Topographic Changes of Posterior Corneal Surface after Photorefractive Keratectomy with Orbscan II(R) Topography.
- Author:
Sung Hyun KIM
1
;
Jae Ho CHO
;
Byung Joo SONG
Author Information
1. Department of Ophthalmology, Hanil General Hospital, Korea.
- Publication Type:Original Article
- Keywords:
Forward shifting;
Orbscan IIR topography;
PRK
- MeSH:
Cornea;
Humans;
Lasers, Excimer;
Photorefractive Keratectomy*
- From:Journal of the Korean Ophthalmological Society
2002;43(10):1858-1863
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
PURPOSE: To investigate the relationship of refraction, geometry of the posterior corneal surface and the residual corneal thickness after excimer laser photorefractive keratectomy. METHODS: Thirty eyes of 15 patients were treated with Star S2 Smooth Scan (VISX, U.S.A.) and followed up for 3 months. The refractive, anteroposterior changes in the posterior corneal surface and residual corneal thickness were measured using slit-scanning topography, Orbscan IIR (Orbtek, Bausch & Lomb) at 1 week preoperatively, and 1 and 3 months postoperatively. RESULTS: Mean forward shift of the posterior cornea surface was 8.83+/-1.34 micrometer, 11.53+/-4.23 micrometer and 14.70+/-3.50 micrometer at 1 week, 1 month, and 3 months respectively. Mean spherical equivalence of posterior cornea was = -7.01+/-0.31 D preoperatively; it changed to -7.17+/-0.47 D, -7.22+/-0.21 D and -7.17+/-0.6 D at 1 week, 1 month and 3 months. The degree of forward shift of posterior corneal surface is correlated with the posterior corneal refractive changes (r=-0.808, P< 0.01). The forward shift of the posterior corneal surface is correlated with the residual corneal thickness (r=-0.483, P< 0.01). CONCLUSIONS: Photorefractive keratectomy significantly influenced the forward shift of the cornea, which is correlated with the residual corneal thickness.
