Femtosecond laser versus Manual dissection for Top hat penetrating Keratoplasty

Abstract

Purpose: to compare the outcomes of intraLase enabled top hat penetrating keratoplasty (IEK) versus retrospective results of manual top hat penetrating keratoplasty (TH-PKP) and conventional PKP.

Patients/Methods: This non-randomized prospective study included 94 eyes: 23 eyes underwent IEK, 36 TH-PKP and 35 conventional PKP.

Preoperative and postoperative manifest refraction, uncorrected and best-spectacle corrected visual acuity (BSCVA), high order ocular aberrations (HOA), endothelial cell counts and complications were analyzed.

Results: At 12 months of follow up, mean log MAR BSCVA was 0.32±0.31 in the IEK group, 0.53±0.36 in the TH PKP group (p=0.03) and 0.39±0.30 in the conventional PKP group (p=0.4). Mean spherical equivalent was similar between the groups and was less than -2.2 Diopters. Mean cylinder was similar in the IEK and conventional PKP group (3.6±1.9 Diopters and 4.1±1.8 Diopters , respectively), and was significantly lower than the TH-PKP group. (5.1±3.2 Diopters, p=0.04).

Complications rate and high order ocular aberrations were similar between the three group studied. Mean endothelial cell loss were significantly higher at 12 months of follow up in the IEK and the TH-PKP groups versus conventional PKP. (32.4% and 22.3% versus 40.8%, respectively) (P=0.05).

Mean time to suture removal was 4.1±1.2 months in the IEK group and 3.9±1.5 months in the TH-PKP group versus 9.7±1.1 months in the conventional PKP group. (P<0.0001)

Conclusions: IEK is a safe and stable procedure. It results in higher endothelial counts and faster suture removal in comparison to the conventional PKP, and has less astigmatism and better BSCVA in comparison to the manual TH-PKP.