Response of the posterior corneal surface to laser in situ keratomileusis for myopia
- 1 January 2005
- journal article
- Published by Ovid Technologies (Wolters Kluwer Health) in Journal of Cataract & Refractive Surgery
- Vol. 31 (1), 61-71
- https://doi.org/10.1016/j.jcrs.2004.09.032
Abstract
To describe the response of the posterior corneal surface in laser in situ keratomileusis (LASIK) and determine whether residual stromal bed thickness or treatment magnitude is predictive of the posterior corneal surface elevation after uneventful LASIK. A private hospital-based refractive surgery practice, Hong Kong SAR, China. Orbscan I (Bausch & Lomb) videokeratography examinations were performed on 1124 patients before and 6 months after LASIK for myopia (mean -6.81 diopters [D] +/- 2.52 [SD]; range -0.88 to -14.50 D). The best-fit sphere (BFS) over the central 9.0 mm region of the posterior corneal surface before and after treatment was compared. The location and magnitude of the 1.0 mm diameter region of highest elevation above the BFS for the central 4.0 mm diameter zone were calculated before and after treatment and compared using a paired t test. Stepwise regression was used to model the best predictors of the posterior radius of the BFS and the central elevation of the corneal surface above the BFS before and after treatment. The mean radius of curvature of the posterior surface BFS decreased 0.10 mm after LASIK, from 6.31 to 6.21 mm (P<.001). Elevation above this BFS was increased 10 microm within a 1.00 mm diameter region of interest, and this was correlated with postoperative corneal thickness, inferotemporal decentration of the highest point, residual myopia, and steeper central posterior radius of curvature. No eye was diagnosed with corneal ectasia at the time of the 6-month postoperative visit. After LASIK, there was a decreased radius of curvature for the BFS of the posterior corneal surface, with the highest elevation point located paracentrally. These findings are similar to the anterior corneal surface changes observed in corneal ectasia after LASIK but smaller in magnitude.Keywords
This publication has 16 references indexed in Scilit:
- Characteristics of Corneal Ectasia After LASIK for MyopiaCornea, 2004
- Early spatial changes in the posterior corneal surface after laser in situ keratomileusisJournal of Cataract & Refractive Surgery, 2003
- Risk factors and prognosis for corneal ectasia after LASIKOphthalmology, 2003
- Keratectasia after laser in situ keratomileusis (LASIK): evaluation of the calculated residual stromal bed thicknessAmerican Journal of Ophthalmology, 2002
- Corneal ectasia induced by laser in situ keratomileusisJournal of Cataract & Refractive Surgery, 2001
- Contact lens fitting in a patient with keratectasia after laser in situ keratomileusisJournal of Cataract & Refractive Surgery, 2001
- Factors affecting the forward shift of posterior corneal surface after laser in situ keratomileusisOphthalmology, 2001
- The Repeatability of Corneal Thickness MeasuresCornea, 2000
- Iatrogenic keratectasia after laser in situ keratomileusis for less than −4.0 to −7.0 diopters of myopiaJournal of Cataract & Refractive Surgery, 2000
- Iatrogenic keratectasia after LASIK in a case of forme fruste keratoconusJournal of Cataract & Refractive Surgery, 1998