Abstract:  Objective To evaluate clinical efficacy after femtosecond laser-assisted in situ keratomileusis (FS-LASIK) myopia correction guided by 0.05 D optometry. Design Retrospective case series. Participants From July 2021 to March 2022, a total of 355 eyes of 178 myopic patients who underwent FS-LASIK surgery were collected in No.988 Hospital of Joint Logistic Support Force of PLA. Methods The medical records of patients were reviewed. The optometry test modality was determined by patients, and all patients were divided into the 0.05 D group (89 cases 177 eyes) and the 0.25 D group (89 cases 178 eyes) according to the method of optometry. The 0.05 D group used 0.05 D optometry method to measure preoperative diopter; meanwhile, the 0.25 D group used 0.25 D optometry method to measure preoperative diopter. All patients underwent FS-LASIK with Zeimer LDV-Z2 and Zeiss Mel-80. The actual corneal ablation depth of the both groups and the corneal ablation depth simulated by 0.25 D optometry of the 0.05 D group were recorded. The patients were followed up for 6 months. And the visual quality questionnaire was conducted at 6 months postoperatively. Main Outcome Measures Visual acuity (LogMAR), diopter, corneal ablation depth, central corneal thickness (CCT), and visual quality questionnaire score. Results The actual corneal ablation depth of the 0.05 D group was (84.98±15.60) μm, which was slightly higher than (78.14±17.68) μm simulated by 0.25 D optometry of the 0.05 D group and (75.42±17.14) μm of the 0.25 D group (all P<0.001). There was no significant difference in the corneal ablation depth between simulated by 0.25 D optometry of the 0.05 D group and the 0.25 D group (P=0.129). The CCT of the both groups after surgery was significantly lower than that preoperative (t=72.459, P<0.001, t=58.693, P<0.001), and there was no significant difference in the CCT between the both groups after surgery (t=-1.890, P=0.060). At 3 months and 6 months after surgery, the uncorrected visual acuity (UCVA) of the 0.05 D group were -0.056±0.498, -0.061±0.479, which were better than 0.003±0.566, -0.002±0.530 of the 0.25 D group (all P<0.001). At 6 months after surgery, the percentage of UCVA better than preoperative best corrected visual acuity (BCVA) of the 0.05 D group was 67.80%, which was higher than 17.42% of the 0.25 D group (P<0.001). Among the adverse visual symptoms, the incidence of glare was the highest and the incidence of distortion was the lowest in the both groups. The incidence of asthenopia of the 0.05 D group was 1.7%, which was less than 6.7% of the 0.25 D group (P=0.018). There was no significant difference in the incidence of other symptoms. The asthenopia and total score of the 0.05 D group were significantly lower than those of the 0.25 D group (U=-2.032, P=0.042, U=-2.247, P=0.025). There was no significant difference in the scores of the questionnaire of other symptoms. Conclusion Compared with 0.25 D optometry, 0.05 D optometry can significantly improve visual acuity and subjective visual quality after FS-LASIK, and has the same surgical safety. (Ophthalmol CHN, 2023, 32: 289-293)

Key words: femtosecond laser-assisted in situ keratomileusis, optometry, myopia