The association between corneal neovascularization and visual acuity: a systematic review.

PURPOSE: Corneal neovascularization (CNV) is thought to negatively influence visual acuity. New therapeutic options that offer a differentiated influence on the ingrowths or regression of either corneal blood or lymphatic vessels force us to re-evaluate the association between CNV and visual acuity.

METHODS

A systematic review was conducted. Electronic databases were searched up to August 2009. Given the heterogeneity in study populations, interventions and measures of association, we were unable to undertake meta-analysis. The association between CNV and visual acuity was reported descriptively for each study.

RESULTS

Eleven studies using either vascular endothelial growth factor inhibitor treatments (i.e. bevacizumab, Avastin(®) ; Hoffmann-La Roche AG, Basel, Switzerland) or an antiangiogenic treatment based on IRS-1 modulation [Gene-Signal (GS) 101, Aganirsen(®) ; GeneSignal, Evry (Paris), France] in a total of 131 patients (142 eyes) with corneal neovascularization were included. Ten of the eleven studies reported evidence of a statistically significant reduction in neovascularization following treatment. However, only four studies reported a statistically significant improvement in visual acuity following therapy. We found no studies that assessed the patient-level association between the change in neovascularization and visual acuity.

CONCLUSION

This systematic review found that there is currently weak evidence to support the hypothesis that in patients with pathological neovascularization, a treatment-related reduction in neovascularization is associated with an increase in visual acuity. There is a need for future appropriately designed studies.