Abstract
Purpose: :
Photochemical collagen crosslinking with riboflavin and UV-A radiation (CXL) is reported to be a save procedure to stop keratectasia in progressive keratoconus. Nevertheless, due to the need of complete epithelial removal several cases of postoperative infectious keratitis have been reported. This risk can further be minimized when faster wound closure is achieved by performing linear abrasion instead of complete epithelial removal. The aim of this retrospective study is to evaluate the long-term effect of this novel CXL-procedure in terms of safety and prevention of keratoconus progression.
Methods: :
35 eyes were included after progression of keratoconus was confirmed by corneal topography and patient history. Epithelial removal was performed with 5-6 linear abrasions of about 1-2mm width each. Riboflavin 0.1% solution was instilled every 2 minutes for 30 minutes, followed by UV-A (365 nm) exposure for another 30 minutes under continuous application of riboflavin. Follow-up examinations after 3, 6 and 12 months included quantification of best corrected visual acuity (BCVA), corneal topography, endothelial cell count and central corneal pachymetry. Additionally, confocal microscopy was performed in 10 eyes at day 1, week 2, 4 and 12.
Results: :
In this study CXL showed no complications within follow-up time. Complete closure of the epithelium occurred at day 1 or 2 in all eyes. Central pachymetry (mean = 514.38µm ±38.29) and endothelial cell count (mean = 2317.47/mm² ±391.23) did not show a statistically significant change. The keratectasia (baseline: 50.96dpt±4.74) remained stable at 3 months (-0.67dpt), 6 months (-0.32) and 12 months (+0.285). BCVA was slightly decreased after 3 months, but returned to baseline values after 6 and 12 months (mean = 20/40).
Conclusions: :
This modified CXL-procedure allows a faster wound closure than the conventional aproach and further minimizes the risk of postoperative infection. These data confirm its capability of preventing the progression of keratoconus after 1 year, but do not show the minor improvements in keratometry values and BCVA as know from the literature.
Keywords: keratoconus • cornea: clinical science