Abstract
Purpose:
To investigate the inner retinal layer outcome after internal limiting membrane (ILM) peeling in idiopathic epiretinal macular membrane (ERM) with new Spectral Domain Optical Coherence Tomography (SD OCT)
Methods:
Prospective, multicentric, comparative study. Vitrectomy and ERM removal were performed using brilliant peel staining before and after ILM peeling. All eyes were examinated pre and postoperatively (W1, M1, M3, M6) using Spectralis HRA (Heidelberg) with autofluorescence, red free, infrared filters and SD OCT with B-scan and C-scan images. Videos of the surgeries are retrospectively analyzed
Results:
41 patients with ERM underwent pars plana vitrectomy with (group B, n= 24) or without (group A, n= 17) ILM peeling associated. The gain of BCVA at M6 was the same (+10 ETDRS letters) between the 2 groups but recovery was slower in the group B, p<0,05. The decrease of the CRT (-75 µm at M6) was the same between the 2 groups, p<0,05. In the group B a dissociated optic nerve fiber layer (DONFL) appearance was detected in 16 eyes (63%), p<0,05. Dimples of the nerve fiber layer are seen in 20 eyes (95%) which correspond to the DONFL appearance, p<0,05. It appears at M1 visit and persists until M6 and was never seen in the non-ILM peeled group. En face OCT shows a dimpling of the inner retinal layer which correspond to the area of the ILM peeling. Swelling of the arcuate nerve fiber layer (SANFL) was detected in 15/24 eyes in the ILM peeled group and in 5/14 eyes in the non ILM peeled group, M3 p<0,05. It appears at W1 and regress at M3 visit with atrophy. Autofluorescence imaging shows a dark point at the beginning of the arcuate striae and correspond to the initiated peeling with the forceps on the video.
Conclusions:
Multimodal examination (HRA and SD OCT) allows us to describe two different ways of healing after ILM removal. SD OCT is more sensitive than Red free photography to detect DONFL appearance which correspond actually to dimples in the inner retina. Autofluorescence and infrared photography show transient SANFL which probably correspond to a direct traumatism when peeling. Thus, peeling ILM in the temporal inferior area, use staining or atraumatic forceps may be the best ways to begin the surgery and avoid microscotoma
Keywords: 762 vitreoretinal surgery