Purpose: We report the 4-year incidence, progression, and risk factors of cataract subtypes in type 2 diabetes.
Methods: A total of 779 subjects completed baseline and 4-year follow-up.
Results: The incidences of nuclear opalescence (NO), nuclear color (NC), cortical cataract (CC), and posterior subcapsular cataract (PSC) were 70%, 55.2%, 25.7%, and 7.3%, respectively. One-step progressions of NO, NC, CC, and PSC were 14.3%, 16.1%, 8.8%, and 8.1%, respectively, and two-step or more progressions were 5.0%, 6.0%, 0.8%, and 6.0%, respectively. Incident NO was seen in patients 50 to 59 (odds ratio [OR] = 3.3), NC in those 50 to 59 (OR = 2.7) and 60 to 69 (OR = 3.9), and CC in those 60 to 69 (OR = 3.3) years old. A lower hemoglobin A1c (HbA1c; OR = 0.7), longer diabetes duration (OR = 1.1), and hyperopia (OR = 4.0) were associated with incident PSC. Women (OR = 1.7) and patients with higher total cholesterol (OR = 1.3) at baseline showed one-step NO progression. Patients 60 to 69 (OR = 2.8) and ≥70 (OR = 3.8) years old showed one-step NC progression, while those 60 to 69 years old showed one-step CC progression (OR = 6.3). A lower HbA1c (OR = 0.3) was associated with one-step PSC progression. A higher low-density lipoprotein (OR = 1.6) was associated with two-step or more NO progression. Patients 60 to 69 years old (OR = 6.7) had a greater risk, while those with hyperopia at baseline (OR = 0.2) had lower risk of two-step or more NC progression. Patients 40 to 49 years old constituted the reference group for all.
Conclusions: The 4-year cumulative incidence of cataract is higher than that of progression. Greater age is a risk factor for incidence and progression of most types of cataract.