[Two-year follow-up study in type 2 diabetic patients with mild visual impairment]

Objective: To determine the 2-year visual prognosis in Chinese type 2 diabetic patients with mild visual impairment and identify the predictors factors. Method: This was a 2-year population-based cohort study. The study population consisted of 650 type 2 diabetic patients with bilateral mild visual impairment in 2014 who were followed up in 2016. The demographic information, systemic and ophthalmological examination results for each participant was collected. Mild visual impairment was defined as best-corrected visual acuity (BCVA)<20/25 to ≥20/63, moderate and severe visual impairment was defined as BCVA<20/63 to ≥20/400, blindness was defined as BCVA<20/400 following the International Council of Ophthalmology (ICO) 2002 definition. The two-year visual prognosis was divided into three groups: visual impairment regression, progression, and stable. Using chi-square test or independent t-test, the predictor factors of visual prognosis and the leading causes of visual impairment were studied. Results: 605 patients completed the follow-up in 2016. Among them, 477 were still bilateral mild visual impairment, accounting for 78.8% (477/605). The level of unilateral or bilateral visual impairment regressed in 8.1% (49/605), while progressed in 13.1% (79/605). Young age (t=2.7, P<0.05), short duration of diabetes (t=2.5, P<0.05), low blood glycemic hemoglobin (t=2.5, P<0.05) and total cholesterol (t=2.8, P<0.05) were associated with regression of visual impairment. Low levels of education (t=5.2, P<0.05), high blood glycemic hemoglobin (t=2.4, P<0.05) and total cholesterol (t=2.4, P<0.05)were associated with progression of visual impairment. Cataracts and diabetic retinopathy were the first and second cause of mild, moderate severe visual impairment or blindness. Conclusions: The percentage of 2-year visual acuity decline is relatively high in type 2 diabetic patients with mild visual impairment. We should strengthen blood glucose and cholesterol control to reduce the progress of visual impairment.(Chin J Ophthalmol, 2021, 57: 766-771).