Abstract
Purpose: :
We evaluated color fundus photographs (FP) and OCT of eyes with DME from DRCRnet clinical studies that developed hard exudate (HE) plaques and/or fibrous scars to explore the development of these lesions, sequelae, and associations with VA.
Methods: :
29 eyes with definite HE plaques or fibrous scars at baseline (BL) or follow-up visits (FV) were evaluated by OCT and FP longitudinally for lesion type, preceding abnormalities, area, (OCT) lesion and retinal thickness at retinal center, density, and location (intra-/sub-retinal). ETDRS VA’s were used from published DRCR.net data sets.
Results: :
Group 1, 7 eyes - HE plaques at BL or during FV that resolve. Mean VA: at 1st plaque visit, 53 (ltrs) (range 36-73), and after resolution, 59(43-78).Group 2, 8 eyes - HE plaques at BL or FV that persist. Mean VA at 1st plaque visit, 40(13-58), relatively unchanged thereafter.Group 3, 4 eyes - HE plaques that convert to fibrous scars. Mean VA: at plaque visit, 46(22-82), and at scar visit, 38(2-73). Abnormalities preceding HE plaque were, in all groups - cysts, Group 1 only- peri-central HE plaques, and Groups 2&3 only- many small peri-central hard exudates (not plaque) and retinal thickness ≥400 µm. In all groups, subretinal deposits were commonly identified by OCT, with increasing prevalence from group 1 to 3.Group 4, 5 eyes - Fibrous scars at BL, persisting thereafter.. Mean VA at BL, 45(21-63), relatively unchanged thereafter. Eyes with less dense scars tended to have higher VA.Group 5, 5 eyes - Fibrous scars developing during FV without prior HE plaque: Mean VA: before scar, 38(8-64), and with scar, 20(5-33). Abnormalities preceding scars were cysts in all eyes, and sensory retinal detachment that resolved before scar onset in 4 of 5.
Conclusions: :
VA in DME is low with HE plaques, and even lower with fibrous scars. Subretinal deposits are more likely seen in eyes with chronic plaques or that develop fibrosis. HE plaques can resolve, persist, or convert to fibrous scars; fibrous scars can develop from persistent plaques, or apparently de novo. With scar onset, VA and retinal thickness decrease markedly.
Keywords: diabetic retinopathy • macula/fovea • lipids