Abstract
Abstract: :
Purpose: To measure corneal autofluorescence after LASIK. Changes in corneal autofluorescence are thought to originate from changes in corneal metabolism. LASIK results in decreased ocular sensitivity accompanied by a decrease in aqueous tear production that could affect corneal metabolism. Methods: Corneal autofluorescence was measured in 36 eyes of 19 patients before and one day, one week, one month, six months and eighteen months after correction of myopia by LASIK (mean preoperative spherical equivalent -4.6 +/-1.86 D). Autofluorescence of the cornea was measured with a fluorophotometer (Fluorotron Master (OcuMetrics Inc)) fitted with an anterior segment adapter. Three fluorophotometrics scans of each cornea were carried out to determine mean corneal autofluorescence. Central corneal pachymetry was measured using an ultrasonic pachometer before and eighteen months after LASIK. Statistical analysis: Repeated analysis of variance measurements and Pearson's correlation coefficient Results: Mean corneal autofluorescence values were as follows: 11,9 +/- 2,06, 11,24+/-2,02, 11,48+/-2,09, 11,08+/-1,73, 9,98+/-2,08 and 10,43+/-1,49 ng eq/ml preoperatively and one day, one week, one month, six months and eighteen months after LASIK. Mean corneal autofluorescence value at each interval after LASIK was significantly decreased from preoperative level. Mean corneal autofluorescence value at six months was significantly decreased from the value at one month. Preoperative mean pachymetry was 540,94+/-36,78 microns and postoperative mean pachymetry was 465,48+/-49,03 microns. There was no significant correlation between the change in corneal autofluorescence and the change in pachymetry. Conclusion: Mean corneal autofluorescence values significantly decreased after LASIK, showing no correlation with the change in pachymetry. This decrease in corneal autofluorescence could represent a change in corneal metabolism after LASIK.
Keywords: 548 refractive surgery: LASIK • 369 cornea: clinical science • 467 metabolism