Retinal vascular arcade angle as a biomarker for visual improvement after epiretinal membrane surgery

OBJECTIVES: To investigate the changes in the temporal vascular angles after epiretinal membrane (ERM) surgery and utilize the angles to predict visual outcomes.

METHODS: A total of 168 eyes from 84 patients with unilateral ERM who underwent vitrectomy were enrolled from a single institution. The angles of temporal venous (angle vein) and arterial arcades (angle artery) were measured on fundus photographs. The relationships between the angles and the best-corrected visual acuity (BCVA) were explored and multivariable logistic models and receiver operating characteristic (ROC) curves were analyzed to identify the factors that predicted visual outcomes.

RESULTS: At baseline, both angle artery and angle vein were narrower in the eyes with ERM than the fellow eyes (p < 0.001 and 0.007) but had no correlation with the baseline BCVA (p = 0.754 and 0.804). Postoperatively, the angle artery and angle vein significantly widened (both p < 0.001) and a greater BCVA improvement was associated with a greater widening of the angle artery (p = 0.029) and angle vein (p = 0.050). Multivariable logistic analyses found a narrower baseline angle artery compared to the fellow eye had a higher chance for BCVA improvement ≧ 2 lines (Odds ratio = 0.97; 95% CI, 0.94-0.99; p = 0.016). ROC curve showed the baseline difference in the angle artery between bilateral eyes predicted BCVA improvement ≧ 2 lines (area under the curve = 0.74; p = 0.035), and a 0.73 sensitivity and 0.80 specificity with a cut-off value of -27.19 degrees.

CONCLUSIONS: The retinal vascular angles widened after ERM surgery and the fundus photograph-derived angles may serve as a highly-accessible biomarker to predict postoperative visual outcomes.