DRVS (n=987) Yorston (n=174) DRIVE UK (n=185) Thompson (n=1007) Ting (n=108)
Follow up 4 years 8 months 12 months At least 6 months 12 months
Visual acuity (VA)          
i. ≥ 20/200  63-68% 71.7% N/A 70% 77%
 ii. ≥ 20/40 28-44% 11% 38% 17% 31%
 iii. No light perception 19-23% 2% 3% 14% 2%
Anatomical success 63-79%  91% 84% 70% 94%
N/A: Not available.

Table 7: Comparative visual and anatomical outcome following diabetic vitrectomy for proliferative diabetic retinopathy.