|Year : 1976 | Volume
| Issue : 1 | Page : 1-14
K Nath, R Gogi
M.U. Institute of Ophthalmology, Aligarh, India
M. U. Institute of Ophthalmology, Aligarh
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Nath K, Gogi R. "The orbit". Indian J Ophthalmol 1976;24:1-14
Increasing interest of ophthalmologist in different fields of orbit is reflected by the huge literature that has collected in the recent years. In this review some of the important articles that appeared in the last five years have been included.
During this period the long awaited Vol. XIII of systematic ophthalmology, dealing with "The Ocular Adnexa" was released. Other books on orbital tumours, ophthalmic surgery and plastic surgery giving detailed' description of orbital surgery have also been published.,,
| Anatomy|| |
In a topographic study of 38 orbits, it was concluded that horizontal and vertical muscles are parallel to the corresponding orbital walls. At the equator of the eyeball, muscles are placed 4-6 mm from the bony orbit. Optic nerve lies supermedially . from the centre of the muscle cone. , Topography of sensory orbital nerves shows wide variations as compared to the motor nerves. Frontal branch may ramify in the lid skin (10.5%). Lacrimal nerve either ramifies inside the lacrimal gland (40.5% ) or before it reaches the gland (52.0%) or even before entering the orbit (7.5%). In 80.7% cases the secretory fibres reach the gland separately without joining the lacrimal nerve.
Sexual dimorphism of outlines of the orbit has been further confirmed. The impression of more angular shape of the male orbit and more smooth orbit of the female skull has been proved by mathematical analysis using Fourier coefficient.
Orbital growth is retarded following enucleation. In a series of fifteen adults with 14.4 years of follow up it was concluded that the enucleation in infancy or childhood was associated with a small reduction in the size of the bony orbit in later years, but this reduction had no cosmetic consequences. A decrease in the orbital measurements up to 15% with orbital implants and 8% without implants has been reported in a 15 years follow up. Similar observations have been recorded in the experimental animals. ,, It was further specified that the size of the orbit decreases if enucleation was performed before the age of 13 years. An orbital implant did not affect subsequent orbital growth unless the enucleation had been performed during the first three years of life. This study was made on 65 cases Barsky (1971) suggested an early fitting of the cosmetic prosthesis in cases of congenital microphthalmos. However, due to a lack of specimens the volumetric measurements of the abnormal anophthalmic orbits could not be carried out, except in another work. A retained phthisical eye causes little change in the orbital rim and volume. Following simple enucleation, changes occur both at the rim and within the orbit, involving all the dimensions.
| Congenital and Developmental Findings|| |
A clinical, statistical and genetic study of 70 cases suggests genetic and infective factors in the causation of microphthalmos. However, in a large number of cases, the cause remains obscure., Many cases of craniofacial dysostoses with different combinations have been reported,,.,,,,,,,,
Fibrous dysplasia can be monostotic and polystotic. Orbital involvement in 55 cases has been studied. Biopsy is needed to diagnose monostatic forms, whereas polystotic forms can be diagnosed radiographically. Two cases of fibrous dysplasias, one affecting the floor of the orbit and zygoma and the other involving frontal bone and greater wing of sphenoid have been reported.
| Examination Techniques|| |
Normal standards for exophthalmometry in children (10-14 ears), in relation to age, height, weight and sexual maturation have been provided.
The entire spectrum of radiological procedures ranging from time tried plain x-rays to the most recent computerized axial tomography have been studied. Venography remains the most popular method because it is simple, most innocuous and can be carried out without anaesthesia even in children. ,,,,,,,,,,,,. Russell and Miller recorded a success rate of 75% in localizing the orbital lesions by this method. They stressed six types of findings viz.: (1) Narrowing of the vein lumen due to decreased blood flow through the vein. This indicates increased intra-orbital pressure. (2) There may be complete obstruction of the vein either due to higher intraorbital pressure as compared to the venous pressure or mechanical compression caused by a mass or an orbital venous thrombosis due to any other cause. (3) The superior ophthalmic vein may be displaced by a mass within or encroaching upon the orbit. (4) Abnormal veins due to venous malformation. (5) Abnormalities affecting the cavernous sinus. (6) Venogram may be normal inspite of the orbital lesion.
Pneumo-orbitography is another simple procedure but rarely an air embolism may take place.
An analysis of 746 cases shows that localization of an orbital tumour can be achieved with 100% accuracy by orbitography. Up to 4 cc of 30% Hypaque or renographin-60 was injected, after diluting it with 2% xylocaine, into the orbit. The absorption is rapid and x-rays are to be taken in the next five minutes. orbitography was carried out by radioactive serum albumin iodide (I 131) in 26 cases of the orbital tumours and was specially useful in lesions located in the supratemporal orbit.
Xeroradiography is a process where photoconductive film is substituted and thus it is a photoelectric and not a photochemical process which can be carried out in daylight. Author studied 309 patients by this method and compared the results with the standard Roentgen ray techniques. The method was more informative, convenient and economical, but required a longer exposure, greater dose per study and sometimes too many confusing shadows were visualized.
Computerized axial topography or computer assisted topography in transverse axial plane is a new method of x-ray diagnosis. This method is a major breakthrough, since the introduction of x-ray in Nov., 1895. Here the photographic film is not used, and sodium iodide crystals are substituted for the film, so that the x-rays are detected by the crystals. The crystals, when exposed to x-rays, emit visible light in a proportional fashion and an electrical signal is generated via a photomultiplier system. The readings are processed by a computer. By this method, one can get the three dimensional view by displaying transverse axial readings on a vertical sequence. The resolution achieved by this method can distinguish the soft tissues whose densities are only slightly dissimilar. This science, now, has been applied to orbital lesions and the practical aspects of examination with results are described.
Radiological examination of orbital lesions should be carried out systematically. Venography of the ophthalmic veins should be preferred while arteriography and gas or opaque orbitography should be limited to selected cases.
Radionuclides hay e been used to study the orbital abnormalities quite frequently in the past few years.,,,,,,,,,,. The radionuclides differ in the reliability with which they can be used to detect orbital abnormalities. In a series of 30 patients, it was found that positive sodium pertechnetate TC 99 m (TPT) scans were associated w ith the orbital inflammatory, highly vascular or neoplastic lesions whereas chlormerodrin Hg 197 was most frequently taken up by other neoplasms. A combination of both can give more accurate results to localize the lesions than the conventional radiographic methods alone.
Infra-red thermography has alone been used as an additional method of investigation in various eye disorders specially, exophthalmos and vascular disturbances.
In a study of sulphahydrylic and disulphide groups in the serum in 15 cases of orbital tumours, it was established that the amount of free sulphahydrylic and disulphide groups in the blood serum decreased in patients with neoplasms of the orbit. In cases of malignant neoplasms the amount of sulphahydrylic, groups was reduced by 21.6 to 37 3%, and that of disulphide by 51.6 to 59.1%. In cases of benign tumours the amount of sulphahydrylic groups was reduced by 5.9 to 17.6% and that of disulphides by 45 to 48%. In the case of pseudotumour the amount of free sulphahydrylic group was normal and that, of disulphides was decreased by only 35%. The findings suggest the possible use of the levels of free sulphahydrylic and disulphide groups in blood serum as a test not only for diagnosing tumours but to some extent also for settling the question about its character.
Diagnosis of orbital tumours by sound waves has also greatly improved. A-scan techniques were initially used and recently B-scan system have made it possible to extend the scanning right upto the orbital apex by using focused ultrasound and higher energy transducers. This B-scan records the accoustic reflections in the plane of the scanning probe. Moreover both A and B scans can be combined.
| Injuries|| |
Orbital fractures constitute 7% of the oculoplastic service. An analysis of 128 patients with orbital fractures, revealed that 87% of cases suffered from classical blow out fractures. Majority were under the age of 15 years. Symptoms improved in 91 % following surgery. The orbital floor fractures can be repaired either by Caldwell-Luc procedure or by an orbital approach with a supportive sling. The post-operative results of 130 cases of orbital floor fractures, repaired by either procedure, have been compared. Authors recommend the use of Caldwell-Luc procedure for recent orbital floor fractures. Conservative treatment for pure blow out fractures has been suggested. In 57 such cases no surgery was done and cases were kept under observation. All these cases improved fairly well perhaps due to the absorption of haemorrhagic oedema of the posterior and inferior orbital fat.
| Orbital Inflammations|| |
Orbital cellulitis, in a pair of identical twins, showed concordance in all respects including response- to the antibiotic therapy . Infections of the paranasal sinuses remain one of the important source for the causation of orbital inflammations.,, - The basic embryological anatomo-topographical and etiological factors for an understanding - bf the pathogenesis of sinusitis in, childhood, have been summarized. . An increasing incidence' of such lesions has been attributed "to -frequent recurrences of influenza epidemics leading to-- ethmoiditis-. In an analysis of 85 children with sinusitis, it was found that periosteitis of orbit and walls `of accessory sinuses (68 cases) was the .commonest complication of sinusitis.}. Other complications were supra-orbital abscess (5), osteomyelitis of frontal bone (3), lid abscess (3), orbital vein thrombosis (1), retrobulbar neuritis (2), and meningitis (3). In the majority of cases it was acute sinusitis rather than chronic which was responsible for orbital cellulitis." There may be formation of gas in the orbit in orbital cellulitis.
Orbital cellulitis due to H. influenza which was not reported in the literature," has been described in seven cases. If generally affected children under the age of 36 months, the colour of the swollen orbital tissues was purple blue, blue or red "and the final diagnosis was based on laboratory examination.
Cases of cavernous sinus thrombosis and orbital cellulitis have been reviewed by Price et al  A rare complication of rhabdomyosarcoma of the middle ear in the form of orbital cellulitis and cavernous sinus thrombosis has also been described. This sequence probably was followed by secondary infection of the ear.
Two cases of orbital phycomycosis in poorly controlled diabetic patients were described. Treatment consisted of correction of hyperglycemia and electrolyte balance. Fungal infection was brought under control by intravenous injections of amphotericin-B. Sporotrichosis of orbital margins has been described in the past and now for the first time the tissue was examined under the electron microscope and the morphology of human sporotrichosis was studied. The existing controversy about the presence of. the capsule of this fungus has been proved. There is an outer mucoid capsule around the organism which' can be antigenic in nature and can play an important' role in the immunological reactions A case report about a rare orbital involvement in systemic North American Blastomycosis has also appeared in the literature. 
Granuloma inguinale is an infectious disease usually affecting the anogenital region. Bony involvement, in extragenital lesions, can occur in 6% of the reported cases and the involvement of orbital bones has been described. The" granuloma was maroon, velvet like a fungating mass. The final diagnosis was confirmed following the demonstration of Donovan .Bodies.
,Hydatid cyst of the orbit is a rare disease. A case with clinical, radiological and pathological features of the disease has been documented. The morphology of the scolices of T. Echinococcus has also been included. Some more cases--have been added to the literature,,, Orbitomyiasis indicates poor hygiene of the orbital affections and such cases have been recorded.,
Some unusual cases such as primary Boeck's Sarcoid of the orbit, intermittent exophthalmos due to hyperplasia of the lacrimal gland associated with dacryolithiasis, and a case of heterotopic orbital bone formation showing osseous pigmentation, have been recorded. The source of pigmentation is perhaps oxidation polymerization of melanin, oxidized epinephrine or oxidized tetracycline. This is the first case of its type.
Wegener's granulomatosis is known to affect orbit., In one such case there was focal glomerulonephritis associated with necrotizing granuloma of the orbit.
| Endocrine Exophthalmos|| |
Inspite of the extensive work on Graves' disease, the pathogenesis of the eye changes remains obscure. The concept relation between the raised level of ACTH and eye changes has been discredited. The role of exophthalmos producing substance (EPS) of pituitary origin, distinct from thyrotropin, has not been settled as yet. The EPS is measured by the increase in proptosis when the gold fish or carp are injected with the test sera.
The efforts to prepare EPS free of TSH from anterior pituitary have largely failed. The long acting thyroid stimulator (LATS) is present in a greater number of cases who show more eye changes of Graves' disease as compared to cases of hyperthyroidism with normal eyes. However, this idea of LATS as the sole mediator of Graves' disease is far too simple. Etiology of this disease in terms of some immunological basis has also been suggested.,,
On the basis of electromyographic studies, it was emphasized that the endocrinal ophthalmoplegias is usually not accompanied by electrophysiological signs of myopathy even when the paresis is so severe as to produce complete immobilization. The muscle fibres are normal and immobilization is due to the increased fluid volume in the interstitial spaces. Decreased potentials in some cases may be secondary to the oedema
Werner and Ingbar have strongly recommended that confusing terms such as malignant. exopthalmos, exophthalmic ophthalmoplegia, or thyrotropic exophthalmos should be replaced, by a six group classification of the disease.. Class 0, when no signs or symptoms are present. Class 1, when only signs are present without symptoms. The signs in this class include upper lid retraction and stare, with or without lid lag and proptosis. Class 2, when, soft tissue involvement is present along with signs and, symptoms. Class 3, when proptosis is present in addition. Class 4, indicates extraocular muscle involvement as well. Class 5 shoes consequent corneal involvement and Class 6, when optic nerve also gets involved, and there is visual loss. A case of myxoedema associated with exophthalmos, digital clubbing and hereditary multiple exostosis has been described.
Medical treatment of eye signs either by topical application of 5% guanethidine sulfate drops, ,, or local prednisolone drops, and systemic prednisolone, or by retrobulbar injections of methyl prednisolone acetate has been reported by different workers. Use of steroids by oral route, is only a palliative treatment specially when the vision is threatened..Orbital x-ray radiation is least commonly used for the ocular changes in Graves' disease. In a study of 37 patients, a total dose of 1500 roentgen in the air directed towards the posterior orbit in ten divided daily doses was applied. The lens was protected, signs of orbital congestion improved in many cases. The best response was obtained in patients with optic nerve involvement.
Surgical treatment for decompression of the orbit, shall be discussed under appropriate head.
One of the four annual bulletins of ophthalmological society of Belgium deals with 'Endocrinal Exophthalmos'. This is a complete and upto date examination of the subject. It deals with clinical picture, anatomic and histologic lesions. pathogenesis, biochemical research information and its management. It is recommended that as soon as the symptoms indicate that endocrinal `exophthalmos is becoming malignant, corticosteroids (80 to 120 mg/day) are to be given for a period of several months in order to support the actions of the immunosuppressors and to inhibit the synthesis of the mucopolysaccharides that play a role in orbital oedema. At the first sign of danger to the cornea, a blepharorrhaphy should be done. Surgical decompression of the orbit is done to prevent damage to the optic nerve. Irradiation of the retro-ocular tissues is to be reserved for patients unable to undergo surgical decompression
| Orbital Tumours|| |
Oncogenicity of virus is a sharply coming up subject. For the first time extraorbital tumours were produced by inoculating human adenovirus type-12 in the vitreous of 12 newly born hamsters. This is a unique oncogenic DNA virus and can induce a malignant tumour in newly born hamsters. A number of workers have used this virus to produce neoplasms in different tissues of the body,,,,,,. It is interesting that intraocular injection did not produce intraocular tumour, but rather orbital tumours which was speculated to have a neurogenic origin and cells might have migrated- along with ciliary nerves to the ciliary ganglion. All tumours occupied the temporal parts of the orbit. Tumour masses showed necrosis and haemorrhages. In three animals solid tumours developed in the liver as well Histopathology of the tumours resembled undifferentiated malignant neoplasm that closely resembled neuroepitheliomas.
Reese, giving Bowman's Lecture, summarized a lifetime experience on tumours of the eye and orbit. He reviewed the findings in 504 consecutive patients with expanding orbital lesions. All lesions "ere diagnosed by biopsy or exploration. Majority of cases (91) were grouped as granulomas to include endocrinal ophthalmopathy, histiocytoses, lymphomatous disease, necrotizing angitis, periarteritis nodosa, dermatomyositis, dysproteinemia, autoimmune disease and miscellaneous conditions. Haemangiomas were the next common cause of proptosis, followed by lymphoma, lymphangioma, rhabdomyosarcoma, lacrimal gland and peripheral nerve tumours. Nath and Gogi in a study of 120 histologically proved cases of primary orbital tumours have reported that pseudotumours are the commonest cause of proptosis. Other causes include a wide spectrum of tumours such as dermoids (26), vascular growths (19), optic nerve tumours (14), mesenchymal tumours (12), peripheral nerve tumours (11), and epithelial tumours (10). In this paper clinical features of various tumours with their clinicopathological correlation has been discussed. Histological typing of various orbital new growths, in a study of 91 primary orbital tumours has also been reported . In, other series primary haemangiomas was the commonest-tumours,_ In a survey of non-endocranial proptosis in 50 cases, the most frequent cause of proptosis was primary orbital tumours (11 cases) An etiological study of 85 cases included neoplastic, infective, traumatic, endocrinal, vascular and unknown causes. The common tumours were meningiomas and haemangiomas. A study of 32 children, between 4 months and 14 years, sarcomas (11) and orbital extensions of retinoblastoma (9) were the commonest orbital tumours. However, authors also included one case of hydatid cyst of the orbit in this group. Whereas in another report, orbital extensions of retinoblastoma was the commonest cause of proptosis, followed by dermoids, vascular growths, pseudotumours, leukemic deposits, optic nerve tumours, mesenchymal and peripheral nerve tumours.
In a series of 341 cases of tumours affecting the nose and paranasal sinuses, 102 cases invaded the orbit. The commonest source was ethmoidal sinus (57.1%), while the most common tumour to invade the orbit was sarcoma (55.1 %). Carcinoma was less common. Amongst 102 cases, cervical metastasis was noted in twenty-nine.
Cysts of the paranasal sinuses, specially from the frontal and ethmoidal sinuses, were the commonest cause of proptosis of rhinological origin in a series of 43 cases studied over a period of 10 years.
Orbital dermoids affected the orbital margins in 21 cases, their clinical features and histopathological findings have been described and depending upon the microscopic structure, cysts were divided into five groups. An unusual case of dermoid, arising from the apex of the orbit and extending through the lateral orbital wall through a fistulous tract in the skin, had to be taken out through Kronlein's orbitotomy. Another case of intraorbital dermoid has been reported. Rarely a dermoid may also arise from the diploe of the orbital bone. Two cases of orbital teratomas, an extremely rare orbital growth, have been reported., A rare sudoriferous cyst of the orbit, appeared as a congenital tumour in an infant.
Pseudotumours are a group of diverse space occupying lesions of the orbit that clinically simulate neoplasia. Garner has given an exhaustive review of the whole subject with its classification. Lymphoid tumours of the orbit, whether benign (pseudotumour) or obviously malignant lymphomas, present a challenging diagnostic problem both for the ophthalmologist and the pathologist. Mortada '  reviewing his 40 cases, has stressed the importance of clinical features that can be helpful in differentiating a malignant lymphoma from a pseudotumour. Findings have been summarized in a table.
Incidence of primary reticulo-endothelial tumours has been reported as 17.1%, 11 % and 12.5% as benign lymphoid pseudotumours. There may be associated increase of Ig A in the serum. Isolated cases, of benign lymphoid tumours, as a part of Hashimoto's disease9J or as orbital manifestation of a malignant lymphoma have appeared. ,,,, Clinical features and histopathology of lymphoid and other types of pseudotumours have been described by some workers.,, There is always a possibility of lacrimal gland tumour manifesting as a part of generalized lymphomas.
Lacrimal gland is the only source of primary epithelial tumours in the orbit. Clinicopathological findings indicate that these tumours may be in the form of pleomorphic adenoma (5), cylindroma (4) or mucoepidermoid carcinoma (1) , Pathology of these tumours has also been reviewed .,, There are case reports describing cystic adenoid carcinoma, as benign mixed cell tumour of lacrimal gland,, and malignant mixed cell tumour as a source of metastatic carcinoma.
A review of 25 cases of primary intraorbital meningiomas constituted about 10% of primary orbital tumours. This is the largest series of such cases affecting 21 females and 4 males. 10 patients were under the age of 20 years. There was proptosis (18), loss of vision (3) papilloedema (10), chemosis with oedema of the lid (6) and limitations of ocular movements (4). On histological examination optic atrophy was present in 22 cases, the tumours being either meningo epitheliomatous or mixed type. The tumours invaded the optic nerve head in two cases and nerve itself in one. Unlike intracranial meningiomas, pure intraorbital types occur in younger age group and are more aggressive. Nath and Gogi reported an incidence of 7.5% in a study of 120 primary orbital tumours. Clinical and histopathological features of these tumours were also studied in an earlier communication. There are other reports on orbital meningiomas.1  Intraorbital optic nerve glioma is a rare tumour. Three such cases with their clinical features gross appearances of the specimens and histological structure have been documented, the youngest being a 4 months old. An electron-microscopic study of the tumour has also been carried out., Clinicopathological features in 5 cases of gliomas were correlated.
Definitive benign mesenchymal tumours of the orbit are not common. The clinical and pathological features in three such cases of orbital fibroma and one case of lipoma have been reported.  One case each of orbital leiomyosarcoma, myxosarcoma, osteoclastoma of orbital rim, leiomyoma, and two cases of a rare tumour, mesenchymal chondrosarcoma, have been recorded, In 10 cases of orbital rhabdomyosarcomas electron-microscopic study was carried out. In another report clinical and histopathological features of this tumour were described. Describing two cases of fibrosarcomas, Jackobiec and Tannenbaum found that one was radiation induced and the other was from maxillary sinus. With light microscopy the diagnosis of malignant Schwannoma and an amelanotic melanoma was made. The correct diagnosis of fibrosarcoma was established only with the help of electron-microscope.
Clinicopathological correlation in 12 different mesenchymal tumours of the orbit was noted Individual case reports of orbital fibroma, and fibrosarcomas have appeared,
A study of orbital vascular malformation constituted 24% space occupying lesions of the orbit  In cases of cavernous haemangioma, emphasis has been laid on the role of orbit venography and ultrasonography in establishing the clinical diagnosis. Cavernous haemangioma may be associated with a similar lesion in the skin and subglottic area. A unilateral proptosis occurred due to cavernous haemangioma of the nose. In a histological study of vascular malformations cavernous haemangiomas (10), capillary haemangiomas (3) and one case each of venous haemangioma, hemangioendothelioma and haemangiopericytoma have been discussed  Clinicopathological features of seven cases of haemangiopericytoma have been noted. Isolated case reports of these tumour have also appeared in the literature,
Clinicopathological features of 19 cases of vascular malformations and tumours are described by Nath and Gogi. This group constituted 15.84% of primary orbital tumours. Orbital lymphangiomas have a disputed origin and one such case has been reported.
Peripheral nerve tumours constituted 9.16% of the primary orbital tumours. They may be in the form of neurilemoma, neurofibroma, or a plexiform neuroma. [20,155 A benign orbital neurilemoma may rarely undergo a sarcomatous transformation specially in association with Von-Recklinghausen's disease. The tumours of this disease, when present in the middle cranial fossa, may invade the orbit
Primary orbital melanoma is extremely rare. Only six such cases were on the record upto 1975,,,,,, Only one such case has been seen in a negro. Other rare primary orbital lesions include pulsating exophthalmos due to intraorbital meningocele, amyloid tumour cholesteatoma, orbital osteoma, nevus of Ota with orbital invasions, aneurysmal bone cyst of the orbit, and six cases of locally aggressive fibrous histiocytomas. In an unusual case of carcinoid syndrome with bilateral metastasis, orbital biopsy demonstrated argentaffin cells with increased urinary 5 hydroxy-indoleacetic acid and raised urinary concentration of serotonin. Granular cell tumour or myoblastoma is a well known tumour of the tongue and skin. Only 11 such cases have been reported.,,,, Another case in a child of 7 years was added.
Neuroblastoma is a malignant tumour arising from the undifferentiated cells of sympathetic nervous system. In a review of 15 cases of neuroblastoma, orbital metastases were observed in 8 cases in the form of proptosis, palpable mass in the orbit, ecchymosis of eye lids and the tumour showed marked tendency for necrosis.
Secondary orbital tumours either from ethmoid, nasopharynx, other paranasal sinuses, or as distant metastasis from prostate, malignant melanoma of skin, breast, or in the form of plasma cell myeloma, have appeared
Three cases of orbital involvement by eosinophilic granuloma were seen,,
| Circulatory Disturbances|| |
Intermittent proptosis is commonly caused by orbital varices.,, A case of orbital varices occurred following orbital trauma . An analysis of 9 cases describes the clinical picture, diagnosis and surgical treatment. In a study of 12 cases, varices originated from posterior bulbar part of the superior ophthalmic vein in 8 cases and in one case from extraorbital portion. Clinical radiological and pathological findings were also studied. In a case report, retrobulbar haemorrhage produced central artery occlusion and post haemorrhagic jaundice.
| Surgery|| |
Less than 10% of patients with progressive space occupying lesions undergo neurosurgery. In the majority Kronlein operation is suitable, as it is not a disfiguring procedure. Inadequate resection of the lateral wall is a common difficulty and the lateral wall must be well resected in order to achieve better exposure. Depending upon the merits of the case, exenteration should be done and generally it is wise to save tissues to improve the cosmetic results. A detailed report of 61 patients operated by transfrontal route for space occupying intra-orbital lesions has appeared. In 44 cases, intradural and in 17 extradural transfrontal orbitotomy was done. This approach was indicated in orbital lesions extending into the cranium or vice versa, and in intraorbital tumours localized on the nasal side of the orbit. In author's opinion this procedure gives wider and better view as compared to lateral orbitotomy. In exploratory surgery by any route it may be difficult to recognize a piece of soft neoplasm obtained by blind deep dissection which may look and feel exactly like a piece of indurated orbital fat. This can be differentiated by putting the specimen into irrigation fluid, when the pieces of orbital fat would float.
In Graves' disease orbital decompression has to be done to save the cornea and the optic nerve. Different workers have claimed better results through different routes, viz. transfrontal decompression transantral approach, lateral orbitotomy,
In craniofacial dysostosis (Crouzon's disease), frontozygomatics sphenoidal approach along with linear craniectomy has been described.  Tessier in a series of 123 patients, performed decompression via cranial route in 40 cases and via infranasal route in 11 cases.
| References|| |
Appelmans, M., Mi.:hiels, J., Kerkhofs, G. 1965, Bull See. Belg. Ophthalmol., 140, 375.
Abrikossoff, Cited by Moscovic, E. A., and Azar, H.A. 1967, Cancer., 20, 2032.
Abucham, R. 1971, Arq. Brasoftal., 34, 310.
Apte, P.V., Patil, R.V. and Lemade, P.T. 1971, East. Arch, Ophthal., 9, 220.
Abdel Razik, F., Attia, 0., Abdalla, M.I. and Ibrahim, S. 1972, Bull Ophth. Sot. Egypt., 65, 513.
Aron Rosa, D.S. and Doyon, D.L. 1972, Amt. Oculist (Paris)., 205, 667.
Algvere. P., Almqvist, S. and Backlund, E.O. 1973, Acta. Ophthal. (Kbh)., 5, 461.
Algvere, P., Almqvist, S. and Backlund, E.O. 1973, Acta. Ophthal. (Kbh)., 51, 475.
Ahluwalia, B.K. and Chandra, P. 1973, East.Arch. Ophthal., 1, 75.
Ahluwalia, B.K., Chandra, P., Gupta, N.C. and Singh, I. 1974, East. Arch. Ophthal., 2, 47.
Ahluwalia, B.K., Chandra, P., Singh, 1. and Kumar, R. 1974, East. Arch. Ophthal., 2, 188.
Almaraz, G.G., Buen, S.D. and Tsutsumi, V. 1975, Amer. J. Ophthal., 79, 606.
Blodi, F.C. 1956, Arch. Ophthal., 56, 698.
Barsky, D. 1971, J(,ur. Pediant. Ophth., 8, 123.
Berkman, N., Joseph, E. 1971, Arch. Ophthal., 31, 613.
Bowen, D.L. Callum, L.M.T., Rees, D.O. 1971, Acta Ophthal. 55, 145.
Babior, S.N. and Vakker, A.V. 1972, Vestn. Oftal., 6, 77.
Bell, R.W. 1972, Ann. Ophthal., 4, 1090.
Bellone, G., Actis, G. and Perotto, M. 1972, Arch.Ras. Italettalmol., 2, 174.
Biernacka, M. and Zielinska, H. 1972, Klinoczna., 4, 1083.
Blake, J. and Fitzpatrick, C. 1972, Trans. Ophthal. Soc. U.K., 92, 825.
Brenner, A., Gaucherie, M. and Bourjat, P. 1972, Klinmbl Augenheilk., 160, 13.
Bruna J. 1972, Radio)., 26, 299.
Babel, J. 1973, Amt. Oculist. (Paris)., 206, 725.
Brewith, H., and Huerkamp., B. 1973, Klinmbl Augenheilk., 162, 247.
Barber, J.C., Barber, L.F., Guerry, D. and Geereets, W.J. 1974, A.M.A. Arch. Ophthal., 91, 45.
Bullock, J.D., Jampol, L.M. and Fezza. A.J. 1974, Amer. J. Ophthal., 78, 811.
Byers, R.M., Berkeley, R.G., Luma, M. and Jesse, R.H. 1975, Anur. J. Ophthal., 79, 53.
Crane, A.R. and Tremblay, R.G. 1945, Amer. J. Pathol., 21, 357.
Cala, R., Zajdela, A., Haye, C. and Schienger, P. 1971, Cancer (Paris)., 58, 329.
Cardenas, L., Albores, J. and De Buen, S. 1971, Arch. Ophthal., 86, 410.
Coleman, D.J. 1971, Vienna, Verlag der Weiner Medizinischen Akadenue., pp. 403.
Chandra, P., Ahluwalia, B.K. and Chugh, T.D. 1972, East. Arch. Ophthal.,10, 84.
Correa Barbosa, J.C. 1972, Arq. Neuro-Psiquait., 30, 171.
Chohan, B.S., Chandra, P. and Luthra, J.K. 1973, East. Arch. Ophthal., 1, 237.
Chohan, B.S. and Sharma, J.L. 1972, East. Arc Ophthal., 10, 29.
Cullen. J.F. 1974, Brit. J. Ophthal., 58, 105.
Dunnington, J.H. 1948, Arch. Ophthal., 40, 14.
Dhermy, P., Morax, P.V., and Jolivet, J. 1966, Ann. Oculistique., 199, 1025.
Dardenne, M.U., Poona Walla, N.H., and Han rath, E.M. 1970, Ophthal. Res. 1, 79.
Dyal, Y., Sood, N.N., Goulatia, R.K. and Bhatia, I.M. 1971, Orient Arch. Ophthal., 9, 176.
Doyon, D. and Aron Rosa. D. 1972, Feuilets Electroradiol, 12, 251.
DeSanto, L.W. 1972, Mayo. Clin. Proc., 47, 989.
DePalma, P. 1972, Arch. Basitalottamol., 2, 292.
De Almeida, A.A. and Higuchi, T. 1973, Rev. Brasoftal., 32, 47.
Duke Elder 1974, `The Ocular Adnexa. Pt. I & Pt. II'. Henry Kimpton, London.
Drews, R.C. 1975, Arch. Ophthal., 93, 335.
Edwards, W.C., Adkew, W. and Weisskopf, B. 1971, Amer. J. Ophthal., 72, 202.
Endicott, J.N., Kirkconnell, W.S. and Deam, D 1972, Arch. Otolaryng., 96, 457.
Fox, S. 1970, Ophthalmic Plastic Surgery, N.Y.,Grane and Stratton Inc.
Filipic, M. 1971, Trans. Austcoll. Ophthal., 3, 64.
Francois, J. and Pierard, J. 1971, Amer. J. Ophthal., 71, 1241.
Filatov, Y.M., Serbinenl:o, F.A. and Padalko, P.1. 1973, Vop. Neirokhir., 37, 14.
Gharib, H. and Mayberry, W.E. 1970, Mayo. Clin. Proc., 45, 444.
Grosz, 1., 1970, Ther. Hung. 18, 83.
Gibson, M.J., Middlemiss, J.H. 1971, Brit. J. Radial., 44, 1.
Goto, K., Usui, J. and Stato, A. 1971, Folia. Ophthal. Tap., 22, 777.
Grove, A.S., Jr. Kolner, L.M., 1971, Trans. Am Acad. Ophthal. Otolaryngo., 75, 496.
Gupta, J.S., Gopal, H., and Dhavan, S.K. 1971, Ind. Jour. Ophthal., 19, 27.
Gerber, F.R., Taylor, F.H. and Delevie, M. 1972 Pa. J. Pediat., 81, 327.
Gupta, S.P., Pratap, V.B. and Kaul, R.I. 1972,Ind. Jour. Ophthal., 20, 189.
Garner, A. 1973, J. Clin. Pathol., 26,639.
Gogi, R. 1973, Thcsis M.D. (Path) AMU. Aligarh.
Goldman, R.J. and Hessburg, P.C. 1973, Amer. J. Ophthal., 76, 152.
Gonzalez, J.M., Ruiz, R.D. Gonzalez, N.A. and Luengo, F. 1973, Rev. E
Gnandoss, A.S. and Vedanayagam, B. 1973, East. Arch. Ophthal. 1, 67.
Guibor, P. 1973, Trans. Amer. Acad. Ophthal. Otolaryngol., 77, 751.
Gupta, A.K., and Chaudhry, S. 1973, East. Arch.Ophthal., 6, 406.
Gupta A.K. and Ramamurthy, S. 1973, Jour.Pediad. Ophthal., 10, 292.
Grove, A.S. (Jr) and Ketner, L.M. (Jr) 1973, Arch. Ophthal., 89, 301.
Grove, A.S. (Jr) and Ketner, L.M. (Jr) 1973 Arch. Ophthal., 89, 13.
Gandhewar, R.N. and Mokadam, P.J. 1974, East. Arch. Ophthal., 2, 72.
Gawler, J., Sanders, M.D. and Bull, J.W.D,, Benlay, G.D., and Marshal, J. 1974, Brit. J. Ophthal., 58, 571.
Greenwald, H., Keney, A.H. and Shannon, C.M. 1974, Anzer. J. Ophthal., 78, 655.
Gogi, R. and Nath, K. 1976, East. Arch. Ophthal (In press).
Gogi, R., Nath, K. and Tyagi, S.P. 1976. Ind. J. Ophthal., (In press).
Huebner, R.J., Rowe, W.P. and Lane, W.T.1962. Proc. Nat. Acad. Sci. 48, 2051.
Howard, G.M., Kinder, R.S.L. and Man Millan A.S. (Jr) 1965, Arch. Ophthal., 73, 80.
Hagler, W. and Brown, C. 1966, Trans. Am Acad. Ophthal. Otolaryngol., 66, 817.
Heddie, O. 1970, Jour. Pediatr., 76, 906.
Hoepner, J., Yanoff, M. 1971, Jour. Pediat Ophthal.. 8, 107.
Honrubia, F.M., Davis, W.H., Moore, M.K. and Elliott. J.H. 1971, Amer. J. Ophthal.,72, 1116.
Henderson, J.W. and Farrow, G.M. 1972, Am. Acad. Ophthal. Otolaryngol., 76, 1487.
Hener, H.E. 1972, Acta. Ophthal. (Kbh)., 50, 160.
Hinzpeter, T. 1972, Radio]. 12, 428.
Hogen, M.J. and Wood, I. 1972, Trans. Amer. Ophthal. Soc., 70, 131.
Hamilton, A.M., Garner, A., Tripathi, R.C. and Sanders, M.M. 1973, Brit. J. Ophthal., 57, 253.
Hempel, E. 1973, Dtschgesundh-Weives., 28,264.
Henderson, J.W. 1973, Philadelphia, W.B., Sanders, pp. 345.
Jay, B. 1965, Brit. J. Ophthal., 49, 359.
Jain, M.R. Agarwal, R.L. and Singhvi, M.S. 1971, East. Arch. Ophthal.. 9, 54.
Jensem. S.F. 1971; Acta. Ophthal., 49, 679.
Jofre, J.A., and Oliva Otere, G. 1972, Medicina (Mex)., 52, 1133.
Johnson, B.L. and Buerger, G.F. Jr. 1972, Arch. Ophthal., 88, 400.
Johnston, M.V. and Larsen, P.R. 1972, Metabolism., 21, 1155.
Jakobiec, F.A., Jones, I.S. and Tannenbaum, M.1973, Brii. J. Ophthal., 57, 825.
Jat obiec, F.A., Howard. G.M., .tones, I.S. and Tannenbaum, M. 1974, Amer. J. Crhthal., 77, 33.
Jakobiec, F.A. and Tannenbaum, M. 1974, Amer J. Ophthal., 77, 899.
Jakobiec, F.A., Ellsworth, R. and Tannenbaum, M. 1974, Amer. J. Ophthal., 78, 24.
Jampol, L.M., Marshi, J.C. Albert, D.M. and Zimmerman, L.E. 1975, Amer. J. Ophthal., 79,279.
Kennedy, R.E. 1965, Amer. J. Ophthal., 60, 277.
Kourtas, D.A., Bouzas, A.G. and Livadas; D.D. 1970, Pharm. Clin., 3, 32.
Kramer, S.F., and Pelcyn, 1970, Trans. Amer. Acad. Ophthal. Otolaryngol., 74, 1240.
King, J.H., and Wadsworth, J.A.G., 1971, An Atlas of Ophthalmic Surgery. Philadelphia, J.B. Lippincott Co.
Kono, M., Takayasu, K. and Miwa, T. 1971, Brain Nerve., 23, 1557.
Kopelow, S.M., Foos R.Y. and Strasatsma, B.R. 1971, Int. Oplithal. Clin. 11, 113.
Kadota, K., Shinohara, T. and Kagawa, M. 1972 Brain Nerve., 24, 1315.
Kennedy, R.E. 1972, Trans. Amer. Ophthal., Soc.70,278.
Kiribuchi, M. 1972, Jap. Jour. Clin. Ophthal., 26, 123.
Kojima, K., and Sakai. T. 1972, Acta. Soc. Ophthal. (Jap)., 76, 74.
Kaluzny, J., Ziemianski, A., and Perzowa, B. 1973, Klin. Oczna., 43, 193.
Koike, Y., Hirano, M. and Kobayashi, J. 1973, Otologia, (Fukuota), 19, 365.
Karp, L.A., Zimmerman, L.E., Borit, A. and Spencer, W. 1974, A.M.A. Arch. Ophthal., 91, 24.
Lavergne, G. and Winand, B. 1970, Ann. Ocul., 203, 469.
Litricin, 0., Pendie, S., Ilie, R. and Belgrade 1971, Ann. Oculist. (Paris). 204, 1317.
Lloyd, G.A.S., Wright, J.E. and Morgan, G. 1971, Brit. Jour. Ophthal., 55, 505.
Lamba, P.A., and Murthy, R. 1972, East. Arch.Ophthal., 10, 279.
Lemire. J. 1972, Canad. J. Ophthal., 7, 375.
Lloyd, G.A.S. 1972, Brit. Jour. Radiol., 45, 405.
Latiergne, G. and Winand, R. 1973. Bull, Soc. Beige. Ophthal. 163, 165.
Leonard, Apt. 1973, A.M.A. Arch. Ophthal. 90. 393.
Londer, L. and Nelson, D.L. 1974, A.M.A. Arch. Ophthal., 91, 89.
Michiels, J., De Rao, M. and Kerkhofs, G. 1966, Bull. Soc. Beige, Ophthal., 143, 578.
Mohan, H., and Sen, D.K. 1970, All, Ind. Ophthal., Soc. Vol. XXVIII : 31.
Mohan, M. 1970, Proc. of All Ind. Ophth. Soc Vol. XXVIII : 55.
Mustarde, J., Jones, L.T., and Callahan, A. 1970, Plastic Surgery. Birmingham, Ala, Aesculapins. Publishing Co.
Maria, D.L. and Kale, M.D. 1971, East Arch. Ophthal., 9, 51.
Mohan, H., Sen, D.K. and Gupta, P.K. 1971, Brit. J. Ophthal., 55, 642.
Maria, D.L., Apie, P, V. and Joshi, B.G. 1971, East. Arch. Ophthal., 9, 59.
Mohan, M., Wadhwa. V.K. and Goswamy, S.1971, East. Arch. Ophthal., 9, 185.
Mohan, H., Sen. D.K. and Chatterjee, P.K. 1971, Ind. Jour. Ophthal., 19, 61.
Mortada, A. 1971, Brit. J. Ophthal., 55, 639.
Mikolajkow, A., and Mroczek Madziar, D. 1972, Endokr. Pol., 23, 11.
Mortada, A. 1972, Amer. J. Ophthal., 74, 307.
Mukai, N., and Kobayashi; S. 1972, Anrer. J. Pathol., 69, 239.
Mukai, N. and Kobayashi, S. 1973, Invest.Ophthal., 12,185.
Miki, H. and Hirano, A. 1975, Amer. J. Ophthal.,79, 589.
Me Fadzean, R.B. 1975, Brit. J. Ophthal., 59,164,
Newell. F.W. 1963, Amer. Acad. Ophthal Otolaryngol., 67,177.
Neiders, M.E., Weiss, L., and Yohn, D.S. 1968 Cancer Res., 28, 577.
Nakagawa, T. 1970, Acta. Soc. Ophthal., Jap. 74, 822.
IBID 1971, Jap. J. Ophthal., 15, 152.
Nehen, J.H. 1972, Acta. Ophthal. (Koh), 50, 495.
Nowicl, a, L., Koszczynski, Z. and Krych, J. 1972, Klinoczna., 42, 103.
Naito, H., Oshida, K. and Kurokawa, K. 1973, Surg. Neurol., 1, 84.
Nakamura, Y., Nose, H., Nose, T. and Satio, S. 1973, Jap. J. Clin. Ophthal., 27, 571.
Newmark, E. and Ange, C. 1973, Ann. Ophthal.,.5, 63.
Nath, K. and Gogi, R. 1973, East. Arch. Ophthal.,,1, 45.
Nath, K., Gogi, R., Khan, A.A. and Hameed, S. 1975, East. Arch. Ophthal., 3, 72.
Nath. K. and Gogi, R. 1975, East. Arch. Ophthal., 3, 67.
Nath, K., Gogi, R., Khan, A.A. and Hameed, S. 1975, East. Arch. Ophthal., (July) (In press).
Nath, K. and Gogi, R. 1975, Ind. Jour. Ophthal., 23, 1.
Nath, K. & Gogi, R. 1975, East. Arch. Ophthal., (July), (In press).
Nath, K. and Gogi, R. 1976, East. Arch. Ophthal. (In press).
Nath, K. and Gogi, R. 1976, Proceedings 6th Afro-Asian Congress. (In press).
Ogawa, K., Tsutsumi, A. and Lwata, K. 1966, Gann., 57, 43.
Ohnishi, Y. and Hirashima, N. 1972, Jap. J. Clin. Ophthal., 26, 19.
Otradovec, J. and Votockova, J. 1973, Cs. Oftal., 29,221.
Osborne, D., Hadden, O. B., and Deeming, L.W. 1974, Amer. J. Ophthal., 77, 756.
P]aniol, T., Morax, P.V. and Jolivet, J. 1967, Ann. Oculist., 200, 609.
Price, C.D., Hameroff, S.B. and Richards, R.D. 1971, Sthmed. Jour. 64, 1243.
Parmar, I.P.S., Chandra, P. and Kumar, A. 1972, East. Arch. Ophthal., 10, 332.
Parmar, I.P.S., Kumar, J. and Nagpal, R.C. 1973, East. Arch. Ophthal., 6, 403.
Pettinati, S., Temporelli, A., Genevese, M.G. and Actis, G.P. 1973, Minerva, Med., 64, 501.
Pollard, Z.F., Calhoun, J. 1975, Amer. J Ophthal., 79, 310.
Putterman, A.M., Stevens, T., and Urist, M.T. 1974, Amer. J. Ophthal., 77, 232.
Poaell, J.O. and Glaser, J.S. 1975, A.M.A Arch. Ophthal., 93, 340.
Rottino, A., and Kelley, A. 1942, Arch. Ophthal., 27,949.
Reese, A.B. 1971; Trans. Ophth. Soc. U.K., 91, 85.
Rogers, P.A., 1971, Trans. Austoll. Ophthal., 3, 61.
Rosa, F., and Ricci, B. 1971, Ann. Ottal., 97, 179.
Remlein Mozolewska, G., Karczweicz, D. and Sulikowski, M. 1972, Klin. Oczna., 42,999.
Riley, F.C. 1972, Mayo. Clin. Proc., 47, 986.
Russell, D.B. & Miller, J.D.R. 1972, Radiology., 103, 267.
Ravin, J.G., Sisson, J.C. and Knapp. W.T. 1975, Amer. J. Ophthal.. 79, 285.
Spjut, H.J., Van Hossier, G.L. and Trentin, J.J. 1967, Arch. Pathol., 83, 199.
Schlesinger, E.B., Trokel, S.I. and Bailey, S. 1969, Trans. Amer. Acad. Ophthal. Otolaryngol., 73, 1005.
Satyendran, O.M. 1970, Proc. of The All Ind Ophth. Soc. Vol. XXVIII: 52.
Scouras, J., Catti A. and Cuendet, J.F. 1970, Ann. Ocul., 203, 953.
Schatz, H. 1971, A.M.A. Arch. Ophthal, 86, 268.
Schleyer, F., Ihm, P., and Bensch, W. 1971, Zrechitsmed., 69, 168.
Sekimoto, T., Nakaseko, H. and Kondo, K. 1971, Folia. Ophthal. Jap., 22, 535.
Sen, D.K. and Mohan, H. 1971, East. Arch Ophthal., 9, 215.
IBID 1971, East. Arch. Ophthal., 9, 217.
Sen, D.K., Mohan, H. and Chatterjee, P.K. 1971, Nose Thr. Monthly., 50, 383.
Storch, J. 1971, Ann. Ocul., 204, 469.
Sugar, A., Bigger, J.F. and Podos, S.M. 1971, Jour. Pediat. Ophthal., 8, 234.
Shah, S.S. and Shah, V.M. 1972, Ind. Jour. Med. Sc., 26, 315.
Sakka, Y. and Takagi, M. 1972, Folia Ophthal Jap., 27, 513.
Saxena, R.C., Garg, K.C. and Meena Bhatia, 1972, Ind. Jour. Ophth. 20, 191.
Schurbert, E. 1972, Klin. Mblaugeheilk., 160, 467.
Schurmann, K., and Voth, D. 1972, Fortschrau genheilk., 25, 188.
Sen, D.K. and Mohan, H. 1972, Jour. Pediat Ophthal., 9, 187.
Singha, S.S. 1971, East. Arch. Ophthal, 9, 211.
Saunders, J.F. 1973, A.M.A. Arch. Ophthal., 89, 205.
Scherbatov, I.I. and Lisitsyn, E.D. 1973, Vesto note-Rino. Laring, 35, 29.
Sevel, D., Tobias, B. Sellars, S.L. and Forder, A. 1973, Brit. J. Ophthal., 57, 133.
Speakman, J.S. and Phillips, M.J. 1973, Canad. Jour. Ophthal., 8, 539.
Shuangshoti, S. 1973, Brit. J. Ophthal., 57, 265.
Sevel, D. 1974, Brit. J. Ophthal., 58, 882.
Streeten, B.W., Rabuzzi, D.D. and Jones, D.B.1974, Amer. J. Ophthal., 77, 750.
Thomson, W.E. 1901, Trans. Ophth. Soc. U.K, 21,258.
Trentin, J.J., Yabe. Y. and Taylor, G. 1962, Science, 137, 835.
Timm, G. and Timmel, H. 1966, Klin. Monatsbl. Augenheilk., 148, 665.
Tessier, P. 1970, Chirurgie., 96, 667.
Takaku, A., Kanayama, S., Shindo, K. and Suzuki, J. 1971, Jap. J. Clin. Ophthal., 25, 2167.
Terracciano, S., Granata, F. and Craziussi, G. 1971, Psichiat., 39, 505.
Trauzettel, H. and Jo. A. 1971, Verhanatge.c (Jana)., 66, 633.
Takagi, I., Kurakazu, K., Nakama, T. and Oniki, S. 1972, Folia. Ophthal. Jap., 23, 640.
Tassone, F. and Stradolini, L. 1972, Gaslini, 4, 30.
Tessier, P. 1972, Scand. J. Plast. Reconst. Surg.,6, 135.
Trokel, S.L. 1972, Int. Ophthal. Clin., 12, 145.
Trokel, S.L., Schlesinger, E.B. and Beaton, H. 1972, Amer. J. Ophthal., 74, 675.
Tremeit, B.A., Zavadskays, Y.S., and Uklein, D.Y. 1973, Acta. Oftalniol., 28, 18.
Vida, L. and Moel, S.A. 1974, Amer. J. Ophthal.,77,240.
Vignaud, J., Clay, C. and Bilaniuk, L.T. 1974, Radiology., 110, 373.
Wolter, J.R., Bryson, J.M. and Blackhurst, R.T.1967, Eye Ear, Nose, Throat. Month„ 45, 64.
Wilson, E.B. and Briggs, R.C. 1969, Radiology 92, 576.
Werner, S.C. and Ingbar, S.H. 1971, N. York,Herper & Row Publishers Co.
Weiter, J. and Farkas, T.G. 1972, Sur. Ophthal., 17. 106.
Werner, S.C. 1972, Mayo. Clin. Proc. 47. 969.
Wolter, J.R. 1972, Ophthal. Surg., 3, 76.
Waller, R.R., Riley, F.C. and Henderson, J.W. 1973, A.M.A. Arch. Ophthal., 90, 297.
Yabet, Y. and Ogawa, K. 1966, Acta. Med. Okayama., 20, 147.
Yee, R.D. and Hepler, R.S. 1973, Amer. J. Ophthal., 75. 876.
Zolong, N., Atanasescu, F., and Aconiu, M. 1971, Klin. Monatsbl. Augenheika., 158, 58.
Zakharia, H.S., Asdourian, K. and Matta, C.S. 1972, Brit. J. Ophthal., 56, 678.
Ziemianski, A. and Pecard, K. 1973, Radiol. Med. Nukl., 37,466.