A preliminary study of the effect of iris registration on the clinical outcomes of wavefront-guided laser in situ keratomileusis (LASIK)

Objective To evaluate whether iris registration (IR) has any effect on the clinical outcomes of wavefront-guided laser in situ keratomileusis (LASIK).Methods 62 eyes of 31 consecutive myopic patients who had bilateral CustomVueTM LASIK but only one eye was iris registrated successfully were involved in the study. Visual acuity (BCVA), refraction and wavefront aberrations were examined before and after LASIK. The outcomes of eyes with successful iris registration and those of the fellow eyes were compared.Results No significant difference was found in the pre-operation examination between the eyes with successful iris registration and the fellow eyes. Both groups had a similar visual acuity after LASIK (P＞0.05 ). The predictablility was better in the groups with successful IR. The RMS of higher-order wavefront aberrations were increased in both groups after LASIK. Z40 (spherical aberration) was increased in both groups (P＜0.01 ), but Z31 ( coma aberration) and Z42 (secondary astigmatism) were only increased in the eyes with an unsuccessful IR. The post-LASIK increase of coma was lower in the eyes with successful IR (P＜0.05 ). The other higer-order wavefront aberration was changed similarly in both groups (P＞0.05 ). Conclusions Iris rehistration (IR) can prevent the increase of coma aberration for the wavefront-guided LASIK, but no significant effect of IR on other clinical outcomes has been found. Key words: Laser in situ keratomileusis (LASIK);  Iris Registration (IR);  Wavefront aberration