Table 3.

Crude prevalence of unilateral low vision and blindness based on best-corrected visual acuity (BCVA) or presenting visual acuity (PVA) by gender and age in type 2 diabetes patients in the Dongguan Eye Study.

Group	Age	Total No. of persons	Based on BCVA				Based on PVA
			Unilateral low vision (20/400 ≤ BCVA < 20/63)		Unilateral blindness (BCVA < 20/400)		Unilateral low vision (20/400 ≤ PVA < 20/63)		Unilateral blindness (PVA < 20/400)
			No. of persons	% (95% CI)	No. of persons	% (95% CI)	No. of persons	% (95% CI)	No. of persons	% (95% CI)
Male
	40–49	156	1	0.6 (0–1.9)	1	0.6 (0–1.9)	5	3.2 (0.4–6.0)	1	0.6 (0–1.9)
	50–59	168	4	2.4 (0.1–4.7)	1	0.6 (0–1.8)	6	3.6 (0.8–6.4)	3	1.8 (0–3.8)
	60–69	158	3	1.9 (0–4.0)	5	3.2 (0.4–5.9)	11	7.0 (3.0–11.0)	5	3.2 (0.4–5.9)
	70–79	46	8	17.4 (6.3–28.5)	2	4.3 (0–10.3)	8	17.4 (6.3–28.5)	2	4.3 (0–10.3)
	≥80	22	3	13.6 (0–28.3)	5	22.7 (4.8–40.7)	4	18.2 (1.6–34.7)	4	18.2 (1.6–34.7)
	total	550	19	3.5 (1.9–5.0)	14	2.5 (1.2–3.9)	34	6.2 (4.2–8.2)	15	2.7 (1.4–4.1)
Female
	40–49	140	1	0.7 (0–2.1)	0	0	7	5.0 (1.4–8.6)	0	0
	50–59	222	7	3.2 (0.8–5.5)	0	0	17	7.7 (4.1–11.2)	2	0.9 (0–2.1)
	60–69	261	16	6.1 (3.2–9.1)	10	3.8 (1.5–6.2)	29	11.1 (7.3–14.9)	10	3.8 (1.5–6.2)
	70–79	131	16	12.2 (6.6–17.9)	9	6.9 (2.5–11.2)	20	15.3 (9.1–21.5)	13	9.9 (4.8–15.1)
	≥80	40	6	13.6 (3.4–23.9)	6	13.6 (3.4–23.9)	11	25.0 (12.0–38.0)	6	13.6 (3.4–23.9)
Male and female
	40–49	296	2	0.7 (0–1.6)	1	0.3 (0–1.0)	12	4.1 (1.8–6.3)	1	0.3 (0–1.0)
	50–59	390	11	2.8 (1.2–4.5)	1	0.3 (0–0.8)	23	5.9 (3.6–8.2)	5	1.3 (0.2–2.4)
	60–69	419	19	4.5 (2.5–6.5)	15	3.6 (1.8–5.4)	40	9.5 (6.7–12.4)	15	3.6 (1.8–5.4)
	70–79	177	24	13.6 (8.5–18.6)	11	6.2 (2.6–9.8)	28	15.8 (10.4–21.2)	15	8.5 (4.4–12.6)
	≥80	66	9	13.6 (5.3–22.0)	11	16.7 (7.6–25.7)	15	22.7 (12.5–32.9)	10	15.2 (6.4–23.9)
	total	1348	65	4.8 (3.7–6.0)	39	2.9 (2.0–3.8)	118	8.8 (7.2–10.3)	46	3.4 (2.4–4.4)