Corneal Endothelial Status 12 to 55 Months after Excimer Laser Photorefractive Keratectomy

• Published in: Ophthalmology (Rochester, Minn.) Vol. 102; no. 4; pp. 544 - 549
• Main Authors: Mardelli, Pierre G., Piebenga, Larry W., Matta, Camille S., Hyde, Lawrence L., Gira, Joseph
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.04.1995
• Subjects: Adult; Cell Count; Cornea - surgery; Endothelium, Corneal - pathology; Female; Follow-Up Studies; Humans; Image Processing, Computer-Assisted; Laser Therapy; Longitudinal Studies; Male; Middle Aged; Myopia - surgery
• ISSN: 0161-6420; 1549-4713
• DOI: 10.1016/S0161-6420(95)30984-0

Purpose: To investigate the long-term effect (range, 12–55 months) of photorefractive keratectomy (PRK) on the human corneal endothelium. Methods: Specular microscopy of the central corneal endothelium was performed on 106 patients who underwent PRK to correct myopia. The duration of follow-up varied from 12 to 55 months (mean, 33 months; median, 37 months). Patients were divided in two groups: group 1 included 32 patients (35 treated eyes) with preoperative and postoperative central endothelial images; group 2 included 26 patients from group 1 and 74 additional patients with postoperative central endothelial images of the treated and untreated fellow eyes. Results: In group 1, preoperative and postoperative values were as follows: mean cell density (± standard deviation), 2950 ± 329 cells/mm2 and 2907 ± 337 cells/mm2, respectively (P = 0.43); polymegathism index, 0.29 ± 0.06 and 0.28 ± 0.05, respectively (P = 0.38); pleomorphism index, 65.8% ± 5.6% and 64.2% ± 5.6%,respectively (P = 0.22); figure coefficient index, 0.86 ± 0.05 and 0.87 ± 0.02, respectively (P = 0.20). In group 2, postoperative values of the treated and untreated eyes were as follows: mean cell density, 2912 ± 363 cells/mm2 and 2922 ± 434 cells/mm2, respectively (P = 0.86); polymegathism index, 0.28 ± 0.05 and 0.30 ± 0.08, respectively (P = 0.04); pleomorphism index, 64.93% ± 7.49% and 64.07% ± 8.31 %,respectively (P = 0.45); figure coefficient index, 0.88 ± 0.03 and 0.88 ± 0.03, respectively (P = 0.79). Conclusions: Photorefractive keratectomy caused no damage to the central corneal endothelium. Polymegathism differences in treated and untreated eyes could be attributed to modifications in corneal metabolism or to a yet unknown mechanism.