Blindness and eye diseases in Tibet: findings from a randomised, population based survey

Wang

et al. 2007

Eye

Aims To determine the prevalence and identify associated risk factors for pterygium in an elderly Mongolian population at high altitude in Henan County, China. Methods A population-based survey was conducted from June 2006 to September 2006. A stratified, clustered, random sampling procedure was used to select 2486 Mongolian people aged 40 years and older. Pterygium was diagnosed and graded clinically as grade 1 (transparent), 2 (intermediate), and 3 (opaque). Risk factors associated with pterygium were evaluated with logistic regression models. Results From 2486 eligible subjects, 2112 (84.9%) were examined. There were 378 people with either unilateral (n ¼ 228) or bilateral (n ¼ 150) pterygia, equivalent to an overall prevalence of 17.9% (95% confidence interval (CI) 16.3, 19.5). The prevalence increased with older age (v 2 -test of trend Po0.001). Visual acuity decreased with higher group of pterygium (v 2 ¼ 97.759, Po0.0001). Pterygium was independently associated with Schirmer's test (p5 mm) (odds ratio (OR) 2.4; 95% CI, 1.9, 3.1), tear breakup time (p10 s) (OR 2.3; 95% CI, 1.8, 2.9), lower education level (o3 years) (OR 2.1; 95% CI, 1.4, 3.2), increasing age (OR 2.0; 95% CI, 1.4, 2.8) for persons 70-79, compared with 40-49, and other risk factors. Conclusions The prevalence of pterygium in an older Mongolian population at high altitude is high, primarily because of ocular sun exposure and the other effects of the unique plateau climate, and representing an important health problem. People should be strongly encouraged to wear a wide-brimmed hat and/or sunglasses whenever they are outside.

Section: Discussionmentioning

confidence: 98%

Pterygium in an aged Mongolian population: a population-based study in China

Wang

et al. 2007

Eye

“…A prevalência geral de deficiência visual aumenta com a idade, conforme registrado em vários estudos e na presente pesquisa 26,27,28,29 . Sobre a dificuldade de enxergar, os resultados mostraram que há uma maior prevalência para o sexo feminino a partir dos 12 anos de idade.…”

Section: Discussionunclassified

Deficiência visual, auditiva e física: prevalência e fatores associados em estudo de base populacional

et al. 2008

“…Other studies have reported a higher proportion for cataract. [27][28][29][30][31][32] Overall, based on the presenting vision, about 84% of the cases of visual impairment and 64% of the cases of blindness can be simply prevented by cataract surgery or correcting refractive errors, which is important in terms of public health.…”

Section: Discussionmentioning

confidence: 99%

Visual impairment in the 40- to 64-year-old population of Shahroud, Iran

Hashemi

Khabazkhoob

Emamian

et al. 2012

Eye

Purpose To determine the prevalence of visual impairment by age and gender in Shahroud. Methods Using random cluster sampling, 6311 Shahroud inhabitants who were between 40 and 64 years old were invited for ophthalmological examinations. Visual acuity worse than 0.5 LogMAR (20/60) and 1.3 LogMAR (20/ 400) in the better eye was regarded as low vision and blindness, respectively. The cause of blindness was determined by an ophthalmologist and in a person with more than one cause, the most correctable cause was regarded as the main cause. Results This study was conducted on 5190 participants (response rate: 82.2%). On the basis of presenting visual acuity, the prevalence of low vision and blindness was found to be 1.8% (95% confidence interval (CI): 1.4-2.10) and 0.5% (95% CI: 0.3-0.7), respectively. Based on corrected vision, these values were 0.5% (95% CI: 0.3-0.7) and 0.3% (95% CI: 0.1-0.4), respectively. Visual impairment increased with age in women (Po0.001). Uncorrected refractive errors (63.9%), cataract (20.2%), and amblyopia (5.9%) were the most common causes of visual impairment based on presenting vision. Based on corrected vision, however, cataract (42.5%), amblyopia (12.5%), and retinitis pigmentosa (7.5%) were the most common causes of visual impairment. Conclusion Although the prevalence of visual impairment in the city of Shahroud was determined to be lower than two previous studies in the country, correction of refractive errors and cataract could minimize the rate of visual impairment in this population as they were shown to comprise 85% of the causes of visual impairment. The elderly women need to receive more attention.