Pars Plana Vitrectomy and Internal Limiting Membrane Peeling in Epimacular Membranes: Correlation of Function and Morphology across the Macula

Purpose: To analyze the correlation between morphological and
functionalresults 12 months after epiretinal membrane (ERM)
surgery. Methods: 31eyes from 31 consecutive patients with
nnetamorphopsia and bestcorrected visual acuity (BCVA) below 20/32
underwent a transconjunctival23-gauge vitrectomy with ERM and
internal limiting membrane peeling. Preoperatively and 3, 6 and 12
months postoperatively, we assessed BCVA,microperimetry (MP-1) and
spectral domain optical coherence tomography(SD-OCT). Photoreceptor
inner and outer segment (IS/OS) was graded onSD-OCT images and
correlated with microperimetry measurements in thefovea and
parafoveal region. Results: The postoperative BCVA wassignificantly
better in eyes with an intact IS/OS junction (p < 0.01).In
addition, the mean defect depth was postoperatively decreased in
thefoveal and parafoveal area in eyes with an intact IS/OS
junction. Acorrelation of SD-OCT IS/OS images and microperinnetry
in eyes withimprovement in BCVA of at least 2 lines revealed a
statisticallysignificant result for the parafoveal quadrants (p
< 0.011 for SD-OCTand p < 0.005 for microperimetry) but not
for the foveal area alone.Conclusions: The IS/OS regeneration in
the parafoveal quadrantscontributes significantly to the recovery
of BCVA following ERM surgery.Consequently, functional and
morphological tests of the macular areashould not be limited to the
fovea but should be extended to theparafoveal region.