The leading cause of avoidable blindness and the second-highest cause of visual impairment worldwide is cataract.[1] Therefore, it is important to understand the prevalence and risk factors of cataract in different parts of the world so as to reduce the same. Guo et al. in their study[2] have brought out well the importance of analyzing the prevalence of cataract. A comparison was made between the past and present prevalence of cataract in South East Asia, wherein they observed that the prevalence remained unchanged since 1990 despite an overall global reduction in cataract prevalence.[3] This indeed is an ironically striking feature because despite the overall advancement of eyecare facilities all over the world, the prevalence of cataract in South East Asia has remained unchanged over a period of 30 years, a difference well brought out.[2] As regards analysis of various risk factors, the authors have found no association of gender, diabetes mellitus, smoking, ocular trauma, and body mass index with cataract. On the other hand, increasing age, rural inhabitants, and hypertensive patients were associated with increased incidence of cataract. The authors have also compared well regarding the type of cataract and its association with the various risk factors: Patients with hypertension were associated with nuclear and cortical cataract whereas rural inhabitants had more frequently cortical cataract. This was compared with other East Asian countries as well. This kind of study definitely helps in understanding the burden of cataract in a particular region, which is an important cause of avoidable blindness. This further helps in better planning and management so as to reduce the prevalence of cataract.
Like any other study, this study too has its own limitations, where sample size was calculated based on visual impairment rather than prevalence of cataract.
Interestingly, the Vientiane study is first of its kind and paradoxically, there is no published data on the prevalence of cataract in the other neighboring countries of Thailand, Cambodia, Vietnam, or the Yunnan Province of China. This calls for more similar studies across the world especially so in the developing countries.
Acknowledgements
We acknowledge Sankara Eye Hospital, Shimoga; Sankara Academy of Vision, Bangalore; family and friends.
References
- 1.GBD 2019 Blindness and Vision Impairment Collaborators;Vision Loss Expert Group of the Global Burden of Disease Study. Causes of blindness and vision impairment in 2020 and trends over 30 years, and prevalence of avoidable blindness in relation to VISION 2020: The right to sight: An analysis for the Global burden of disease study. Lancet Glob Health. 2021;9:e144–60. doi: 10.1016/S2214-109X(20)30489-7. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 2.Guo B, Tan Y, Nygaard S, Carrillo C, Nouansavanh KO, Souksamone K, et al. Prevalence and risk factors for cataracts in the Lao People's Democratic Republic: The Vientiane Eye Study. Indian J Ophthalmol. 2022;70:1599–605. doi: 10.4103/ijo.IJO_2137_21. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 3.Keefee J, Casson RJ, Pesudovs K, Taylor HR, Cicinelli MV, Das A, et al. Prevalence and causes of vision loss in South-east Asia and oceania in 2015: Magnitude, temporal trends and projections. Br J Ophthalmol. 2019;103:878–84. doi: 10.1136/bjophthalmol-2018-311946. [DOI] [PubMed] [Google Scholar]