ABSTRACT
Purpose: The goal of this study was to compare the difference in binocular visual function for high and low?moderate myopes before and after femtosecond laser?assisted in situ keratomileusis (FS?LASIK). Methods: Thirty?three subjects (17 males and 16 females) were divided into two groups according to their preoperative refractive errors in spherical equivalent (SE): low?moderate myopia group (SE ??6.00 D) and high myopia group (SE <?6.00 D). The binocular visual function including accommodative amplitude (AA), accommodative facility (AF), positive and negative relative accommodation (PRA and NRA, respectively), horizontal phoria measurement, positive and negative fusion vergence, accommodative–convergence over accommodation (AC/A) ratio, and stereopsis were assessed with the best?corrected vision before patients received FS?LASIK and 7 and 30 days after the surgery. Repeated measures analysis of variance (ANOVA) was applied to study the change in binocular visual function. Results: The AF values in both groups were significantly reduced after 7 days of FS?LASIK (baseline vs. day 7 (mean): high myopia group: 7.85 vs. 5.62 cpm, repeated ANOVA, P = 0.01; low?moderate myopia group: 5.95 vs. 4.40 cpm, repeated ANOVA, P = 0.04). This change returned to the baseline level 30 days after the operation. In addition, the horizontal phoria values in both groups were significantly reduced for both distant (P = 0.019 and P = 0.001, respectively) and near (P = 0.003 and P = 0.049, respectively) 7 days after the operation, but they rebound to preoperative state after 30 days. Conclusion: A transient change in binocular visual function was noticed after 7 days of FS?LASIK operation, which could cause symptoms of asthenopia. Our data showed all the binocular visual functions returned to baseline level after 30 days of operation.
ABSTRACT
Purpose: This study aimed to evaluate the outcomes of astigmatic correction by single?step transepithelial photorefractive keratectomy (TransPRK) and femtosecond?assisted laser in?situ keratomileusis (Femto?LASIK) surgeries. Methods: A total of 218 subjects received TransPRK or Femto?LASIK surgery for the treatment of myopia and astigmatism (?2.25 to ?0.25 D). Refraction errors and uncorrected (UDVA) and corrected distance visual acuity (CDVA) were examined before and at 3 months after surgery. Astigmatism changes were assessed by vector analysis. Results: Preoperative parameters of the TransPRK group were similar to the Femto?LASIK group. UDVA and CDVA at 3 months were similar between both groups. Manifest refraction (MR) spherical equivalent in the TransPRK group (0 ± 0.20 D) was slightly lower compared with the Femto?LASIK group at 3 months (0.11 ± 0.25 D, P = 0.001). MR cylinder was ?0.06 ± 0.19 D in the TransPRK group and ?0.02 ± 0.15 D in the Femto?LASIK group at 3 months (P = 0.135). The index of success (IS) was 0.15 ± 0.36 in the TransPRK group and 0.06 ± 0.17 in the Femto?LASIK group (P = 0.125). The correction index (CI) was 1.03 ± 0.19 in the TransPRK group and 1.01 ± 0.11 in the Femto?LASIK group (P = 0.815). Conclusion: For low to moderate myopic astigmatism, TransPRK provided a comparable astigmatic treatment effect as Femto?LASIK. Myopic astigmatism was both slightly overcorrected after TransPRK and Femto?LASIK surgeries
ABSTRACT
Purpose: To evaluate the outcomes of transepithelial phototherapeutic keratectomy (transepithelial PTK) for treatment of posttraumatic recurrent corneal erosions. Methods: Twenty?four eyes of 22 patients with posttraumatic recurrent corneal erosions who were treated with transepithelial PTK from April 2018 to July 2020 were included in this retrospective study. The rates of recurrent erosions and complications were evaluated during the follow?up after surgery. Visual acuity and refraction were recorded preoperatively and 1 year after surgery. Total corneal astigmatism, total corneal irregular astigmatism, and total corneal spherical aberrations were recorded using corneal tomography preoperatively and 1 year after surgery. Results: Mean postoperative follow?up was 13 months (range: 12� months). None of the patients suffered from any complications or further erosions. Uncorrected distance visual acuity, best?corrected distance visual acuity, spherical equivalent, and cylinder remained stable at 1?year postoperatively compared with the baseline (P = 0.214, P = 0.461, P = 0.084, and P = 0.879, respectively). Moreover, there was no significant difference in total corneal astigmatism, total corneal irregular astigmatism, and total corneal spherical aberrations between baseline and 1?year postoperative visit (P = 0.938, P = 0.136, and P = 0.981, respectively). Conclusion: Transepithelial PTK was an effective treatment for patients with posttraumatic recurrent corneal erosions.