Prevalence rates of cataract and cataract surgery in elderly Chinese people living in suburban Shanghai: the Pujiang Cataract Cohort Study

PURPOSE: To estimate the prevalence rates of cataract and cataract surgery in suburban Shanghai, China. METHODS: This population-based, cross-sectional study was carried out in Pujiang Town, Shanghai, China, using a random cluster sampling strategy. A total of 5846 participants (11,657 eyes) aged ≥65 years were enrolled. Detailed eye examinations included presenting visual acuity (VA), best-corrected VA, non-contact tonometry, measurement of ocular parameters using IOLMaster 700, slit-lamp assessment of lens opacities using the Lens Opacities Classification System III and dilated fundus evaluation. RESULTS: Cataract was present in 57.0% of participants (53.8% of eyes). Cortical, nuclear and posterior subcapsular cataract (PSC) were found in 41.3%, 41.0% and 12.6% of participants. Among participants with any cataract, VA was <20/40 in 32.5%. According to Global Burden of Disease Study visual impairment (VI) criteria, 52.5% of participants with PSC had VI, 4.9% were considered blind (VA <20/400) and 31.9% had moderate VI (VA ≥20/400 to <20/63). This rate was significantly greater than that in participants with cortical (32.0%) or nuclear (38.0%) cataract (P<0.05). Cataract surgery was performed in 8.1% of eyes (men, 3.1%; women, 5.0%) or 10.9% of participants (men, 4.2%; women, 6.7%). CONCLUSIONS: The Pujiang Cataract Cohort Study has revealed the prevalence rates of cataract and cataract surgery among elderly individuals in suburban Shanghai, China. Although the frequency of cataract surgery has increased in China in recent decades, the high prevalence of cataract-related VI among older people suggests further attention to primary eyecare and medical awareness is necessary.