EVALUATION OF COLLAGEN CROSS LINKING IN KERATOCONUS EYES WITH KERA INTRACORNEAL RING IMPLANTATION

To assess the outcome of collagen cross-linking (CXL) in keratoconus eyes after implantation of Kera intracorneal ring segments

Mansoura Ophthalmic Center, Mansoura University, Mansoura, Egypt

twenty one eyes of 13 patients suffering from mild to moderate degree of Keratoconus were included in this study.  All eyes had uneventful surgery for Kera intracorneal ring segment implantation followed by collagen cross-linking (CXL) treatment after at least 3 months of the implantation. Inclusion criteria were absence of corneal scarring and corneal thickness higher than 400 mm. Uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), spherical equivalent and cylinder refraction, and the mean keratometric (K) values were evaluated pre and postoperatively.  

The mean age was 21.36 ± 4.46 (range 16- 28) years. Mean time between implantation of Kera ring and CXL was 4.56 ± 3.2 months. The mean Baseline UCVA and BCVA were 0.05 ± 0.02 and 0.18 ± 0.1 respectively; after kera ring, the mean UCVA and BCVA were 0.23±0.17 and 0.39 ±0.18 (p =0.000) respectively. CXL after Kera ring resulted in an additional change in UCVA and BCVA to become 0.23±0.17 (p=0.951) and 0.41 ±0.18 (p =0.08) respectively. Also, CXL results in an additional change in spherical equivalent, cylindrical and the mean keratometric values. The decrease in spherical equivalent, cylindrical and mean keratometric value was 2.8diopters (D) (p <0.05), 2.1 D (P < 0.05) and 2.5 D (P < 0.05) respectively after Kera ring treatment. An additional decrease of 0.11 D (P > 0.05), 0.01 D (P > 0.05) and 0.09 D (P > 0.05) was obtained after CXL in each respective parameter

Collagen cross-linking has an additive effect after kera ring implantation and may be considered as an enhancement/stabilizing procedure