Zhiyuan Zheng1, Mingzhi Zhang1, Vishal Jhanji1,2, Lixia Sun1, Jinyu Li1, Riping Zhang3. 1. Joint Shantou International Eye Center of Shantou University and the Chinese University of Hong Kong, Shantou, 515041, China. 2. Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA. 3. Joint Shantou International Eye Center of Shantou University and the Chinese University of Hong Kong, Shantou, 515041, China. zrp@jsiec.org.
Abstract
PURPOSE: To evaluate the clinical outcomes of small incision lenticule extraction (SMILE) and aberration-free transepithelial photorefractive keratectomy (AF t-PRK) in patients with low to moderate myopic astigmatism, including visual acuity, refractive outcomes, astigmatic vector analysis and corneal aberrometric changes. METHOD: This retrospective comparative case series study involved 110 right eyes of 110 patients who underwent either SMILE (55 eyes) or AF t-PRK (55 eyes). Visual acuity, manifest refractive error and corneal higher-order aberrations (HOAs) were measured and analyzed at baseline, 1 month and 3 months after operation. The safety and efficacy indices, and vector parameters were also compared. RESULT: 1 month postoperatively, the mean uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA) and spherical equivalent refraction (SE) were better after SMILE than AF t-PRK (logMAR UDVA, - 0.03 ± 0.07 and - 0.006 ± 0.07, P = 0.050; logMAR CDVA, - 0.06 ± 0.07 and - 0.03 ± 0.07, P = 0.043; SE, - 0.04 ± 0.25 and 0.15 ± 0.26, P < 0.001). However, these parameters were comparable between the groups at 3 months after surgery. Residual astigmatism ≤ 0.25 diopters was observed in 74.5% and 90.9% (P = 0.023) of the eyes at one month and in 87.3% and 85.5% (P = 0.781) of the eyes at 3 months after SMILE and AF t-PRK, respectively. There were no significant differences between the groups in any of the vector parameters at 1 month or 3 months after surgery. Coma and total HOAs after SMILE were significantly higher than AF t-PRK (1 month coma, 0.49 ± 0.23 and 0.29 ± 0.15, P < 0.001; 1 month total RMS HOAs, 0.65 ± 0.20 and 0.54 ± 0.14, P = 0.001; 3 months coma, 0.50 ± 0.22 and 0.30 ± 0.17, P < 0.001; 3 months total RMS HOAs, 0.68 ± 0.20 and 0.55 ± 0.17, P < 0.001). CONCLUSION: In this study, both SMILE and AF t-PRK were effective and comparable for correction of low to moderate myopic astigmatism. AF t-PRK group induced less coma and total HOAs than SMILE.
PURPOSE: To evaluate the clinical outcomes of small incision lenticule extraction (SMILE) and aberration-free transepithelial photorefractive keratectomy (AF t-PRK) in patients with low to moderate myopic astigmatism, including visual acuity, refractive outcomes, astigmatic vector analysis and corneal aberrometric changes. METHOD: This retrospective comparative case series study involved 110 right eyes of 110 patients who underwent either SMILE (55 eyes) or AF t-PRK (55 eyes). Visual acuity, manifest refractive error and corneal higher-order aberrations (HOAs) were measured and analyzed at baseline, 1 month and 3 months after operation. The safety and efficacy indices, and vector parameters were also compared. RESULT: 1 month postoperatively, the mean uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA) and spherical equivalent refraction (SE) were better after SMILE than AF t-PRK (logMAR UDVA, - 0.03 ± 0.07 and - 0.006 ± 0.07, P = 0.050; logMAR CDVA, - 0.06 ± 0.07 and - 0.03 ± 0.07, P = 0.043; SE, - 0.04 ± 0.25 and 0.15 ± 0.26, P < 0.001). However, these parameters were comparable between the groups at 3 months after surgery. Residual astigmatism ≤ 0.25 diopters was observed in 74.5% and 90.9% (P = 0.023) of the eyes at one month and in 87.3% and 85.5% (P = 0.781) of the eyes at 3 months after SMILE and AF t-PRK, respectively. There were no significant differences between the groups in any of the vector parameters at 1 month or 3 months after surgery. Coma and total HOAs after SMILE were significantly higher than AF t-PRK (1 month coma, 0.49 ± 0.23 and 0.29 ± 0.15, P < 0.001; 1 month total RMS HOAs, 0.65 ± 0.20 and 0.54 ± 0.14, P = 0.001; 3 months coma, 0.50 ± 0.22 and 0.30 ± 0.17, P < 0.001; 3 months total RMS HOAs, 0.68 ± 0.20 and 0.55 ± 0.17, P < 0.001). CONCLUSION: In this study, both SMILE and AF t-PRK were effective and comparable for correction of low to moderate myopic astigmatism. AF t-PRK group induced less coma and total HOAs than SMILE.