Posters

The results of corneal cross-linking in the treatment of keratoconus

Poster Details

First Author: S.Sefic-Kasumovic BOSNIA AND HERZEGOVINA

Co Author(s):    S. Pavljašević   E. Čabrić   M. Jankov        

Abstract Details

Purpose:

To estimate CXL not only as a tretment to heal and increase the corneal stability then to consider it as a refractive procedure.

Setting:

Eye clinic 'Dr. Sefic' in Bosnia and Herzegovina.

Methods:

Keratoconus is a condition of cornea caracterised by asymetric, bilateral, progressive and noninflamatory ectasia due to the instability of cornea. The prevalence in general population is 50-200 per 100 000(1). 20% of patients suffer of severe visual deterioration due to irregular astigmatism, myopia and corneal scaring. In many cases spectacles and rigid gas permeabile contact lenses do not offer and visual improvement (2). Corneal cross-linking with riboflavin and UVA (CXL) is a standard clinical technique of corneal tissue strengthening that combines the use of riboflavin and UVA irradiation. Riboflavin works as a fotosensitizer for the induction of cross links between collagen fibrils and at the same time act as a shield from the penetration of UVA in the underlying tissues (3). CXL, as a primary intervention, should be considered to potentially incrrease the biomechanical stability of the corneal tissue and postopone the need of lamellar or penetrating keratoplasty, 28 eyes of 22 patients with progressive keratokonus were enrolled in prospective comparative study. Average follow up was 9 +- 2 month (range 5 to 12 months). The worse eye was treated with collagen cross linking and the fellow eye served as the control. Corneal epithelium was mechanically removed. Riboflavin 0,1 % solution in Dextran T -500 20% solution was applied every 2-3 minutes for 30 minutes throught the irradiation, Ultraviolet A irradiation (370 nm) was performed using a commercially available UVA lamp for 30 minutes. After the treatment , the local antibiotic was applied and the bandage contact lens was fit to anterior cornea until final re-epitalization. The bandage contact lens was removed 3 days postoperatively. Topical steroid and antibiotics drops were administered for four times daily with gradual decrease of dosage over the following 2 months.

Results:

The UCVA before the operation was 0,12 (0,09 -0,32) and was statistically significant higher according to UCVA one month after the CXL treatement 0,1 (0,1-0,25) respectively (p= 0,003). Three months later UCVA was 0,1 (range 0,1 -0,3) and was not statistically significant according to results before or one month later after the treatement. 6 months later UCVA was 0,2 ( range 0,1 -0,5) and was significant higher to UCVA one month after the operation but not different to the results of UCVA before the CXL and three months later. The BCVA of the patients before the treatement was 0,4 ( range 0,2 -0,6) . It was statistically higher one month later 0,3 ( range 0,2-0,4). The difference was statistically relevant ( p=0,032). Three months later BCVA was 0,6 (range 0,4-0,8). The result shows statistically relevant differrence ( p= 0,048). The result was similar one month after the treatement (p= 0,0004). The BCVA 6 months after CXL was 0,8 ( range 0,57 -1,0) and was extremelly higher then before the intervention ( p= 0,003), one month after CXL ( p= 0,001) and significantlly higher threee months later ( p=0,011).

Conclusions:

When compared to other treatment methods for keratoconus such as penetrating keratoplasty, deep lamelar keratoplasty, intracorneal rings , the corneal cross-linking shows evident reduction in spherical equivalent refraction, cylinder and max K. The collagen cross-linking method used in the present study stops or slows down the progression of keratoconus. According the results of our study the CXL is not only the procedure for corneal tissue streghthening then the procedure which results with the improval of BCVA even UCVA. These findings are opening the new view to the benefits of CXL. FINANCIAL INTEREST: NONE