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; ZZ-IEK=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.