Safety and efficacy of femtosecond laser-assisted arcuate keratotomy to treat irregular astigmatism after penetrating keratoplasty

PURPOSE: To determine the refractive efficacy, predictability, stability, and complication rate of Intralase femtosecond laser assisted astigmatic keratotomy (AK) for irregular astigmatism after penetrating keratoplasty (PKP). SETTING: Ophthalmology Department, Hotel-Dieu, Paris, France. DESIGN: Retrospective case series. METHODS: Femtosecond laser assisted AK was performed to treat high irregular astigmatism (>5.0 diopters [D]) after PKP. The uncorrected (UDVA) and corrected (CDVA) distance visual acuities, manifest refraction, vector analysis, and complications were evaluated. RESULTS: The study evaluated 62 eyes of 57 patients over a mean follow-up of 28 months +/- 3.5 (SD). Preoperatively, the mean CDVA was 0.51 +/- 0.26 logMAR and the mean UDVA was 0.98 +/- 0.24 logMAR; 6 months postoperatively, the mean CDVA and UDVA improved to 0.40 +/- 0.22 logMAR and 0.60 +/- 0.2 logMAR, respectively (both P <.01). The mean preoperative absolute astigmatism was 7.1 +/- 1.72 D; 6 months postoperatively, the mean refractive astigmatism was 2.6 +/- 2.4 D (P<.001). The UDVA, CDVA, and astigmatism remained stable up to the end of follow-up. The efficacy index was 0.81 at 6 months and 0.67 at 2 years. There were 2 cases of microperforation, 3 cases of infectious keratitis, 3 graft rejection episodes, and 1 case of endophthalmitis. Overcorrection occurred in 12 eyes. CONCLUSIONS: Femtosecond laser assisted AK was effective in reducing irregular astigmatism after PKP. Predictability of astigmatism correction is variable over time with a decrease in the efficacy index 2 years postoperatively. Refinement of the treatment nomogram for femtosecond laser assisted AK for high astigmatism after PKP remains a major issue. (C) 2015 ASCRS and ESCRS