Evaluation of Retinal Parameters in Patients With Epiretinal Membrane After Vitrectomy

Evaluation of Morphological and Functional Changes in Eyes With Epiretinal Membrane After Vitrectomy

The goal of this interventional study is to assess the dynamics of structural and functional retinal changes in eyes with epiretinal membrane (ERM) after pars plana vitrectomy (PPV). Other study objectives include:

• Identification of preoperative prognostic factors associated with better postoperative outcomes.
• Evaluation of the utility of advanced, highly specialized retinal function testing as diagnostic-prognostic tools in patients after ERM surgery.
• Definition of updated qualification criteria and surgical indications for vitrectomy in patients with ERM.

Researchers will compare a laser-treated group (additional subthreshold micropulse yellow laser (577 nm) at 1 month post-PPV) with a nonlaser group (no additional laser) to see whether early postoperative subtreshold micropulse laser therapy (SMLT) affects selected functional and morphometric retinal parameters after ERM peeling.

This prospective, randomized, controlled, single-center study includes 100 pseudophakic patients scheduled for surgical ERM removal.

Eligibility requires a visually significant ERM with metamorphopsia and/or reduced best-corrected visual acuity.

Participants are classified preoperatively by OCT-based Govetto staging and randomized 1:1 to either the laser-treated group or the non-laser (control) group. All patients undergo standard 25-gauge PPV with ERM peeling, followed by ILM peeling and SF₆ gas tamponade, performed by a single experienced vitreoretinal surgeon.

Follow-up visits occur preoperatively, and at 1 and 4 months postoperatively; SMLT is performed at 1 month in the laser arm. Baseline questionnaire captures metamorphopsia presence (yes/no) and duration (<6, 6-12, >12 months).

Assessments include:

• best corrected visual acuity (BCVA) [Snellen and ETDRS charts]
• enhanced depth imaging optical coherence tomography (EDI-OCT) [retinal thickness in the nine Early Treatment Diabetic Retinopathy Study (ETDRS) subfields (μm); total retinal volume (mm³); subfoveal choroidal thickness (μm); choroidal area (mm²)]
• OCT angiography (OCTA) [foveal avascular zone (FAZ) area in both the superficial (SVC) and deep vascular complexes (DVC) (mm²)]
• multifocal electroretinography (mfERG) [P1-wave retinal response density (nV/deg²) in rings R1-R6; P1-wave implicit (peak) time in rings R1-R6 (ms)]
• microperimetry (average threshold (dB); fixation stability P1/P2; fixation variability via 63% and 95% bivariate contour ellipse area (BCEA)]
• wide-field fundus imaging

Statistical analyses will be performed at a significance level of p<0.05, using appropriate parametric or nonparametric methods selected based on data distribution and measurement scale.

Inclusion Criteria:

• Epiretinal membrane (ERM) - either associated with metamorphopsia or causing a marked reduction in best corrected visual acuity
• Pseudophakia

Exclusion Criteria:

• Coexisting ocular or retinal diseases other than ERM
• Evidence of ocular inflammation or any active intraocular inflammatory process