JUN 28, 2019
Investigators report outcomes of wavefront-guided photorefractive keratectomy (WG-PRK) for high astigmatism after keratoplasty.
This retrospective study included 13 eyes from 12 patients with a history of penetrating (n=12) or deep anterior lamellar (n=1) keratoplasty. The average preoperative astigmatism was 3.98 D (range 3–5 D). Surgeons performed WG-PRK using the Wavescan wavefront aberrometer and the Star S4 IR laser platform (Abbott). Mitomycin C 0.02% was applied over the stroma for 12 to 60 seconds, according to the surgeon’s preference. Patients were followed for an average of 14 months.
Uncorrected distance visual acuity (UDVA) improved from 0.97 logMAR at baseline to 0.13 logMAR at 6 months and 0.14 logMAR at the final follow-up. By the last visit, almost all eyes had a UDVA greater than 20/40 and 6 eyes had a UDVA greater than 20/25.
The average astigmatism improved from -3.98 D to -1.27 D and -1.40 D at 6 months and final follow-up, respectively (both P=0.001). Preoperative astigmatism was greater than 3 D in all eyes but was less than 2.5 D in all eyes by 6 months; 7 eyes had astigmatism less than 1.0 D. The safety index was 1.050 at the final appointment and there were no intraoperative complications.
Two eyes required PRK enhancement approximately 6 months after WG-PRK to address residual refractive errors. Although there were no intraoperative complications, 1 patient developed anterior stromal haze and underwent phototherapeutic keratectomy 16 months after WG-PRK; this patient’s final follow-up data was included in the analysis. One patient had endothelial graft rejection 20 months following WG-PRK.
In this small cohort, WG-PRK was generally safe and effective in the treatment of high and regular post-keratoplasty astigmatism. A small percentage of eyes, however, needed enhancement to achieve the final desired outcome.