Zig Zag versus Top Hat configuration in IntraLase-enabled penetrating keratoplasty

Aim: To compare the outcomes with IntraLase-enabled keratoplasty using (IEK) Top Hat (TH) versus Zig Zag (ZZ) configuration. Methods: Retrospective comparative series of 24 eyes that underwent TH and 10 eyes that underwent ZZ IEK. Results There were no significant differences in LogMar Best-spectacle corrected visual acuity (TH- IEK=0.3; ZZIEK= 0.18, p=0.18), spherical equivalent (TH-IEK= -3.55 ±3.7 dioptres (D); ZZ-IEK=-2.69±4.85 D, p=0.60), manifest cylinder (TH- IEK=3.79±2.43 D; ZZ- IEK=4.61 ±3.29 D, p=0.45), topographic astigmatism (TH-IEK=3.67±2.34 D; ZZ-IEK=4.26±1.1 D, p=0.63), total higher-order aberrations (TH- IEK=8.26±3.53; ZZ-IEK=8.1±4.71, P=0.92), endothelial cell density change from baseline (TH- IEK= - 41.55%±15.86; ZZ-IEK=-25.45%±30. 66, p=0.22) or time to suture removal in months (TH- IEK=7.48±4.07; ZZ- IEK=6.93 ±2.71, p=0.75). There was no difference in requirements for astigmatic keratectomy (TH-IEK=54.2% ±13; ZZ-IEK=50%±5, OR=1.18) or complications (TH-IEK=25%±6; ZZ-IEK=30%±3, OR=0.78). Conclusions: TH-IEK and ZZ-IEK have comparable visual and refractive outcomes, wound healing and endothelial cell counts at 1-year.