OCTA Biomarkers Underlying Structure-Function Correlations in Idiopathic Epiretinal Membrane: A Systematic Review

Area of Science:

• Ophthalmology
• Retinal Imaging
• Vascular Biology

Background:

• Idiopathic epiretinal membrane (iERM) is a common condition in elderly patients, often linked to posterior vitreous detachment.
• Pars plana vitrectomy (PPV) with membrane peeling is the standard treatment, but optimal surgical timing and patient selection remain unclear.
• Optical coherence tomography angiography (OCTA) is emerging as a key tool for identifying biomarkers in iERM due to its ability to assess retinal vascular morphology and function.

Purpose of the Study:

• To systematically review and synthesize evidence on OCTA-derived biomarkers in iERM.
• To correlate these biomarkers with visual function before and after surgery.
• To evaluate the prognostic value of OCTA biomarkers for surgical outcomes.

Main Methods:

• A systematic search of PubMed/MEDLINE and Scopus was conducted following PRISMA guidelines.
• Included studies involved iERM patients undergoing vitreoretinal surgery, utilizing OCTA for pre/postoperative assessment and investigating structure-function correlations.
• Eligible studies were observational, clinical trials, or case series with >10 patients, excluding non-English or studies without separate iERM analysis.

Main Results:

• The review included 43 observational studies encompassing 1958 eyes from 1953 patients.
• Frequently investigated OCTA biomarkers included foveal avascular zone (FAZ) area, vessel density (VD), and foveal density 300 (FD-300).
• Other assessed parameters included vessel length (VL), blood flow area, vessel length density (VLD), vessel tortuosity (VT), fractal dimension (FD), and perfusion capacity (PC).

Conclusions:

• OCTA-derived metrics show potential as biomarkers for iERM severity and surgical prognosis, offering insights into visual decline mechanisms.
• The review consolidates current evidence on structure-function correlations in iERM.
• Limitations include the observational nature of all studies and heterogeneity in OCTA methodology, highlighting the need for standardization.