Prevalence and risk factors of diabetic retinopathy among an elderly population with diabetes in Nepal: the Bhaktapur Retina Study.

AIM: Diabetic retinopathy (DR) is an emerging cause of blindness in developing countries. This study aimed to explore the prevalence and risk factors of DR in an elderly population in Nepal. SUBJECTS AND METHODS: This is a population-based, cross-sectional study. A total of 1860 subjects at the age 60 years and above participated (response rate 88.6%). A detailed history was obtained, presenting and best-corrected visual acuity were measured, and anterior segment and posterior segment examinations were carried out. Blood pressure and random blood sugar were recorded; body mass index was calculated, and abdominal girth was measured. DR was graded by clinical examination using Early Treatment Diabetic Retinopathy Study criteria. RESULTS: Diabetes was found in 168 (9%) subjects (mean age 69.6 years), 31 (18.5%) of whom were newly diagnosed. The prevalence of DR was 23.8% (95% confidence interval [CI]: 17.7%-31%) among the persons with diabetes. The prevalence of DR among newly diagnosed subjects with diabetes was 6.5% (95% CI: 0.8%-21.4%). The prevalence of vision-threatening DR was 9.5% (95% CI: 5.5%-15%) and was higher in males. The prevalence of DR was 83.3% (95% CI: 35.9%-99.6%) among those with diabetes for over 20 years. In multivariable logistic regression analysis, duration of diabetes, hypertension, and alcohol consumption were significantly associated with DR. CONCLUSION: DR is a common problem among the elderly population with diabetes in Nepal. The duration of diabetes, hypertension, and alcohol consumption are the risk factors for the development of DR. Strategies have to be developed for timely diagnosis of diabetes and screening for DR.

A population-based survey of the prevalence and types of glaucoma in Nepal: the Bhaktapur Glaucoma Study.

OBJECTIVE: To determine the prevalence and types of glaucoma in a Nepalese population. DESIGN: Cross-sectional, population-based survey. PARTICIPANTS: A total of 4800 subjects aged 40 years or older from the Bhaktapur district of Kathmandu valley. METHODS: Subjects aged 40 years or older were selected using a cluster sampling procedure and door-to-door enumeration for a population-based, cross-sectional study. All subjects underwent a detailed ocular examination at the base hospital, which included logarithm of minimal angle of resolution visual acuity, refraction, applanation tonometry, gonioscopy, Lens Opacities Classification System II cataract grading, retinal examination, and Swedish Interactive Thresholding Algorithm standard perimetry when indicated. MAIN OUTCOME MEASURES: Diagnosis of glaucoma was based on criteria described by the International Society for Geographic and Epidemiological Ophthalmology. RESULTS: A total of 4003 subjects underwent a comprehensive eye examination (response rate 83.4%), and complete data were available in 3991 subjects. The mean intraocular pressure was 13.3 mmHg (97.5th and 99.5th percentiles, 18 and 20 mmHg, respectively), and the mean vertical cup-to-disc ratio was 0.26 (97.5th and 99.5th percentiles, 0.6 and 0.8 mmHg, respectively). There were 75 subjects with glaucoma, an age- and sex-standardized prevalence of 1.80 (95% confidence interval [CI], 1.68-1.92). Age- and sex-standardized prevalence was 1.24% (95% CI, 1.14-1.34) for primary open-angle glaucoma (POAG), 0.39% (95% CI, 0.34-0.45) for primary angle-closure glaucoma (PACG), and 0.15% (95% CI, 0.07-0.36) for secondary glaucoma. The prevalence of glaucoma increased with an increase in age with no significant difference in gender. Primary angle-closure glaucoma was 3 times more common in women. Nine eyes were blind, and 2 subjects were bilaterally blind from glaucoma. CONCLUSIONS: The overall prevalence of glaucoma was 1.9%. Of all glaucoma cases, POAG accounted for 68%, PACG accounted for 22.67%, and secondary glaucoma accounted for 9.33%. Among the subjects with POAG, 96.08% had not been previously diagnosed.

Outcomes of cataract surgery: a population-based developing world study in the Bhaktapur district, Nepal.

BACKGROUND: To evaluate the visual outcome after cataract surgery in a population of Nepal. DESIGN: Population-based cross-sectional study. PARTICIPANTS: Forty years and above residing in Bhaktapur district. METHODS: Subjects were selected from 30 clusters using cluster sampling procedure. All underwent a detailed examination at the base hospital, including logarithm of minimal angle of resolution visual acuity, refraction, applanation tonometry, cataract grading, retinal examination and perimetry when indicated. MAIN OUTCOME MEASURES: Visual acuity after cataract surgery. RESULTS: Out of 4003 subjects examined, 151 had undergone cataract surgery. Pseudophakia was present in 142 (94.0%), aphakia in nine (6%). Presenting and best-corrected visual acuity ≥6/18 was achieved in 123 (54.4%) and 164 (72.4%) eyes, respectively. Among the pseudophakic eyes, at presentation 122 (57.5%), 72 (33.9%), 18 (8.5%) and after best correction 162 (76.2%), 33 (15.8%), 17 (8.0%) had visual acuity of ≥6/18, <6/18-≥6/60 and <6/60, respectively. Retinal disease (35.5%), surgical complications (27.4%) and posterior capsular opacification (14.5%) were the principle causes of visual impairment after best correction in all eyes. There was no significant association in visual outcome based on age, sex, literacy and the duration of surgery. CONCLUSION: Correction of refractive errors, preoperative screening of coincidental diseases, reduction in surgical complication rates and monitoring of postoperative follow-up care has to be addressed seriously in order to improve the outcome of cataract surgery to meet standards proposed by the World Health Organization. In the future, longitudinal studies need to be undertaken to provide specific information on the outcomes of cataract surgery in this community.

Prevalence of visual impairment, cataract surgery and awareness of cataract and glaucoma in Bhaktapur district of Nepal: the Bhaktapur Glaucoma Study.

BACKGROUND: Cataract and glaucoma are the major causes of blindness in Nepal. Bhaktapur is one of the three districts of Kathmandu valley which represents a metropolitan city with a predominantly agrarian rural periphery. This study was undertaken to determine the prevalence of visual impairment, cataract surgery and awareness of cataract and glaucoma among subjects residing in this district of Nepal. METHODS: Subjects aged 40 years and above was selected using a cluster sampling methodology and a door to door enumeration was conducted for a population based cross sectional study. During the community field work, 11499 subjects underwent a structured interview regarding awareness (heard of) and knowledge (understanding of the disease) of cataract and glaucoma. At the base hospital 4003 out of 4800 (83.39%) subjects underwent a detailed ocular examination including log MAR visual acuity, refraction, applanation tonometry, cataract grading (LOCSΙΙ), retinal examination and SITA standard perimetry when indicated. RESULTS: The age-sex adjusted prevalence of blindness (best corrected <3/60) and low vision (best corrected <6/18 ≥ 3/60) was 0.43% (95%C.I. 0.25 - 0.68) and 3.97% (95% C.I. 3.40 - 4.60) respectively. Cataract (53.3%) was the principal cause of blindness. The leading causes of low vision were cataract (60.8%) followed by refractive error (12%). The cataract surgical coverage was 90.36% and was higher in the younger age group, females and illiterate subjects. Pseudophakia was seen in 94%. Awareness of cataract (6.7%) and glaucoma (2.4%) was very low. Among subjects who were aware, 70.4% had knowledge of cataract and 45.5% of glaucoma. Cataract was commonly known to be a 'pearl like dot' white opacity in the eye while glaucoma was known to cause blindness. Awareness remained unchanged in different age groups for cataract while for glaucoma there was an increase in awareness with age. Women were significantly less aware (odds ratio (OR): 0.63; 95%, confidence interval (CI): 0.54 - 0.74) for cataract and (OR: 0.64; 95% CI: 0.50 - 0.81) for glaucoma. Literacy was also correlated with awareness. CONCLUSION: The low prevalence of visual impairment and the high cataract surgical coverage suggests that cataract intervention programs have been successful in Bhaktapur. Awareness and knowledge of cataract and glaucoma was very poor among this population. Eye care programs needs to be directed towards preventing visual impairment from refractive errors, screening for incurable chronic eye diseases and promoting health education in order to raise awareness on cataract and glaucoma among this population.