Choroidal neovascular membrane in the macular area is one of the leading causes of severe visual loss. Usually a manifestation in elderly population, it is often associated with age-related macular degeneration. The current mainstay of management is early diagnosis, usually by fundus examination, aided by angiography and photocoagulation in selected cases. Various other modalities of treatment including surgery are being considered as alternate options, but with limited success. The purpose of this review is to briefly outline the current concepts and the management strategy from a clinician's viewpoint.

Glaucoma is fast emerging as a major cause of blindness in India. In order to estimate the prevalence of primary open angle glaucoma (POAG) and primary angle closure glaucoma (PACG) in an urban South Indian population, we examined 972 individuals aged 30-60 years, chosen using a cluster sampling technique from 12 census blocks of Vellore town. They underwent a complete ocular examination, including applanation tonometry and gonioscopy, at the Medical College Hospital. Characteristic field defects on automated perimetry was a diagnostic requisite for POAG. Prevalence (95% CI) of POAG, PACG, and ocular hypertension were 4.1 (0.08-8.1), 43.2 (30.14-56.3), and 30.8 (19.8-41.9) per 1,000, respectively. All the PACG cases detected were of the chronic type. Hitherto unavailable community-based information on primary glaucoma in our study population indicates that PACG is about five times as common as POAG.

In the presence of proliferations anteriorly, adequate excision of the vitreous base is essential. To enable a good vitreous base excision, removal of lens often becomes necessary as it may be damaged while attempting to remove peripheral vitreous. To avoid damage or the need to remove the crystalline lens we have used a new modified curved vitreous cutter along with a wide angle observation system binocular indirect ophthalmomicroscope (BIOM). Use of BIOM during vitreous surgery enables easy viewing of the retinal periphery without the need for scleral depression. Sclerotomies are made as for any regular three-port vitrectomy procedure and the vitrectomy is carried out using the curved vitreous cutter, including the vitreous base, avoiding damage to the crystalline lens. The modified curved vitreous cutter is helpful in removing the peripheral vitreous without damaging the crystalline lens, giving the patient the advantage of intraocular lens implantation at a later date.

Three patients with intraocular foreign bodies and traumatic cataracts underwent single stage pars plana lensectomy with anterior capsule preservation, vitrectomy, removal of the foreign body, and intraocular lens implantation. The preserved anterior capsule permitted support for the placement of an intraocular lens in the posterior chamber in the ciliary sulcus. The procedure enabled early visual rehabilitation. This procedure seems useful in the management of posterior segment intraocular foreign body associated with cataract.

Blindness is usually defined by visual acuity criteria. Patients with markedly constricted visual fields are visually impaired even if they have good visual acuity. To our knowledge, no standardised criteria exist to determine the extent of constriction for fields done with the currently used automated static perimetry. The purpose of this study was to suggest a simple method to do so which would help in determining blindness due to field constriction. We reviewed a number of constricted visual fields obtained with Humphrey automated static perimetry. The central 30° field was divided into six concentric zones. By trial and error, we devised criteria for defining visual field constriction based on absolute loss of sensitivity (≤0 dB) and relative loss of sensitivity (≤5 dB). We suggest that if a zone has at least 75% test points ≤0 dB and no point >10 dB, it be considered to have absolute loss of sensitivity for the purpose of defining visual field blindness. Two exceptions to this are also suggested to prevent this criterion from becoming too rigid. Examples are shown to demonstrate application of these criteria in defining blindness due to visual field constriction to <10° as suggested by the World Health Organization. Standardised determination of visual field constriction with automated perimetry could be useful in more accurate estimation of blindness in surveys, as well as in assessing eligibility for being classified as blind for legal benefits.

The aim of this study was to determine the bacterial growth inhibitory activities of ampicillin in aqueous humor and serum of patients administered ampicillin-sulbactam combination intramuscularly prior to cataract surgery. 43 patients received a combination of both antibiotics intramuscularly at varying periods (60-140 minutes) prior to surgery. Aqueous humor and venous blood were collected at the beginning of the surgery. For microbiological assay, spores of Bacillus subtilis were incorporated in the agar. The test sample and the standard solutions (calibrators) of ampicillin and ampicillin-sulbactam combination were placed in 3 mm wells in the agar. The diameter zones of growth inhibitory activities of ampicillin of the calibrators and the test samples measured in mm were extrapolated to the standard curve and were recorded as ampicillin activity in (μg/ml. The results of the assay were placed in 5 groups according to the time intervals between injection and collection of serum and aqueous humor (≤70, 75, 80, 90, >90 minutes). Ampicillin activities in sera and aqueous humor of group 5 (>90 minutes) were significantly higher than the others (p<0.001). The ratio of ampicillin activities of sera and aqueous humor in group 5 patients was significantly lower indicating higher concentration of ampicillin activity in aqueous humor during this period. Bacterial growth inhibitory activities of ampicillin-sulbactam combination were adequate in aqueous humor of all patients with highest activity being 90 minutes after intramuscular administration indicating the potential usefulness of this antibiotic combination as chemoprophylaxis prior to cataract surgery.

The prothrombin time was recorded for 87 primary retinitis pigmentosa (RP) patients belonging to three different clinical categories. All categories showed prothrombin time higher than normal. There was no correlation between the age of onset and the prothrombin time, nor between duration of disease and the prothrombin time. The high prothrombin time in patients with RP suggests that further study of prothrombin time and related factors may help in better understanding of the pathogenesis of RP.

Science, medicine and ophthalmology have all evolved and progressed through varied but powerful influences over the centuries. While the tremendous technological advances in ophthalmology in the past 20 years are readily appreciated, many clinicians fail to grasp the impact of the several clinical trials that have contributed to better patient care. This article briefly traces the history of science, medicine and ophthalmology, and explains how scientific thinking could be applied to the clinical and academic aspects of ophthalmology.

Precautions to prevent spread of infection through tonometers and gonioscopes are described in this article. Tonometers and gonioscopes should not be used in the presence of clinically manifest conjunctivitis and keratitis. The Schiotz tonometer should be dipped in a 1:1000 merthiolate solution, and rinsed in saline/ distilled water prior to use. The Goldmann applanation prism tip can be wiped with gauze soaked in 70% isopropyl alcohol and then dried before use. Gonioscopes should be cleaned in running water, wiped with gauze soaked in 70% isopropyl alcohol, and then dried before use. Koeppes and goniotomy lenses can be sterilized with ethylene oxide, prior to use in surgery.

Reduction of blindness in children assumes particular significance since a blind child suffers from more blind-years than a blind adult. Estimates of the number of children blind in India and the causes of blindness are relatively crude as there are little reliable epidemiologic data. As a result of this, there is no organised approach to the control of childhood blindness in India. In order to address this issue, a workshop on childhood blindness was held at the L.V. Prasad Eye Institute, Hyderabad in November 1996. The aim of this workshop was to review available data, consider possible strategies, and make recommendations concerning the control of childhood blindness in India. These recommendations along with background information about childhood blindness are presented in this paper.