AIM: To investigate the prevalence of and risk factors for lens opacities in populations living at two different altitudes in China. METHODS: A total of 813 subjects aged ≥40y in Lhasa (Tibet Autonomous Region, China. Altitude: 3658 m) and Shaoxing (Zhejiang Province, China. Altitude: 15 m) were underwent eye examinations and interviewed in this cross-sectional study. Participants' lens opacities were graded according to the Lens Opacities Classification System II (LOCS II) and the types of opacities with LOCS II scores ≥2 were determined. Univariate and stepwise logistic regression were used to evaluate the associations of independent risk factors with lens opacities. RESULTS: Lens opacities were significantly more prevalent in the high-altitude than in the low-altitude area (χ (2)=10.54, P<0.001). Lens opacities appear to develop earlier in people living at high than at low altitude. The main types of lens opacity in Lhasa and Shaoxing were mixed (23.81%) and cortical (17.87%), respectively. Independent risk factors associated with all lens opacities were age, ultraviolet (UV) radiation exposure, and educational level. Compared with participants aged 40-49y, the risk of lens opacities increased gradually from 2 to 85 times per 10y [odds ratio (OR)=2.168-84.731, P<0.05). The risk of lens opacities was about two times greater in participants with the highest UV exposure than in those with the lowest exposure (OR=2.606, P=0.001). Educational level was inversely associated with lens opacities; literacy deceased the risk by about 25% compared with illiteracy (OR=0.758, P=0.041). CONCLUSION: Old age, higher UV exposure and lower educational level are important risk factors for the development of lens opacities. Lens opacities are more prevalent among high-altitude than low-altitude inhabitants.
AIM: To investigate the prevalence of and risk factors for lens opacities in populations living at two different altitudes in China. METHODS: A total of 813 subjects aged ≥40y in Lhasa (Tibet Autonomous Region, China. Altitude: 3658 m) and Shaoxing (Zhejiang Province, China. Altitude: 15 m) were underwent eye examinations and interviewed in this cross-sectional study. Participants' lens opacities were graded according to the Lens Opacities Classification System II (LOCS II) and the types of opacities with LOCS II scores ≥2 were determined. Univariate and stepwise logistic regression were used to evaluate the associations of independent risk factors with lens opacities. RESULTS:Lens opacities were significantly more prevalent in the high-altitude than in the low-altitude area (χ (2)=10.54, P<0.001). Lens opacities appear to develop earlier in people living at high than at low altitude. The main types of lens opacity in Lhasa and Shaoxing were mixed (23.81%) and cortical (17.87%), respectively. Independent risk factors associated with all lens opacities were age, ultraviolet (UV) radiation exposure, and educational level. Compared with participants aged 40-49y, the risk of lens opacities increased gradually from 2 to 85 times per 10y [odds ratio (OR)=2.168-84.731, P<0.05). The risk of lens opacities was about two times greater in participants with the highest UV exposure than in those with the lowest exposure (OR=2.606, P=0.001). Educational level was inversely associated with lens opacities; literacy deceased the risk by about 25% compared with illiteracy (OR=0.758, P=0.041). CONCLUSION: Old age, higher UV exposure and lower educational level are important risk factors for the development of lens opacities. Lens opacities are more prevalent among high-altitude than low-altitude inhabitants.
Authors: Amy Z Fan; Yan Li; Xinzhi Zhang; Ronald Klein; Ali H Mokdad; Jinan B Saaddine; Lina Balluz Journal: Ophthalmic Epidemiol Date: 2012-02 Impact factor: 1.648
Authors: Jessica R Chang; Euna Koo; Elvira Agrón; Joelle Hallak; Traci Clemons; Dimitri Azar; Robert D Sperduto; Frederick L Ferris; Emily Y Chew Journal: Ophthalmology Date: 2011-11 Impact factor: 12.079
Authors: M Amparo Díez-Ajenjo; M Carmen García-Domene; José M Artigas; Adelina Felipe; Cristina Peris-Martínez; José Luis Menezo Journal: Eur J Ophthalmol Date: 2011 Nov-Dec Impact factor: 2.597