John S M Chang1, Silvania Y F Lau. 1. Guy Hugh Chan Refractive Surgery Centre, Department of Ophthalmology, Hong Kong Sonatorium and Hospital, Happy Valley, Hong Kong. johnchangsm@gmail.com
Abstract
PURPOSE: to investigate the refractive outcomes and stability of conductive keratoplasty (CK) for retreatment of myopic LASIK overcorrection. METHODS: seven eyes (six patients) that were overcorrected after myopic LASIK by +1.00 to +2.75 diopters (D) manifest refraction spherical equivalent (MRSE) were retreated using CK. All eyes had insufficient stromal thickness for LASIK retreatment. LightTouch CK was performed at least 1 year after LASIK. Either 8 or 16 spots were applied at 7- and/or 8-mm zones on the cornea. Uncorrected distance visual acuity, manifest refraction, corrected distance visual acuity (CDVA), and postoperative complications were analyzed. RESULTS: mean MRSE after CK at last follow-up was +0.38 ± 0.52 D (range: -0.38 to +1.13 D). The change in MRSE ranged from -0.63 to -2.38 D. Mean MRSE after CK changed from -0.60 ± 2.07 D (range: -3.38 to +1.50 D) at 1 week to +0.45 ± 0.69 D (range: -0.38 to +1.38 D) at 12 months. Two eyes experienced an initial overcorrection of -2.75 D and -3.38 D, respectively, at 1 week after CK. Cylinder ≤0.75 D was induced in four eyes, whereas one eye had a 0.75-D reduction in cylinder. All eyes had CDVA of logMAR 0.10 or better. Two eyes lost one line of CDVA and no eyes lost more than one line. CONCLUSIONS: lighttouch CK retreatment for over-corrected myopic LASIK can reduce the hyperopia but produces minimal change in cylinder, and may be appropriate for eyes with insufficient stromal tissue for repeated excimer laser surgery. Early regression occurs commonly.
PURPOSE: to investigate the refractive outcomes and stability of conductive keratoplasty (CK) for retreatment of myopic LASIK overcorrection. METHODS: seven eyes (six patients) that were overcorrected after myopic LASIK by +1.00 to +2.75 diopters (D) manifest refraction spherical equivalent (MRSE) were retreated using CK. All eyes had insufficient stromal thickness for LASIK retreatment. LightTouch CK was performed at least 1 year after LASIK. Either 8 or 16 spots were applied at 7- and/or 8-mm zones on the cornea. Uncorrected distance visual acuity, manifest refraction, corrected distance visual acuity (CDVA), and postoperative complications were analyzed. RESULTS: mean MRSE after CK at last follow-up was +0.38 ± 0.52 D (range: -0.38 to +1.13 D). The change in MRSE ranged from -0.63 to -2.38 D. Mean MRSE after CK changed from -0.60 ± 2.07 D (range: -3.38 to +1.50 D) at 1 week to +0.45 ± 0.69 D (range: -0.38 to +1.38 D) at 12 months. Two eyes experienced an initial overcorrection of -2.75 D and -3.38 D, respectively, at 1 week after CK. Cylinder ≤0.75 D was induced in four eyes, whereas one eye had a 0.75-D reduction in cylinder. All eyes had CDVA of logMAR 0.10 or better. Two eyes lost one line of CDVA and no eyes lost more than one line. CONCLUSIONS: lighttouch CK retreatment for over-corrected myopic LASIK can reduce the hyperopia but produces minimal change in cylinder, and may be appropriate for eyes with insufficient stromal tissue for repeated excimer laser surgery. Early regression occurs commonly.