it has oc­curred in agricultural surroundings.

Examinations of corneal scrapings to rule out bacteria as well as fungi should be a routine procedure. If earlier ex­amination of the scrapings does not re­veal any pathogenic bacteria, a fungus infection of the cornea should be en­tertained. Although surface discharge may reveal fungal elements, scrapings from beneath the surface at the edge of the ulcer where the tissue and or­ganisms are not yet quite so necrotic, should be taken and examined both by smear and cultural methods. Gentle wiping or swabs often give a negative culture as mycotic elements tend to in­vade deeper tissues. Culture is more positive than scrapings. The tissue ob­tained by debridement or curetting the ulcer is good material for diagnotic purpose. While taking material for culture, it is essential to rinse the con­junctival sac with sterile normal saline after instillation of local anesthesia as anesthetics contain preservatives, which are anti-fungal as well as anti­bacterial. The Gram stain or Giemsa stain or lactophenol blue and P.A.S. are sufficient to stain the fungi. Histo­pathological examination with special stains, Gomoris Methenamine, Silver Nitrate technique and Gridley's me­thod used for fungi are more reliable. Where smears are reported negative, culture may be positive and so the cul­ture tubes should not be discharged for at least three weeks as fungi grow slow­ly. Repeated smears and cultures should be taken in all cases of corneal ulcers presumably caused by unidenti­fied micro-organisms. Artifacts must be distinguished from fungi. The mo­saic fungus, oil droplets, vegetable fib­res, hydroxide crystals, fat laden mac­rophages, erythrocytes and amorphous debris may be confused with various forms of fungi and this pitfall should be avoided while examining smears. Positive cultures should not be ignored as merely culture contaminants, spe­cially so when the culture is positive from the cornea of a farmer engaged in agricultural operations. Contamina­tions are minimal when Litman Oxgall agar is used for primary isolation.


  Types of Keratomycosis Top


The clinical picture of mycotic ulcer of the cornea presents pleomorophic features, varying from individual to in­divial, largely depending on the type of mycotic organisms, the severity of the invading pathogen and its strain, the corneolytic toxin, the resistance of the host tissue and on the age of the patient. It runs a tragic course in de­bilitated and old individuals and in diabetics. An attempt is made to classi­fy the ulcer according to the etiological agent.

Aspergillus Keratitis : Aspergillus is one of the commonest mycotic organ­isms that invade the cornea, tearduct and orbit. It belongs to the ascomy­cetes group of true fungi. Generally, in Aspergillus keratitis superficial layers of the cornea are involved and a typi­cal ulcer is described as a raised circu­lar gray plaque with well demarkated rolled edges. But other types of cor­neal lessions, like "Cauliflower like ele­vation" are described (Bothman and Crowe. [18] ) Corneal ulcers with perfora­tion have been reported (Castroviejo and Munoz Urra [22] . In our series of mycotic infections of the cornea, as­pergillus was responsible for the majo­rity of infections (16 cases). Puttanna, Ramanda Rao, Sirsi and Swami­Nathan [75] reported primary Aspergillus keratitis and have produced experimen­tally inflammatory response on ani­mal's cornea by injecting culture iso­late of the fungus from the clinical cases. Aspergillus flavus oryzae, A. niger and A. nidulans, A. fumigatus­were the strains isolated from the cli­nical cases and the inflammatory res­ponse was not uniform in all cases.

Experimental injection of Aspergil­lus niger into rat's cornea produced marked keratitis and left a vascularised thin scar in the course of 3 weeks [Figure - 10]. Sections showed giant cells engulfing fungal elements [Figure - 11]. Aspergillus nidulans resulted in mild keratitis resolving in 3 weeks.

I would like to report four cases of Aspergillus keratitis to illustrate the varied inflammatory response seen ex­perimentally on animals.

Case 1.

The first case was of a farmer's wife who gave a history of injury to the left eye by a cotton plant twig while work­ing in the field and had received some native treatment before coming to the hospital. She had a circular corneal ulcer 5 x 5 mm in diameter, hypopyon 5 mm in height and low tension. There was yellowish exudate in the pupillary area. The lacrimal sac was infected which was excised. Corneal scrapings from the ulcer showed hyphae [Figure - 1]. The culture from the corneal scraping and from the fluid from the lacrimal sac was positive for Aspergillus flavus oryzae group on Sabouraud's media at 37° C. The characteristic features of the isolate on Czapek's agar are seen in [Figure - 2],[Figure - 3],[Figure - 4].

The culture was injected into the stroma of rat's cornea at 2 o'clock position at the limbus of the left cor­nea, the right eye being kept as control.

Signs of marked Keratitis were noticed after 72 hours (Rat 3) [Figure - 5], and the left cornea of rat 8 became infiltrated and ulcerated in 3 days and perforated on the 9th day with bleeding from the ulcer (rat 8-[Figure - 6]). Marked inflam­mation limited to the anterior segment of the eye was observed on sectioning.

The second case was that of a farm­er aged 60 years with a history of in­jury to the right eye by an inflores­cence of jola of 15 days duration. He had an ulcer extending over almost the whole cornea leaving the periphery clear from 10 o'clock to 4 o'clock with a dense pigmented area in the centre, 3 mm. in diameter, surrounded by a less denser area and hypopyon, 4 mm in height [Figure - 7]. Corneal scrapings revealed no bacteria but fungal hyphae were seen. Culture from the scrapings were positive for Aspergillus niger (grown on Saboururaud's media at 37° C. [Figure - 8],[Figure - 9] show the charac­teristic features of the isolates on Czapek's agar.

Scarification with material from the identified culture on rat's cornea pro­duced fairly marked keratitis. Injec­tions into rat's cornea at 2 o'clock po­sition produced marked keratitis which finally resolved leaving a thin scar which was vascularized from the peri­phery in the course of six weeks [Figure - 10]. Fungus elements were also de­monstrated from the corneal scrapings of the rat. The scrapings from the rat's cornea when cultured was positive to Aspergillus niger. Microscopic exami­nation of a section of the enuclated eyeball shows giant cells engulfing fungal elements. [Figure - 11]

The third case was of a farmer aged 25 years, with a history of injury of 8 days duration from an inflorescence of jola. He had an ulcer cornea L.E. 4 mm in diameter at 6 o'clock position extending towards the centre [Figure - 12]. Scrapings from the cornea showed no bacteria but were positive for fungal hyphae [Figure - 13]. Culture for bacteria was negative but was positive for As­pergillus nidulans on Sabouraud's me­dia at 37°C.

The characteristic features of the isolate on Czapke's agar can be seen in [Figure - 14],[Figure - 15].

Injection of the culture to rat's cor­nea at 2 o'clock position produced mild keratitis and the keratitis became loca­lised at the centre and resolved finally in about 3 weeks. Fungus elements were demonstrated from the scrapings of the rat's cornea.

The fourth case was of a farmer aged 35 years with a history of foreign body falling into the left eye while working in the field. Eight days later he had a central ulcer 3 mm in diameter with hypopyon 3 mm in height pupilary area filled with yellowish exudate. [Figure - 16]. Corneal scrapings were positive for fungus hyphae and negative for bac­teria. Culture was negative for bacte­ria but fungus grew on Sabouraud's media at 37°C. The colonies on Sa­bouraud's media were more or less flucose with slight tufted aerial mycel. lium to deep felted or extremely flu­cose forms, white at first, becoming green with the development of conidial heads. Seen on the reverse, the sub­stratum of Sabouraud's media had changed to yellowish tinge. Conidial heads were columnar compact and the fungus was identified as Aspergillus fumigatus [Figure - 17].

The culture isolate was injected into the centre of the right and left cornea of an albino rat which had previously received cortisone eye drops for one week in the right eye only, the left eye being kept as control. Signs of keratitis were seen in three days in both eyes, the right side being more pro­nounced than the left. Note reverse nounced than the left. The right cor­nea became infiltrated and ulcerated in the course of nine days and reached the climax in 22 days.

The culture isolate was also injected into rabbit's cornea which resulted in marked keratitis with engorgement of limbal vessels of both eyes [Figure - 18],[Figure - 19]. Positive signs were noticed on the third day, climax being reached on the 12th day. The left eye [Figure - 19] which did not receive cortisone developed marked keratitis. The scrapings from the rat's cornea revealed hyphae.

The animal experiments showed that the inflammatory response varied wide­ly in the same genera of Aspergillus both in animal cornea and in human lesions. Further the eyes which did not receive cortisone also developed le­sions thus proving that primary fungus keratitis could be a clinical entity.

Leber [53] reported Aspergillus as the causative agent in a hypopyon ulcer. Gingrich [40] has reported two cases of Aspergillus keratitis due to flavus and A. fumigatus of which ore case ended in perforation and staphyloma forma­tion and the other in Descemetocele fol­lowed at a later date by keratoplasty, giving hand motion vision. Castroviejo and Munoz-Urra [22] have reported 2 cases. In Fazaka's [33] 11 cases of corneal involvement, six were primary and five were secondary. Of the six primary cases three were superficial keratomy­cosis and three were keratomycosis pro­funda. The secondary infections were associated with dendritic ulcers, ulcus serpens, eczematous pannus and inclu­sion catarrah. The same author re­ported that almost 50 percent of the secondary mycotic invader in 20 pri­mary viral or bacterial infections of the external eye belonged to Aspergillus group.

Agarwal et al [2] (1965) in their experi­mental fungal uveitis came to the con­clusion that bacteria in combination with fungus produce severe clinical picture which may probably be an ad­ditive effect. They are of opinion that Aspergillus being a larger filamen­tous fungus resists invasion by the cellular defence mechanism and is pro­bably more resitant to bacterial anti­biotics.

Histopathological studies show ad­vanced necrosis with a fibrinous network of mycelia. Leucocytes surround the lesion while round cells infiltrate the iris and ciliary body. Hypopyon is due to the chemotactic effect of the corniolytic toxin liberated by the fun­gus. The perforated ulcer in our ex­perimental series (Rat No. 11) on section showed giant cells engulfing fungal elements as in [Figure - 13].

Candida Keratitis: Candida albicans, the causative agent is an yeast-like or­ganism. Cornmeal agar is used to differentiate the albicans species from the non-pathogenic types. On this me­dium it appears as treelike branching filaments with large round chlamy­dospores. This affects lids, conjunc­tiva, cornea, tear duct and uvea. In our series we had four cases infected with candida species. Mendelblatt [63] reported the first case of corneal in­volvement due to candida albicans. Gingrich [40] reported the two cases of keratomycosis due to candida albicans which responded to Thimerosal oint­ment I : 5000.

Corneal ulcers due to candida are shallow and indolent with under­mined and infiltrated edges (Birge [16] ) The floor of the ulcer is usually cover­ed with a thin dry membrane which adheres to the corneal tissue. It is as­sociated with iritis and hypopyon. The other type of corneal lesion is super­ficial punctate keratitis (Mathur [60] ). Vanwinkle, Melvin, Rehins and Suie [92] have produced experimental candida corneal infection by scarification me­thod and showed 66 per cent of the in­fected eyes which received antibiotic treatment developed severe corneal ulceration. Graf [41] reported a corneal ulcer in a 53 year old man after injury due to candida albicans proved by cul­ture and pathogenicity proved experi­mentally on rabbits' corneas. The ulcer responded to electro-coagulation and topical application of iodine. Manches­ter [59] (1957) has reported corneal ulcer due to candida parapsilosis. Ainley and Smith' reported secondary kerato­mycosis due to candida parapsilosis which responded to mystatin 25000 units ml. The same species of fungus can produce quite different lesions of varying severity from a benign ulcer to progressive necrotic lesions ending in perforation [Figure - 20],[Figure - 21]. Hana­busa [47] has shown that candida may elaborate a heat stable toxin capable of producing conjunctivitis.

Fusarium, Keratitis : Fusarium is a soil saprophyte which may cause potato wilt can invade plant and human tis­sue. It can be isolated from almost any soil or water sample. Septate my­celium is white, conidia are fusiform, conidiophores simple produced on loose mycellium, conidia terminal, single. The infection is said to occur at the time of injury with plant tissue. Sigtenhorst and Gingrich [81] reported for the first time Fusarium as an etiological factor in fungus keratitis. Puttanna [74] reported corneal ulcer infected with cephalosporium and fusarium species of fungus. Gingrich [40] reported 3 cases of keratitis due to fusarium species of fungus, which perforated inspite of treatment. Mikami and Stemmermann [66] have reported a case of keratomycosis caused by fusarium oxysporium from Hawaii. Anderson and Chick [7] report­ed 9 mycotic corneal ulcers of which four were caused by fusarium and res­ponded well to amphotericin B. thera­py.

Puttanna [76] has also reported another case of corneal ulcer due to fusarium species of fungus after instillation of herbal juice used as native treatment. It is believed that the fungus entered the eye through the herbal juice or through the grass leaf used to scratch the ulcer as part of native treatment [Figure - 22],[Figure - 23]. Fusarium keratitis appears to be toxic as the ulcer ended in perforation inspite of treatment. The fungal elements from culture were in­jected into rat's cornea which showed signs of keratitis 24 hours after in­jection and a circumscribed ulcer six days after injection. It is not known whether it produces a proteolytic en­zyme which dissolves the cornea as does cephalosporium serrae.

Fusarium ulcer though circumscrib­ed was covered with brownish pigment­ed slough which made us suspect that it could be of mycotic origin.

Cephalosporium Keratitis : Colonies on Czapke's agar spreading felty to fluccose. Pure white consisting of creeping, septate, dichotomously bran­ched hyphae, reverse side colourless. Conidiophores arise as branches of aerial hyphae, short upto 25 µ long. Conidial heads round, conidia elongate, ellipitcal hyaline 9 to 10 µ x 3.5 - 4. Bedell [11] reported a corneal ulcer from an injury of a cow's tail from which Cephalosporium was isolated. Puttanna [74] reported a case of corneal ulcer due to cephalo-sporium species. Injection of culture isolate into rat's cornea produced marked keratitis at the site of injection which spread stea­dily for the first two weeks, finally re­solved leaving a thin scar in the course of six weeks. Fungus elements were also demonstrated from the corneal scrapings of the rat. Gingrich [40] re­ported a case of cephalosporium kera­titis which ended in perforation in­spite of treatment with amphoterecin B and sulphacetamide iontophoresis. Burda and Fisher [19] have extracted a potent proteolytic enzyme from cepha­losporium serrae which produced cor­neal destruction in 2 to 4 hours in rab­bits by ulceration and exudative liquifaction and are of opinion that the proteinase may be responsible for the clinical picture of cephalo-sporium keratitis. The exact action of the en­zyme is still unestablished and is said to act on the collagen bundles present in the stroma of the cornea. The pro­teinase activity appears to be active during the initial phases of germination and proliferation of the spores.-Byers, Holland and Allen. [20]

Penicillium Keratitis : Hyphae creep­ing, conidiophores erect apically irre­gularly whorled, penicillately (tufted or brush-like) branched, conidia spheri­cal, hyaline. Early colony white, round, semitranslucent, radiating silk like hyphae. In a course of four days, the colour changes to dirty green and a spore zone appears. These have sterig­mata and produce spore chains simi­lar to Aspergillus but lack in vesicle at the end of the conidiophore. In its place the conidophore has numerous branches each with a sterigmata that produce a chain of spores. Thus this will have a brush like (penicillate) ap­pearance [Figure - 24]. Puttanna [74] reported a case of corneal ulcer due to penicil­lium species (Ramigena series) and the culture isolate when injected into rat's cornea produced slight keratitis at the site of injection. Scrapings from the rat's cornea showed hyphae. In our series there were 3 corneal ulcers due to the Penicillium species.

Rhizopus Keratitis (phycomycetes group of fungi) phycomycetes are found in tissues as branching non­septate hyphae measure 5-40 µ in dia­meter. On artificial media these fungi grow rapidly, forming serial mycelia and characteristic spores of each gene­ra. Puttanna [76] reported two cases of Rhizopus keratitis after instillation of herbal juice as a part of native treat­ment [Figure - 25]. The culture isolate was injected into rat's cornea, which show­ed keratitis 48 hours after injection and there was a haemorrhagic patch on the iris six dys after injection. [Figure - 26]. The cornea became opaque and bulged with prominent keratitis after 7 days.

Lasio diplodia keratifis : Puttanna [76] reported two cases of Lasiodip­lodia l; eratitis after instillation of herbal juice as part of native treat­ment. White woolly colonies at first, changed in course of time to black re­sembling the colour of the pigment seen in the centre of the ulcer. Spores were seen after 12 days [Figure - 27]. The culture isolate was injected into rat's cornea and keratitis developed 72 hours after injection which reached its climax after 6 days [Figure - 28]. The corneal scrapings of the rat was po­sitive for fungal elements. Fungus ino­culated in the stem of a plant showed luxuriant growth [Figure - 29]. Lasio dip­lodia appears to be toxic like fusarium clinically as well as in experimental animals.

Cryptococcus Keratitis : Cryptococ­cus neoformans the causative agent of torulosis does not produce mycelia or spores. In artificial media the colo­nies are mucoid and appear whitish to tan. Individual cells measure 5 to 20 µ . are round to ovoid and are surrounded by wide, gelatinous, polysacharide cap­sules. Budding is evident. Fazakas [31] reported a case of Keratomycosis due to cryptococcus. He describes the corneal involvement as being deep and very extensive which resulted in thin opacity rather transparent.

Prognosis : Prognosis in a mycotic ulcer of the cornea is still unpredic­table. It depends on the host resist­ance, severity of the pathogen, type and strain of the invading fungi and the corneolytic substance produced by it, the available fungi-static or fungicidal agents, early diagnosis, and institution of energetic and immediate treatment. The response to antifungal agents is very varied and no uniformity has been observed. This may be due to poor penetration of the drug and the fact that myceliae have a tendency to bur­row deeper into the tissues where the drug does not reach and also due to nonavailability of a universal broad spectrum antifungal agent. Further, the exact nature of the corneolytic toxin is not yet known to us. The known antifungal agents that are in use have side effects as well as toxic to normal tissue. Therapeutic keratoplasty offers an hope but it should be considered before the ulcer spreads in depth as well as in area. Further, lamellar or penetrating keratoplasty depends upon the type of fungus whether mycellial or yeast like type isolated from the cul­ture.

Prophylaxis : The only key to the problem is prevention. Early diagno­sis is very essential and many eyes can be saved if the routine repeated smear and cultural examination is followed in every case of ulcer cornea, specially in those engaged in agricultural occupa­tion. Any recalcitrant corneal ulcer which does not respond to the usual line of treatment should arouse suspi­cion of mycotic ulcer. The fact of se­condary micotic infection should also be borne in mind while instituting pro­longed corticosteroid therapy for eye conditions. A careful history of trau­ma to the eye by vegetable agents like corn-stalks, inflorescence, twigs or branches, instillation of herbal juice or native medicine may aid a presumptive diagnosis of mycotic infection.


  Treatment Top


Therapy of mycotic keratitis can be considered under three sub-divisions (1) Prevention, (2) Medical, (3) Surgi­cal.

Prevention : Farmers should be edu­cated regarding the dangers of mycotic infections and should be advised to wear protective safety glasses to avoid dust and minor trauma to the eyes. In­troduction of mechanical devices in agricultural occupations may minimize the incidence of mycotic ulcers, of the cornea. Personal cleanliness in wash­ing hands before touching eyes is essen­tial to avoid fungal infections from out­side agencies as in fungal vaginitis. To prevent post-operative infections and possibility of infection during opera­tions, care should be taken to avoid air-borne organisms, spores in glove powder, inadequate sterilisation of in­struments by soaking in contaminated solution and drugs and fungi in the ocular and periocular tissues of the patient. Pre-operative prophylaxis with antifungal agents like sodium propionate, argyrol or amphotericin B eye drops is advocated. Routine anti­biotic programme and lavish post­operative steroid therapy should be re­orientated and should be used with great caution as both are double edged swords. Routine use of fungicidal sprays in the operating room is desir­able. Rigid operating room cleanliness by modern methods should be adopt­ed to see that no dust is stirred up during cleaning. Precautions against contamination of fungi from outside agencies like street dust, shoes and other uncovered clothing should be rigidly followed.

Medical: Physical measures sug­gested in the treatment of mycotic ulcers of the Cornea are (1) Ultravio­let phototherapy as suggested by Chick, Huddell and Sharp [24] , (2) Thermophore suggested by Allen. [5]

Various forms of chemo-therapy like 30% Sodium Sulphacetamide solution by iontophoresis, 1: 1000 Merthiolate ophthalmic ointmentt, oral Sodium Iodide with local 0.125% Copper Sul­phate and Tincture Iodine, Amphoteri­cin B and nystatin and local cyclohexi­mide have been tried with varying re­sults. The disappointing results are due to poor intra-ocular penetration and local toxicity of the recent anti-fungal drugs. Some fungi are sensitive to some of the sulphonamides and some of the antibiotics. Others seem to flourish in the presence of these agents.

Leber [53] (1879) was the first to diag­nose and report a clinical case of my­cotic keratitis, to reproduce the dis­ease in animals and to cure his clinical case he used a combination of curettage and chemical cautery with carbolic acid. The treatment begins with de­bridement of devitalized tissues which provides material for smear and cul­ture. Debridement helps in the removal of nutrient clinical medium for the fungi and better evaluation of the ulcer and facilitates penetration of the avail­able antifungal drugs used as drops or ointments. Puttanna [74] has reported good clinical response to instillation of 0.125% copper sulphate and 10%, so­dium propionate drops and ointment combined with systemic iodine. Put­tanna, Ramananda Rao, Sirsi and Swaminathan [75] have conducted the antifungal activity of potassium iodide 1%, copper sulphate 1%, salicylic acid 1%, phenol 1%, sodium propionate 20%, Pimaricin 200 u, Mycostatin 200 u. on Aspergillus strains in vitro and showed that copper sulphate, sodium propionate, pimaricin and Mycostatin have antifungal effects. Sodium sul­phacetamide has slight fungistatic pro­perties and requires very long term therapy.

Sightenhorst [81] et al (1957) found sul­facetamide and thimerosal to have ge­neral activity against 25 fungi tested in vitro. Thiomersal inhibited all 25 fungi cultures in concentration from 0.0005 to 0.01 mg per ml indicating the greatest sensitivities of all the fungi to all the preparations tested.

Gingrich [40] advocated 30% sodium sulfacetamide iontophoresis (using the negative electrode and at least 3.0 ml. of solution with a current of three to five ma. for 5-10 minues, every six to eight hours for the first five days. This is followed by Thiomerasal 1 in 1000 ointment at the close of each iontopho­resis and repeated three hours later. The active antimycotic factor is heavy metal mercury which like ionic copper or nickel, penetrates the well wall and oxidizes the essential sulphydryl group of enzymes necessary for vital meta­bolic pathways.

Miller and McCallon [67] found that silver ions one part per million were effective in releasing cell contents of fungus spores and inhibiting germina­tion of spores. Argyrol is a mild sil­ver protein preparation containing 20% silver and is used preoperatively in Massachussets Eye and Ear Infirmary of Boston and absence of post-opera­tive fungal infections is claimed.

Thiomersal (Merthiolate) is used in a dilution of 1 in 1000 of physiological saline as drops every hour during the day and every two hours at night. It is often combined with oral and topical nystatin.

Allen [5] recommended oral sodium iodide one gr. to 10 lbs. body weight, three times a day (about 3 gm. per day, for the average male patient). He also advocated focal heat with the Thermophore. for localised or super­ficial infection. Cautery with tincture of iodine and topical application of 0.125% copper sulphate are also re­commended.

A few antifungal agents that have come into recent use are amphotericin B. and nystatin derived from Strepto­myces cultures. These have poor pe­netrating power except by direct intro­ocular injection. These are used either as drops or as ointments. They are effective only on the superficial corneal layers and the fungal elements may persist in deeper layers. Both are highly toxic and have side effects. Mangiarcin and Liebman [59] have suc­cessfully treated a case of hypopyon keratitis due to Aspergillus fumigatus with nystatin. Montana and Serry [63] showed definite inhibition of candida albicans infection of rabbit's cornea by nystatin and amphotericin B. Sensiti­vity tests with these agents demons­rated fungistatic activity in fairly low dilutions. Dieckhues [29] treated kerato­mycosis with Nystatin and Pimaricin.

Amphotericin B is fungistatic against a wide variety of yeast and fungi in­cluding Coccidiodes, Histoplasma. Blastomyces and Candida. It is heat labile and light sensitive. It is used in 5% dextrose and is given intravenously in concentrations of 0.1 mg/cc. as it is not readily absorbed from the gas­trointestinal tract.

Chick, Huddell and Sharp [24] used ultra-violet rays with amphotericin B in the form of eye drops 1.0 mg/ml and felt that higher concentration upto 4 mg /ml could be used. Currie [26] re­ported 3 cases of mycotic keratitis which responded to topical application with amphotercin B. In each of these, there was a history of injury to the eye by vegetable matter. Fine [35] ob­served that amphotericin B is very irri­tating to the infected human eye. The drug is too toxic and hence should not be used in vague and undiagnosed con­ditions. Dosage should be adjusted to minimise toxic effects. Daily dosage should not exceed 1.5 mg/kg of body weight. The initial daily dosage is 0.20 mg/kg to be gradually increased as to­lerated. It should be given under close clinical supervision. Side effects like chills, fever, headaches, anorexia and chemical thrombophlebitis have been observed. Kidney function tests and blood urea nitrogen levels should be checked periodically if therapy is pro­longed. Sub-conjunctival injection of 125 mg of amphotericin B is tolerated. Drops are used as often as every 15 minutes.

Nystatin : inhibits the growth of a wide variety of fungi, molds and yeasts. It is reasonably well tolerated as a topi­cal application in ointment form con­taining 100,000 units/gm or by sub­conjunctival injection of 5000 units suspended in 0.5 cc saline. Dieckhues, Jper and Fegeler [28] reported a case of corneal fungus infection treated suc­cessfully with Nystatin.

Gingrich [40] found that Nystatin was effective for the early superficial fusa­rium keratitis but ineffective for the deep infection because of poor pene­tration. Roberts [78] used Nystatin in the treatment of Monilia Kerato conjunc­tivitis.

Casero [21] reported a case of Asper­gillus Keratitis recovered under local and general mycostatin therapy and ce­phalo-sporium keratitis responding to the instillation of Tricomycin and an­other case caused by Aspergillus fumi­gatus recovered under the instillation of tricomycin.

Gri€cofulvin (Sporostanin) is orally administered and effective in cutaneous fungus infections like athlete's foot. It is of doubtful value in corneal affec­tions though Batista [10] reports good res­ponse by oral administration. Morales [71] reported a case of mycotic corneal ul­cer which cleared up by oral adminis­tration of Grisofulvin.

Hamycin : Ahuja Bal, Nath and Nema [3] tried Hamycin in Glycerine sus­pension on experimental Keratomyco­sis and are of opinion that the drug appeared to be effective in candida in­fections and not with Aspergillus fu­migatus.

Thiabindazole : 2-4'-Thiazolyl)­benzimidazole. This drug is unusually potent and broad spectrum anti-heli­methic. Besides, it possesses in vitro anti-mycotic properties against sapro­phytic and some pathogenic fungi. Blank and Rebell [17] found that it is both fungistatic and fungicidal in vitro against the fungi of dermatophytosis, mycetomas and chromomycosis. It is slightly soluble in water and a 0.3% solution was tried in kerato-chromo­mycosis by Wilson et al [95] . A 12% suspension in 1% sodium Carboxy­cellulose might be more effective.

Cycloheximide was used by Lynn [57] in the treatment of Fusarium keratitis. Cycloheximide is an antifungal anti­biotic used in Mycology Laboratories to inhibit the growth of "Saprophytes in pathogenic fungus cultures. Cyclo­heximide was tolerated by the human eye in aqueous concentration of 0.06%. It has good lipid solubility and unlike Nystatin and Amphotericin B is also soluble in water at concentration of 2%; so one could predict that its ocu­lar penetration would be good.

X 597 C (Hoffman-la-Roche) a new drug is of value in systemic mycosis such as histoplasmosis, blastomycosis and in few cases of systemic aspergil­losis.

The curent therapy of Mycotic Kera­titis as recommended by Anderson et al begin with Amphotericin B Solution 0.25-0.4% every one to two hours. If this fails, Mycostatin 10,000 µ/gm. is then used as an ointment with the same frequency of application.

The prolonged medical therapy of fungus disease suggests that the bio­chemical composition of the fungus is a complicated one and demands ad­ministration of more potent anti-fungal agent to kill the fungus and excite the host's immunologic reaction, but no such agent has yet been discovered. Lack of response to medical treatment may mean that the therapeutic agent is of low specific activity against the in­vading pathogen or it may mean that insufficient drug reaches the site where it is needed. Before surgical measures are thought of, the current antifungal armamentarium should be given a fair trial.

Pimaricin, a fungicide isolated from streptomyces natalensis is effective against spores. Puttanna et al [75] have shown its antifungal activity on dif­ferent species of aspergillus invitro and appears to be effective. Francois ob­tained good results with pimaricin, the dose being 50 mg. four times daily in combination with local pimaricin. Kaufman and Wood [50] used with favour­able result pimarcin in a case of Kera­tomycosis.

Polymyxin : Jawetz (1956) reported that polymyxin B in vitro in high con­centrations (20-250 µg/ml) may be fungicidal or fungi-static against seve­ral organisms including candida albi­cans.

Surgical treatment : Physcal and che­mical cautery, paracentesis, keratecto­my and excision with keratoplasty and conjunctival hooding have been tried with varying results. Medical cure often leaves an ugly corneal scar and if central, will interfere with vision which may need keratoplasty at a later date. Keratoplasty has been advocated in active mycotic infection as a thera­putic measure. Successes and failures are on record. Gingrich [40] has perform­ed successful keratoplasty 56 hours af­ter perforation of the fungal ulcer due to cephalosporium serrae with vision of handmotion 2 months later. Some are of opinion that keratoplasty should be considered only after control of the situation to avoid further spread of the fungi resulting in resistant emdoph­thalmitis. McLean [62] (1963) has stated in regard to fungal keratitis "Certainly it would seem preferable to recognise the situation, control the fungal infec­tion if possible and graft the healed scar in the absence of active infection. The type of keratoplasty-Lamellar or penetratitng depends on the depth and area of mycotic infection and the type of fungus, mycelial or yeast type. A penetrating keratoplasty is probably contra-indicated in the presence of an active yeast infection, as the organism may gain entry into the anterior cham­ber due to lack of mycelial barrier. Berson, Kobayashi and Oglisby [15] in their experimental fungal keratitis pro­duced by candida albicans confirm this view. The mold type of fungi with their hyphae interwoven prevents the organisms from falling off into the an­terior chamber during penetrating ke­ratoplasty. So an early penetrating keratoplasty is recommended in case of central mycotic ulcer due to mold spe­cies of fungs. Dhanda [27] recommends lamellar kerato-plasty in mycotic ul­cers in the early phase before the le­sion spreads deeply in the corneal stroma. The trephine disc should be located in the healthy recipient bed and the dissection should proceed deeper to the infiltrating zone. The size and thickness of the graft depend on the extent of the ulcer. According to Kaufman and Wood [50] . lamellar keratoplasty is contraindicated and preserved cornea should never be used if one is driven to do lamallar kerato­plasty in mycotic keratitis. However, decision should be taken with careful balancing of the calculated risks and each case deserves balanced judge­ment.

Conjunctival Hooding : Since our experience has shown that it is very difficult to evaluate the stage of the dis­ease at the time of the treatment and the fungi differ from case to case, it is worthwhile to consider this method as a practcal one as there is difficulty in our country to get suitable eyes for therapeutic keratoplasty. As we are still in darkness regarding the me­chanism of pathogenicity in various types of keratomycosis and looking at the confusing results obtained from medical therapy, the conjunctival hood method should be tried at an early phase if medical treatment is unsuc­cessful. The rationale of this treatment is still not clear but recent studies sug­gest a serum-fungal inhibiting factor rather than a conjunctival antifungal substance. Kozinn, Caroline and Tas­chdjian [51] , Lorincz, Priestly and Jacob. [55] The flap may not contribute to the strength to the thin cornea but the vessels of the flap may help in rapid healing of the diseased tissue.

Cryotherapy : is also suggested. A slow freeze to the range of 44° c with a thaw might disrupt the hyphal ele­ments and result in destruction of the tissue mycelium.


  Conclusion Top


The problem of therapy of mycotic ulcers of the cornea is still today an open chapter and the future line of research should be directed in detect­ing a more potent, less toxic, broad spectrum antifungal agent and to de­termine the exact nature of the corneo­lytic substance produced by the patho­gen. If the toxin is species specific the therapy of fungal ulcers becomes more confusing and complicated. As there is some degree of anti-biosis be­tween bacteria and fungi, as cultures for bacteria are negative it is worth­while to observe whether there is any antibiosis between nonpathogenic bac­teria and fungi and this may throw a new light in our therapeutic approach to fungal ulcers in the future. This study is still in progress.

To summarise, I would once again stress the early diagnosis clinicallly confirmed by rapid laboratory diag­nosis by smear, culture and sensitivity test if possible to select the drug of choice. If the medical treatment fails it is safer to adopt the simple surgi­cal procedure of conjunctival hooding fairly early to save the eye rather than think of therapeutic keratoplasty, whose results are still unpredictable so far in the surgical treatment of mycotic keratitis.

In conclusion, I am deeply thankful to the Scientific Committee of the All India Ophthalmological Society for having nominated me to deliver the oration this year in memory of Dr. E. Sreenivasan and I consider it a great honour to do so and if my remarks have revealed the growing and chal­lenging problem of keratomycosis fac­ing us today and the use of antibiotics and corticosteroids more sparingly and precisely, I think we have honoured the person, as he was cautious and conser­vative in therapeutic approach inspite of tempting new technique and new drugs coming to light in the advancing field of Medicine.[98]

 
  References Top

1.
Agarwal. L. P.. Malik, S. R. K., Madan-Mohan and Khosla. P. K.: Mycotic corneal Ulcers. Brit. J. Ophthal 47: 109. (1963).  Back to cited text no. 1
    
2.
Agarwal, L. P., and Khosla. P. K.: Mycotic Keratitis (experimental and clinical study). J. All-India. Ophth. Soc. 15: 1-10 (1967).  Back to cited text no. 2
    
3.
Ahuja, O. P. Bal, A., Nath, K., and Nema, H. V.: Hamycin in experimental Keratomycosis. J. All-India-Ophth Soc. 15: 19-22 (1967).  Back to cited text no. 3
    
4.
Ainley, R., and Smith, Brenda: Fungal Flora of the conjunctival Sac in healthy and diseased Eyes. Brit. J. Ophth. 49: 10 (1965).  Back to cited text no. 4
    
5.
Allen, J. H. (In discussion) Haggerty, T. E. Zimmerman, L. E.: Mycotic Ke­ratitis. Southern. Med. J. 51: 153 (1958).  Back to cited text no. 5
    
6.
Anderson, B., Roberts, S., Jr. Gon­zalez, C. and Chick, E. W.: Mycotic ulcerative Keratitis A.M.A. Arch. Ophthal (Chicago). 62: 169-179 (1959).  Back to cited text no. 6
    
7.
Anderson, B. Jr. and Chick. E. W.: Mycokeratitis, Treatment of fungal cor­neal Ulcers with Amphotericin B and mechanical Debridement. Southern Med. J. 56: 270 (1963).  Back to cited text no. 7
    
8.
Balakrishna, E.: Mycotic Keratitis caused by Aspergillus fumigatus. Brit. J. Ophth. 45: 828-830 (1961).  Back to cited text no. 8
    
9.
Barsky, D.: Keratomycosis. A Report of six Cases Arch. Ophth (Chicago). 61: 547 (1959).  Back to cited text no. 9
    
10.
Batista and Filno, J.: Grisco-fulvin in the Treatment of Mycotic Keratitis. Arq. Brasil. oftal 24: 13-14 (1961).  Back to cited text no. 10
    
11.
Bedell, A. J.: Cephalo-sporium Kera­titis. Trans. Amer. Ophthal. Soc. 44: 80 (1946).  Back to cited text no. 11
    
12.
Berliner (1882) Quoted by Sykes (1946) in ref. 83.  Back to cited text no. 12
    
13.
Benham. R. W. and Hopkins, A.: Yeast like Fungus found on the Skin and in the Intestines of normal Subjects. A survey of one hundred persons. J.A. M.A. 181: 255-257 (1933).  Back to cited text no. 13
    
14.
Bernard, J. S., Race, G. J. and Guy, L. R.: Nonpathogenic Fungi in ton­sillar Crypts. J.A.M.A. 181: 255-257 (1962).  Back to cited text no. 14
    
15.
Berson, E. L., Kobayashi, G. S. and Oglesby, R. B.: Experimental Fungal Keratitis. Arch. Ophthal. (Chicago). 74: 403-410 (1965).  Back to cited text no. 15
    
16.
Birge, H. L.: Ocular Aspects of Mycotic Infection. Amer. J. Ophth. 24: 682 (1941).  Back to cited text no. 16
    
17.
Blank, H. and Rebell, G.: Thiabenda­zole. Activity against the Fungi of Dermatophytosis Mycetomas and Chro­momycosis. J. Invest. Derm. 44: 219 (1965).  Back to cited text no. 17
    
18.
Bothman, L. and Crowe, S. J.: The 1947 year hook of the Eye, ear, nose and throat : Chicago. P. 43.  Back to cited text no. 18
    
19.
Burda, C. D. and Fischer, E. J.: Cor­neal Destruction by Extracts of Cepha­losporium Mycelium, Amer. J. Ophth. 50: 926-937 (1960).  Back to cited text no. 19
    
20.
Byers, J. L., Holland, M. G. and Allen, J. H.: Cephalosporium Keratitis. Amer. J. Ophth. 49: 267 (1960).  Back to cited text no. 20
    
21.
Caseoo, L.: Keratomycosis. Arch. Soc. oftal. Hispano-amer. 22: 293-309 (1962).  Back to cited text no. 21
    
22.
Castroviejo, R. and Munoz Urra, F.: 'Aspergillosis Ocular' Archi. Oftal Hisp-amer. 21: 453 (1921).  Back to cited text no. 22
    
23.
Chick. E. W. and Conant, N. F.: My­cotic ulcerative Keratitis. A review of 148 cases from the literature. Invest. Ophthal. 1: 419 (1962).  Back to cited text no. 23
    
24.
Chick, E. W., Huddell, A. B. and Sharp, D. G.: Ultra-violet Sensitivity of Fungi associated with Mycotic Kerati­tis and other Mycoses. Sabouraudia 2: (Pt 4): 193 (1963).  Back to cited text no. 24
    
25.
Conant, M. R., Smith, D. T., Baker, R. D., Callaway, J. L., and Martin, D. S.: "Manual of Clinical Mycology" second edition. Saunders. Philadelphia (1954).  Back to cited text no. 25
    
26.
Currie, D: Mycotic Keratitis. Arch. Ophth. (Chicago) 70: 335-336 (1963).  Back to cited text no. 26
    
27.
Dhanda, R. P.: "Therapeutic Kerato­plasty in Corneal Ulcers. Proc. All­India-Ophthal. Soc. 1965.  Back to cited text no. 27
    
28.
Dieckhues, B., Jper, J. and Fegeler, F.: Therapy Corneal Mycotic Infection. (In German) Klin Mbl. Augenh. 141:912 (1962).  Back to cited text no. 28
    
29.
29 Dieckhues, B.: Treatment of Keratomy­cosis with Nystatin and Pimaricin (In German). Klin Mbl. Augenh 148: 895-896 (1966).  Back to cited text no. 29
    
30.
Drault-Toufesco: Mycotic Keratitis (In French). Bull. Soc. Franc. Ophthal. 75: 171-179 (1962).  Back to cited text no. 30
    
31.
Fazakas, A.: The Mold Fungi of the Healthy and Diseased Eye (In Ger­man). Arch. f. Ophth. 138: 416-423 (1938).  Back to cited text no. 31
    
32.
Fazakas, A.: A comprehensive Report on Investigations on ophthalmic Fungi. Ophthalmologica 126: 91-109 (1953).  Back to cited text no. 32
    
33.
Fazakas, A.: Summarizing Report on Mycotic Superinfection in Diseases of the Lid borders. Conjunctiva and Cor­nea. Ophthalmologica 138: 108 (1959).  Back to cited text no. 33
    
34.
Fazakas, A.: A concise Report of my academic Study of Opthalmologicai Fungi. Ophthalmologica. 128: 163-179 (1954).  Back to cited text no. 34
    
35.
Fine, B. S.: Intra-ocular mycotic In­fections; Lab. Invest. 11: pt. 2-1161 (1962).  Back to cited text no. 35
    
36.
Foster. J.B.T. et al: Some intraocular and conjunctival Effects of Amphoteri­cin B. in Man and in the Rabbit: Arch. Ophthal (Chicago): 60: 555 (1958).  Back to cited text no. 36
    
37.
Frenkel, J. K.: Role of Cortico-steroids as predisposing Factors in Fungal Dis­eases, Lab. Invest. 2: 1192-1208 (Pt 11) (1962).  Back to cited text no. 37
    
38.
Gale. G. R.: Experimental Chemothe­rapy of fungus Infections. Lab. Invest 11, Pt. 2, 1209 (1962).  Back to cited text no. 38
    
39.
Gillespie, F. D.: Fungus corneal Ulcer. Amer. J. Ophth. 56: 823-825 (1963).  Back to cited text no. 39
    
40.
Gingrich, W. D.: Keratomycosis, J.A. M.A. 179: 662 (1962).  Back to cited text no. 40
    
41.
Graf, K.: A case of Keratomycosis of the human Cornea caused by Candida Albicans (In German). Klin. Mbl. Augenheil. 142: 578-581 (1963).  Back to cited text no. 41
    
42.
Gridley, M. F.: A Stain for Fungi in tissue Sections. Amer. J. Clin Path 23: 303 (1953).  Back to cited text no. 42
    
43.
Grocott. R. G.: A Stain for Fungi in tissue Sections and Smears using Gom­eris Methenamine Silver Nitrate Tech­nique. Amer. J. Clin Path 25: 975 (1965).  Back to cited text no. 43
    
44.
Haggerty, T. E. and Zimmerman, L. E.: Mycotic Keratitis. Southern M. J. 51: 153-159 (1958).  Back to cited text no. 44
    
45.
Halde, C. and Okumoto, M.: Ocular Mycosis: XX Concilium Ophthal Ger­mania Acta Part 11-705 (1966).  Back to cited text no. 45
    
46.
Hammeke, J. C. and Ellis, P. E.: My­cotic Flora of the Conjunctiva. Am. J. Ophthal, 49: 1174-1178 (1960).  Back to cited text no. 46
    
47.
Hanabusa, J.: Toxin of Candida Albi­cans-Act Soc. Ophth. Jap: 57: 158-160 (1953).  Back to cited text no. 47
    
48.
Hirose, K. Yoshioka, ABE, Kanimetsu and Kiya: Experimental Studies in Keratomycosis. The Effect of Cortsone on experimental Keratomycosis. Acta. Soc. Ophth Jap. 61: 1106-1133 (1957).  Back to cited text no. 48
    
49.
Huppert, M., Mcpherson, P. A. and Cazin, J.: Pathogenesis of Candiba Al­bicans Infection following Antibiotic Therapy. J. Bact. 65: 171 (1953).  Back to cited text no. 49
    
50.
Kaufman, H. and Wood. R.: Mycotic Keratitis. Amer. J. Ophthal. 59: 993 (1965).  Back to cited text no. 50
    
51.
Kozinn, P., Caroline, L. and Taschjian, C. L.: Conjunctiva contains Factor in­hibiting Growth of Candida Albicans. Science 146: 1479, (1964).  Back to cited text no. 51
    
52.
Kronfeld, P. C.: A Cross Section through Ophthalmology. Tr. Amer. Acad. Ophth, 66: 13-19 (1962).  Back to cited text no. 52
    
53.
Leber, T.: Aspergillus as an etiological Agent in Hypopyon Keratitis (In Ger­man). V. Graefe's Archiv. fur Oph­thal. 25: 285-301 (1879).  Back to cited text no. 53
    
54.
Ley, A. P. and Sanders. T. E. Fungus Keratitis. A Report of three Cases. Arch. Ophthal. (Chicago) 56: 257 (1956).  Back to cited text no. 54
    
55.
Ley, A. P.: Experimental fungus Infec­tions of the Cornea. Amer. J. Ophth 42: 59-71 (Oct pt 11) (1956).  Back to cited text no. 55
    
56.
Lorincz, A., Priestly, J., and Jacob, P.: Evidence for Humoral Mechanism which prevents Growth of Dermato­phytes. J. Invest. Derm 31: 15 (1958).  Back to cited text no. 56
    
57.
Lynn, J. R.: Fusarium Keratitis treated with Cycloheximide. Amer. J. Ophthal. 58: 637 (1964).  Back to cited text no. 57
    
58.
Manchester, P. T. and George, L. K.: Corneal Ulcer due to Canadida Parap­silosis. J.A.M.A., 171: 1639 (1959).  Back to cited text no. 58
    
59.
Mangiarcine. A. and Liebman, S.: Fungus Keratitis (Aspergilus Fumigatus) A.M.A. Arch. Ophth. (Chicago) 58: 695 (1957).  Back to cited text no. 59
    
60.
Mathur, S. P.: Ocular Complications of cutaneous Moniliasis. Ophthalmolo­gica, 139: 112 (1960).  Back to cited text no. 60
    
61.
Mcgrath, H. and Singer, J.: Amer. J. Ophth. 35: 102 (1952).  Back to cited text no. 61
    
62.
McLean, J. M.: Oculomycosis. Amer. J. Ophthal 56: 537 (1963.  Back to cited text no. 62
    
63.
Mendelblatt. D. L.: Moniliasis Review and Report of first Case demonstrat­ing Candida Albicans in Cornea. Amer. J. Ophth 36: 379-385 March (1953).  Back to cited text no. 63
    
64.
Melvin, S., Rheins. Tedsuic and van Winkle, M. G.: Antibiotics and Candida Corneal Ulcers. Amer. J. Ophthal. 59: 221-225 Feb (1965).  Back to cited text no. 64
    
65.
Melvin, S. Reheins Tedsuie, Patrica, A., Pixley and Keates R. H.: Diagnosis of Fungal Ulcers, Amer. J. Ophth 62: 5, 892. Nov. (1966).  Back to cited text no. 65
    
66.
Mikami, R. and Stemmermann, G. N.: Keratomycosis caused by Fusarium Oxysporum. Amer. 1. Clin. Path 29: 257-262 March (1958).  Back to cited text no. 66
    
67.
Miller, L. P. and McCallon, S. E. A.: Toxic action of metal ions to Fungus Spores. Agric and Food Chem 5: 116­122 Feb (1957).  Back to cited text no. 67
    
68.
Mitsui, Y. and Hanabusa, J.: Corneal Infections after Cortisone Therapy Brit. J. Ophthal. 39: 244 (1955).  Back to cited text no. 68
    
69.
Montana, J. A, and Sery, T. W.: Effect of fungistatic Agents in corneal Infec­tions with Candida Albicans, Arch. Ophth (Chicago) 60: 1-6 July (1958).  Back to cited text no. 69
    
70.
Moore, M.: In Vivo and Vitro Effect of Aueromycin Hydrochloride on Syrin­gospora (Monilia Candida albicans) J. Lab. and Clin. Med. 37: 703 (1951).  Back to cited text no. 70
    
71.
Moralies, M.: Micotic Keratitis treat­ed with Griscofulvin. Arch Chilenos Oftal 17: 47-50 (1960).  Back to cited text no. 71
    
72.
Pappenfort, R. P. and Schnall, E. P.: Moniliasis in Patients Treated with Aureomycin Arch. Int. Med. 88: 729 (1951).  Back to cited text no. 72
    
73.
Post, L.: Thermophore Therapy and experimental Studies. Trans. Amer. Ophthal. Soc. 22: 353 (1924).  Back to cited text no. 73
    
74.
Puttanna, S. T.: Primary Fungus Kera­titis. Trans. 1st Cong. Asia-pacific Acad Ophth 471-478 (1960).  Back to cited text no. 74
    
75.
Puttanna, S. T., Ramanda Rao G., Sirsi, M. and Swaminathan, M.: Prim­ary Aspergillus Keratitis. Orient Arch. Ophth 1: 191-196 (1963).  Back to cited text no. 75
    
76.
Puttanna, S. T.: Primary Fungus Kera­titis after Instillation of herbal Juice as part of Native Treatment. Trans. 2nd Cong. Asia-Pacific Acad Ophth (1964).  Back to cited text no. 76
    
77.
Puttanna, S. T.: Mycotic Infections of the Cornea. J. All India Ophth Society 15: 11-18 (1967).  Back to cited text no. 77
    
78.
Roberts, S. S.: Nystatin in Monilia Keratoconjunctivitis, Amer. J. Ophthal 44: 108 (1957).  Back to cited text no. 78
    
79.
Robinson, H. J., Phares, H. and Graes­sle, O.: Antimycotic Properties of Thia­bendazole. J. Invest. Derm. 42: 479 (1964).  Back to cited text no. 79
    
80.
Seligman, E.: Virulence enhancement of Candida Albicans by Antibiotics and Cortisone. Proc-Soc. Exper. Biol. and Med. 83: 778 (1953).  Back to cited text no. 80
    
81.
Sigtenhorst, M. L. and Gingrich, W. D.: Bacteriological Studies of Keratitis. Southern Med. J. 50: 346-350 (1957).  Back to cited text no. 81
    
82.
Swartz, J. J. and Jankelson, I. R.: In­cidence of Fungi in the Stools of non­specific ulcerative Colitis Am. J. Dig. Dis., 8: 211-214 (1941).  Back to cited text no. 82
    
83.
Sykes, E. M.: Fungus Infection of Cornea. Case report of Keratomycosis due to Monilia. Texas J. Med. 42: 330-332 Sept (1946).  Back to cited text no. 83
    
84.
Sreenivasa Rao, P. N. and Ramakrishna, T.S.: Studies of the Fungus diseases af­fecting man in and around Manipal-­III Fungi and diseases of the eye. Ind. Jour. Path and Bac (1967).  Back to cited text no. 84
    
85.
Tanaka, C.: Acta Soc. Ophthal. Jap 56: 635 (1952).  Back to cited text no. 85
    
86.
Tedsuie and Havener, W. H.: Mycology of the eye. Am. J. Ophth. 56: 63-74 (1963).  Back to cited text no. 86
    
87.
Theodore, F. H.: Use of Propionates in Ophthalmology Arch Ophth. (Chicago) 41: 83 (1949).  Back to cited text no. 87
    
88.
Theodore, F. H.: Use of Sodium Pro­pionate in external Infections of the Eye, J.A.M.A. 143: 226 (1950).  Back to cited text no. 88
    
89.
Thygeson, P., Hogan, M. J. and Ki­mura, S. J.: Cortisone and Hydrocorti­sone in Ocular Infections. Trans. Amer. Acad Ophthal Otolarying 157: 64 (1953).  Back to cited text no. 89
    
90.
Torack. R. M.: Fungus Infections as­sociated with Antibiotic and Steroid Therapy. Am. J. Med. 22: 872 (1957).  Back to cited text no. 90
    
91.
Urrets-Zavalia, A., Remonda, C. and Ramacciotti, N.: Amer. J. Ophth-46: 170 (1958).  Back to cited text no. 91
    
92.
van Winkle, M. G.. Melvin, S. Reheins and Ted Suie: Effects of Antibiotics on experimental Candida corneal Infec­tions. Amer. J. Ophth. 57: 54-87, (1964).  Back to cited text no. 92
    
93.
van Winkle, M. G., Reheins, M. S. and Ted Suie: Effects of Antibiotics on experimental Candida Infections. Amer. J. Ophthal 57: 84 (1964).  Back to cited text no. 93
    
94.
Veirs, E. R. and Davis, C. T.: Fungus Infections of the Eye and Orbit. Arch. Ophth. (Chicago) 59: 172-176 (1958).  Back to cited text no. 94
    
95.
Vogel, R. A., Michel, M. Jr. and Timple, A.: Amer. J. Path. 31: 535 (1955).  Back to cited text no. 95
    
96.
Wilson, I.., Sexton, R. and Ahearn, D.: Keratochrome-mycosis. Arch Ophth (Chicago) 76: 811-816.  Back to cited text no. 96
    
97.
Zimmerman, L. E.: Keratomycosis. Survey Ophthal. 8: 1 (1963).  Back to cited text no. 97
    
98.
Zimmerman, L. E.: Mycotic Keratitis. Lab. Invest 11, pt 2, 1151 (1962).  Back to cited text no. 98
    


    Figures

  [Figure - 1], [Figure - 2], [Figure - 3], [Figure - 4], [Figure - 5], [Figure - 6], [Figure - 7], [Figure - 8], [Figure - 9], [Figure - 10], [Figure - 11], [Figure - 12], [Figure - 13], [Figure - 14], [Figure - 15], [Figure - 16], [Figure - 17], [Figure - 18], [Figure - 19], [Figure - 20], [Figure - 21], [Figure - 22], [Figure - 23], [Figure - 24], [Figure - 25], [Figure - 26], [Figure - 27], [Figure - 28], [Figure - 29], [Figure - 30]
 
 
    Tables

  [Table - 1], [Table - 2], [Table - 3], [Table - 4], [Table - 5], [Table - 6], [Table - 7], [Table - 8], [Table - 9]



 

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