Table 1.

Definitions for Diabetic Retinopathy Improvement or Worsening During Follow up

	Non-Proliferative Diabetic Retinopathy (NPDR) at baseline	Proliferative Diabetic Retinopathy (PDR) at baseline
Improvement in retinopathy was achieved if both of the following criteria were met during follow up
Documentation on case report form†	(1) no PRP, vitrectomy, or anti-VEGF injection (to manage PDR or its complications) was performed, and no vitreous hemorrhage, retinal detachment (traction, rhegmatogenous, combined, or unspecified), anterior segment neovascularization, or neovascular glaucoma was identified
Assessment of annual fundus photographs by reading center	(2a) improvement by 2 or more levels on the ETDRS diabetic retinopathy scale vs. baseline
	(2b) regression of active PDR (level 61 or higher) to no PDR (level 53 or lower if no prior PRP, or to level 60 if PRP was present at entry)
Baseline DR severity ineligible for improvement	Microaneurysms only or less (level 10, 12, 14, 15, or 20)	Inactive PDR (level 60)
Sustained Improvement in retinopathy was achieved if improvement was demonstrated at the 1-year visit and there were gradable photographs at the 3-year visit that confirmed improvement relative to baseline.
Worsening of diabetic retinopathy included any of the following events during follow up
Documentation on case report form†	(1) PRP, vitrectomy, or anti-VEGF injection (to manage PDR or its complications), vitreous hemorrhage, retinal detachment, or neovascularization of the iris or angle or neovascular glaucoma
Assessment of annual fundus photographs by reading center‡	(2) worsening by 2 or more levels on the ETDRS severity scale vs. baseline
	(3a) worsening from no PDR to PDR (≤ level 53 progressing to level 60 or higher)	(3b) progression from less than high risk PDR to advanced PDR (level 60 to 75 progressing to level 81 or 85)
Baseline DR severity ineligible for worsening	N/A	Advanced PDR (level 81 or 85)

ETDRS= Early Treatment Diabetic Retinopathy Study; Anti-VEGF=anti-vascular endothelial growth factor.

^†Eyes that manifested worsening of retinopathy with any PDR related event were considered as non-improvers from that point foward in the improvement analysis.

^‡Cases with missing photograph data or nongradable photographs at a completed follow-up visit were considered as no event for the photograph component in the composite worsening outcome at that annual time point.