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INTRODUCTION: Dry eye can compromise corneal astigmatism measurement repeatability during preoperative cataract surgery examination. No previous studies have analyzed the effectiveness of long-acting 3% diquafosol sodium (LA-DQS) on astigmatism measurement repeatability. This research assessed the effect of LA-DQS on astigmatism measurement repeatability in preoperative patients with cataract and short tear break-up time (TBUT) type dry eyes in both eyes of the same patient. Correlations between repeatability and TBUT, corneal high-order aberrations (HOAs), and corneal astigmatism magnitude were also analyzed. METHODS: In total, 122 eyes (61 patients) with short TBUT-type dry eye were enrolled. Preoperatively, only one eye of all patients was treated with LA-DQS for 4 weeks. TBUT and corneal HOAs were checked using CASIA 2 before and 4 weeks post-treatment. The cylindrical power and meridian of astigmatism were measured at 3- and 4-week post-treatment using IOLMaster 700. Power vectors J0 and J45 were used for astigmatism calculations. Repeatability of astigmatism measurements was assessed as the within-subject standard deviation (Sw). The relative effects of TBUT and HOAs on J0 Sw and J45 Sw were also analyzed. Comparative changes in these variables were evaluated between treated and non-treated eyes, with additional analysis of their correlations. RESULTS: Treated eyes exhibited significant improvements in TBUT, HOAs, and post-treatment measurements of J0 Sw and J45 Sw at 3 and 4 weeks. In non-treated eyes, J0 Sw and J45 Sw showed significant correlation with TBUT and corneal HOAs. HOAs showed stronger relative associations with J0 Sw and J45 Sw than TBUT. In non-treated eyes, no significant correlation was found between cylindrical power and astigmatism measurement repeatability. CONCLUSIONS: In short TBUT-type dry eye, preoperative treatment with LA-DQS significantly improved astigmatism measurement repeatability. This may improve the precision of intraocular lens (IOL) power calculations regardless of the magnitude of corneal astigmatism, especially when toric IOLs are used.
ABSTRACT
INTRODUCTION: Although uncommon, incomplete capsulotomy, anterior capsule tags and anterior capsule tears are still encountered during femtosecond laser-assisted cataract surgery (FLACS), resulting in surgical complications. This highlights the need to improve femtosecond laser-assisted capsulotomy technique to reduce capsulotomy-related complications. Therefore, the purpose of this study was to investigate the efficacy of a newly developed, modified technique of setting capsulotomy irradiation thickness in lowering the incidence of capsulotomy-related complications in FLACS. METHODS: This open-label prospective, comparative cohort study included 440 eyes (220 patients) treated with FLACS using the LenSx laser system (Alcon Laboratories, Inc. Fort Worth, TX, USA). Varying capsulotomy irradiation thicknesses were applied in each eye of the same patient. In Group 1, capsulotomy irradiation thickness was set between the upper edge of the highest point of the anterior capsule and the lower edge of the lowest point of the anterior capsule (modified technique). In Group 2, this was set between the center of the highest point of the anterior capsule and the center of the lowest part of the anterior capsule (conventional technique). Incidence rates of incomplete capsulotomy, anterior capsule tags and tears, and posterior capsule tears were compared. RESULTS: Preoperative baseline characteristics showed no significant differences. Mean total of the irradiation thicknesses was 877.1 ± 81.9 µm in Group 1 and 808.9 ± 80.0 in Group 2, with a statistically significant difference (P < 0.001). Incidences of incomplete capsulotomy were 1.8% and 7.7%, anterior capsule tags were 2.3% and 8.6%, and anterior capsule tears were 0% and 3.2% in Groups 1 and 2, respectively. These differences were statistically significant (P = 0.006, 0.005, and 0.015, respectively). No posterior capsule tears were reported in either group. CONCLUSION: The modified technique for capsulotomy in FLACS may significantly reduce the occurrence of capsulotomy-related complications, maximizing the benefits of FLACS.
ABSTRACT
BACKGROUND: Differences between programmed capsulorhexis diameter and actual resulting capsulorhexis diameter (ARCD) are commonly encountered in femtosecond laser-assisted cataract surgery (FLACS). The purpose of this study was to identify the preoperative ophthalmic variables influencing capsulorhexis diameter index (CDI) in FLACS for adults and create a multiple linear regression model for obtaining a more accurate capsulorhexis diameter. METHODS: This retrospective study involved sixty-seven eyes of 44 patients who received FLACS and intraocular lens implantation. The ARCD was measured using anterior segment swept-source optical coherence tomography (CASIA 2). Keratometry (K1, K2 and average K), anterior chamber depth (ACD), lens thickness (LT), anterior chamber width (ACW), white-to-white (WTW), curvature radius of anterior lens capsule (Front R) and axial length (AL) were all measured preoperatively. Based on the derived data, LT/ACW, LT/AL, LT/ACD and LT/ACW/Front R were calculated. The ratio of the programmed capsulorhexis diameter and ARCD was defined as the CDI. Correlation analysis was conducted to examine the relationship between preoperative variables listed above and the CDI. Multiple linear regression analysis was applied to select the most influential preoperative variables on CDI. RESULTS: ACD, LT, ACW, Front R, AL, LT/ACW, LT/AL, LT/ACD, and LT/ACW/Front R showed significant correlation with CDI. Front R and LT/ACW/Front R were selected as constants in the multiple linear regression model using stepwise variable selection. The following equation represents the multiple linear regression model: CDI = 1.306-4.516 × LT/ACW/FrontR-0.011 × Front R, when P < 0.0001, adjusted R-squared = 0.919, variance inflation factor = 8.389, and Durbin-Watson ratio = 1.846. Predicted postoperative capsulorhexis diameter (PPCD) equation was created based on CDI equation as follows: PPCD = programmed capsulorhexis diameter × 1.306-4.516 × LT/ACW/FrontR-0.011 × Front R. CONCLUSION: Front R and LT/ACW/Front R were found to be the most significant influencing factors of capsulorhexis size. CDI and PPCD calculation equations presented in this study may be useful in setting up more accurate programmed capsulorhexis diameter for FLACS in adults, resulting in a precise ARCD.
