Burma Vision Meiktila Eye Study (rural central Myanmar)
To determine the prevalence of refractive error and associated risk factors
in the Meiktila District of central rural Myanmar. DESIGN: Population-based
PARTICIPANTS: Randomized stratified cluster sampling of the inhabitants 40 years or older from villages in Meiktila was performed; 2481 eligible participants were identified, 2076 participated in the study, and adequate refractive data were obtained on 1863 individuals (75.1%).
METHODS: Demographic data including age, gender, and education level were obtained from all participants. The ophthalmic examination included autorefraction, nuclear opalescence (NO) grading at the slit lamp, and applanation tonometry.
MAIN OUTCOME MEASURES: Refractive errors were classified by type of ametropia and their prevalence was determined. Univariate and multivariate analyses were performed and odds ratios were calculated for the predictors of refractive error within the statistical models.
RESULTS: Mean refractive error measured -1.3 diopters (D) (standard deviation [SD], 2.9) and mean cylindrical error measured 1.1 D (SD, 1.5). Myopia of >-1.0 and >-6.0 D occurred in 42.7% (95% confidence interval [CI], 40.4%-44.9%) and 6.5% (95% CI, 5.4%-7.6%) of subjects, respectively. Myopic refractive error was associated significantly with a higher degree of NO (P<0.001) and age. Hypermetropia of >+1.0 D occurred in 15% (95% CI, 5.4%-7.6%) of the population and was associated with higher education levels (P<0.001). Astigmatism worse than 1.0 D occurred in 30.6% (95% CI, 28.5%-32.7%) of the population and was associated with age (P<0.001) and NO (P<0.001).
CONCLUSION: Myopia was more prevalent in older subjects and in those with increased NO. The prevalence rates of myopia in the > or =40 age group are higher than those found in other Asian regions and are likely to contribute to visual impairment.(Gupta et al. 2008)
PURPOSE: To study the association between adult stature and ocular biometric parameters and refraction.
METHODS: In a population-based cross-sectional ophthalmic survey of 2418 adults (> or = 40 years old) living in the rural villages in central Myanmar, height and weight were measured using a standardized protocol, and body mass index was calculated. Non-cycloplegic refraction and corneal curvature were determined by an autorefractor. Ultrasound pachymetry was performed and ocular biometry, including axial length, anterior chamber depth, lens thickness and vitreous chamber length were measured using A-mode ocular ultrasonography.
RESULTS: Height and weight were significantly correlated with age, gender and all the ocular biometric parameters, except lens thickness. After adjusting for age and gender, taller and heavier persons had eyes with longer axial length, deeper anterior and vitreous chambers, and flatter and thicker corneas than shorter persons. Height was not significantly correlated with refraction, and heavier persons tended to be less myopic (P < 0.001). Multivariate linear regression models revealed consistent results with the findings for association between height, weight and ocular biometry and refractive error.
CONCLUSIONS: Adult stature is independently associated with vitreous chamber length and corneal radius in this Burmese population. Heavier persons were slightly hyperopic.(Wu et al. 2007)
OBJECTIVE: To determine the prevalence and causes of visual impairment in the Meiktila district of central, rural Myanmar. DESIGN: Population-based cross-sectional study.
PARTICIPANTS: Random, stratified, cluster sampling of the inhabitants 40 years of age and older from villages in the Meiktila district was performed; 2481 eligible participants were identified and 2076 participated in the study.
METHODS: The ophthalmic examination included presenting and pinhole Snellen visual acuity with an illiterate E chart, slit-lamp examination of the anterior segment, and dilated stereoscopic fundus examination. The principal cause of visual impairment was recorded.
MAIN OUTCOME MEASURES: Visual impairment and blindness were defined by both presenting and corrected visual acuity according to World Health Organization criteria: better eye < 6/18 and < 3/60, respectively.
RESULTS: Comprehensive examinations, including Snellen visual acuity, were performed on 2073 participants (83.6%) The prevalence estimate of presenting visual impairment was 40.4% (95% confidence interval [CI], 36.1-44.7) and of presenting blindness was 8.1% (95% CI, 6.5-9.9). After pinhole correction, the corresponding prevalences were 26.8% (95% CI, 23.5-30.1) and 5.3% (95% CI, 4.0-6.6). Cataract, uncorrected refractive error, and glaucoma were the most common causes of visual impairment.
CONCLUSIONS: Visual impairment and blindness remain major public health problems in rural Myanmar. Specific programs directed toward reducing the cataract burden need to be implemented.(Casson et al. 2007b)
Casson, R. J., Newland, H. S., Muecke, J., et al. Prevalence of glaucoma in rural Myanmar: the Meiktila Eye Study. Br J Ophthalmol (2007a) 91(6):710-4.
Casson, R. J., Newland, H. S., Muecke, J., et al. Prevalence and causes of visual impairment in rural myanmar: the Meiktila Eye Study. Ophthalmology (2007b) 114(12):2302-8.
Durkin, S. R., Casson, R. J., Newland, H. S., et al. Prevalence of trachoma-related trichiasis and corneal opacity in rural Myanmar: the Meiktila Eye Study. Ophthalmology (2007) 114(5):e7-11.
Gupta, A., Casson, R. J., Newland, H. S., et al. Prevalence of refractive error in rural Myanmar: the Meiktila Eye Study. Ophthalmology (2008) 115(1):26-32.
Wu, H. M., Casson, R. J., Newland, H. S., et al. Anisometropia in an adult population in rural myanmar: the Meiktila Eye Study. Ophthalmic Epidemiol (2008) 15(3):162-6.
Wu, H. M., Gupta, A., Newland, H. S., et al. Association between stature, ocular biometry and refraction in an adult population in rural Myanmar: the Meiktila eye study. Clin Experiment Ophthalmol (2007) 35(9):834-9.