Abstract
Purpose :
Corneal astigmatism after penetrating keratoplasty (PKP) is among the most common causes of suboptimal vision in the presence of a clear graft. We evaluated the effectiveness and safety of the toric intraocular lens (IOL) in managing astigmatism in stable grafts after corneal transplant.
Methods :
We conducted a retrospective review of 51 eyes in 47 patients with previous PKP followed by phacoemulsification and toric IOL implantation (Acrysof SN6AT, T3-T9; Alcon, Fort Worth, TX). Prior to cataract surgery, each graft demonstrated significant residual astigmatism after full suture removal. Primary outcomes included uncorrected and corrected distance visual acuity (UDVA, CDVA), manifest refraction spherical equivalent (MRSE), and manifest refraction astigmatism. When applicable, the paired and unpaired T-test was used to compare subgroups.
Results :
Mean length of follow up after cataract surgery was 18.9 ± standard deviation 13.8 months. A significant improvement in UDVA (logMAR 1.14±0.434 to 0.431±0.253, p<0.001) and CDVA (logMAR 0.419±0.404 to 0.199±0.156, p<0.001) occurred from the preoperative to last postoperative visit after IOL implantation. Average UDVA and CDVA did not change significantly from the postoperative 1 month (logMAR 0.419±0.214, 0.185±0.144) to the final postoperative visit (p=0.78 and 0.64 respectively). Mean MRSE improved significantly from -1.70±5.54 diopters(D) to -0.04±1.21 D (p=0.041), and this remained stable between the postoperative 1 month (-0.185±1.07 D) and final visit (p=0.530). Manifest refraction astigmatism improved from 3.73±1.92 D to 1.88±1.06 D (p<0.001) and did not change significantly from the postoperative 1 month (1.45±1.37 D) to final visit (p=0.09). No IOL required realignment after surgery. Four eyes (7.8%) experienced a single episode of mild graft rejection post-IOL implantation at 2, 3, 4, and 10 months respectively; all of which resolved quickly with topical steroids. No episode of major graft rejection occurred. Postoperatively, best CDVA was 20/40 or better in 96% of eyes, and UDVA was 20/40 or better in 51% of eyes.
Conclusions :
Implantation of toric IOLs during cataract surgery in eyes with residual astigmatism after PKP and full suture removal effectively reduces manifest refraction astigmatism and improves UDVA and CDVA. These improvements were stable over the duration of follow up. The few episodes of graft complications were mild and easily managed.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.