Summary of findings 3. Prognostic factors for the development and progression of PDR in people with diabetic retinopathy: ocular factors.

Population: people with diabetes  Outcome: progression to PDR
Prognostic factors	Study results: effect estimates (95% confidence interval (CI))	Certainty of evidence	Plain text summary
DR severity at baseline (Refer to Table 25 for adjustment factors)	T1Dand T2D (follow‐up 1 to 25 years) Adjusted OR ranged from 1.38 (1.29 to 1.48) to 12.40 (5.31 to 28.98) Data from 3321 participants in 3 studies  Adjusted RR 5.99 (3.03 to 11.9) Data from 322 participants in 1 study Adjusted HR ranged from 23.09 (10.68 to 49.91) to 14.80 (12.10 to 18.09). Data from 35,176 participants in 2 studies	Moderatea	Evidence suggests DR severity at baseline is likely associated with risk of progression to PDR
DR features at baseline (Refer to Table 26 for adjustment factors)	T1Dand T2D (follow‐up 4 to 5 years) Adjusted HR  1.77§ (1.25 to 2.49) 1.47* (0.94 to 2.31) Data from 2823 participants in 1 study Adjusted OR  1.04Ϯ (1.02 to 1.07) 1.05§§ (1.01 to 1.09) 5.77**(2.24 to 14.89) Data from 236 participants in 1 study	Very lowa,b,c	Evidence is very uncertain about the effect of DR features at baseline on risk of developing PDR
Retinal vessel caliber (Refer to Table 27 for adjustment factors)	T1Dand T2D (follow‐up 6 to 14 years) Adjusted OR (T1D) 3.49ϮϮ (1.44 to 8.46) Adjusted RR (T1D) 4.28¶ (1.50 to 12.19) Adjusted HR (T2) 1.17¶ (0.68 to 2.04)	Lowa,b	Evidence suggests larger central retinal venular diameter may be associated with increased risk of progression to PDR in T1D
Intra‐ocular pressure (Refer to Table 28 for adjustment factors)	T1Dand T2D (follow‐up 4 years) Adjusted OR (T1) 1.04 (0.96 to 1.13); (T2) 0.95 (0.85 to 1.08)	Very lowa,b,c	Evidence is very uncertain about the effect of intra‐ocular pressure on risk of developing PDR

CI: confidence interval; HR: hazard ratio; OR: odds ratio; PDR: proliferative diabetic retinopathy; RR: risk ratio; T1D: type 1 diabetes; T2D: type 2 diabetes

^aDowngraded one level for risk of bias: more than 80% of studies at high or unclear risk of bias
^bDowngraded by one level for inconsistency: significant differences in effect estimates reported by studies
^cDowngraded by one level for imprecision: wide 95% CIs

^§Intraretinal microvascular abnormalities (IRMA) vs. venous beading in four quadrants
^*Dot/blot haemorrhages vs. venous beading in four quadrants
^ϮDifference in number of microaneurysms at baseline and follow‐up
^§§Ratio between number of microaneurysms at baseline and follow‐up
^**Difference of ≥ 16 microaneurysms at baseline and follow‐up
^ϮϮCentral retinal venular equivalent ≥ 272.27 vs ≤ 235.97
^¶Larger retinal venular equivalent