Comparing the Early Changes in Classified Higher-Order Aberrations Before and After Non-Toric and Toric Implantable Collamer Lens V4c Implantation.

PURPOSE: This study aimed to compare early changes in classified higher-order aberrations (HOAs) pre- and postsurgery in patients who received nontoric versus toric implantable collamer lenses (ICL; ICL Model V4c; STAAR Surgical, Monrovia, CA, USA). METHODS: This prospective study included 124 eyes of 64 patients: 49 eyes were treated using a nontoric implantable collamer lens (ICL), and 75 eyes were treated using a toric implantable collamer lenses (TICL). Refractive parameters and ocular aberrations were examined before and 1 month after surgery. RESULTS: At one month, the safety indices were 1.24 ± 0.17 in the ICL group and 1.20 ± 0.25 in the TICL group (p = 0.39). The efficacy indices were 1.07 ± 0.17 in the ICL group and 1.15 ± 0.26 in the TICL group (p = 0.02). The root mean square (RMS) values of whole-eye total HOAs, trefoil, corneal total HOAs, spherical aberration, and intraocular spherical aberration significantly increased postoperatively in both groups. The RMS of intraocular total HOAs in the TICL group significantly increased 1 month postoperatively. No statistically significant differences were observed in HOA changes between the ICL and TICL groups. CONCLUSIONS: The dominant increases in short-term aberrations after ICL and TICL V4c implantation were in corneal trefoil and intraocular spherical aberrations, which were related to the corneal incision and implanted lens. The HOA changes post-surgery were not statistically different between the two lens types.

Immediate versus delayed sequential bilateral ICL implantation: A retrospective comparison of vault height and visual outcomes.

PURPOSE: To compare the visual outcomes and risks of suboptimal vault-related complications between immediate sequential bilateral ICL surgery (ISBICLS) and delayed sequential bilateral ICL surgery (DSBICLS). DESIGN: A retrospective cohort study. METHODS: Patients who underwent bilateral ICL implantation between November 2014 and December 2021 at the Eye and ENT Hospital of Fudan University (Shanghai, China) were included and divided into two groups: (1) ISBICLS: both eye surgeries performed on the same day, and (2) DSBICLS: second eye surgery performed < 7 days following the first one. Propensity score matching (PSM) was performed to compare the visual outcomes. Multivariable logistic regression models were used to estimate the odds ratios (ORs) of the suboptimal vaults. RESULTS: Finally, 10,985 eyes were included. After PSM, 204 first surgery eyes and 162 s surgery eyes with complete postoperative data were matched. The safety and efficacy indices did not statistically differ between groups (all > 1.00), except that ISBICLS first surgery eyes achieved better efficacy index than DSBICLS group (1.03 ± 0.26 vs. 1.08 ± 0.23, P = 0.034). Excessive vault was observed in eight (4.06 %) ISBICLS first eyes, one (0.50 %) DSBICLS first eye, and none in the second surgery eye in either group. An insufficient vault was observed in one second eye and one DSBICLS second eye. We found no evidence of differences in the rate of excessive vault (OR = 0.831, 95 % CI: 0.426-1.622, P = 0.588) or insufficient vault (OR = 0.609, 95 % CI:0.062-5.850, P = 0.668). CONCLUSION: ISBICLS provided safety, efficacy, and refraction predictability comparable to DSBICLS without increasing the risk of suboptimal vault-related complications.

Effects of Decentration of Implantable Collamer Lens V4c on Visual Quality With the OPD-Scan III Aberrometer.

PURPOSE: This study aimed to analyze the relationship between visual quality and implantable collamer lenses (ICL) decentration. DESIGN: Prospective treatment evaluation clinical study METHODS: This prospective study included 119 eyes with ICL implantation. Refractive parameters and ocular aberrations were examined pre- and postoperatively. ICL decentration and higher-order aberrations (HOAs) were evaluated using the OPD-Scan III aberrometer. RESULTS: At the 1-month follow-up, the mean values for decentration were 0.38 ± 0.19 mm (0.02-0.78). Regarding the position of decentration in right and left eyes, 22.8% and 17.7% were located in the superior nasal section, 0% and 6.5% in the inferior nasal section, 50.9% and 53.2% in the superior temporal section, and 26.3% and 22.6% in the inferior temporal section, respectively. The root mean square values of whole-eye total HOAs, coma, and trefoil had significantly increased. Decentration had a significant negative correlation with variation in the pre- and postoperative trefoils of the whole eye. CONCLUSIONS: ICL decentration had a slightly negative correlation with trefoil and slightly affected visual quality.

Predicting Vault and Size of Posterior Chamber Phakic Intraocular Lens Using Sulcus to Sulcus-Optimized Artificial Intelligence Technology.

PURPOSE: To investigate the accuracy of posterior chamber phakic intraocular lens (PIOL) vault and size prediction models based on sulcus to sulcus (STS) optimized artificial intelligence and big data analysis technology. DESIGN: Big data and artificial intelligence prediction model. METHODS: We included 5873 eyes with posterior chamber PIOL implantation, and the postoperative vault was measured using an anterior segment analyzer (Pentacam AXL) 1 month postoperatively. A random forest regression model and classification model were used to predict the postoperative vault and PIOL size. The postoperative vault and PIOL size were set as output features; other vault-related eye parameters were set as input features. The influence of white to white (WTW), horizontal sulcus to sulcus (STS), and vertical STS on predicting postoperative vault and PIOL size was analyzed and compared. RESULTS: The mean preoperative WTW diameter was 11.64 ± 0.37 mm, the mean horizontal STS diameter was 11.85 ± 0.47 mm, and the mean vertical STS diameter was 12.39 ± 0.52 mm. In the regression model for numerical prediction of the vault, the combination of WTW, horizontal STS, and vertical STS was the most optimal for vault prediction (R2 = 0.3091, root mean square error [RMSE] = 0.1705); solely relying on WTW was the least optimal (R2 = 0.2849, RMSE = 0.1735). Among the models for classification prediction of the vault, the combination of WTW, horizontal STS, and vertical STS was the most accurate (accuracy, 0.6302; mean area under the curve, 0.8008; and mean precision recall rate, 0.6940). Moreover, the combination of WTW, horizontal STS, and vertical STS exhibited the highest accuracy for classification prediction of PIOL size (accuracy, 0.8170; mean area under the curve, 0.9540; and mean precision recall rate, 0.8864). Whether in the regression prediction models of vault values or in the classification prediction models of vault and PIOL size, the accuracy of STS optimized model was significantly improved compared with the traditional WTW model (P < .001). CONCLUSION: Artificial intelligence combined with STS optimization contributes to the accuracy of PIOL size and vault prediction models. The random forest machine-learning model optimized by STS is superior to the traditional WTW model.

Effect of long-term rotation on astigmatism following EVO-toric intraocular collamer lens implantation.

Objective: To evaluate the effect of long-term rotation on astigmatism following Evolution-toric intraocular collamer lens (EVO-TICL) implantation. Methods: Forty eyes of 22 patients were enrolled in this prospective study. Visual acuity, refractive parameters, and axial position of the EVO-TICL by OPD-Scan III aberrometer were measured preoperatively, 1 month and 3 years postoperatively. Results: Last visit, the safety index was 1.32 ± 0.15 and the efficacy index was 1.01 ± 0.23. The best-fitting curve of the attempted versus achieved correction was y = 0.9751x + 0.001. The mean spherical equivalent (SE) decreased from -8.94 ± 2.72D preoperatively to 0.06 ± 0.24D and - 0.36 ± 0.46D 1 month and 3 years postoperatively, respectively. The mean target and surgical induced astigmatism were 1.55 ± 0.61D and 1.67 ± 0.94D 3 years postoperatively. The average expected axis of the TICL was-1.15 ± 9.07 (-21-19°). One month and 3 years postoperatively, the average actual axis was -0.70 ± 9.86 (-20-20°) and - 0.35 ± 11.72 (-25-30°), respectively. The absolute rotation of the TICL was 3.70 ± 4.42 (0-22°) and 6.00 ± 6.70 (0-32°) 1 month and 3 years postoperatively, respectively (p < 0.001). The expected astigmatism was -0.10 ± 0.12D, and the mean actual astigmatism was -0.21 ± 0.30D and - 0.44 ± 0.45D 1 month and 3 years postoperatively, respectively. The mean absolute rotation without postoperative astigmatism was 3.73 ± 2.69 (0-9°) and 1.67 ± 1.66 (0-5°) for low (<2D) and high (≥2D) astigmatic TICL, respectively (p < 0.05). Conclusion: EVO-TICL implantation is safe and effective, with good predictability and stability. OPD-Scan is a fast device to detect the axial position of the TICL without mydriasis, and the axial position is relatively stable in the long term postoperatively. A slight rotation of low-astigmatic TICL may not cause postoperative astigmatism, whereas rotation of the high-astigmatic TICL may cause it.

Artificial intelligence-based refractive error prediction and EVO-implantable collamer lens power calculation for myopia correction.

BACKGROUND: Implantable collamer lens (ICL) has been widely accepted for its excellent visual outcomes for myopia correction. It is a new challenge in phakic IOL power calculation, especially for those with low and moderate myopia. This study aimed to establish a novel stacking machine learning (ML) model for predicting postoperative refraction errors and calculating EVO-ICL lens power. METHODS: We enrolled 2767 eyes of 1678 patients (age: 27.5 ± 6.33 years, 18-54 years) who underwent non-toric (NT)-ICL or toric-ICL (TICL) implantation during 2014 to 2021. The postoperative spherical equivalent (SE) and sphere were predicted using stacking ML models [support vector regression (SVR), LASSO, random forest, and XGBoost] and training based on ocular dimensional parameters from NT-ICL and TICL cases, respectively. The accuracy of the stacking ML models was compared with that of the modified vergence formula (MVF) based on the mean absolute error (MAE), median absolute error (MedAE), and percentages of eyes within ± 0.25, ± 0.50, and ± 0.75 diopters (D) and Bland-Altman analyses. In addition, the recommended spheric lens power was calculated with 0.25 D intervals and targeting emmetropia. RESULTS: After NT-ICL implantation, the random forest model demonstrated the lowest MAE (0.339 D) for predicting SE. Contrarily, the SVR model showed the lowest MAE (0.386 D) for predicting the sphere. After TICL implantation, the XGBoost model showed the lowest MAE for predicting both SE (0.325 D) and sphere (0.308 D). Compared with MVF, ML models had numerically lower values of standard deviation, MAE, and MedAE and comparable percentages of eyes within ± 0.25 D, ± 0.50 D, and ± 0.75 D prediction errors. The difference between MVF and ML models was larger in eyes with low-to-moderate myopia (preoperative SE > - 6.00 D). Our final optimal stacking ML models showed strong agreement between the predictive values of MVF by Bland-Altman plots. CONCLUSION: With various ocular dimensional parameters, ML models demonstrate comparable accuracy than existing MVF models and potential advantages in low-to-moderate myopia, and thus provide a novel nomogram for postoperative refractive error prediction and lens power calculation.

Clinical Evaluation Of a 0.05 D-step Binocular Wavefront Optometer in Young Adults in China.

CLINICAL RELEVANCE: Myopia has become a public health priority as its prevalence increases worldwide, and in clinical practice, the precise evaluation of refraction errors is necessary. BACKGROUND: This study aimed to compare objective and subjective refraction measured by a binocular wavefront optometer (BWFOM) in adults with conventional objective and subjective refractions measured by an optometrist. METHODS: This cross-sectional study included 119 eyes of 119 participants (34 men and 85 women; mean age:27.5 ± 6.3 years). Refractive errors were measured using BWFOM and conventional methods, with and without cycloplegia. The mean outcome measures were spherical power, cylindrical power, and spherical equivalence (SE). The agreement test was assessed using a two-tailed paired t-test and Bland - Altman plots. RESULTS: Under noncycloplegic conditions, there were no significant differences in the objective SE between BWFOM and Nidek. Significant differences in subjective SE were observed between BWFOM and conventional subjective refraction (-5.79 ± 1.86 vs -5.65 ± 1.75 D, P < 0.01). Under cycloplegic conditions, the mean objective SE was significantly different between BWFOM and Nidek (-5.70 ± 1.76 vs -5.50 ± 1.83 D, P < 0.001); the mean subjective SE was significantly different between BWFOM and conventional subjective refractions (-5.52 ± 1.77 vs -5.62 ± 1.79 D, P < 0.001). The Bland - Altman plots revealed mean percentages of 95.38% and 95.17% for the points within the limits of agreement between BWFOM and conventional measurements and those between noncycloplegic and cycloplegic refractions, respectively. CONCLUSION: The BWFOM is a new device that measures both objective and subjective refraction. It is more convenient and faster to obtain a proper prescription at a 0.05-D interval. The subjective refraction results of the BWFOM and the conventional subjective refraction were in good agreement.

Long-Term Vault Changes in Different Levels and Factors Affecting Vault Change After Implantation of Implantable Collamer Lens with a Central Hole.

INTRODUCTION: This study evaluated vault changes in eyes implanted with an implantable Collamer lens (ICL) with a central hole (ICL V4c) for myopia and astigmatism correction as well as factors related to vault changes over time. METHODS: This retrospective study enrolled 169 myopic eyes from 169 patients (137 women and 32 men) who underwent ICL V4c implantation to correct myopia and astigmatism. Vault values were measured quantitatively using a rotating Scheimpflug camera. Each patient underwent at least four postoperative follow-up visits at 1 month, 6 months, 1 year, and more than 2 years. We compared postoperative values between groups and identified factors affecting vault changes over time. RESULTS: The mean vaults at 1 month (baseline), 6 months, 1 year, and the last follow-up time following ICL implantation were 540.83 ± 186.13, 520.00 ± 196.08, 503.79 ± 198.30, and 471.42 ± 211.35 µm, respectively. Eyes with baseline vaults of 250-750 and ≥ 750 µm exhibited a trend of vault decrease over time, and the differences were statistically significant (P < 0.05) at 6 months and 1 year postoperatively, respectively. The variables relevant to the value of vault decrease between baseline and last follow-up time were anterior chamber depth (ACD) and ICL power (adjusted R2 = 0.121, P < 0.001). CONCLUSIONS: We found a trend of decreased mean objective vault values over time, which was more obvious in eyes with higher baseline vault values. The vault value of the ICL decreased more in eyes with shallower ACDs, higher ICL power, or both. Moreover, the decrease in vault values became statistically significant earlier in eyes with higher baseline vaults or shallower ACDs.

Comparisons of objective and subjective refraction with and without cycloplegia using binocular wavefront optometer with autorefraction and retinoscopy in school-age children.

PURPOSE: To compare school-age children's objective and subjective refraction using a binocular wavefront optometer (BWFOM) with autorefraction and retinoscopy before and after cycloplegia. METHODS: Eighty-six eyes from 86 children (6-15 years old) were enrolled in this cross-sectional study. BWFOM objective and subjective refractions were compared with autorefraction and retinoscopy under cycloplegia. BWFOM refraction was evaluated before and after cycloplegia. Measurements were compared using a paired t-test; agreement was assessed using Bland-Altman plots. RESULTS: Under cycloplegia, the sphere, spherical equivalence, and J45 were significantly more negative on BWFOM objective refraction than autorefraction (- 1.39 ± 2.20 D vs. - 1.28 ± 2.23 D, P = 0.003; - 1.84 ± 2.38 D vs. - 1.72 ± 2.43 D, P = 0.001; - 0.02 ± 0.17 D vs. 0.03 ± 0.21 D, P = 0.004). The subjective sphere of BWFOM was less myopic, and the cylinder and the J45 were more negative than those with retinoscopy (- 1.17 ± 2.09 D vs. - 1.25 ± 2.20 D, P = 0.02; - 0.91 ± 0.92 D vs. - 0.76 ± 0.92 D, P < 0.001; - 0.01 ± 0.15 D vs. 0.03 ± 0.21 D, P = 0.028). For both BWFOM objective and subjective refraction, sphere and spherical equivalence with noncycloplegia were more myopic than those with cycloplegia (objective: - 1.76 ± 2.10 D vs. - 1.39 ± 2.20 D, - 2.21 ± 2.30 D vs. - 1.84 ± 2.38 D, P < 0.001; subjective: - 1.57 ± 1.92 D vs. - 1.17 ± 2.09 D, - 2.01 ± 2.13 D vs. - 1.62 ± 2.27 D, P < 0.001). Bland-Altman plots showed good agreement in spherical equivalence between BWFOM objective refraction and autorefraction (mean difference = 0.12 D, 95% confidence interval [CI] - 0.52 to 0.76), subjective refraction with retinoscopy (mean difference = - 0.01 D, 95% CI - 0.65 to 0.64), and BWFOM refractions with or without cycloplegia (objective: mean difference = - 0.37 D, 95% CI - 1.31 to 0.57; subjective: mean difference = - 0.39 D, 95% CI - 1.30 to 0.51). The time cost by BWFOM was significantly less than the total time of autorefraction and retinoscopy (264.88 ± 90.67 s vs. 315.89 ± 95.31 s, P < 0.001). CONCLUSION: BWFOM is a new device that realizes both objective and subjective refraction. For children's refractive errors, it is more convenient and quicker to obtain the proper prescription at a 0.05-D interval, and it is more accurate than autorefraction and retinoscopy under cycloplegia.

Immediate or Delayed Sequential Bilateral ICL Surgery: a Survey of Chinese Ophthalmologists.

INTRODUCTION: In China, the demand for implantable collamer lens (ICL) surgery is booming. Immediate sequential bilateral ICL surgery (ISBICLS) benefits patients and clinics, but it remains controversial and lacks standardization. We aim to investigate the prevalence of, factors for, and surgeon attitudes toward ISBICLS. METHODS: In this cross-sectional survey study, an electronic questionnaire about the practice and attitudes toward performing ISBICLS or delayed sequential bilateral ICL surgery (DSBICLS) was distributed to 792 qualified ICL surgeons in Mainland China, between 4 April and 22 April 2022. RESULTS: A total of 531 surgeons (66.79%) from 30 provinces in Mainland China responded. Among them, 374 (67.23%) were currently performing ISBICLS. Fifty-two percent (277) of surgeons reported performing ISBICLS more than 50% of the time, while 85.05% of surgeons chose to perform the second eye surgery 1 day after the first eye surgery. Seventy percent (248) of surgeons performing ISBICLS chose to perform the second eye surgery less than 30 min after the first eye surgery. Surgeons who started ICL surgery earlier (before 2010, OR = 2.772, 95% CI = 1.290-5.957, P = 0.009; 2011-2013, OR = 2.479, 95% CI = 1.060-5.800, P = 0.036), completed one-eye ICL surgery faster (< 3 min, OR = 3.936, 95% CI = 1.505-10.293, P = 0.005) and modified the second eye ICL selection less frequently (1-25%, OR = 0.203, 95% CI = 0.054-0.771, P = 0.019; 26-50%, OR = 0.173, 95% CI = 0.041-0.726, P = 0.017; 51-75%, OR = 0.299, 95% CI = 0.041-0.726, P = 0.123; 76-100%, OR = 0.163, 95% CI = 0.039-0.688, P = 0.014) tended to perform ISBICLS. No significant association was found among clinical settings, preoperative measurement devices, and hospital policies with performing ISBICLS. Regarding their attitudes toward ISBICLS, 54.63% preferred ISBICLS and 45.37% preferred DSBICLS. The main supporting reasons were patient convenience (98.64%), faster vision rehabilitation (73.56%), and improved perioperative compliance (73.22%). The concerns regarding ISBICLS included the risk of endophthalmitis (62.22%), lack of recommendation in expert consensus (61.67%), and decreased vault predictability (60.93%). The most common desires for further adoption were expert consensus on surgical criteria and patient indicators for ISBICLS (82.3%). CONCLUSIONS: ISBICLS has been gradually adopted in Mainland China, but has not been widely accepted as a routine procedure. Surgeons' experience and skills mainly influence whether ISBICLS is performed. Further research is needed to explore standardized protocols to prevent endophthalmitis, the appropriate time interval of two eye surgery, and requisitions for surgeon skills.