The Prevalence and Causes of Visual Impairment in Type 2 Diabetes Mellitus in Northeast China

Table 5

Frequency of visual impairment in each individual eye stratified by reference standard diabetic retinopathy (DR) grading according to the best-corrected visual acuity (BCVA).

BCVA	No retinopathy	Mild and moderate NPDR	Severe NPDR	PDR	CSME	Photocoagulation or vitrectomy
	N (%)	N (%)	N (%)	N (%)	N (%)	N (%)
N	2272	1117	128	137	127	73
≧20/60	2177 (95.82)	1055 (94.4)	117 (91.4)	69 (050.40)	75 (59.06)	41 (56.2)
<20/60 and ≧20/400	83 (3.65)	60 (5.5)	9 (7.00)	47 (34.3)	46 (36.22)	26 (35.6)
<20/400	12 (0.53)	2 (0.2)	2 (1.60)	21 (15.3)	6 (4.72)	6 (8.2)

NPDR: nonproliferative diabetic retinopathy; PDR: proliferative diabetic retinopathy; CSME: Clinically significant macular edema.