Table 4.
Causes of bilateral low vision and blindness based on best-corrected visual acuity (BCVA) or presenting visual acuity (PVA) in type 2 diabetes patients in the Dongguan Eye Study (per person).
| Causes | Bilateral low vision and blindness based on BCVA | Bilateral low vision and blindness based on PVA | ||||
|---|---|---|---|---|---|---|
| Bilateral low vision (BCVA < 20/63 and ≥20/400) No. at risk (%) | Bilateral blindness (BCVA < 20/400) No. at risk (%) | Bilateral visual impairment (BCVA < 20/63) No. at risk (%) | Bilateral low vision (PVA < 20/63 and ≥20/400) No. at risk (%) | Bilateral blindness (PVA < 20/400) No. at risk (%) | Bilateral visual impairment (PVA < 20/63) No. at risk (%) | |
| Cataract | 29 (76.3) | 5 (55.6) | 34 (72.3) | 66 (60.6) | 5 (45.5) | 71 (59.2) |
| Other retinal disease | 3 (7.9) | 1 (11.1) | 4 (8.5) | 4 (3.7) | 1 (9.1) | 5 (4.2) |
| Diabetic retinopathy | 2 (5.3) | 1 (11.1) | 3 (6.4) | 2 (1.8) | 1 (9.1) | 3 (2.5) |
| Pterygium | 3 (7.9) | 0 | 3 (6.4) | 4 (3.7) | 0 | 4 (3.3) |
| Myopic maculopathy | 1 (2.6) | 0 | 1 (2.1) | 1 (0.9) | 0 | 1 (0.8) |
| Corneal opacity | 0 | 1 (11.1) | 1 (2.1) | 0 | 1 (9.1) | 1 (0.8) |
| ARM | 0 | 1 (11.1) | 1 (2.1) | 1 (0.9) | 1 (9.1) | 2 (1.7) |
| Uncorrected refractive error | 0 | 0 | 0 | 30 (27.5) | 2 (18.2) | 32 (26.7) |
| Amblyopia | 0 | 0 | 0 | 1 (0.9) | 0 | 1 (0.8) |
| Total | 38 (100) | 9 (100) | 47 (100) | 109 (100) | 11 (100) | 120 (100) |
Visual impairment: low vision plus blindness; Other retinal disease: retinal disease except diabetic retinopathy and ARM; ARM: age-related maculopathy.