[Corneal cross-linking--modern method of keratoconus treatment]

The aim of research study was to evaluate the effect of corneal cross-linking (CXL) in the frame of patients with progressive keratoconus 1 year after treatment.

There were 40 eyes of 35 patients with mean age 28, 45 +/- 9.3 (SD) (15 to 48 years) included in the study. Patients were treated with standard protocol of CXL with abrasion of corneal epithelium. Complete ophthalmological examination included best corrected spectacles visual acuity (BCSVA), slit-lamp microscopic finding, corneal topography and corneal thickness measured with ultrasound method was performed before, on the 5-th day, 1. 6., 12. month after CXL. We divided patients according to the stage of keratoconus into 2 groups (stage I. and stage II.) and according to the age into 3 groups (until 20, from 21 to 39, over 40 years).

In all treated eyes, the CXL was without relevant complications. The only complication was stromal haze of cornea. In the evaluation based on stage of keratoconus, in the first group any patient became a haze of cornea in 1 year after CXL. In the second group 35.7% of patients had a haze of cornea. The average BCSVA 1 year after treatment was improved in the 1. group about 5.38 letter and in the 2. group about 1.25 letter. Topographic analysis showed decrease of simulated keratometry and refraction (1. group--0.1 D, 2. group--0.17 D), maximal keratometry and refraction (1. group--0.67 D, 2. group--0.76 D). Minimal keratometry and refraction in the 1. group decreased (1.17 D) and increased in the 2. group (1.09 D). In the evaluation based on the age was haze monitored in the first group one year after CXL in 12.5% of researched eyes. In the second group was haze of cornea in 20% of eyes and in the third group consisting of patients over 40 years old, in 50% of eyes. The average BCSVA was improved in the 1. group (2.85 letter), and in the 2. group (3.68 letter).The average BCSVA was decreased in the oldest patients in about 1.43 letter. In the 1. and 2. group the topographic analysis showed decrease of simulated keratometry and refraction (1. group--0.12D, 2. group--0.21D), maximal keratometry and refraction (1. group--1.13 D, 2. group--0,68D), minimal keratometry and refraction (1. group--1.17D, 2. group--0,69 D). In the 3. group the topography analysis showed increase of simulated keratometry and refraction (0,8D), maximal keratometry and refraction (0,98D), minimal keratometry and refraction (0,28D). Corneal pachymetry remained stable in all researched groups of patients.

CXL is considered as safe procedure to stop progression of keratoconus also for patients until 19 years old. The best effect and minimal complications were by patients until 40 years old and by patients with the I. grade.