Accuracy Validation of the New Barrett True Axial Length Formula and the Optimized Lens Factor Using Sum-of-Segment Biometry.

Objectives: This study aims to verify the accuracy of a new calculation formula, Barrett true axial length formula (T-AL), and the optimized lens factor (LF) for predicting postoperative refraction after cataract surgery. Methods: We included 156 Japanese patients who underwent cataract surgery using Clareon monofocal intraocular lenses at our clinic between January 2022 and June 2023. Postoperative spherical equivalent was calculated using subjective refraction values obtained 1 month post-surgery. The LFs were optimized so that the mean prediction error (PE) of each calculation formula was zero (zero optimization). We calculated the mean absolute PE (MAE) to assess accuracy and used a Friedman test for statistical comparisons. The accuracy of T-AL and the optimized LFs was compared with that of the conventional Barrett Universal II formula for ARGOS (AR-B) and OA-2000 (OA-B) with equivalent refractive index. Results: For T-AL, AR-B, and OA-B, the MAEs ± standard deviations were 0.225 ± 0.179, 0.219 ± 0.168, and 0.242 ± 0.206 D, respectively. The Friedman test showed no statistically significant differences among the three groups. The device-optimized LFs were 2.248-2.289 (T-AL), 2.236-2.246 (AR-B), and 2.07-2.08 (OA-B); the corresponding zero-optimized LFs were 2.262-2.287 (T-AL), 2.287-2.303 (AR-B), and 2.160-2.170 (OA-B). Conclusion: There were no significant differences in prediction accuracy among the formulas. However, the accuracy of LF optimization varied by device, with T-AL being closest to the value under zero optimization. This suggests that T-AL is clinically useful for predicting an accurate postoperative refraction without zero optimization.

Changes in cataract and refractive surgery practice patterns among JSCRS members over the past 20 years.

PURPOSE: To evaluate changes in cataract and refractive surgery practice patterns among members of the Japanese Society of Cataract and Refractive Surgery (JSCRS) over the past 20 years. STUDY DESIGN: Questionnaire survey study. SUBJECTS AND METHODS: Clinical surveys were conducted annually between February and April from 2004 to 2023. Survey questions covered various areas, including cataract surgical techniques, anesthesia, endophthalmitis prophylaxis, toric and presbyopia-correcting intraocular lenses (IOLs), complications, and refractive surgery. RESULTS: The highest (n=554 [36.8%]) and lowest (n=316 [19.1%]) numbers of responses were collected in 2012 and 2016, respectively. In perioperative management, the intraoperative use of polyvinyl alcohol-iodine solution and topical antibiotic prescription 3 days before surgery has increased. The use of intracameral injection at the end of surgery has also significantly increased, although it has not been established as common practice. In anesthesia, there is a clear polarization between the use of topical drops and tenon injection. The use of toric IOLs and presbyopia-correcting IOLs has significantly increased from 2010 to 2023. In the latter, the use of trifocal IOLs has particularly increased. Regarding IOL power calculations, the Barrett True K and the Barrett Universal II formulas are rapidly gaining popularity for application with and without post-laser vision correction, respectively. In refractive surgery, phakic IOLs and corneal refractive therapy have attracted considerable interest, followed by laser in situ keratomileusis. CONCLUSIONS: Evaluation of annual clinical survey data over the past two decades provided valuable insights into the shifting practice patterns and clinical opinions among JSCRS members.

Modulation transfer function of implantable phakic intraocular contact lens (IPCL) for myopia and presbyopia.

PURPOSE: This study aimed to assess the optical quality of myopic and presbyopic IPCLs with different additional powers, and to investigate the effects of pupil size on the optical quality of these IPCLs using an in-vitro modulation transfer function (MTF) measurement system. METHODS: Linear scatter functions (LSFs) were recorded using the OPAL Vector system and an eye phantom consisting of wet cells filled with a balanced salt solution. A myopic IPCL or a presbyopic IPCL was placed in the posterior chamber of this model. The MTF was calculated from the LSF using the fast Fourier transform techniques. The effective apertures were set at 2.0 to 5.0 mm in 1.0 mm steps. RESULTS: The in-focus MTF values of the myopic IPCL and presbyopic IPCL with additional powers of + 2.0 and + 4.0 diopters at 100 cycles/mm for an effective aperture of 3.0 mm were 43%, 27%, and 24%, respectively. The in-focus MTF value of both myopic and presbyopic IPCLs was the highest when the effective aperture was set at 3.0 mm, and it gradually worsened when the effective aperture became larger than 3.0 mm at 20, 60, and 100 cycles/mm. CONCLUSIONS: Both myopic and presbyopic IPCLs provided excellent MTF values, but the additional power profile can deteriorate optical performance in presbyopic IPCL-implanted eyes, even with a low additional power. Pupil size can influence visual quality in IPCL-implanted eyes for both myopia and presbyopia.

Evaluation of the Accuracy of Intraocular Lens Power Calculation Formulas in Phacovitrectomy.

INTRODUCTION: The aim of this study was to evaluate the refractive error in patients undergoing combined phacovitrectomy with and without gas tamponade. METHODS: This was a retrospective chart review including patients undergoing phacoemulsification alone (Group 1), combined phacovitrectomy for epiretinal membrane (Group 2), and combined phacovitrectomy with gas tamponade for rhegmatogenous retinal detachment (RRD) (Group 3). Axial length and keratometry were measured using an optical biometric system (Argos, Alcon Laboratories. Inc.), and a three-piece intraocular lens (IOL; NX-70S) was implanted in all groups. In each group, the prediction error at 3 months was calculated using IOL power calculation formulas (SRK/T, Hill-RBF, Kane, and Barrett Universal II) for each eye. Outcome measures included the mean prediction error (MPE), its standard deviation (SD), and the mean absolute error (MAE). The change in IOL position at 3 months was also assessed using anterior segment optical coherence tomography. RESULTS: A total of 104 eyes were included (Group 1: 30; Group 2: 34; Group 3: 40 eyes). The MPE was -0.08 ± 0.37 diopters (D), -0.26 ± 0.32 D, and -0.59 ± 0.34 D in Group 1, Group 2, and Group 3, respectively, using the Barrett Universal II formula (P < 0.01, ANOVA). The movement forward in the IOL position was 0.95 ± 0.16 mm, 0.94 ± 0.12 mm, and 1.07 ± 0.20 mm in Group 1, Group 2, and Group 3, respectively (P < 0.01). No significant difference was shown in MPE among the four formulas after combined phacovitrectomy with gas (P = 0.531). CONCLUSIONS: Phacovitrectomy in RRD induced a significant myopic shift using any of the clinically available formulas. This suggests that myopic shift should be taken into consideration for better refractive outcomes in phacovitrectomy with gas tamponade in RRD.

Accuracy of intraocular lens power formulas in eyes with keratoconus: Multi-center study in Japan.

PURPOSE: To assess the accuracy of intraocular lens (IOL) power formulas, namely, SRK/T, Haigis, Barrett Universal II, Barrett True-K for keratoconus, Kane formula, and Kane formula for keratoconus, for cataract with keratoconus in Japanese eyes. SETTING: Five surgical sites in Japan. DESIGN: A retrospective case series. METHODS: Eyes with keratoconus undergoing cataract surgery were included. Postoperative refraction was compared with the prediction by the formulas. Visual acuity, manifest spherical equivalent, prediction error (PE), and mean absolute errors (MAEs) were determined 1 month postoperatively. The PE within 0.50 diopter (D), 1.00 D, and 2.00 D were compared between IOL formulas. Subgroup analysis based on the steepest keratometry (stage 1, ≤ 48 D; stage 2, > 48 D and ≤ 53 D; and stage 3, > 53 D) was performed. The relationship between PE and preoperative biometric data were assessed. RESULTS: Fifty eyes were included. The MAE of the Barrett True-K for keratoconus, Kane keratoconus, and Kane formulas were significantly lower than that of Haigis. A statistically significant difference in the prediction accuracy within ± 0.50 D was found between Kane keratoconus and Haigis. The prediction accuracy of the Barrett True-K for keratoconus, SRK/T, and Kane within ± 1.00 D was statistically significant compared with that of Haigis. In stage 3, the Barrett True-K for keratoconus had a significantly lower MAE than SRK/T and Haigis. CONCLUSION: Keratoconus-specific formulas were more accurate than existing formulas in Japanese eyes. The Barrett True-K formula for keratoconus had higher prediction accuracy in severe keratoconus.

Wavelength Characteristics and Visual Function of Photochromic Contact Lenses in Indoor and Outdoor Conditions.

PURPOSE: To examine the wavelength characteristics of photochromic contact lenses (CL) and evaluate the impact of tinting on visual function in indoor, outdoor, and glare environments. METHODS: A total of 33 healthy individuals with refractive errors were recruited and fully corrected for refractive errors. Three groups were established, including non-activated photochromic CL, activated photochromic CL, and lenses without photochromic properties, which replicated the dimming characteristics of CL. Visual acuity and contrast sensitivity were measured and compared among the three groups. RESULTS: Statistically significant differences were observed in the spatial frequency (6, 12 cpd) and contrast sensitivity outdoors, with improved values recorded in the activated photochromic-CL group. In subsequent comparisons, the activated-photochromic-CL group demonstrated significantly better contrast-sensitivity values than the non-photochromic-CL group, as well as significant improvement in contrast sensitivity compared to the non-activated-photochromic-CL group. No significant differences were observed in the indoor or outdoor visual acuity. CONCLUSION: Our results suggest that photochromic CL enhances visual function in outdoor environments, while maintaining visual function indoors and under glare, thereby improving the quality of vision (QOV) in severe light conditions where exposure to sunlight and ultraviolet light is anticipated.

Prevalence of Accommodative Microfluctuations in Eyes after Cataract Surgery.

BACKGROUND: We aimed to evaluate the existence of accommodative microfluctuations in eyes after cataract surgery. METHODS: This retrospective observational cohort study included 1160 eyes of 713 patients (mean age: 72.5 ± 8.3 years) who underwent phacoemulsification, intraocular lens insertion, and an evaluation of accommodative microfluctuations with an autorefractometer. Patients with posterior segment disorders resulting in visual acuity impairment and those with unavailable medical information were excluded. High-frequency components (HFCs), between 1.0-2.3 Hz, based on fast Fourier transform analysis of the accommodative microfluctuation data were examined at postoperative 2-3 (2 M) and 6 months (6 M). The relationships between the HFCs and patient age, manifest refraction, and axial length were analyzed. RESULTS: Increased HFC values (>65) were observed at a constant rate after cataract surgery, with prevalence rates of 33.4% at 2 M and 34.7% at 6 M. Postoperatively, at 2 M, increased HFC values were significantly more common for eyes with axial length ≥26 mm than for those with axial length <26 mm (p = 0.0056). However, they were not significantly correlated to age or postoperative manifest refraction. CONCLUSIONS: At 2 M postoperatively, increased HFC values presented more frequently in eyes with a greater axial length; hence, the precise detection and understanding of postoperative accommodative spasms in high myopia patients is important.

Effect of Photochromic Contact Lens Wear on Indoor Visual Performance and Patient Satisfaction.

INTRODUCTION: To quantitatively assess visual performance and patient satisfaction during photochromic contact lens (CL) wear in an indoor environment. METHODS: This observational study comprised 82 eyes of 41 healthy subjects (mean age ± standard deviation, 21.7 ± 0.7 years) who had no ophthalmic diseases except for refractive errors at Kitasato University in 2021. We prospectively compared visual acuity, kinetic visual acuity, functional (time-dependent) visual acuity, the maintaining rate of visual acuity, the response time, contrast sensitivity function, higher-order aberrations, and patient satisfaction score for overall vision in such subjects during photochromic and non-photochromic CL wear in such an environment. RESULTS: The kinetic visual acuity at 30 km/h was 0.32 ± 0.21 and 0.41 ± 0.24 in the photochromic and non-photochromic CL groups, respectively (p = 0.008). The kinetic visual acuity at 60 km/h was 0.32 ± 0.21 and 0.41 ± 0.24, respectively (p = 0.034). The functional visual acuity was 0.00 ± 0.21 and 0.05 ± 0.25, respectively (p = 0.030). The average response time was 1.19 ± 0.15 s and 1.23 ± 0.15 s, respectively (p = 0.029). The patient satisfaction score for overall visual performance was 4.22 ± 0.11 and 3.59 ± 0.68, respectively (p < 0.001). Otherwise, we found no significant differences in visual acuity, the maintaining rate, higher-order aberrations, or contrast sensitivity function (p = 0.116, p = 0.053, p = 0.371, or p = 0.943). We found no apparent complications such as ocular discomfort, superficial punctate keratitis, conjunctival injection, or infectious keratitis during the observation period. CONCLUSIONS: According to our experience, the photochromic CL showed good visual quality, especially in terms of kinetic and functional visual acuities and subsequent high patient satisfaction, even in an indoor environment, suggesting its viability of visual correction not only in daily activities but also in indoor sports activities.

Evaluation of ocular biometry in the Japanese population using a multicenter approach: Prospective observational study.

This prospective observational study aimed to evaluate the ocular biometry of Japanese people through a multicenter approach. The uncorrected and corrected distance visual acuity (UDVA and CDVA, respectively) in the log minimum angle of resolution (logMAR), subjective and objective spherical equivalent values (SE) of ocular refraction, anterior and posterior corneal curvature (ACC and PCC, respectively), anterior and posterior corneal asphericity (ACA and PCA, respectively), central corneal thickness (CCT), anterior chamber depth (ACD), and ocular axial length (AL) were measured in the eyes of 250 participants (mean age = 46.5 ± 18.0 years, range: 20-90 years) across five institutions in Japan. The mean UDVA, CDVA, subjective SE, objective SE, ACC, PCC, ACA, PCA, CCT, ACD, and AL were 0.68, -0.08, -2.42 D, -2.66 D, 7.77 mm, 6.33 mm, -0.31, -0.39, 0.55 mm, 2.92 mm, and 24.78 mm, respectively. Age-related changes and sex-based differences were noted in the visual acuity, refraction, corneal shape, ACD, and AL. Our results serve as basis for future studies aiming to develop refractive correction methods and various vision-related fields.

Predictability of combined cataract surgery and trabeculectomy using Barrett Universal â ¡ formula.

PURPOSE: To compare the predictability of intraocular lens (IOL) power calculation using the Barrett Universal II and the SRK/T formulas in eyes undergoing combined cataract surgery and trabeculectomy. METHODS: We retrospectively reviewed the clinical charts of 56 consecutive eyes undergoing cataract surgery and trabeculectomy. IOL power calculations were performed using the Barrett Universal II and SRK/T formulas. We compared the prediction error, the absolute error, and the percentages within ± 0.5 D and ±1.0 D of the targeted refraction, 3 months postoperatively, and also investigated the relationship of the prediction error with the keratometric readings and axial length, using the two formulas. RESULTS: The prediction error using the SRK/T formula was significantly more myopic than that using the Barrett Universal II formula (paired t-test, p<0.001). The absolute error using the Barrett Universal II formula was significantly smaller than that using the SRK/T formula (p = 0.039). We found significant correlations of the prediction error with the axial length (Pearson correlation coefficient, r = 0.273, p = 0.042), and the keratometric readings (r = -0.317, p = 0.017), using SRK/T formula, but no significant correlations between them (r = 0.219, p = 0.167, and r = -0.023, p = 0.870), using the Barrett Universal II formula. CONCLUSIONS: The Barrett Universal II formula provides a better predictability of IOL power calculation and is less susceptible to the effect of the axial length and the corneal shape, than the SRK/T formula. The Barrett Universal formula, rather than the SRK/T formula, may be clinically helpful for improving the refractive accuracy in such eyes.

Comparison of Laser Iridotomy and Lensectomy Outcomes for Acute Primary Angle Closure.

Purpose: To compare the clinical outcomes of the different treatments for acute primary angle closure (APAC). Methods: We retrospectively reviewed the clinical charts of 87 eyes of 87 patients undergoing treatment for APAC. We investigated the best spectacle-corrected visual acuity (BSCVA), intraocular pressure (IOP), corneal endothelial cell density (ECD), and secondary interventions after each treatment. Results: The pretreated IOP was 56.4 ± 9.0 mmHg. As the first treatment for APAC, all eyes underwent topical 2% pilocarpine and systemic mannitol administration. Subsequent laser iridotomy (LI) and lensectomy were necessary in 29 eyes (33%) and 35 eyes (40%), respectively. Bullous keratopathy developed in 1 eye (1%), and following glaucoma surgery was required in 7 eyes (8%). The BSCVA at the final follow-up was 0.16 ± 0.53 and 0.01 ± 0.20 logMAR (Mann-Whitney U test, p=0.149), the IOP was 12.8 ± 2.6, and 12.6 ± 2.9 mmHg (p=0.860), and the ECD was 2295.9 ± 658.2 and 2244.1 ± 622.0 cells/mm2 (p=0.735) in the LI and lensectomy groups, respectively. Conclusions: Approximately 26% of eyes with APAC were resolved after the initial medical treatment, and subsequent surgical treatments, such as LI and lensectomy, were required in 33% and 40% of eyes, respectively. We found no significant differences in the BSCVA, the IOP, or the ECD among LI and lensectomy treatment groups.

A Nationwide Multicenter Study on 1-Year Outcomes of Posterior Chamber Phakic Intraocular Lens Implantation for Low Myopia.

Purpose: To assess the nationwide multicenter outcomes of posterior chamber phakic intraocular lens implantation with a central hole (EVO-ICL, STAAR Surgical) for patients with low myopia. Methods: This multicenter study comprised 172 eyes of 111 consecutive patients undergoing hole ICL implantation to correct low myopia and myopic astigmatism [manifest spherical equivalent (MSE);-3 diopters (D) or less] at seven nationwide major surgical facilities. We retrospectively determined safety, efficacy, predictability, stability, and adverse events at 1 week, 1, 3, 6, and 12 months postoperatively, and at the final visit. Results: The mean follow-up period was 1.4 ± 1.0 years. Uncorrected and corrected visual acuities at 1 year postoperatively were -0.17 ± 0.12 and -0.24 ± 0.07 logarithm of the minimal angle of resolution (logMAR), respectively. At 1 year postoperatively, 91% and 100% of eyes were within 0.5 and 1.0 D of the target correction, respectively. No significant manifest refraction changes of -0.07 ± 0.26 D occurred from 1 week to 1 year. No vision-threatening complications occurred at any time in this series. Conclusions: According to our experience, the EVO-ICL performed well without significant complications throughout the 1-year observation period, even for the correction of low myopia. It is suggested that current ICL implantation is one of the viable surgical options for correcting low myopia.

Posterior chamber phakic intraocular lens implantation after laser in situ keratomileusis.

BACKGROUND: To assess the multicenter outcomes of posterior chamber phakic intraocular lens implantation with a central hole (EVO-ICL, STAAR Surgical) for patients undergoing previous laser in situ keratomileusis (LASIK). METHODS: This case series enrolled 31 eyes of 21 consecutive patients undergoing EVO-ICL implantation to correct residual refractive errors after LASIK at 7 nationwide major surgical sites. We investigated safety, efficacy, predictability, stability, and adverse events at 1 week, 1, 3, and 6 months postoperatively, and at the final visit. RESULTS: The mean observation period was 1.6 ± 1.8 years. Uncorrected and corrected visual acuities were - 0.14 ± 0.11 and - 0.22 ± 0.09 logMAR at 6 months postoperatively. At 6 months postoperatively, 81% and 100% of eyes were within ± 0.5 D and ± 1.0 D, respectively, of the targeted correction. We found neither significant manifest refraction changes of 0.05 ± 0.38 D from 1 week to 6 months nor apparent intraoperative or postoperative complications in any case. CONCLUSIONS: Our multicenter study confirmed that the EVO-ICL provided good outcomes in safety, efficacy, predictability, and stability, even in post-LASIK eyes. Therefore, EVO-ICL implantation may be a viable surgical option, even for correcting residual refractive errors after LASIK. Trial registration University Hospital Medical Information Network Clinical Trial Registry (000045295).

Multicenter clinical outcomes of hole implantable collamer lens implantation in middle-aged patients.

To assess the multicenter clinical outcomes of the implantation of hole implantable collamer lens (Hole ICL, ICL KS-AquaPORTTM; STAAR Surgical, Nidau, Switzerland) in patients of 45 years or more. We retrospectively assessed the surgery's safety, efficacy, predictability, stability, and adverse events before surgery and after the surgery at 1 week; 1, 3, and 6 months; and 1 year, followed by once every year for approximately 2.2 years. A total of 118 eyes of 65 patients aged 45-65 years with myopic refractive errors ranging from - 2.13 to - 18.75 diopters (D) underwent hole ICL implantation and routine postoperative examinations. The average observation period was 2.2 ± 1.0 years. The safety and efficacy indices were 1.08 ±  0.21 and 0.87 ± 0.25, respectively. Manifest refraction changes of - 0.20 ± 0.43 D occurred from 1 month to the final visit after ICL implantation. Eight eyes (6.8%) developed asymptomatic anterior subcapsular cataract (ASC) immediately after surgery, and three eyes (2.5%) developed clinically significant symptomatic nuclear cataracts during the follow-up period. According to our experience, hole ICL implantation offered favorable outcomes in all measures of safety, efficacy, predictability, and stability, even in middle-aged patients, during the 2.2-year observation period.

Hyperopia-Correcting Phototherapeutic Keratectomy and Its Comparison With Conventional Phototherapeutic Keratectomy.

Purpose: To evaluate hyperopia-correcting phototherapeutic keratectomy (HC-PTK) and to compare the visual and refractive outcomes of HC-PTK and conventional PTK. Methods: This study comprised a total of 72 eyes of 72 consecutive patients who underwent HC-PTK and conventional PTK for granular corneal dystrophy or band-shaped keratopathy. Preoperatively and 6 months postoperatively, we assessed visual acuity, manifest refraction, and mean keratometry, as well as postoperative corneal higher-order aberrations and adverse events in each PTK group, and compared these metrics between the two groups. Results: LogMAR BSCVA significantly improved from 0.43 ± 0.47 preoperatively to 0.21 ± 0.38 postoperatively in the HC-PTK group (Wilcoxon signed-rank test, p < 0.001). It was also significantly improved from 0.22 ± 0.21 preoperatively to 0.15 ± 0.12 postoperatively in the conventional PTK group (p = 0.031). Mean refraction significantly changed from 0.27 ± 1.55 diopter (D) preoperatively to 0.50 ± 1.77 D postoperatively, in the HC-PTK group (p = 0.313). By contrast, it was significantly hyperopic from -0.15 ± 2.41 D preoperatively to 1.45 ± 2.46 D postoperatively, in the conventional PTK group (p < 0.001). No significant complications occurred in any case during the follow-up period. Conclusion: Both HC-PTK and conventional PTK showed a significant improvement of BSCVA and no vision-threatening complications at any time in this series. HC-PTK significantly reduced a hyperopic shift in refraction compared with conventional PTK, suggesting its viability for patients requiring PTK, especially in consideration of preventing this hyperopic issue.

Multicenter survey on implantable collamer lens dislocation.

This study aimed to investigate the incidence, patient background, and postoperative prognosis of implantable collamer lens (ICL) dislocation. We retrospectively reviewed all cases of ICL dislocation at four major refractive surgery centers in Japan until December 2019. The incidence, patient background, cause of dislocation, complications of repositioning surgery, and postoperative visual function were investigated. Seven ICL dislocations [0.072% of total ICL-implanted eyes (9775 eyes)] occurred at an average of 28.6 months (11-82 months) postoperatively. All patients were male. Five eyes were injured during sports activities, one due to a fall from a bicycle, and another due to ocular blunt trauma caused by a mortuary tablet. Two patients had re-dislocation in the same eye. Retinal detachment occurred after repositioning surgery in one patient, and scleral buckling surgery was performed without ICL removal. ICL dislocation is a rare complication of ICL surgery; repositioning surgery is effective, but retinal complications may occur.