Clinically observed complicated cataracts, generally do not have a definite causal factor. We studied the effects of E. coli toxin injected suprachoroidally, to simulate the effect of toxins released by extraocular organisms on the lens. 79.2% of eyes had a definable cataract at the end of the 6th week of observation. The biochemical changes portrayed an increased oxidative activity in the lens, evidenced by a fall in glutathione concentration, and the consequent tertiary reorientation of proteins to increase insoluble proteins, forming a cataract.

The synergistic effects of protein deficiency and U-V radiation is cataractogenic as seen in our experimental model though individually these had no damaging effect on enzymatic profile and clinical appearance.

Forty aphakic eyes, with secondary pupillary membranes, underwent pars plana membranectomy and YAG laser discission randomly. Visual improvement was similar in both the groups. IOP remained low for a week in pars-plana membranectomy while it transiently increased following YAG laser discission Complications like anterior chamber reaction, corneal edema and CME were more after pars plana membranectomy than in YAG laser discission. In membranes thicker than 1.2 mm, only pars plana membranectomy is recommended.

The management of cases with common canalicular obstruction poses a difficult problem. Nineteen patients presenting with common canalicular obstruction of unknown cause or in association with trauma, encysted mucocoele and previous sac surgery, were operated on by the modified canaliculodacryocystorhinostomy technique. The surgery involves a microsurgical dissection at the site of the common canalicular obstruction followed by anastomosis to the sac or nasal mucosa with silicone tube intubation of the passage using an improvised metallic introducer. The procedure was successful in 13 of the cases in a follow-up period varying from 4 months to 15 months. The complications included extrusion of the tube and nasal bleeding. The indications of the procedure, the precise technique and precautions to avoid intra and post operative complications have been elaborated in the paper.

A variety of methods and materials have been used for the treatment of the problems relating to the canalicular system. An insight into the rail roading technique for intubation of the canaliculi with sutupak in cases of common canalicular duct obstruction is presented here. About 30 patients with block at the common canalicular duct, which was detected by dacryocystography were operated for dacryocystorhinostomy with intubation of both the canaliculi with sutupak No. 0 by rail roading technique with good results.

A modified technique of peribulbar anaesthesia consisting of a single injection of anaesthetic solution with a 26G, half inch insulin needle was evaluated in 50 eyes. The operative procedures included extracapsular cataract extraction with intraocular lens implantation in 20 eyes, intracapsular lens extraction in 20 eyes, and trabeculectomy in 10 eyes. Complete anaesthesia was obtained in 45 eyes (90%). No significant complications were observed except for mild to moderate conjunctival chemosis in 40 eyes (80%). The technique is easy to learn, safe, effective and relatively economical.

One hundred consecutively excised and histologically diagnosed limbal neoplasms were analyzed. Majority (56%) of the affected patients were less than 30 years old. Benign tumours (77%) outnumbered the malignancies. Dermoids (29%) and hyperplastic squamous epithelium or 'epidermalization' (26%) were the commonest benign neoplasms. Squamous cell carcinoma, including frank and non-invasive carcinoma (23%) was the most frequent malignant tumour. These observations were compared with previous Indian and Western studies and the implications discussed.

Physiological aniseikonia is the basis of stereopsis but beyond certain limits it becomes an obstacle to fusion. It is not well established as to how much aniseikonia can be tolerated by the fusional mechanism. Different tests under different testing conditions have given a wide range of variation. On the synoptophore we had observed tolerance upto 35% aniseikonia in some cases. Under more physiological conditions on a polaroid dissociation stereoprojector we observed lesser baseline fusional vergences but tolerance in about 70% of the cases upto 30% aniseikonia while 25% could tolerate even 35% aniseikonia. However we realise that these indicate the maximal potential and not the symptom free tolerable limits.

Juvenile diabetics have severe loss of beta cell function and require replacement therapy with insulin. Insulin antigenicity can produce anti-insulin antibodies resulting in allergic reactions and insulin resistance. The role of insulin-anti-insulin antibody complexes in the development and progress of chronic diabetic complications like microangiopathy is not very clear. In the present study, there was statistically a significant trend of higher insulin antibody binding levels in IDDM patients who developed retinopathy. Though there was a trend of higher insulin antibody in IDDM patients with retinopathy, there was no association between insulin antibody and HLA antigen which some authors have reported.

The present paper is the result of the study of frequent occurrences of ocular myiasis due to the infection by the insect larva in 14 patients. The collected larvae were identified as first stage larva of oestrus ovis. The results of the examinations of the infected eyes show swollen conjunctiva, redness and watering of the eyes. These symptoms may be mistaken for mucopurulent conjunctivitis. The above results are discussed with earlier literature.

The eyes of 28 patients of Neurofibromatosis type 1 were examined. Lisch spots were present in all the patients above 20 years. Their clinical appearance is being presented as seen in Indian subjects.

A 47 year old man with episodes of attacks of pain, redness and mild blurring of vision was investigated for narrow angle glaucoma in view of shallow anterior chambers and a cupped optic disc. The history was reviewed following a spontaneous attack in hospital, which had features other than acute glaucoma. A diagnosis of cluster headache was made on the basis of tests. Cluster headache has been defined as unilateral intense pain, involving the eye and head on one side, usually associated with flushing, nasal congestion and lacrimation; the attacks recurring one or more times daily and lasting 20 - 120 minutes. Such attacks commonly continue for weeks or months and are separated by an asymptomatic period of months to years. This episodic nature, together with unilaterality and tendency to occur at night, closely mimics narrow angle glaucoma. Further, if patients have shallow anterior chambers and disc cupping, the differentiation becomes more difficult yet critical. Resource to provocative tests is often the only answer as the following case report demonstrates.

Duane's retraction syndrome is a well known congenital musculo-facial anomaly. Various explanations have been given for the aetiology of this syndrome. Inverse Duane's retraction syndrome is a condition with reverse clinical features. Abduction of the affected eye is possible to some extent and is accompanied by retraction of the eyeball, narrowing of the palpebral fissure and pseudoptosis. There may be some restriction of movement on adduction. The primary lesion is suspected to be in the medial rectus muscle. Frequently the muscle is found to be entrapped following trauma to the medial wall of the orbit. A case of bilateral inverse Duane's retraction syndrome and convergent squint along with left-sided perceptive deafness is reported. As is usually the case there was no structural abnormality or entrapment of the muscle from trauma.

Septo optic dysplasia is a rare developmental anomaly involving bilateral optic nerve hypoplasia, midline anomalies of the brain and hypothalamo-pituitary dysfunction. A case of septo-optic dysplasia with pituitary dwarfism, optic nerve hypoplasia and absent septum pellucidum is reported.

A case of blow out fracture of the medial wall and floor of the orbit with herniation of the eyeball into the ethmoid sinus diagnosed on CT scan is reported. To the best of our knowledge there is no previous report of prolapse of eyeball into the ethmoid sinus.