THE CORNEAL ENDOTHELIUM 12 MONTHS AFTER PHOTOREFRACTIVE KERATECTOMY IN HIGH MYOPIA

Purpose: To determine if photorefractive keratectomy with a 193 nm exc imer laser could cause human corneal endothelial changes, mainly in hi gh dioptric treatments. Methods: 18 patients underwent a treatment ran ging from 7 to 13 diopters at the corneal apex (mean 10.3 +/- 1.4 SD) with an estimated corneal thinning ranging from 62 to 116 microns (mea n 90.7 +/- 12 SD). In these patients a comparison between the number a nd shape of the corneal endothelial cells has been performed before an d 12 months after PRK. Results: The mean cell density was 2818 +/- 337 mm(2), before surgery, and 2894 +/- 301 mm(2) after 12 months. The po lymorphic index was 79.0 +/- 2.3, before surgery, and 81.0 +/- 5.0 aft er 12 months with no significant changes (p = 0.16 and P = 0.09, respe ctively). Conclusions: These results shaw that photorefractive keratec tomy does not cause any significant observable damage to the central c orneal endothelium up to 12 months after surgery, even in high myopic treatments.