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    AAO 2020 Video Program
    Refractive Mgmt/Intervention

    The 3Z application was developed for accurate Contoura Vision surgery planning, for optimal outcome in complex cases where there is a mismatch between Topolyzer and manifest refraction using an inbuilt artificial intelligence (AI) algorithm that was computed using experience from 150 surgeries. Three treatment groups were made using the 3Z rule (zonules and accommodation, Zernike analysis, zero rule for ablation). Zero rule by definition means changing the modified refraction to 0. The application considers Topolyzer and manifest refraction with minimum and maximum ablation thicknesses from Contoura. After three months, no patient had a loss of line compared to preoperative best corrected visual acuity (BCVA). Seventy percent of patients were found to gain two lines in BCVA. One hundred percent of patients showed postoperative uncorrected visual acuity of 20/20. All patients had residual astigmatism of <0.5 D. The change in defocus was significantly lower in Group 3 compared to Groups 1 and 2 (P = .02). Change in lower-order root mean square (RMS) was significantly different between Group 3 and Group 2 (P = .01). None of the other ocular aberrations, including higher order RMS, changed during accommodation irrespective of the study groups (P > .05).