Age-related macular degeneration (AMD) is a leading cause of blindness in the elderly population. The prevalence is reported to be 1.2-1.4% in several population-based epidemiological studies. Currently 25-30 million people worldwide are blind due to AMD. With the aging world population it is bound to increase significantly, and could become a significant public health problem in next two decades, with serious socio-economic implications. Several strategies are today available to treat the wet form of AMD, which is responsible for significant visual loss. These were until recently confined to laser photocoagulation, and subretinal surgery, but today two other modalities, namely, radiation and photodynamic therapy, are available. These treatment modalities however, are aimed at preservation of vision only, and not at reversing the process of the disease. Further research on antiangiogenic drugs and gene therapy could significantly help AMD patients.

Purpose: Pathogenesis of Acanthamoeba keratitis involves breakdown of epithelial barrier, stromal invasion by Acanthamoeba, loss of keratocytes, inflammatory response and finally stromal necrosis. The loss of keratocytes, believed to be due to the phagocytic activity of the parasite, occurs disproportionate to and independent of the parasite load, thereby suggesting additional modes of cell loss. To test our hypothesis that the loss of keratocytes in Acanthamoeba keratitis is due to apoptosis, we did both histology and histochemistry on the corneal tissues. Methods: Routine Haematoxylin and Eosin, Gomori's Methenamine Silver and Periodic acid Schiff stained sections of five corneal tissues from penetrating keratoplasty and eviscerated eyes were reviewed. TUNEL staining was done for morphological detection of apoptosis in three cases, using formalin-fixed, paraffin-processed tissues. Results: Histological changes were epithelial ulceration, loss of keratocytes in all layers, inflammation in anterior two-thirds of the stroma with necrosis, and deeper quiet stroma. Acanthamoeba trophozoites were found in the anterior stroma while the cysts were more in the deeper stroma, with minimal or no inflammatory response. TUNEL staining was positive in keratocytic nuclei in all layers. Conclusions: This study demonstrates that one of the modes of keratocyte loss in Acanthamoeba keratitis is by apoptosis, possibly in addition to the necrotic process and phagocytic activity of the parasite. The death of inflammatory cells also appears to be mediated by apoptosis.

Purpose: This study aimed to evaluate the clinical efficacy of contact diode trans-scleral cyclophotocoagulation (TSCPC) for treatment of refractory glaucomas. Method: Fifty two eyes of 52 patients, (post-penetrating keratoplasty glaucoma: 16 eyes; adherent leucoma with secondary glaucoma: 8 eyes; aphakic glaucoma: 6 eyes; neovascular glaucoma: 6 eyes; narrow angle glaucoma: 6 eyes; and other secondary glaucomas: 10 eyes) were followed up from 3.5 -18 months (average 12 months) after TSCPC. The treatment parameters using the contact G probe were - energy: 3-4J; area: 40 spots spread over 360°; site: 1.2-1.5 mm posterior to limbus. Retreatments (22 eyes; 42%) were given whenever intraocular pressure (IOP) exceeded 22 mmHg despite maximum tolerable topical therapy. Results: IOP decreased from a baseline of 44.7 (± 7.3) mmHg to 15 (± 3.7) mmHg at first week and was 15.2 ± (8.2) mmHg at the last follow up. Successful control of IOP (<22mmHg) occurred in 30 (58%) eyes after a single treatment and in 48 (92%) eyes following retreatment. Complications included reduction in visual acuity from light perception (LP) only to no light perception (NLP) in two eyes and phthisis bulbi in one eye. Conclusion: Contact trans-scleral diode laser cyclophotocoagulation is effective in lowering IOP in eyes with intractable glaucoma with few side effects in Indian subjects.

Purpose: To compare the detection and assessment of progression of visual field defects in primary open-angle glaucoma with manual suprathreshold perimetry on Goldmann perimeter and automated static threshold perimetry on Humphery visual field (HVF) analyzer. Methods: 105 eyes of 54 patients of primary open-angle glaucoma were followed up with 3-monthly perimetry on Goldmann perimeter and HVF analyzer, for a period of 9 months. Results: HVF analyzer picked up visual field defects in 48 (46%) eyes whereas Goldmann perimeter picked up visual field defects in 26 (25%) eyes. HVF analyzer demonstrated progression in 14 eyes whereas Goldmann perimeter detected progression in 7 eyes during follow up of 9 months. Conclusions: HVF analyzer is superior to Goldmann perimeter to document and to demonstrate progression of visual field defects in primary open-angle glaucoma.

BACKGROUND: Platelets are an elective site for oxidative stress owing to their high content of polyunsaturated fatty acid. Increased lipid peroxidation and elevated platelet thiobarbituric acid-reacting substances (TBARS) signal oxidative stress. This possibly leads to retinal neovascularization in Eales' disease. METHODS: TBARS levels were estimated in consecutive cases of Eales' disease with neovascularisation (n = 26), Eales' disease without neovascularisation (n = 17) and healthy controls (n = 17). RESULTS: Platelet TBARS levels in the cases of Eales' disease with neovascularisation, Eales' disease without neovascularisation, and healthy controls were 0.66 +/- 0.1, 0.57 +/- 0.11 and 0.42 +/- 0.14 n moles TBARS formed/hour/10(8) platelets respectively. Student's t-test showed a significant increase in platelet TBARS levels in cases with neovascularisation as compared to cases without neovascularization (p < 0.05) and healthy controls (p < 0.01). CONCLUSION: The increase in platelet TBARS levels in proliferative Eales' disease is consistent with an emerging view that lipid peroxides may be associated with retinal neovascularisation.

Diabetic retinopathy remains a major cause of blindness despite increased understanding of this disease and identification of successful treatments. The Diabetic Retinopathy Study identified risk factors associated with a high risk of blindness and confirmed the benefits of panretinal photocoagulation. The Early Treatment Diabetic Retinopathy Study defined the retinal characteristics, indications of treatment and results of laser treatment of clinically significant macular oedema. The Diabetic Retinopathy Vitrectomy study established the benefits and timing of vitrectomy for non-clearing vitreous haemorrhage and severe proliferative diabetic retinopathy. The Diabetes Control and Complications Trial and the United Kingdom Prospective Diabetes Study have also demonstrated the value of tight control of blood sugar and blood pressure in diabetic retinopathy. These studies developed specific recommendations for the management of diabetic retinopathy. Optimum use of this information can minimize visual loss due to diabetic retinopathy.