SPECIFIC CORNEAL PARAMETERS AND VISUAL ACUITY CHANGES AFTER CORNEAL CROSSLINKING TREATMENT FOR PROGRESSIVE KERATOCONUS.

Abstract

To evaluate the effect of crosslinking (CXL) therapy on the change in the quality of visual acuity and the change in the topographic properties of the cornea - curvature, pachymetry, and change of astigmatism, coma abberation and CLMIaa (Cone Localisation and Magnitude Index). Aretrospective analytical study included 29 eyes of 24 patients who had progressed in the last 12 months and were suitable candidates for CXL surgery. The monitored parameters were the steepest, flatest and mean anterior instantaneous curvature (AICS, AICF, AICM) and the steepest, flatest and mean posterior instantaneous curvature (PICS, PICF, PICM) of the cornea, corneal thickness in the centre of the cornea (PACHC) and in the thinnest point of the cornea (PACHT), corneal astigmatism (ASTIG). coma (COMA), Cone Localization and Magnitude Index (CLMIaa) and uncorrected distance visual acuity (UDVA) with corrected distance visual acuity (CDVA). Data were analysed before surgery and 12 months after surgery. The AIC, COMA, CLMIaa and ASTIG parameters were analysed by paired t test. As the parameters of UDVA, CDVA, PIC and PACH did not meet the conditions of normal distribution, the Wilcoxon test was used to investigate the change in these parameters after CXL. Twelve months after the procedure, we recorded an improvement in UDVA (p=0.371) and CDVA (p=0.825), an increase in PICS, PICF and PICM (p=0.902; p=0.87 and p=0.555), adecrease in PACHCC (p=0.294) and adecrease in CLMIaa (p=0.113) that did not reach statistical significance. The decrease in PACHT (p=0.027), decrease in COMA (p=0.037) and decrease in anterior corneal curvature of AICS, AICF and AICM were statistically significant (p=0.019; p=0.010 and p=0.005). The decrease in the value of astigmatism did not show statistical significance, as p=0.297. CXL corneal therapy has been shown to be an effective method to stabilize the cornea in progressive keratoconus, and to improve the higher order of coma. This contributes to the possible improvement of UDVA and CDVA.