gms | German Medical Science

Purpose: To evaluate and correlate morphological and functional early-outcomes after idiopathic Epiretinal Membrane surgery using SD-OCT retinal layers segmentation software and Microperimetry MP-1.

Methods: 15 consecutive eyes (15 patients) with idiopathic Epiretinal Membrane (iERM) diagnosis underwent standard 23 gauge Vitrectomy with G brilliant blue-assisted ILM peeling. Preoperative and 3 months follow-up data were assessed, including BCVA, macular layers mean thickness, integrity of External Limiting Membrane (ELM), Ellipsoid Zone (EZ) and Cone Outer Segment Tips (COST) line and, therefore, mean retinal sensivity and fixation stability (BCEA). SD-OCT Fast macular layer thickness was considered at the level of the central circle of the ETDRS plot and at each of the 4 external subfield (nasal, superior, temporal and inferior). All retinal layers thicknesses, from RNFL to RPE, were obtained by manual correction using the Heidelberg segmentation software. Preoperative quantitative (macular layers thickness) and qualitative (ELM, EZ and COST line) measurements were correlated with BCVA and microperimetry data.

Results: Mean BCVA improved from 0,51 logMAR to 0,28 logMAR (p=0,000). Total macular and RNFL thickness were significantly reduced in all the 5 sectors analyzed at 3 months follow-up; IPL and OPL showed significant thickness reduction in the central section of the ETDRS plot and in at least 3 external subfields; GCL and INL thickness were respectively reduced only in the nasal and in the inferior sector of ETDRS plot. Postoperative SD-OCT data revealed significant recovery of EZ (p=0,009) and COST line (p=0,041). No significant differences were observed for retinal sensivity and fixation stability during follow-up, even in the presence of mild improvement in BCEA. Preoperative central total macular and ONL thickness were correlated with postoperative BCVA (respectively r=0,719 p=0,003; r=0,835 p=0,000) and with postoperative retinal sensivity (r=-0,603 p=0,017; r=-0,533 p=0,41) and fixation stability (r=0,549 p=0,034; r=0,759 p=0,001). No significant correlations were found between preoperative photoreceptor integrity and microperimetry measurements.

Conclusion: The present data indicate that SD-OCT retinal layer segmentation software represents a usefool tool to better understand anatomical changes induced by iERM surgery. Preoperative high ONL thickness is a negative prognostic factor for post-operative visual recovery.