EyeWorld Asia-Pacific September 2014 Issue

61 EWAP rEfrActivE September 2014 continued on page 64 40 patients were treated with lenticule extraction and 40 underwent femtosecond LASIK. No explanation was provided as to how and why patients were selected for either procedure. Lack of randomization in this prospective study limits validity of conclusions, although differences in gender, age, baseline manifest refraction, mean K and CCT between the two groups were not significant. Thirty-seven versus 34 eyes reached the 6-month follow- up mark in SMILE and LASIK groups, respectively. The fact that three additional patients— representing nearly 10% of the cohort—completed follow-up for SMILE may bias results in favor of SMILE. Measurements of corneal biomechanics were taken preoperatively and at postoperative week 1, and months 1, 3 and 6. Three measurements for each patient were obtained and then averaged for inclusion in statistical analysis. No data was provided in regard to the variation of the three measurements for each patient, and if significant, could represent a major limitation. If variation in CH or CRF for each measurement approached the value of delta between the two groups, then no conclusion can really be drawn from the data. Postoperative CH and CRF decreased in both groups, and values for the SMILE group were higher at each postoperative time point. Baseline CH and CRF values were not provided; however, Figure 2 in the paper suggests that the lenticule extraction group started off with slightly higher CH and CRF, making comparison of postoperative difference between groups difficult. The delta CRF and CH per patient seems to be the most relevant comparison for the paper, as less of a change from baseline would be preferred no matter the value or specific application of the property. Only the delta CRF values reached significance in this comparison and came out in favor of SMILE (i.e., less of a decrease in CRF postoperatively). The mechanism proposed by the authors is the greater weight on P1 (initial applanation event) in calculating CRF and potential contribution of the anterior stroma to this value. Correlation between residual stromal thickness (RST) index and // TRUE LIVING VISION MADE BY ZEISS True Living Vision becomes reality with ZEISS AT LISA ® tri and ZEISS AT LISA tri toric. Excellent near, far and intermediate vision. Under all light conditions. For maximized independency from spectacles. Stay in touch with latest development in ophthalmology. Gain hands-on expertise in the ZEISS Cataract Experience Theater. www.meditec.zeiss.com/escrs-2014 The moment you help your patients see the whole picture. This is the moment we work for. ZEISS AT LISA tri and ZEISS AT LISA tri toric are not available for sale in the U.S.