Comparison Of The Post Operative Objective Scatter Index And Quality Of Vision Following Smile Versus Eyecryl Phakic Intraocular Lenses For Correction Of High Myopia And Astigmatism.

To objectively study and compare, the post-operative visual quality using the OQAS (HD Analyzer) in eyes undergoing Eyecryl phakic IOL (EPIOL) (Biotech Vision Care, Luzern, Switzerland) implantations vs SMILE Pro (Carl Zeiss Meditec, Jena, Germany) for high  myopia and myopic astigmatism, and 

To evaluate the effect of decentration of the central hole (with respect to the pupillary center) in the EPIOL group and treatment decentration in the SMILE Pro group and its effect on objective scatter index (OSI)

Nethradhama Superspeciality Eye Hospital, Bangalore, India

This prospective study included 60 eyes of 60 non-consecutive patients in the EPIOL and Smile groups that met the inclusion criteria. The eyes were evaluated preoperatively for their OSI, Modulation transfer function (MTF), Non-invasive tear breakup time(NIBUT), and optical aberrations. Postoperatively on Day 1, 2 weeks, and 3 months both groups were evaluated for OSI, MTF, NIBUT, and aberrations, An undilated anterior segment photo was taken for the EPIOL to note decentrations, and intraoperative treatment decentration was noted  for the Smile group. A subjective questionnaire to score the post-operative haloes and glare was also taken by patients in both groups. 

The pre-op indices were comparable between the groups. The post-op OSI was significantly higher in the SMILE group at each follow-up stage (p <0.001). MTF was significantly higher in the EPIOL group at post-op day 1 (p- 0.02) but the difference was not significant at 2 weeks and 3 months. NIBUT was statistically better in the EPIOL group on days 1 and 2 weeks (p- 0.01, 0.04). Higher order, spherical aberrations, and coma were greater in the Smile group on days 1 and 2 weeks. Mean decentration was 0.5±0.24 in the EPIOL group with no effect on the post-op OSI, and 0.15±0.08 in the Smile group with a strong positive correlation to OSI (p < .00001). Glare and halo profiles were better in the EPIOL group but were statistically insignificant. 

The postoperative visual quality in the EPIOL group was significantly better than the SMILE group in patients with high myopia. EPIOL decentration did not seem to affect the OSI, however, decentration of treatment significantly correlated with the intraocular scatter after SMILE.