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Comparative Study between Conventional and Custom Lasik Ablation in The Treatment of Myopic Astigmatism

Background: The popularity of laser-assisted in situ keratomileusis (LASIK) stems from its ability to treat a wide range of refractive errors with rapid visual recovery and minimal patient discomfort. The conventional treatment is a Munnerlyn based spherocylindrical ablation, Customized Ablation is a topography and wavefront guided ablation treating corneal high-order aberrations Objective: to evaluate the visual and refractive outcomes of customized ablation and conventional ablation in the treatment of myopic astigmatism. Patients and Methods: This randomized prospective comparative study was carried out on 60 eyes of 34 patients with compound myopic astigmatism (myopic sphere ≤ -10.0 D and myopic cylinder ≤ - 4.0D) with age range between 18 and 50 years at Al-Azhar University Hospital, Assuit and Al-Nahar Eye Centre, Assuit, between April 2018 and October 2018. These patients were divided into two groups: Group (1) included 30 eyes of 18 patients who had Standard LASIK ablation. Group (2) included 30 eyes of 16 patients who had WFG (Custom) LASIK ablation. Results: Regarding the refractive safety, both procedures were highly safe (all the patients maintained the preoperative BSCVA in the 6th month). It was obvious that the WFG LASIK was superior to the conventional LASIK in the visual outcome and this can be approved by applying the efficacy index for the procedures (mean postoperative UCVA/mean preoperative BSCVA), and it was 1.14 in the custom group and 0.97 in the conventional group in the 1st month. Improving the visual acuity after custom LASIK, in spite of similar refractive results (predictability) indicates that not only the defocus, but also the high order aberrations affect the final visual acuity level. Conclusion: the two procedures have high degree of safety, refractive stability and predictability but the custom LASIK is superior to the conventional LASIK.