Under-reporting of road traffic injuries to the police: results from two data sources in urban India.

OBJECTIVE: To report the magnitude of under-reporting of road traffic injury (RTI) to the police from population-based and hospital-based data in the urban population of Hyderabad, India. METHODS: In a cross-sectional population-based survey, 10 459 participants aged 5-49 years (94.3% participation), selected using three-stage systematic cluster sampling, recalled the reporting of non-fatal RTIs to the police in the preceding 12 months and fatal RTIs in the preceding 3 years. In addition, 781 consecutive RTI cases presenting to the emergency department of five hospitals provided information on RTI reporting to the police. RESULTS: In the population-based study, of those who had non-fatal RTIs and sought outpatient or inpatient services, 2.3% (95% 1.1% to 3.5%) and 17.2% (95% CI 3.5% to 30.9%), respectively, reported the RTI to the police. Of the non-fatal consecutive RTI cases presenting to emergency departments, 24.6% (95% CI 21.3% to 27.8%) reported the RTI to the police. In the population-based study, 77.8% (95% CI 65.1% to 90.5%) of the fatal RTIs were reported to the police, and of the consecutive fatal RTI cases presenting to emergency departments, 98.1% (95% CI 95.5% to 100%) were reported to the police. The major reasons cited for not reporting RTIs to the police were "not necessary to report" and "hit and run case". CONCLUSIONS: As road safety policies are based on police data in India, these studies highlight serious limitations in estimating the true magnitude of RTIs from these data, indicating the need for better methods for such estimation.

Incidence and burden of road traffic injuries in urban India.

BACKGROUND: The scale of road traffic injuries (RTIs) in India is uncertain because of limitations in the availability and reliability of incidence data. OBJECTIVE: To report these data for Hyderabad city in southern India. METHODS: In a cross-sectional population-based survey, 10 459 participants aged 5-49 years (94.3% participation), selected using three-stage systematic cluster sampling, were interviewed. Participants recalled RTIs in the preceding 3 months and RTI-related death and disability in the household in the preceding 3 years. RTI was defined as an injury resulting from a road traffic crash irrespective of the severity. RESULTS: The age/sex-adjusted annual incidence of non-fatal RTI requiring a recovery period of < or =7, 8-29, and > or =30 days was 13% (95% CI 12.6% to 13.4%), 5.8% (95% CI 5.5% to 6.0%), and 1.2% (95% CI 1.1% to 1.4%), respectively. The overall adjusted rate for non-fatal RTI was 20.7% (95% CI 20.0% to 21.3%). The relative risk of RTI requiring a recovery period of >7 days was significantly higher in the third per capita monthly income quartile (1.24 (95% CI 1.12 to 1.37); p<0.05). The incidence of non-fatal RTI was highest in pedestrians, motorized two-wheeled vehicle users, and cyclists: 6.4, 6.3, and 5.1/100 persons/year, respectively. Annual RTI mortality and disability rates were 38.2 (95% CI 17.5 to 58.8) and 35.1 (95% CI 12.4 to 57.7) per 100,000 population, respectively. CONCLUSIONS: There is a high burden of RTI in this urban population. With the recent attention focused on RTI by the Government of India, these findings may assist in planning appropriate initiatives to reduce the RTI burden.

Evaluation of the Murex HIV Ag/Ab Combination assay when used with dried blood spots.

This study evaluated the ability of the Murex HIV Ag/Ab Combination assay to detect human immunodeficiency virus (HIV) antibodies in 12 617 dried blood spots (DBSs) on filter paper. The assay had an overall sensitivity of 99.6% and a specificity of 99.9%. In view of its ability to detect p24 antigen and both HIV-1 and HIV-2 antibodies in samples collected in the form of DBSs, the Murex Ag/Ab Combination assay is suitable for use as a standard screening assay for seroprevalence studies, as well as for routine diagnostic use in clinical laboratories.

Cost and efficiency of HIV voluntary counselling and testing centres in Andhra Pradesh, India.

BACKGROUND: [corrected] As part of the effort to control HIV/AIDS, the number of HlV voluntarycounselling and testingcentres (VCTCs) is increasing rapidly in the public health system of the Indian state of Andhra Pradesh, which is estimated to have one of the highest rates of HIV infection in India. However, systematic data on the cost and efficiency of providing VCT services in India are not available to help guide efficient use of resources for these services. METHODS: We used standardized methods to obtain detailed cost and output data for the 2002-03 fiscal year from written records and interviews in 17 VCTCs in the public health system in Andhra Pradesh. We calculated the economic cost per client receiving VCT services, and analysed the variation and determinants of total and unit costs across VCTCs. We used multivariate regression techniques to estimate incremental unit costs. We assessed hurdles towards serving an optimal number of clients by VCTCs. RESULTS: In the 2002-03 fiscal year, 32 413 clients received the complete sequence of services at the 17 VCTCs, including post-HIV test counselling. The number of clients served by each VCTC ranged from 334 to 7802 (median 979). The overall HIV-positive rate in post-test counselled clients was 20.5% (range 5.4%-52.6%). The cost per client for the complete VCT sequence varied 6-fold between VCTCs (range Rs 141.5-829.6 [US 2.92-17.14 dollars], median Rs 363.5 [US 7.51 dollars]). The cost per client was significantly lower at VCTCs with more clients (p < 0.001, R2 = 0.83; power function) due to substantial fixed costs. Personnel made up the largest component of cost (53.7%). The cost per client had a significant direct relation with percent personnel cost for VCTCs (p < 0.001, R2 = 0.58; exponential function). A multiple regression model revealed that the incremental cost of providing complete VCT services to each HIV-positive and -negative client was Rs 123.5 (US 2.54 dollars) and Rs 59.2 (US 1.22 dollars), respectively. Fourteen VCTCs (82.4%) reported that they could serve more clients with the available personnel and infrastructure, and that inadequate demand for their services was the main hurdle towards achieving this. CONCLUSION: These data suggest that the efforts of the National AIDS Control Organisation of India and the Andhra Pradesh State AIDS Control Society in increasing VCTCs could yield even higher benefit if the demand for these services was enhanced, as this would increase the number of clients served and reduce the cost per client. Ongoing systematic cost-efficiency analysis is necessary to help guide efficient use of HIV-control resources in India.

Selective effects of experimental glaucoma on axonal transport by retinal ganglion cells to the dorsal lateral geniculate nucleus.

Rapid-phase axonal transport to the dorsal lateral geniculate nucleus (dLGN) was determined autoradiographically in seven macaque monkey eyes with chronic intraocular pressure (IOP) elevation, in four eyes with an acute IOP elevation, and in three eyes with normal IOP. The monkeys with chronic IOP elevation showed a greater decrease in radioactive labeling of the magnocellular layers of the dLGN than the parvocellular layers by qualitative examination. Grain counts in selected specimens confirmed that transport to the magnocellular layers was less than to the parvocellular layers in monkeys with chronic IOP elevation. This selectivity was present in mildly damaged specimens and increased with greater ganglion cell loss. In monkeys with acute IOP elevation, qualitative evaluation suggested no consistent difference in transport among the dLGN layers; one animal in this group had less transport to the parvocellular than to the magnocellular layers by grain counts. Starting in early stages of the disease, chronic experimental glaucoma causes preferential damage to the ganglion cells that project to the magnocellular layers of the dLGN.

Refractive errors in an urban population in Southern India: the Andhra Pradesh Eye Disease Study.

PURPOSE: To assess the prevalence, distribution, and demographic associations of refractive error in an urban population in southern India. METHODS: Two thousand five hundred twenty-two subjects of all ages, representative of the Hyderabad population, were examined in the population-based Andhra Pradesh Eye Disease Study. Objective and subjective refraction was attempted on subjects >15 years of age with presenting distance and/or near visual acuity worse than 20/20 in either eye. Refraction under cycloplegia was attempted on all subjects < or =15 years of age. Spherical equivalent >0.50 D in the worse eye was considered as refractive error. Data on objective refraction under cycloplegia were analyzed for subjects < or =15 years and on subjective refraction were analyzed for subjects >15 years of age. RESULTS: Data on refractive error were available for 2,321 (92.0%) subjects. In subjects < or =15 years of age, age-gender-adjusted prevalence of myopia was 4.44% (95% confidence interval [CI], 2.14%-6.75%), which was higher in those 10 to 15 years of age (odds ratio, 2.75; 95% CI, 1.25-6.02), of hyperopia 59.37% (95% CI, 44.65%-74.09%), and of astigmatism 6.93% (95% CI, 4.90%-8.97%). In subjects >15 years of age, age-gender-adjusted prevalence of myopia was 19.39% (95% CI, 16.54%-22.24%), of hyperopia 9.83% (95% CI, 6.21%-13.45%), and of astigmatism 12.94% (95% CI, 10.80%-15.07%). With multivariate analysis, myopia was significantly higher in subjects with Lens Opacity Classification System HI nuclear cataract grade > or =3.5 (odds ratio, 9.10; 95% CI, 5.15-16.09), and in subjects with education of class 11 or higher (odds ratio, 1.80; 95% CI, 1.18-2.74); hyperopia was significantly higher in subjects > or =30 years of age compared with those 16 to 29 years of age (odds ratio, 37.26; 95% CI, 11.84-117.19), in females (odds ratio, 1.86; 95% CI, 1.33-2.61), and in subjects belonging to middle and upper socioeconomic strata (odds ratio, 2.10; 95% CI, 1.09-4.03); and astigmatism was significantly higher in subjects > or =40 years of age (odds ratio, 3.00; 95% CI, 2.23- 4.03) and in those with education of college level or higher (odds ratio, 1.73; 95% CI, 1.07-2.81). CONCLUSIONS: These population-based data on distribution and demographic associations of refractive error could enable planning of eye-care services to reduce visual impairment caused by refractive error. If these data are extrapolated to the 255 million urban population of India, among those >15 years of age an estimated 30 million people would have myopia, 15.2 million hyperopia, and 4.1 million astigmatism not concurrent with myopia or hyperopia; in addition, based on refraction under cycloplegia, 4.4 million children would have myopia and 2.5 million astigmatism not concurrent with myopia or hyperopia.

Blindness in the Indian state of Andhra Pradesh.

PURPOSE: To determine the current prevalence and causes of blindness in the Indian state of Andhra Pradesh to assess if blindness has decreased since the last survey of 1986-1989. METHODS: A population-based epidemiology study, using a stratified, random, cluster, systematic sampling strategy, was conducted in the state of Andhra Pradesh in India. Participants of all ages (n = 10,293), 87.3% of the 11,786 eligible, from 94 clusters in one urban and three rural areas representative of the population of Andhra Pradesh, underwent interview and a detailed dilated ocular evaluation by trained professionals. Blindness was defined as presenting distance visual acuity < 6/60 or central visual field < 20(o) in the better eye. RESULTS: Two hundred seventy-five participants were blind, a prevalence of 1.84% (95% confidence interval, 1.49%-2.19%) when adjusted for the age, sex, and urban-rural distribution of the population in 2000. The causes of this blindness were easily treatable in 60.3% (cataract, 44%; refractive error, 16.3%). Preventable corneal disease, glaucoma, complications of cataract surgery, and amblyopia caused another 19% of the blindness. Blindness was more likely with increasing age and decreasing socioeconomic status, and in female subjects and in rural areas. Among the 76 million population of Andhra Pradesh, 714,400 are estimated to have cataract-related blindness (615,600 cataract, 53,200 cataract surgery-related complications, 45,600 aphakia), and 228,000 refractive error-related blindness (159,600 myopia, 22,800 hyperopia, 45,600 refractive error-related amblyopia). If 95% of the cataract and refractive error blindness in Andhra Pradesh had been treated effectively, 3.4 and 7.4 million blind-person-years, respectively, could have been prevented. If 90% of the blindness due to preventable corneal disease and glaucoma had been prevented, another 2.7 million blind-person-years could have been prevented. CONCLUSIONS: The prevalence of blindness in this Indian state has increased from 1.5% in the late 1980s to 1.84% currently, as against the target of the National Program for Control of Blindness to reduce the prevalence to 0.3% by 2000. The number of people with cataract-related blindness has not reduced even with the eye care policy focus on cataract. Reduction of blindness in India will require strategies that are more effective than those that have been pursued so far.

Variability of depth measurements of the optic nerve head and peripapillary retina with computerized image analysis.

Computerized topographic mapping of 10 repeated fundus images of one eye each in 10 healthy subjects and in 10 subjects with elevated intraocular pressures (IOPs) was performed with the Humphrey Retinal Analyzer. The variability of depth measurements at 400 to 650 individual locations in the optic nerve head and peripapillary retina was evaluated. The average size of the 95% confidence intervals for individual depth measurements for healthy subjects and those with elevated IOPs were 166 and 232 microns in the optic nerve head and 205 and 261 microns in the peripapillary retina, respectively. Variability was significantly less for healthy subjects than for those with elevated IOPs. Variability was significantly greater for depth measurements in the peripapillary retina than for measurements in the optic head. Knowledge about variability of individual depth measurements is useful for proper interpretation of computerized topographic mapping to detect retinal nerve fiber damage.

Quantitative regional structure of the normal human lamina cribrosa. A racial comparison.

We digitized magnified photographs of cross-sections of the laminae cribrosae of 16 normal subjects 50 or more years of age. The sample included 7 blacks and 9 age-matched whites. Connective tissue area as a proportion of the lamina cribrosa area was significantly less and pores were significantly larger in the superior and inferior than in the nasal and temporal quadrants of the lamina cribrosa. These differences were more pronounced for peripheral as compared with central regions of the lamina cribrosa. Less connective tissue support for nerve fibers in the superior and inferior quadrants of the optic nerve head could contribute to their greater susceptibility to glaucoma damage by allowing greater distortion of these regions at elevated intraocular pressures. The least connective tissue support was present in the inferoperipheral region of the lamina cribrosa, which may be related to the greater frequency of superior visual field defects in glaucoma. Blacks had larger total lamina cribrosa area, indicating a larger optic nerve head, and also a greater number of laminar pores than whites. However, the connective tissue proportion and pore size distribution in the laminae cribrosae of blacks were almost identical to those of whites. We found no evidence suggesting that the greater susceptibility of blacks to glaucoma damage is due to less connective tissue support for nerve fibers passing through their laminae cribrosae than in whites.

Reliability of optic nerve head topographic measurements with computerized image analysis.

We evaluated the reliability of optic disk area and disk rim area measurements obtained with the Humphrey Retinal Analyzer from ten repeat fundus images each of one eye of ten normal subjects and ten subjects with increased intraocular pressure. Variability of rim and disk areas was not significantly different between these two groups (P greater than .05), nor was it significantly different between images acquired during the same session and those acquired during different sessions (P greater than .05). Variability was significantly different between subject groups based on the distinctness of the disk edge and the slope of the cup wall (P less than .01). The average minimum change in the measurements on the same eye that would exceed variability of the technique at the 95% confidence level was 0.20 mm2 and 0.47 mm2 for rim area for the least variable and most variable subject groups based on optic nerve head characteristics, and 0.09 mm2 and 0.32 mm2 for disk area for the corresponding subject groups. Operator input contributed significantly to overall variability. Reliability of rim and disk areas in this study was comparable to that reported for other computerized image analyzers.

Population-based assessment of the outcome of cataract surgery in an urban population in southern India.

PURPOSE: To assess the outcome of cataract surgery in an urban population in southern India. METHODS: As part of a population-based cross-sectional epidemiologic study, the Andhra Pradesh Eye Disease Study, 2,522 people of all ages, including 1,399 individuals 30 years of age or older, from 24 clusters representative of the population of Hyderabad in southern India underwent a detailed interview and ocular evaluation including logarithm of minimal angle of resolution (logMAR) visual acuity, refraction, slit-lamp biomicroscopy, applanation tonometry, gonioscopy, dilation, cataract grading, aphakia/pseudophakia status, and stereoscopic fundus evaluation. Automated threshold visual fields and slit-lamp and fundus photography were performed when indicated by standardized criteria. Very poor outcome in an eye that had undergone cataract surgery was defined as presenting distance visual acuity worse than 20/200, and poor outcome was defined as visual acuity worse than 20/60 to 20/200. RESULTS: In subjects 50 years of age or older, after adjustment for age and sex distribution, the rate of having had cataract surgery in one or both eyes was 14.6% (95% confidence interval [CI], 11.4% to 17.8%). Of 131 eyes (91 subjects) that had undergone cataract surgery, 28 (21.4%; 95% CI, 14.4% to 28.4%) had very poor outcome and another 40 (30.5%; 95% CI, 22.6% to 38.4%) had poor outcome. The very poor outcome in 20 (71.4%) of 28 eyes and poor outcome in 23 (57.5%) of 40 eyes could be attributed to surgery-related causes or inadequate refractive correction. With multivariate analysis, very poor outcome as a result of surgery-related causes or inadequate refractive correction was more likely to be associated with intracapsular cataract extraction than with extracapsular cataract extraction (odds ratio, 9.34; 95% CI, 2.49 to 35.06) in subjects belonging to the lowest socioeconomic status (odds ratio, 4.92; 95% CI, 1.16 to 20.93) and with date of surgery 3 or fewer years before the survey than with more than 3 years (odds ratio, 4.52; 95% CI, 1.33 to 15.39). Also, very poor or poor outcome as a result of surgery-related causes or inadequate refractive correction was associated with women (odds ratio, 2.55; 95% CI, 1.06 to 6.16). CONCLUSIONS: The very high rate of very poor and poor visual outcome, predominantly as a result of surgery-related causes and inadequate refractive correction, in this urban population of India suggests that more attention is needed to improve the visual outcome of cataract surgery. In order to deal with cataract-related visual impairment in India, as much emphasis on surgical quality, refractive correction, and follow-up care is necessary as on the number of surgeries.

Childhood blindness in India: a population based perspective.

AIM: To estimate the prevalence and causes of blindness in children in the southern Indian state of Andhra Pradesh. METHODS: These data were obtained as part of two population based studies in which 6935 children

Corneal blindness in a southern Indian population: need for health promotion strategies.

AIM: To assess the distribution and causes of corneal blindness in a population in southern India. METHODS: A total of 11 786 people of all ages from 94 clusters representative of the population of the Indian state of Andhra Pradesh were sampled using a stratified, random, cluster, systematic sampling strategy. These participants underwent a detailed interview and eye examination including measurement of visual acuity with logMAR charts, refraction, slit lamp biomicroscopy, applanation tonometry, gonioscopy, and stereoscopic dilated fundus evaluation. An eye was considered to have corneal blindness if the visual acuity was <20/200 due to a corneal disease. RESULTS: Of those sampled, 10 293 (87.3%) people participated in the study. Corneal blindness in at least one eye was present in 86 participants, an age, sex, and urban-rural distribution adjusted prevalence of 0.66% (95% confidence interval 0.49 to 0.86), which included 0.10% prevalence of corneal blindness in both eyes and 0.56% in one eye. The most frequent causes of corneal blindness in at least one eye included keratitis during childhood (36.7%), trauma (28.6%), and keratitis during adulthood (17.7%). Nearly 95% of all corneal blindness was avoidable. Multivariate analysis showed that the prevalence of corneal blindness was significantly higher with decreasing socioeconomic status and with increasing age. Of the 99 eyes with corneal blindness, 51 (51.5%) had visual acuity of inaccurate projection of light or no perception of light. CONCLUSIONS: There is a significant burden of corneal blindness in this population, the majority of which is avoidable. Eye health promotion strategies are warranted to raise awareness about the causes and prevention of corneal blindness.

Utilisation of eyecare services in an urban population in southern India: the Andhra Pradesh eye disease study.

AIM: To assess utilisation of eyecare services by people with visual impairment <6/18 or equivalent visual field loss in the better eye in the urban population of Hyderabad in southern India. METHODS: 2522 subjects of all ages, representative of the population of Hyderabad city, underwent a detailed interview and dilated examination as part of the population based Andhra Pradesh eye disease study. Subjects more than 15 years of age were interviewed regarding the use of eyecare services. RESULTS: Of 250 subjects with presenting distance visual acuity <6/18 or equivalent visual field loss in the better eye, information on utilisation of eyecare services was available for 229 (91.6%). Of these 229 subjects, 44 (19%) had visual acuity <6/60 or equivalent visual field loss in the better eye, and 202 (88.2%) had noticed decrease in vision over the past 5 years. Multivariate analysis showed that this decrease in vision was noticed significantly less by subjects with refractive error as the cause of visual impairment (odds ratio 0.34, 95% confidence interval 0.12-0.93). Of the 229 subjects who were visually impaired, 108 (59%) did not seek treatment. Multivariate analysis revealed that the odds for seeking treatment were significantly lower for Hindus than Muslims (odds ratio 0.53, 95% confidence interval 0.28-0.98). The reasons for not seeking treatment could be classified as personal (49.5%), economic (30.8%), and social (19.6%). CONCLUSION: A large proportion of subjects with visual impairment in this urban population in India did not seek treatment even after noticing decrease in vision. Projecting these data to the 155 million urban population >15 years of age in India, there may be 4.9 million (95% confidence interval 4.3-5.5 million) people in urban India who are not seeking treatment for their visual impairment even after noticing decrease in vision. These data suggest that efforts have to be made to better understand the reasons for this phenomenon so that optimal utilisation of the available eyecare services in urban India can be planned.

Survival analysis and visual outcome in a large series of corneal transplants in India.

AIM/BACKGROUND: The public health significance of corneal transplantation in dealing with corneal blindness in the developing world would depend upon the survival rate of transplants. This study was done to analyse the survival rate of corneal transplants in a large series in India, and to evaluate the influence of various risk factors on transplant survival. METHODS: The records of a series of 1725 cases of corneal transplants carried out during 1987-95 at a tertiary eye care institution in India were reviewed. The Kaplan-Meier method was used to determine 5 year survival rates of corneal transplants performed for the various categories of preoperative diagnosis. Multivariate Cox proportional hazards regression was used to assess how preoperative diagnosis, socioeconomic status, age, sex, vascularisation of host cornea, quality of donor cornea, and training status of surgeon influenced transplant survival. The effect of these variables on visual outcome was assessed using multiple logistic regression. RESULTS: The survival rates at 1, 2, and 5 years for all corneal transplants performed for the first time in 1389 cases were 79.6% (95% confidence interval = 77.3-81.9%), 68.7% (65.7-71.7%) and 46.5% (41.7-51.3%). The 5 year survival rate was highest if the corneal transplant was done for keratoconus (95.1% (84.8-100%)) and lowest if carried out for previous transplant failure (21.2% (13.8-28.6%)). The relative risk of transplant failure was higher if the preoperative diagnosis was previous transplant failure (2.04 (1.62-2.55)), aphakic bullous keratopathy (1.78 (1.38-2.28)), corneal clouding due to miscellaneous causes including congenital conditions and glaucoma (1.63 (1.21-2.19)), or adherent leucoma (1.11 (0.81-1.51)) than for the other preoperative diagnoses. Patients with lower socioeconomic status had higher relative risk of transplant failure (1.28 (1.16-1.42)), as did patients < 10 years of age (1.42 (1.23-1.64)). Higher relative risk of transplant failure was associated with vascularisation of the host cornea before transplantation (1.15 (1.04-1.27)), and with the use of fair quality donor cornea for transplantation compared with excellent, very good, or good quality donor cornea (1.26 (1.06-1.52)). Before corneal transplant 80.2% of the eyes were blind (visual acuity < 3/60), whereas at last follow up 41.8% eyes were blind. The odds of having visual acuity > 6/18 were higher if the transplant was done for keratoconus (9.99 (6.10-16.36)) or corneal dystrophies (1.77 (1.21-2.58)) than for the other preoperative diagnoses. CONCLUSION: Reasonable success with corneal transplantation is possible in the developing world if data from this part of the world regarding the different survival rates for the various preoperative diagnoses and the influence of risk factors on transplant survival and visual outcome are taken into account while determining priority for transplant cases in the present situation of limited availability of donor corneas.

Population based assessment of uveitis in an urban population in southern India.

AIM: To assess the prevalence of active and inactive uveitis unrelated to previous surgery or trauma in an urban population in southern India. METHODS: As part of the Andhra Pradesh Eye Disease Study, 2522 subjects (85.4% of those eligible), a sample representative of the population of Hyderabad city in southern India, underwent interview and detailed dilated eye examination. Presence of sequelae of uveitis without current active inflammation was defined as inactive uveitis. RESULTS: Unequivocal evidence of active or inactive uveitis unrelated to previous surgery or trauma was present in 21 subjects, an age-sex adjusted prevalence of 0.73% (95% confidence interval (CI) 0.44-1.14%). Active uveitis was present in eight subjects, an age-sex adjusted prevalence of 0.37% (95% CI 0. 19-0.70), of which 0.06% was anterior, 0.25% intermediate, and 0.06% posterior. The 0.36% (95% CI 0.17-0.68%) prevalence of inactive uveitis included macular chorioretinitis scars (0.26%), anterior (0. 07%) and previous vasculitis involving the whole eye (0.03%). The prevalence of visual impairment due to uveitis of less than 6/18 in at least one eye was 0.27%, less than 6/60 in at least one eye was 0. 16%, and less than 6/60 in both eyes was 0.03%. CONCLUSION: These population based cross sectional data give an estimate of the prevalence of various types of uveitis in this urban population in India. Active or past uveitis that might need treatment at some stage was present in one of every 140 people in this population.

The familial contribution to non-syndromic ocular coloboma in south India.

AIMS: To identify the proportion of familial cases of isolated ocular colobomatous malformations in a case series from south India. METHODS: Children with ocular coloboma without systemic features were recruited from multiple sources in Andhra Pradesh, India. Their families were traced, pedigrees drawn, and family members examined. RESULTS: 56 probands, 25 females (44.6%) and 31 males (57.4%) with a colobomatous malformation were identified. In 12 cases (21.4%) another family member was affected. The risk to siblings was 3.8%. The parents were consanguineous in 25 cases (44.6%). CONCLUSIONS: 21.4% of cases of isolated ocular coloboma in this highly consanguineous population of south India were familial, with both autosomal dominant and autosomal recessive mechanisms likely in different families.

Population based assessment of diabetic retinopathy in an urban population in southern India.

AIM: To assess the prevalence of diabetic retinopathy and the visual impairment caused by it in an urban population in southern India in order to determine its public health significance. METHODS: 2522 subjects (85.4% of those eligible), a representative sample of the population of Hyderabad city in southern India, underwent interview and detailed dilated eye examination during 1996-7 as part of the Andhra Pradesh Eye Disease Study. RESULTS: 124 subjects, all >/=30 years old, reported that they had diabetes, an age-sex adjusted prevalence of 7.82% (95% confidence interval (CI) 5.76-9.88%) in this age group. Diabetes was diagnosed at age >/=30 years in all but two subjects. The duration since diagnosis of diabetes was <10 years in 75.6% and >/=15 years in 6.7%. Diabetic retinopathy was present in 28 subjects, 1.78% (95% CI 1.09-2.48%) of those >/=30 years old. Most of the diabetic retinopathy was of the mild (50%) or moderate (39.3%) non-proliferative type; one subject (3.6%) had proliferative retinopathy. Multiple logistic regression revealed that the odds of having diabetic retinopathy were significantly higher in those >/=50 years than in those 30-49 years old (odds ratio 7.78, 95% CI 2.92-20. 73). Three subjects had visual impairment between 6/12 and 6/38 in either eye due to diabetic retinopathy, 0.19% (95% CI 0-0.41%) of those >/=30 years old. CONCLUSION: Visual impairment due to diabetic retinopathy was relatively uncommon in this urban Indian population in 1996-7. However, this could change in the near future with an increase in duration of diabetes because of the anticipated aging of India's population and the recent suggestion of increase in diabetes prevalence in urban India, and therefore should be monitored.

Moderate visual impairment in India: the Andhra Pradesh Eye Disease Study.

AIM: To assess the prevalence and demographic associations of moderate visual impairment in the population of the southern Indian state of Andhra Pradesh. METHODS: From 94 clusters in one urban and three rural areas of Andhra Pradesh, 11 786 people of all ages were sampled using a stratified, random, cluster, systematic sampling strategy. The eligible people were invited for interview and detailed dilated eye examination by trained professionals. Moderate visual impairment was defined as presenting distance visual acuity less than 6/18 to 6/60 or equivalent visual field loss in the better eye. RESULTS: Of those sampled, 10,293 (87.3%) people participated in the study. In addition to the previously reported 1.84% prevalence of blindness (presenting distance visual acuity less than 6/60 or central visual field less than 20 degrees in the better eye) in this sample, 1237 people had moderate visual impairment, an adjusted prevalence of 8.09% (95% CI 6.89 to 9.30%). The majority of this moderate visual impairment was caused by refractive error (45.8%) and cataract (39.9%). Increasing age, female sex, decreasing socioeconomic status, and rural area of residence had significantly higher odds of being associated with moderate visual impairment. CONCLUSIONS: These data suggest that there is a significant burden of moderate visual impairment in this population in addition to blindness. Extrapolation of these data to the population of India suggests that there were 82 million people with moderate visual impairment in the year 2000, and this number is likely to be 139 million by the year 2020 if the current trend continues. This impending large burden of moderate visual impairment, the majority of which is due to the relatively easily treatable refractive error and cataract, would have to be taken into account while estimating the eye care needs in India, in addition to dealing with blindness. Specific strategies targeting the elderly population, people with low socioeconomic status, those living in the rural areas, and females would have to be implemented in the long term to reduce moderate visual impairment.

Prevalence of visual impairment in children: a review of available data.

Data on the prevalence, magnitude and causes of blindness and severe visual impairment in children are needed for planning and evaluating preventive and curative services for children, and for planning special education and low vision services. Prevalence data can be obtained from a variety of different sources, each of which has limitations. The available data suggest that there may be a ten-fold difference in prevalence between the wealthiest countries of the world and the poorest, ranging from as low as 0.1/1000 children aged 0-15 years in the wealthiest countries to 1.1/1000 children in the poorest. In this paper, the available data are reviewed and the epidemiological methods and findings are discussed.