Abstract
Purpose: :
To assess whether cross-linking, already shown to be effective in arresting progressive keratoconus, can also be used to treat post-LASIK ectasia.
Methods: :
Thirteen eyes from 5 female and 8 male patients (mean age 42±8.2 years) with topographically documented progressive post-LASIK ectasia were treated with cross-linking. The standard treatment procedure was used, applying riboflavin 0.1% following epithelial abrasion. The cornea was then irradiated with UVA light. The eyes were monitored for a minimum of 12 months. Best spectacle corrected visual acuity (BSCVA), topography, cornea thickness and corneal volume were documented at regular intervals.
Results: :
At 12 months after cross-linking, mean BSCVA had significantly improved from 0.73±0.57 to 0.83±31 (decimal scale). Topography maps showed examples of markedly reduced steepest points as early as 4 months following treatment, as well as stability of keratometry readings over 6 months and more. Mean central corneal thickness decreased significantly (p<0.05) from 425±26 µm prior to cross-linking to 402±24 µm at one year. Corneal volume also decreased significantly (p<0.05) from a preoperative 57.97±4.82 mm3 to 54.16±3.02 mm3 at 12 months postoperatively.
Conclusions: :
Cross-linking appears to be effective in arresting progressive post-LASIK ectasia. The parameters used to monitor the action of cross-linking on keractasia reflect results very similar to those obtained when treating progressive keratoconus. This finding may be explained by the observation that the chronic biomechanical failure process involved in post-LASIK ectasia is similar to that seen in keratoconus.
Keywords: cornea: clinical science • refractive surgery: LASIK