Influence Of Ocular Residual Astigmatism On The Correction Of Myopic Astigmatism In Small-Incision Lenticule Extraction
Published 2023 - 41st Congress of the ESCRS
Reference: PP21.04 | Type: Free paper | DOI: 10.82333/za9p-vx70
Authors: Cindy Yi-Yu Hsu* 1 , Chen-Cheng Chao 2 , Chao-Kai Chang 3
1Nobel Eye Institute,Taipei,Taiwan, Province of China;Ophthalmology,Taiwan Adventist Hospital,Taipei,Taiwan, Province of China, 2Nobel Eye Institute,Taipei,Taiwan, Province of China;Optometry,MacKay Junior College of Medicine, Nursing, and Management,Taipei,Taiwan, Province of China, 3Nobel Eye Institute,Taipei,Taiwan, Province of China;Optometry,Da-Yeh University,Changhua,Taiwan, Province of China
Purpose
To analysis the association between ocular residual astigmatism (ORA) and amplitude of astigmatism correction in small-incision lenticule extraction (SMILE).
Setting
This study was retrospectively conducted in Taipei Nobel Eye Clinic. Patients with myopic astigmatism who received SMILE through a 500 kHz Visumax platform and followed up for at least three months were included. Inclusion criteria for this study were age between 20 and 50 years old, corrected distance visual acuity (CDVA) of both eyes reaches 0.1 logarithm of the minimum angle of resolution (logMAR), and has stable refractive errors of myopia and astigmatism.
Methods
This is a retrospective, single-centered study. Patient’s demographic and clinical characteristics such as visual acuity, refractive status and corneal tomography were recorded. The patients were examined preoperatively as well as at 1 day, 1 week, and 1 month and 3 months after surgery. Vector analysis included targeted induced astigmatism vector, surgically induced astigmatism vector (SIA), difference vector(DV) and correction index(CI) were calculated using AstigMATIC software version 2.0. ORA was calculated through ASSORT Ocular Residual Astigmatism calculator.
Results
There were 444 patients and 888 eyes included in our study (mean age: 32.4±7.1 years old). Mean preoperative sphere and cylinder was -5.45 ± 1.98 (range: -10.00-0) and -0.89 ± 0.70 (range -4.00-0) diopter. Calculated ORA was 0.68±0.35 diopter (range 0.07-3.53). Postoperative logMAR uncorrected visual acuity was 0.03 ± 0.31. Mean postoperative sphere and cylinder was -0.10 ± 0.56 (range: -1.5-+1.0) and -0.51±0.37 (-1.5-0.0) diopter. Pearson correlation test revealed preoperative sphere, steep K and ORA were statistically correlated with amplitude of astigmatism correction. (P < 0.001). Generalized estimating equations analysis showed that ORA was negatively correlated with amplitude of astigmatism correction after adjustment. (P < 0.001)
Conclusions
Our study suggests that preoperative higher ORA may be associated with lower magnitude of astigmatism correction after SMILE surgery. This is the first large scale, comprehensive study covering various amounts of preoperative astigmatism.