Abstract
Purpose: :
To evaluate prospectively the course of keratoconus, a corneal noninflammatory ectatic degeneration with progressive asymmetric and mostly bilateral thinning, by means of uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), and corneal topography/keratometry (k-readings) pre- and postoperatively after corneal collagen crosslinking therapy, the latest developed procedure which is a combined Riboflavin/UVA treatment to prevent penetrating keratoplasty in patients with keratoconus.
Methods: :
15 patients with keratoconus who were treated with corneal crosslinking (combined UVA/Riboflabin therapy) were examined according to a standardized protocol including slit-lamp examination, biomicroscopy, pre- and postoperative UCVA and BCVA, central corneal pachymetry and refraction. Examinations were performed preoperatively, one, three and 6 months postoperatively. Evaluation of the keratoconus postoperatively was performed by means of clinical examination, VA and corneal topography. Course of VA and keratometry was evaluated by means of Wilcoxon-Test.
Results: :
15 patients age ranging from 17 to 61 years (mean age 36,8 years) were treated with a collagen crosslinking therapy. The range of BCVA was from 0.3 to 1.0 preoperatively (pre), one, three and six months postoperatively (po). The median BCVA improved from 0.6 (pre) over 0.7 (1 month po; p=0.79), 0.75 (3 month po;p= 0.46) to 0.8 (6 month po; p=0,08). After 6 month the procedure caused a myopic shift (refraction) in 50 % and a hyperopic shift in 50%. The shift was from -3.3 dpt to +2.25 dpt (median= 0 dpt); p=0,96. Topography showed an average Ks of 50.85 dpt (pre), 49.76 dpt. (1 month po), 48.91 dpt. (3 month po) and 50.16 dpt. (6 month po). The K-readings didn't show any statistically significant changes.
Conclusions: :
Combined UVA/Riboflavin crosslinking of the cornea in patients with keratoconus seems to be a useful procedure to avoid progression and thus penetrating keratoplasty. The procedure shows a trend for an amelioration of BCVA.
Keywords: keratoconus • topography • visual acuity