|Year : 1956 | Volume
| Issue : 1 | Page : 7-14
Leprous lesions of the eye
|Date of Web Publication||10-May-2008|
E J Somerset
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Somerset E J. Leprous lesions of the eye. Indian J Ophthalmol 1956;4:7-14
The incidence of leprosy probably varies considerably in different parts of India but most ophthalmologists will be familiar with the disease. Nevertheless, it is hoped that a general description, illustrated with slides, of some of the more important aspects of ocular involvement may be of interest, particularly to those who have not had much opportunity of studying the disease in their own area.
The proportion of cases of leprosy which eventually show ocular involvement also probably varies in different parts of the world and also in different parts of India. For example, Lopez (1890) in Havana, Santonestaso (1932) in Italy, Pinkerton (1927) in Hawaai, Poole (1934) in Honolulu considered that all cases eventually show some ocular involvement. On the other hand. Rogers & Muir (1946) in India, put the incidence at only 5-10% of all cases. It is not easy to say what the incidence of ocular involvement is in Eastern India. One has seen many lepromatous cases of 20 or more years duration in which the eyes were not involved even though the skin tests were still positive. In a series of 300 lepromatous cases, examined at the Hospital for Tropical Diseases, Calcutta, about 25% showed direct ocular involvement.
Details of leprous lesions of the eye are of considerable importance to the ophthalmologist for several reasons. Firstly, lesions due to leprosy ;are often similar to those due to other causes and it is therefore important always to have leprosy in mind, and secondly, quite often a case of leprosy presents himself in the first place to the ophthalmologist.
| Classification of Leprosy|| |
As is well known, leprosy is a chronic infective granulomatous disease caused by Mycobacterium leprae, the manifestations of which in the vast majority of cases can be classified into two types, (1) non-lepromatous (neural) and (2) lepromatous.
Non-Lepromatous (neural) The lesions appear in the skin and peripheral nerves and are characterised by epithelioid cells surrounded by round cell infiltration somewhat similar to that seen in tuberculosis. Scrapings from the skin may reveal occasional bacilli. Caseation with the formation of cold abscess is sometimes seen. Clinically, the skin shows patches or macules which are clearly defined, round oval or irregular areas from 2 to 10 inches in diameter. The patches show depigmentation of the nerves supplying the area. Sometimes the lesions show considerable thickening and erythema and loss of hair in the area is characteristic. Besides the skin lesions there is direct involvement of the peripheral nerves which are thickened and infiltrated with resulting loss of cutaneous sensitivity, paresis and wasting of the muscles leading subsequently to trophic lesions. The 5th and 7th cerebral nerves are frequently involved and are of special interest to ophthalmologists.
| Eye Signs in Non-Lepromatous Leprosy|| |
In this type of leprosy there is no direct infiltration of the globe by leprosy bacilli. Ocular involvement is secondary to involvement of the skin of the lids and the 5th cerebral nerves. Paralysis of the 7th nerve gives rise to the weakness of the orbicularis muscle with ectropion and lagophthalmos. In mild cases there may be little disability excepting slight epiphora. Usually the action of the levator palpebrae superioris lacking the opposing tone of the orbicularis produces a slight widening of the aperture. This, together with the less of eyebrows gives rise to a very typical facial appearance of leprosy [Figure - 1]. Paralytic ectropion and lagophthalmos subsequently give rise to exposure keratitis, corneal ulceration and subsequent scarring. All the usual complications of corneal ulceration may supervene with the advent of secondary infection. Hypopion. iritis. secondary glaucoma or phthisis bulbi are frequent complications too well known to ophthalmologists to require any further description. In regard to lagophthalmos, it should be remembered that although usually due to paralysis of the orbicularis muscle from interference with its nerve suppy, it is sometimes due to rigidity and immobility of the lids when involved in a thickened lesion of the skin of that area. [Figure - 2].
Lepromatous Type: In this type there is infiltration of the subcutaneous tissues and mucous membranes of the eye and respiratory tract in addition to the skin infiltration. Histologically there is comparatively little reaction and bacilli can be found in: enormous numbers. Clinically, the macules formed in the skin arc much less well-defined than in the neural variety. Depigmentation is less and there is often no paralysis. Sometimes the skin shows thickening and erythema. Nearly all cases will show lesions on the face, and loss of eyebrows especially in the outer half is very characteristic. In this type of leprosy there is actual lepromatous infiltration of the episclera, cornea and iris. It is this direct involvement of the globe which produces some characteristic appearances.
| Eye Signs in Lepromatous Leprosy|| |
Eye Lids-We have already mentioned the infiltration of the skin, the loss of brows and lashes. [Figure - 3] Some degree of lagophthalmos may be seen sometimes.
Conjunctiva-In spite of the fact that scrapings of the conjunctiva will sometimes reveal leprosy bacilli, a true leprous conjuctivitis does not seem to occur, although secondary infection is of course common in the type of patient who suffers from leprosy.
Episclera-Just as the leprosy bacillus infiltrates the deeper layers of the skin so it invades the episclera beneath the conjunctiva and produces small raised chronic nodules commonly situated at the limbus. They are more common on the nasal side and in the upper than the lower portion. They are usually from 2 to 8 mm. in diameter and associated with slight hyperaemia of the surrounding vessels. They are dirty yellow in colour and are extremely chronic and may remain for many years without changing. Sometimes the lesions become more active for a few months giving rise to some general ocular symptoms. These nodules sometimes extend into the cornea as we shall see. [Figure - 4].
Cornea-Considering the extensive infiltration of the skin in lepromatous leprosy, perhaps the odd thing about the cornea is that it may escape involvement for very many years. In view of the fact that the skin and the cornea are developmentally similar, this is rather strange.
(a) Superficial Punctate Keratitis -Symptoms of this are very slight or absent although there may be mild watering. Occasionally ciliary congestion may be seen but this is unusual. On the cornea and particularly in the upper and outer quadrant may be seen large numbers of superficial punctate opacities. These are often similar in appearance to those of virus origin except that they do not usually stain with fluorescein and of course are immensely chronic. They appear to be just under the epithelium. Sometimes these spots have the appearance of minute grains of chalk and are then pathognomonic of leprosy. [Figure - 5] is a good example of this. These spots of superficial punctate keratitis vary in size from 0.5 mm, and arc much larger than the white dots seen in the epithelium in ariboflavinosis. Superficial vascularisation is not common and its absence serves to distinguish the condition from trachoma. Tile spots may disappear but usually permanent opacities result. They seldom lead to much loss of vision.
(b) Interstitial Keratitis-This is usually an extension of an episcleral nodule into the substantia propria of the cornea and is seldom seen in the absence of episcleral involvement. The upper and outer quadrant is most commonly invaded and tile condition is often bilateral. A grey opacity is seen at the limbus contiguous with an episcleral nodule extending towards the centre of the cornea. The surface epithelium is either normal or may be tile site of some superficial punctate opacities. Circumcorneal congestion may or may not be present. A small amount of deep vascularisation of the cornea may be seen but is not characteristic and the absence or paucity of blood vessels helps to distinguish the condition from syphilitic interstitial keratitis. The distribution in the upper and outer quadrant also differentiates it from interstitial keratitis where tile lesions are usually more central except in the very early stages. Sometimes the cornea may become thickened, a condition described as hyperplastic keratitis. Occasionally, the interstital keratitis and episcleral nodules may almost surround the cornea. [Figure - 6].
(c) Deep Punctate Keratitis-This is a variety of interstitial keratitis in which the opacity takes a punctate form and scattered throughout the deeper layers of the substantia propria.
(d) Corneal Nerves and Sensation --The slit-lamp will occasionally reveal thickened corneal nerves but my experience in Bengal is that this is most unusual. It is not easy to decide whether the sensitivity of the cornea is normal or slightly diminished because the clinical method of testing is relatively crude. In the absence of gross corneal lesions, there does not seem to be much loss of corneal sensitivity and a true neuro-paralytic keratitis is a rarity.
(e) Late Corneal Degeneration As in any other infective or degenerative condition of the cornea. bandshaped opacities may sometimes be seen.
Iris-Involvement of the iris in the lepromatous process is one of the most serious aspects of ocular leprosy and is likely to lead to ultimate blindness. The presence of iritis probably indicates the duration of the disease of some 10 years. The manifestations are as follows:
(a) Chronic Iritis-In these cases there is often no history of pain, redness or epiphora and superficially the eye looks normal. Careful examination with the loupe and focused light will reveal a few posterior synechia. Apparently, in many cases the condition has been so chronic and symptomless that the patient does not know that his eye has affected. In some cases, minute nodules or "pearls" will be seen on the surface of the iris or on the posterior synechia. [Figure - 7],[Figure - 8]. They are extremely small being about 0.3 to 1.0 mm. in diameter. There may be only one or two or possibly a dozen or more. These minute pearls arc situated superficially on the iris or synechia and in the absence of signs of recent infiltration are pathognomonic of leprosy. They are dull yellow in colour and are distinguished from the nodules of secondary syphilis by their smallness and absence of iris reaction and general signs of acute iritis. Tuberculous nodules are much larger and greyer in colour and are usually associated with K.P. These pearls on the iris may disappear. Sometimes some activity is shown and new pearls appear as others disappear. In any case, the clinical change usually takes some months. Sometimes larger nodules are seen particularly at the periphery of the iris. in the angle of the anterior chamber and forbode an ultimate bad prognosis.
(b) Acute Diffuse Iritis-The usual signs of a subacute iritis may be seen. This stage lasts for some weeks or months and subsequently subsides into the chronic condition already described.
(c) Late Results of Iritis--The usual complications and sequelae of iritis supervene and need not be elaborated as they are only too well known to ophthal mologists.
Retinochoroiditis-It is extremely rare to see involvement of the fundus oculi in leprosy. Duke Elder (1940) states that fundus lesions were first described by Trantus (1899) and since then other cases have been described, on the other hand. Kirwan (1948), Soto (1948) and Aparsi (1950) have doubted the existence of fundus lesions. Do Barros (1939) in an extensive monograph does not mention fundus lesions and Harley (1946) in a systematic examination of 150 cases in Panama and Gibson (1950) who examined 55 cases in Australia could not find retinal lesions. However, in recent times Elliott (1948-49) has described six cases of fundus involvement from America, while Somerset and Sen (1956) have found two cases in a series of 300 leprosy patients examined in Calcutta. These nodules are situated towards the periphery of the retina and are about a quarter of a disc diameter in size. They are yellow in colour and have sharp edges. [Figure - 9],[Figure - 10]. There is no surrounding reaction in the retino-choroidal tissues and no pigmentary disturbance. They may show no change for many months or even years and may then gradually disappear. In one of these cases the nodules disappeared after about one year. One of the reasons why fundus leprosy is so little known and has so seldom been seen is because many cases have a co-incidential iritis with synechia so that dilatation of the pupil is impossible. One is not likely to find nodules without being able to obtain. reasonable dilatation of the pupil.
I am most grateful to Dr. Dharmendra of the School of Tropical Medicine. Calcutta for permission to examine the cases and for much help and advice and to Dr. N. R. Sen who assisted with the general examination.
| Summary|| |
The main manifestations of leprosy of the eye as seen with the lens, loupe and ophthalmoscope in all cases of leprosy are described in datail.
| Discussion|| |
Dr. B. N. Bhaduri : Episcleritis in leprosy not only extends on the surface but goes deeper and invades the sclera and then the lesion becomes painful. We have seen penetration of the sclera over a fairly large area exposing the choroid.
We have examined more than 5CC leprosy cases in the course of 25 years and some of them we have had opportunity of following for a long time. We have seen minute nodules near the ciliary border of the iris besides those over the sphinter muscle region. We have not met with a single case of choroiditis in a series of 150 cases, some with iridocyclitis and others without, all having lepromatous lesions of the skin. One should not compare leprolin reactions in the eye with the conjunctivitis or anterior uveitis due to Bacillus Lepri involving the ocular tissues. These ocular lesions can be controlled but if repeated attacks are left unchecked, the chance of ocular lesions are hastened. I thank Maj. Somerset for demonstrating choroidal lesions in leprosy for the first time.
Col. B. Basis : I have had beneficial results from subconjunctival injections of penicillin (50000 units) in cases of pupils resistant to atropine and also other eye reactions in Leprosy. Will the speaker coroborate this finding?
Dr. J. Bose : May I know what is the clinical difference of superficial punctate keratitis of leprotic and viral origins?
Dr. K. N. Mother : I have observed that conjunctival smear is positive for Lepra in the 30 cases that we did in which skin test and nasal smear was positive. Conjunctival smear test is the easiest method to diagnose Leprosy. We did not observe any ocular lesion in any of these positive smear case. May I know if there is any relation between the ocular lesion and the positive conjunctival smear?
Dr. M. Sengupta : I want to know if there is any explanation for the statement that.
(1) The folds of skin of the lids are not affected in leprosy.
(2) Whether the lacrimal gland is affected and whether there is any change in the secretion of the lacrimal gland which may be responsible for the superficial affections of cornea (upper and outer part).
(3) Why the leprosy nodule in the iris is yellow ? Whether any histochemical or histopathological examination of the nodule has been done.
Dr. V. Seshagirirao : May I know whether leprosy bacilli can be found in the scrapings of episcleritic and corneal lesions
Dr. E. J. Somerset's reply:
In reply to Dr. J. Bose, I think the distribution of superficial punctate keratitis is characteristically central. In leprosy it is usually seen in the upper and outer quadrant and is synmptonmless. In virus disease the spots are seen all over the cornea and produce symptoms.
In reply to Dr. M. Sengupta I think that infiltration of the lids right up to the lid margin is in fact a common experience, Enlargement of the lacrymal gland is rare in East India. We have so far not yet had the opportunity of making a histological preparation of a leprotic iris.
We have not seen involvement of the optic nerve though it is described in the literature.
There is probably little relationship between conjunctival smears and the clinical manifestations of the disease in the eve. Dr. Mathur's observations are the same as we have found.
In reply to Col. Basu, I have not used sub-conjunctival injections of penicillin in leprous iritis. Penicillin is not usually considered to have much beneficial effect on purely leprotic conditions.
| References|| |
Aparsi (1950) Arch. Soc. Oftal. Hispano-Amer, 10, 107.
de Barros (1939) Aspectos Clinocos do Comprometimento Ocular da Lepra. Quarta Mono
grafia dos Arquivos Sanatorio Padre Bento. Sao Paolo.
Duke-Elder (1940) Textbook of Ophthalmology, Vol. 3, Henry Kimpton, London. p. 2673. Elliott (1948) Intcnat. J. Leprosv, 16, 347.
Elliott (1949) internat. J. Leprosy, 17, 229.
Gibson (1950) Med. J. Aust.. 1, 8.
Harley (1946) Amer. J. Ophthal. 29, 295.
Kirwan (1948) Trans. R. Soc. Trop. Med. & Hyg. 41, 5. Lopez (1890) Arch. f. Augen. 22, 318.
Pinkerton (1927) Arch. of Ophth.. 56, 42.
Poole (1934) Tr. Amer. O. S. 32, 596.
Rogers & Muir (1946) Leprosy. London.
Santonestaso (1932) An. di Ott. 60, 21.
Somerset & Sen (1956) Brit. J. Ophthal. 40, 167.
Soto (1948) Arch. Ofta1., Buenos Ayres. 23, 51.
Trantas (1899) Ball. fr. d'o., 17, 275.
[Figure - 1], [Figure - 2], [Figure - 3], [Figure - 4], [Figure - 5], [Figure - 6], [Figure - 7], [Figure - 8], [Figure - 9], [Figure - 10]
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