LASIK for post penetrating keratoplasty astigmatism and myopia

Abstract

Aims-To report the results of a series of patients who were treated with LASIK to correct post penetrating keratoplasty ametropia. Methods-26 eyes of 24 patients underwent LASIK to correct astigmatism and myopia after corneal transplantation; 14 eyes also received arcuate cuts in the stromal bed at the time of surgery. The mean preoperative spherical equivalent was −5.20D and the mean preoperative astigmatism was 8.67D. Results-The results of 25 eyes are reported. The mean 1 month values for spherical equivalent and astigmatism were −0.24D and 2.48D respectively. 18 eyes have been followed up for 6 months or more. The final follow up results for these eyes are −1.91D and 2.92D for spherical equivalent and astigmatism. The patients undergoing arcuate cuts were less myopic but had greater astigmatism than those not. The patients receiving arcuate cuts had a greater target induced astigmatism, surgically induced astigmatism, and astigmatism correction index than those eyes that did not. One eye suVered a surgical complication. No eyes lost more than one line of BSCVA and all eyes gained between 0 and 6 lines UCVA. Conclusions-LASIK after penetrating keratoplasty is a relatively safe and eVective procedure. It reduces both the spherical error and the cylindrical component of the ametropia. Correction of high astigmatism may be augmented by performing arcuate cuts in the stromal bed. (Br J Ophthalmol 1999;83:1013-1018

Implantation of a customized toric intraocular lens for correction of post-keratoplasty astigmatism

“…At a mean follow-up of 17.2 months, the mean ECD was reduced to 1144 ± 282 cells/mm 2 , giving a mean reduction of 9.9%. No graft failure was observed in our study throughout the follow-up period.…”

“…For instance, PRK can result in irregularity of the corneal surface and has a high tendency of regression, 18 whereas LASIK has microkeratome-associated complications. 19 PE with toric IOL implantation for correcting post-PK astigmatism and cataract was first described in 1999 by Frohn et al 11 This was an exciting advancement as this approach allowed correction of both condition with one procedure. Subsequently, good post-operative visual and refractive outcomes had been consistently reported in several case reports.…”

“…It has been reported that astigmatism induced by PK can be as high as 4-6 diopters (D), 1,2,3 thus severely undermining the visual outcome following transplantation. A broad spectrum of therapeutic modalities has been proposed and employed to correct post-PK astigmatism.…”

“…Alternatively, treatments like selective suture removal, relaxing incisions, wedge resections, compression sutures, photorefractive keratectomy (PRK), and laser-assisted in situ keratomileusis (LASIK) all serve as feasible options in correcting astigmatism. [2][3][4][5] There is emerging evidence advocating the use of customized toric intraocular lens (IOL) as a novel approach to correct high post-PK astigmatism. 6,7 Not uncommonly, patients with post-PK astigmatism can also develop cataract in the previously operated eye at the later stage of their lives.…”

Management of Post-Penetrating Keratoplasty Astigmatism

“…28,60,[64][65][66] Factors that may influence the outcome of astigmatism treatment by LASIK other than the wound-healing process are the position of the hinge in relation to the location of the visual axis, flap diameter relative to the PK donor button diameter, and flap thickness. 55,67 In addition, corneal graft thickness and the amount of refractive error may limit the efficacy of the procedure. 68 The disadvantages include limited correction of astigmatism and potential for flap complications such as epithelial ingrowth, button hole, free or incomplete flaps 28,68 as well as an increased risk of photoablation-induced graft rejection [69][70][71] .…”