Abstract
Purpose:
To study a cohort of patients affected with different grades of corneal neovascularization (CNV) and define its etiology. To test whether CNV extent is correlated with (i) best spectacle corrected visual acuity and (ii) corneal sensitivity.
Methods:
Medical records were searched for the presence of corneal neovascularization. Among these patients, best spectacle corrected visual acuity (BSCVA) and corneal sensitivity were also measured. Spearman correlation test was used to search for correlations between (i) BSCVA and CNV; (ii) BSCVA and sensitivity. Chi-square test for trend was used to quantify correlation between corneal sensitivity and CNV.
Results:
Six hundred and fifty patients (803 eyes) who visited the San Raffaele Hospital Cornea Clinic between Jan 2004 and June 2012 were included in the study. Of these, 497 presented with monolateral corneal neovascularization and 153 with bilateral CNV. Mean patient age was 54±20 (M=53%; F=47%). CNV followed infectious keratitis in 31%, non-infectious keratitis in 57%; while the cause was unknown in 12% of cases. Among infectious keratitis cases, 74% were viral. Among non infectious keratitis cases, corneal dystrophies, including keratoconus (32%) were the most prevalent. CNV developed as a consequence of ocular surgery in 18% of cases. Patients affected with CNV involving 1 (P<0.01) and 4 (P<0.05) corneal quadrants were significantly more likely to have better and lower BSCVA respectively. BSCVA was significantly higher in patients with normal vs. absent corneal sensitivity (P=0.001). Finally, patients who maintained normal corneal sensitivity were significantly less vascularized (P=0.005).
Conclusions:
Corneal neovascularization is common in patients presenting to a third-level cornea clinic. Its impact on visual acuity is, however, still under scrutiny. Our study shows that extensive corneal neovascularization is significantly associated with a reduction in BSCVA. We suggest that strategies aimed at controlling CNV should be improved. Additionally, the fact the CNV is associated with reduced corneal sensitivity, and, potentially, nerve dysfunction, confirms previous data obtained in animal models.