Intraocular Lens Research Articles

Impact of Calcium and Phosphorus Levels on Optical Deterioration in Primary and Secondary Intraocular Lens Calcification.

The purpose of this study was to investigate the impact of calcium and phosphorus levels on optical deterioration in primary and secondary intraocular lens (IOL) calcification. A total of 18 explanted IOLs, 10 with primary, and 8 with secondary calcification, were examined. Straylight and light loss were evaluated as predictors of optical impairment. The individual amount of calcium and phosphorus was determined using thermogravimetry followed by emission spectroscopy (ICP-OES). The relationship between calcification and optical impairment was investigated. Primary calcified IOLs contained significantly higher amounts of calcium and phosphorus compared to secondary calcified IOLs (calcium P < 0.02 and phosphorus P < 0.01), translating to greater light loss and significantly higher straylight mean values. In secondary calcification, light loss and straylight were highly dependent on calcium (r² = 0.90, P < 0.001 and r² = 0.70, P < 0.01) and phosphorus (r² = 0.66 and r² = 0.65, both P < 0.02), whereas these correlations were much lower in primary calcification (all r = 0.25, P > 0.05). ICP-OES is the first methodology to precisely assess the calcium and phosphorus content in IOL calcification thus based on mass ratios allowing improved molecular characterization. Primary calcification showed higher amounts of calcium and phosphorus, translating to higher straylight and light loss and thus a higher risk for impairment of visual quality than secondary calcification. This study is the first to quantify calcification and demonstrate the relationship to optical deterioration in IOLs, substantially contributing to understand how visual impairment arises in patients with calcified IOLs.

Rotational stability of plate-haptic toric intraocular lenses implantation with a capsular tension ring: a prospective randomized paired-eye study.

To compare the rotational stability and visual outcomes of plate-haptic toric intraocular lenses (IOLs) with and without a capsular tension ring (CTR) in paired eyes. Eye and Ears, Nose, and Throat Hospital of Fudan University, Shanghai, China. Prospective, randomized, paired-eye study. Patients with bilateral cataracts and coexisting regular corneal astigmatism were enrolled. The two eyes of each patient were randomly assigned to the CTR or non-CTR (NCTR) group. Both eyes of each patient were subjected to phacoemulsification and toric IOL implantation. CTRs were implanted into the eyes of the CTR group. All patients were followed-up for 12 months; the uncorrected distance visual acuity (UDVA), residual astigmatism (RAS), and rotational degree of the toric IOL were recorded. In total, 186 eyes of 93 patients were eligible for analysis. At each visit, UDVA improved significantly after surgery in all eyes (p < 0.001). The mean rotational degree and RAS were significantly smaller in the CTR group at the 2-week visit (p < 0.05). The toric IOLs achieved rotational stability at 1 week postoperatively in the CTR group while at 2 weeks postoperatively in the NCTR group. In the subgroup analyses, CTR co-implantation significantly reduced the 2-week IOL rotation in eyes meeting specific ocular measurements. CTR co-implantation could increase the rotational stability of plate-haptic toric IOLs, by reducing the amount of the IOL rotation in the early postoperative period and accelerating the stabilization of IOLs in the capsular bag.

Hierarchy-constructed superhydrophobic and transparent coating modified intraocular lens by layer-by-layer self-assembly for glistening reduction and antiadhesion

Intraocular lens (IOL) implantation surgery is the most effective treatment for cataract. However, glistening formed by the incoming liquid microvacuoles can significantly damage postoperative visual quality after prolonged implantation, for which there is still lack of effective clinical treatment. In this study, inspired by the amazing water-repellency of natural superhydrophobic surface, a functionalized IOL material modified with the superhydrophobic and transparent coating was prepared using layer-by-layer electrostatic self-assembly technique combined with fluorination. After the alternate deposition of multiple cationic/anionic polyelectrolytes and silica nanoparticles of varying sizes on IOL materials, the constructed multilayered films with special surface roughness were further fluorinated to reduce surface energy. In addition to its excellent superhydrophobicity and transparency, this multilayered coating could efficiently eliminate the glistening formation of IOL under accelerated condition in vitro. Furthermore, the in vitro experiments with water droplets, cells, and bacteria suggested the superior antiadhesion property of such coating modified materials. The biocompatibility evaluation, both in vitro and in vivo, demonstrated the great biocompatibility of the materials modified with superhydrophobic and transparent coating. Therefore, this multilayered coating with excellent superhydrophobic and transparent characteristics can provide an available approach aiming at anti-glistening and antiadhesion of IOL materials. Advances in the fabrication process of surface coating with specific functions will enhance the practical application and clinical success of modified IOLs.

Power profile and optical performance of two extended range-of-vision intraocular lens designs.

To assess the power profile and optical performance of 2 extended range-of-vision (ERV) intraocular lenses (IOLs), TECNIS Eyhance (ICB00) and LuxSmart, and compare them with their monofocal counterpart lenses with similar platforms and materials: TECNIS 1-piece (ZCB00) and LuxGood, respectively. Optics and Optometry Faculties of Complutense University (Madrid) and Universitat Politècnica de Catalunya BarcelonaTech (Terrassa) in Spain. Laboratory investigation on optical bench. For each design, the power distribution and (fourth and sixth-order) spherical aberration (SA) across the lens aperture were measured as well as the optical performance using modulation transfer function-based metrics with through-focus evaluation. 3 nominal powers (+10.00 diopters [D], +20.00 D, and +30.00 D) and 3 pupil sizes (2.0 mm, 3.0 mm, and 4.5 mm) were considered to assess whether the base power of the lens and pupillary dynamics have an influence on the depth-of-focus extension. TECNIS Eyhance and LuxSmart IOLs had different power and SA profiles, but both designs shared a positive add power in their central region in comparison with their monofocal counterparts. LuxSmart had a greater add power while TECNIS Eyhance showed higher peak optical quality but smaller depth of focus. Differences of focus extension between the 2 ERV IOL designs are related to differences of power and SA profile. The nominal base power of the IOLs has little effect on their optical quality. However, pupil dynamics plays a key role since it determines the effective add power and optical performance of the ERV IOLs.

Prospective Evaluation of Clinical and Patient-Reported Outcomes Following Contralateral Implantation of an Extended Depth of Focus (EDOF) and Hybrid EDOF-Multifocal IOL.

To evaluate clinical outcomes following contralateral implantation of a diffractive extended depth of focus (EDOF) and a hybrid EDOF-multifocal intraocular lens (IOL) with a violet filter in a U.S.-based population. In this prospective, non-comparative study, 60 eyes of 30 patients aged 40 years and older underwent bilateral cataract surgery and implantation of a DXR00V IOL (Tecnis Symfony OptiBlue) in the dominant eye and a DFR00V (Tecnis Synergy) IOL in the non-dominant eye. Outcome measures included uncorrected (UDVA) and corrected (CDVA) distance visual acuity, distance-corrected intermediate (DCIVA, 66 cm), near and very near visual acuity (DCNVA, 40 and 33 cm), and patient-reported outcomes. At 6 months postoperatively, binocular mean UDVA and CDVA were -0.10 ± 0.07 and -0.11 ± 0.05 logarithm of the minimum angle of resolution (logMAR), respectively. The mean DCIVA was 0.26 ± 0.08 logMAR in the DXR00V eyes and 0.23 ± 0.06 logMAR in the DFR00V eyes. The mean DCNVA at 40 and 33 cm were 0.28 ± 0.12 and 0.30 ± 0.15 logMAR, respectively, in the DXR00V eyes and 0.07 ± 0.08 and 0.07 ± 0.10 logMAR, respectively, in the DFR00V eyes. The mean binocular DCIVA and DCNVA at 33 and 40 cm were 0.18 ± 0.05, 0.06 ± 0.08, and 0.06 ± 0.07 logMAR, respectively. The percentages of patients achieving spectacle independence at far, intermediate, and near distances were 100%, 100%, and 81%, respectively. Contralateral implantation of the diffractive EDOF and a hybrid EDOF-multifocal IOL yielded excellent binocular visual acuity at all distances, as well as high patient satisfaction and functional performance on visual tasks. [J Refract Surg. 2024;40(10):e699-e705.].

Evaluation of Intermediate Visual Outcomes in Eyes Implanted with Bilateral Advanced Monofocal Intraocular Lens Targeting for Mini-Monovision and Its Association with Age and Corneal Asphericity.

To assess the visualoutcomes in patients bilaterally implanted with novel Clareon® intraocular lens when targeting mini monovision post-operatively. The study was conducted at Laxmi Eye Institute; itis a tertiary care eye institution in Panvel, India. This is an investigator initiated, prospective, single-centre longitudinal study of 45 patients to assess the visual outcomes in patients who were implanted with Clareon ® IOL bilaterally. Patients with corneal astigmatism of ≤0.75 D who underwent bilateral cataract surgery with pseudophakic mini-monovision and implanted with novel Clareon® intraocular lens were included. Patients having post op manifest refraction >±0.25 D in the dominant eye and <-0.5 D or >-0.75 D in the non-dominant eye were excluded. The main study outcomes were assessed at 1 and 3 months; itincluded uncorrected visual acuities assessment, defocus curve, and patient reported spectacle use. The mean (SD) binocular distance corrected intermediate visual acuity at 3 months was 0.22 (0.09) LogMAR. At 3 months, 54% of patients enjoyed 0.4 LogMAR or better BUCNVA. The defocus curve showed good distance and intermediate visual acuity with >0.2 LogMAR vision from +0.50 D to -1.50 D. We found a positive correlation between the Q value of the dominant eye and the BCIVA at 3 months postoperatively, however it was not statistically significant. The Q value was more negative when the intermediate vision was closer to 0 LogMAR. Post operatively, at3 months,95% patients did not need glasses for distance and intermediate vision and 73% of patients were comfortable for intermediate vision without glasses all the time. Mini-monovision with Clareon® monofocal IOL implantation can offer overall satisfactory vision for far and intermediate distances with minimal need for use of spectacles for near vision.

Clinical Performance of an Extended Range of Vision Intraocular Lens After LASIK.

To evaluate the clinical and patient-reported outcomes (PROMs) of cataract surgery with implantation of a wavefront-shaping extended depth of focus (EDOF) intraocular lens (IOL) in eyes with previous laser in situ keratomileusis (LASIK) for myopia correction. This prospective observational study enrolled 50 eyes with previous LASIK from 25 patients (age: 46 to 70 years) who underwent cataract surgery with implantation of the AcrySof IQ Vivity IOL (Alcon Laboratories, Inc). Visual and refractive outcomes were evaluated during a 3-month follow-up. PROMs were evaluated with the Intraocular Lens Satisfaction (IOLSAT; Alcon Vision, LLC) (general satisfaction), Catquest-9SF (difficulty in doing vision-related activities), and Questionnaire for Visual Disturbances (QUVID; Alcon Vision, LLC) (photic phenomena) questionnaires. Mean 3-month postoperative binocular uncorrected distance, intermediate, and near visual acuities were 0.02 ± 0.11, -0.02 ± 0.09, and 0.14 ± 0.13 logarithm of the minimum angle of resolution (logMAR), respectively. Mean binocular distance-corrected intermediate and near visual acuities were 0.05 ± 0.11 and 0.32 ± 0.14 logMAR, respectively. All eyes had a postoperative spherical equivalent within ±0.75 diopters (D). The mean defocus curve showed visual acuity values better than 0.20 logMAR for defocus levels from +0.50 to -1.50 D. Most patients (92.0%) confirmed that they had no vision-related difficulties limiting their normal daily life. Perception of starbursts, halos, glare, hazy vision, blurry vision, and double vision was referred by 24%, 24%, 28%, 28%, 8%, and 4% of patients, respectively. Most of symptoms were described as mild and not or a little bothersome. The wavefront-shaping EDOF IOL evaluated provides efficacious distance, intermediate, and near visual restoration in eyes with previous LASIK, with minimal photic phenomena associated. [J Refract Surg. 2024;40(10):e742-e753.].

Distribution of Ocular Biometry and Intraocular Lens Power in Patients Undergoing Cataract Surgery in an Eye Camp in Northern Pakistan

Purpose: To report ocular biometric data of patients undergoing cataract surgery in an eye camp in a city of Northern area of Pakistan. Design: Cross-sectional descriptive study. Place and Duration of Study: A surgical eye camp was set up in the month of September 2022 for 6 days in a private hospital in Skardu. Methods: A total of 119 patients were selected with a non-probability consecutive sampling technique. Ocular biometry of permanent local residents with significant cataractswas included. Incomplete biometry data and coexisting diseases like corneal opacity, pterygium, and severe dry eye causing errors in biometry were excluded. Keratometry was done with an automated refractor-keratometer. Axial length was calculated with an A-scan (ultrasound contact method) and intraocular lens (IOL) power was calculated. Results: A total of 119 patients were selected for biometry among 3908 individuals visiting an eye camp. The mean axial length was 22.13 ± 1.25 SD mm. The mean keratometry readings (K1) was 43.28 ± 1.83 Diopter and (K2) 44.26 ± 1.67 D. The mean intraocular lens (IOL) power was 24.78 ± 3.43 D. The mean K readings were more in males as compared to females (p-value &lt;0.005). There was no significant difference in axial length and IOL power among genders. Conclusion: This study gives normative data on ocular biometric parameters of patients undergoing cataract surgery at high altitudes in Skardu, Pakistan. These biometric values can be used as reference values in the local population

Through-focus performance and off-axis effects in aspheric monofocal intraocular lenses.

This study aimed to determine the through-focus performance and the effect of misalignment on the optical quality of different aspheric monofocal intraocular lenses (IOLs). To this end, optical quality was assessed in three IOL models with different optic surfaces: standard aberration neutral model and two spherical aberration (SA) correcting, one of which utilizes higher-order aspheric terms. The optical quality was measured by means of the modulation transfer function at 3- and 4.5-mm pupils and under monochromatic and polychromatic light with different corneal SA. The optically derived range of vision and tolerance to misalignment were also tested. The study demonstrated that the type of IOL surface affects the monofocal implant's performance. Although a standard primary-SA correction may improve scotopic image quality, misalignment may diminish this advantage. The higher-order aspheric surface used to correct SA provided an improved performance against decentration and offered a higher optical quality than the aberration-neutral design when tested in a model eye. The latter, however, demonstrated a high tolerance to misalignment, offering a slight extension of the range of vision, potentially resulting from uncorrected optical aberrations.

Phakic intraocular lens exchange due to severe uveitis/inflammation: case report

Introduction: Phakic intraocular lenses (IOLs) provide excellent visual and refractive outcomes with a high safety profile. This report illustrates a case of a rare episode of severe anterior segment inflammation after iris-claw foldable lens implantation, which required surgical reintervention. Patient and Clinical Findings: A 22-year-old woman was submitted to Artiflex implantation for the correction of myopia. Three months postoperatively, a severe anterior segment inflammation developed with pigment deposition, pupillary membrane formation, and decreased visual acuity in the left eye. Diagnosis, Intervention, and Outcomes: Given the nonresponse to medical treatment (topical and systemic corticosteroid for 3 months), surgical explantation of the IOL with peeling of a pigmentary membrane over the crystalline lens was performed. During a 24-month follow-up period, the patient was monitored to exclude the development of cataract or glaucoma. Afterward, an implantable collamer lens was implanted with an uneventful intraoperative and postoperative period. During the long-term follow-up, no further pigment dispersion, uveitis, or cataract was described. Conclusions: Persistent anterior uveitis with pigmentary membrane formation after iris-claw lens implantation is a rare complication. IOL explantation needs to be considered to prevent further sequelae after severe uveitis when the situation is unresponsive to medical treatment.

Intraoperative Aberrometry versus Preoperative Biometry for Intraocular Lens Power Calculations: A Report by the American Academy of Ophthalmology

To evaluate the published literature to compare intraoperative aberrometry (IA) with preoperative biometry-based formulas with respect to intraocular lens (IOL) power calculation accuracy for various clinical scenarios. Literature searches in the PubMed database conducted in August 2022, July 2023, and February 2024 identified 157, 18, and 6 citations, respectively. These were reviewed in abstract form, and 61 articles were selected for full-text review. Of these, 29 met the criteria for inclusion in this assessment. The panel methodologists assigned a level of evidence rating to each of the articles; 4 were rated level I, 19 were rated level II, and 6 were rated level III. Intraoperative aberrometry performed better than traditional vergence formulas, including the Haigis, HofferQ, Holladay, and SRK/T, and similarly to the Barrett Universal II and Hill-RBF with respect to minimization of spherical equivalent (SE) refractive error. For toric IOLs, IA outperformed formulas that only considered anterior corneal astigmatism and was similar to formulas like the Barrett Toric Calculator (BTC), which empirically account for the contribution from the posterior cornea. In eyes with a history of corneal refractive surgery, IA performed similarly to the Barrett True-K and slightly better than other tested methods, including the Haigis-L, Shammas, and Wang-Koch-Maloney formulas. Intraoperative aberrometry corresponds well with modern vergence formulas, including the Barrett Universal II, Hill-RBF, BTC, and Barrett True-K. It has greater accuracy than traditional vergence-based IOL power calculation formulas in eyes with and without a history of corneal refractive surgery. Proprietary or commercial disclosure may be found after the references.

Comparison Between Monofocal and Aspheric Monofocal Intraocular Lens With Higher Order Aspheric Optic in Pediatric Patients: Early Outcomes.

To retrospectively compare the visual acuity outcomes for far, intermediate, and near vision of an aspheric monofocal intraocular lens (IOL) with higher order aspheric optic with a monofocal IOL in pediatric patients. Thirty-eight eyes of 38 patients (mean age: 9.0 ± 2.3 years) affected by monolateral infantile cataract were evaluated 6 months after surgery performed with simultaneous IOL implantation. The Tecnis Eyhance ICB00 aspheric monofocal IOL (Johnson & Johnson Vision) was implanted in 17 eyes (Tecnis Eyhance group, mean age: 8.9 ± 2.5 years) and the Tecnis PCB00 monofocal IOL (Johnson & Johnson Vision) was implanted in 21 eyes (control group, mean age: 9.1 ± 2.2 years). Corrected visual acuity expressed in logarithm of the minimum angle of resolution (logMAR) was assessed for distance (CDVA) and, expressed in Jaeger standard, for intermediate (DCIVA) and near vision (CNVA). DCIVA was measured with distance correction and without addition. The Mann-Whitney test for two independent samples was performed, and a P value less than .05 was considered statistically significant. Six months postoperatively, mean CDVA was 0.20 ± 0.2 logMAR and mean DCIVA and CNVA were 5 ± 1 and 2 ± 1 Jaeger, respectively, in the Tecnis Eyhance group. In the control group, mean CDVA was 0.21 ± 0.2 logMAR and mean DCIVA and CNVA were 8 ± 1 and 3 ± 1 Jaeger, respectively. Only DCIVA showed a significant statistical difference between groups (P < .0001). In pediatric patients, the aspheric monofocal IOL with higher order aspheric optic seems to provide better intermediate distance visual acuity than a monofocal one, whereas no significant difference was observed for CDVA and CNVA. [J Refract Surg. 2024;40(10):e724-e727.].

Evaluation of Visual Outcomes in Patients With Aberrated Corneas Implanted With the IC-8 Small-Aperture IOL.

To assess the visual outcomes in patients with cataract implanted with a small-aperture intraocular lens (IOL) in eyes with aberrated corneas. This prospective, non-interventional, single-center clinical study was conducted at Singapore National Eye Centre, Singapore. Twenty-one patients with aberrated corneas had IC-8 IOL (Bausch & Lomb, Inc) implantation. An aberrated cornea was defined as from natural causes: keratoconus (n = 1, 4.8%), high coma (n = 2, 9.5%), corneal scar (n = 1, 4.8%), or iatrogenic causes: keratorefractive procedure (n = 17, 86%). Uncorrected and corrected visual acuities were measured at distance (600 cm) (UDVA and CDVA), intermediate (66.7 cm) (UIVA and CIVA), and near (40 cm) (UNVA and CIVA). Defocus curve was tested monocularly and binocularly. Contrast sensitivity (CS) was measured under photopic and mesopic conditions with and without glare. In IC-8 eyes, the mean ± standard deviation UDVA, UIVA, and UNVA was 0.24 ± 0.18, 0.19 ± 0.18, and 0.14 ± 0.14 logMAR, respectively. Mean CDVA, CIVA, and CNVA in IC-8 eyes was 0.12 ± 0.17, 0.16 ± 0.15, and 0.19 ± 0.13 logMAR, respectively. Binocular mean UDVA, UIVA, and UNVA was 0.07 ± 0.10, 0.07 ± 0.10, and 0.13 ± 0.12 logMAR, respectively. Defocus curve testing yielded a depth of focus of 1.50 D monocularly and 2.00 D binocularly at a 0.2 logMAR threshold. Photopic binocular CS with and without glare improved over monocular CS of IC-8 and fellow eyes under all spatial frequencies. Mesopic binocular CS with and without glare were similar among monocular IC-8 and fellow eyes across spatial frequencies. Most patients reported low levels of visual symptoms. The IC-8 IOL provides good monocular and binocular visual outcomes for patients with cataract who had aberrated corneas. [J Refract Surg. 2024;40(10):e716-e723.].

Visual, Refractive, Functional, and Patient Satisfaction Outcomes After Implantation of a New Trifocal Diffractive Intraocular Lens.

To describe the visual, refractive, functional, and patient satisfaction outcomes of the Clareon® PanOptix® trifocal intraocular lens (IOL). This was a prospective longitudinal descriptive study. Patients who underwent cataract surgery with implantation of Clareon® PanOptix® (Alcon Laboratories, Inc.) were included. Monocular refractive outcomes and visual acuity at distance, intermediate, and near were evaluated 1- and 6-months post-op. Binocular contrast sensitivity (M&S® Technologies), binocular defocus curve, and patient satisfaction with the IOL Satisfaction (IOLSAT) and Questionnaire for Visual Disturbance (QUVID) questionaries were assessed at 6-month post-op. Seventy-six Clareon® PanOptix® were implanted bilaterally in 38 patients. The mean age of the patients was 67.63±5.18 years. At 1-month post-op, the monocular Corrected Distance Visual Acuity (CDVA), CIVA and CNVA were 0.00±0.09, 0.02±0.17, and 0.12±0.12 LogMAR, respectively, and CDVA and CNVA were stable at 6-month post-op (p>0.05). No statistical differences were found in post-op spherical equivalent at 1 and 6 months (-0.08±0.27 D and -0.05±0.24 D; p=0.351). A 100% of eyes were within ±0.5 D at 1 month and 6-month post-op. Binocular defocus curve shows three peaks of maximum visual acuity (VA) at 0D (-0.04±0.08 LogMAR), at -1.50D, and -2.50 D (0.01±0.10 LogMAR and 0.03±0.07 LogMAR, respectively). Contrast sensitivity decreased at high spatial frequencies. In patient satisfaction, IOLSAT questionary reveals 78.94% patients "Never" or "Rarely" Needing Glasses and according QUVID questionnaire, 100% of patients report no hazy vision. The PanOptix® IOL platform with the new material Clareon® provides good visual outcomes for distance, intermediate, and near vision, with adequate contrast sensitivity and low visual disturbances.

Unintended placement of intraocular lens haptics in the sulcus and its association with posterior capsular opacification in pseudophakic post-mortem eyes

ObjectiveTo assess the prevalence of unintended placement of intraocular lens (IOL) haptics in the sulcus and its association with posterior capsular opacification (PCO). DesignCross-sectional study. Participants428 post-mortem pseudophakic human eyes. MethodsEyes were obtained from the Lions Gift of Sight and imaged in Miyake-Apple view (MAV). IOL haptic placement (bag–bag, bag–sulcus, sulcus–sulcus) was determined from the MAV images. IOL-capsular bag complexes were extracted and analyzed via Automated Detector Opacification Software to quantify PCO and Soemmering's Ring (SR). SR distribution was categorized as focal, diffuse, or none. Mean differences in PCO and SR between haptic groups were assessed via Welch's t-test. Odds ratios were used to compare the risk of SR distribution patterns between both haptic groups. Sex, clinical history (diabetes, smoking, hypertension, glaucoma, cancer, age-related macular degeneration [AMD], hypercholesterolemia, cardiovascular disease), and IOL model and specifications were collected. Results20 eyes (4.67%) had unintended sulcus placement of haptics. Mean PCO (p = 0.0367) and SR (p = 0.0414) were significantly higher in sulcus eyes. Sulcus eyes were significantly more at risk of focal SR distribution (OR 8.715; p < 0.0001) and significantly less at risk of diffuse SR distribution (OR 0.168; p = .0007). Sulcus eyes had significantly higher frequencies of glaucoma (p < 0.0001) and AMD (p = 0.0023) on clinical history. ConclusionsThis study demonstrates that unintended sulcus placement of IOL haptics may be associated with an increased risk of PCO and SR formation. This study offers clinical signs of sulcus haptic placement that may prompt physicians to seek earlier appropriate intervention.

Prediction of vaults in eyes with vertical implantable collamer lens implantation.

To design formulas for predicting postoperative vaults in vertical Implantable Collamer Lens (ICL) implantation and to achieve more precise predictions using machine learning models. Retrospective observational study. XXXX (anonymized for review). We retrospectively reviewed the medical records of 720 eyes in 408 patients who underwent vertical ICL implantation. The data included age, sex, refractions, anterior segment biometric data, and surgical records. We designed three formulas (named V1-V3 formulas) using multiple linear regression analysis, and tested four machine learning models. Predicted vaults by V1-V3 formulas were 444.17 ± 93.83 μm, 444.08 ± 98.64 μm, and 444.27 ± 108.81 μm, with mean absolute error of 127.97 ± 107.92, 126.41 ± 105.86, and 122.90 ± 103.00 μm. There were no significant differences in error among the V1-V3 formulas, despite the fact that the V1 and V2 formulas referred to limited parameters (three and four, respectively), and the V3 formula referred to all 12 parameters. Two of four machine learning models, XGBoost and Random Forest Regressor, showed a better performance in predicted vaults: 444.52 ± 120.51 and 446.00 ± 102.55 μm and mean absolute error: 118.31 ± 100.55 and 118.63 ± 99.34 μm, respectively. This is the first study to design V1-V3 formulas for vertical ICL implantation. The V1 and V2 formulas exhibited good performance despite the limited parameters. In addition, two of the four machine learning models predicted more precise results.

Cost-effectiveness of low-astigmatism correction with toric or spherical intraocular lenses combined with corneal incisions: an economic evaluation.

To assess the cost-effectiveness of the treatment of low corneal astigmatism (≤1.5 diopters) at the moment of cataract surgery. Qvision, Ophthalmology Department, VITHAS Almería Hospital, Spain. Economic evaluation. A decision tree was used to assess the cost-effectiveness of implanting spherical vs toric intraocular lenses (IOLs) or spherical lens combined with the following corneal incisions: limbal-relaxing incisions conducted manually (M-LRI) or assisted by femtosecond laser (F-LRI), arcuate keratotomies conducted manually (M-AK) or assisted by femtosecond laser (F-AK), and intrastromal arcuate keratotomies (F-iAK). Outcomes of cost were selected from a patient perspective considering the gross cost of each one of the surgeries at European centers, and the effectiveness variable was the probability of achieving a visual acuity of 20/20 postoperatively. A sensitivity analysis was conducted to assess the uncertainty considering the evidence retrieved from the transition probabilities of the model, effectiveness, and cost. F-AK or toric IOLs were the most effective treatments, increasing an 16% or 9%, respectively, in the percentage of eyes attaining 20/20 vision. The M-LRI, F-iAK, and F-LRI procedures were strongly dominated while the M-AK and toric IOL were weakly dominated by the F-AK. A patient with low corneal astigmatism would need to be willing to pay 360€ (95% CI, 231-1224) with F-AK and 472€ (95% CI, 149-4490) with toric IOLs for a 10% increase in the probability of achieving 20/20 vision. From patient perspective, F-AK was generally the most cost-effective treatment, although toric IOLs can dominate in some countries.

TiO2-Nanoparticle-Enhanced Sonodynamic Therapy for Prevention of Posterior Capsular Opacification and Ferroptosis Exploration of Its Mechanism.

To explore the application and potential ferroptosis mechanisms of sonodynamic therapy (SDT) using titanium dioxide nanoparticles (TiO2-NPs) as sonosensitizers for the prevention of posterior capsule opacification (PCO). We fabricated TiO2-NP-coated intraocular lenses (TiO2-IOLs) using the spin-coating method, followed by ultrasound activation of the photosensitizer TiO2. In vitro experiments were performed with human lens epithelial cells (HLECs) to explore the appropriate concentration of TiO2 and ultrasonic parameters. Investigations included reactive oxygen species (ROS) generation, glutathione (GSH) depletion, glutathione peroxidase 4 (GPX4) western blot analysis, lipid peroxidation assays, and transcriptomics analysis. Finally, TiO2-IOLs were implanted in rabbit eyes to explore the in vivo performance of SDT. Through both in vitro and in vivo experiments, the study determined that the ultrasound parameters of 5-minute duration, 1-MHz frequency, 50% duty cycle, and 1.2-W/cm2 intensity were reliable and valid for killing HLECs without damaging other ocular structures. In vitro experiments demonstrated that SDT generated excess ROS, which disrupted the mitochondrial membrane potential and significantly reduced the GSH content. Additionally, the downregulation of GPX4, accumulation of lipid peroxides, and alteration of mitochondrial morphology were observed, suggesting that ferroptosis may be the underlying mechanism. The RNA-sequencing analysis results also showed an increase in the expression of multiple pro-ferroptosis genes and the ferroptosis marker gene PTGS2. Animal experiments preliminarily demonstrated the safety and effectiveness of SDT in treating PCO in vivo. TiO2-IOLs combined with SDT effectively prevented PCO by generating ROS and intracellular ferroptosis.

One-Year Results of a Posterior Chamber Toric Phakic Intraocular Lens Implantation in Patients with Keratoconus.

To determine clinical and refractive results after the implantation of EyeCryl Phakic Toric intraocular lens in patients with stable keratoconus. The study included all patients diagnosed with keratoconus who underwent implantation of an EyeCryl Phakic Toric intraocular lens (Biotech Healthcare Holding; Ahmedabad, India) in at least one eye and had a follow-up of at least 12 months. Visual and refractive data were collected for all patients, along with corneal tomography measurements using Pentacam, and vault measurement using optical coherence tomography. This retrospective study was conducted at a high-volume private refractive surgery center in Medellín, Colombia. A total of 83 eyes from 47 patients were included in the study. The majority (71.1%) were female, with a mean age of 31.2 ± 5.1 years. After 12 months of follow-up post-surgery, the spherical equivalent improved significantly from -8.19 ± 4.04 D to -0.06 ± 0.48 D (p < 0.001). Furthermore, 77% of eyes had a post-surgical spherical equivalent within ±0.50 D, while 92% had residual astigmatism ≤0.50 D. Twelve months after surgery, mean manifest astigmatism was -0.28 ± 0.27 D. Uncorrected visual acuity also showed improvement, from 1.11 ± 0.35 LogMAR to 0.14 ± 0.11 LogMAR. Moreover, 52.4% of eyes demonstrated an improvement of at least one line in best-corrected visual acuity. Notably, no intraoperative or postoperative complications were observed in the study population. The implantation of EyeCryl Phakic Toric intraocular lenses represents a highly effective and safe option for correcting refractive errors in patients with a history of keratoconus. Refractive accuracy is excellent, and a significant proportion of patients experienced an improvement in their best-corrected vision by at least one line.

Comparison of the Accuracy Between the Z CALC2 Calculator and Barrett Toric Calculator in Toric IOL Calculation.

To compare the accuracy of the Z CALC2 calculator and Barrett toric calculator in toric intraocular lens (IOL) calculation. Eighty-five eyes of 85 patients who underwent uneventful cataract surgery with toric IOL implantation were included. The accuracy was compared between the Z CALC2 calculator and Barrett toric calculator under two calculation modes: using simulated keratometry (SimK) from the IOLMaster 700 (Carl Zeiss Meditec AG) for posterior corneal astigmatism (PCA) prediction and employing total corneal astigmatism (total corneal refractive power [TCRP] or measured PCA) obtained from the Pentacam (Oculus Optikgeräte GmbH). The centroid of prediction errors, percentage of eyes with prediction errors within ±0.50 diopter (D), mean prediction error, and mean absolute prediction error were calculated. Subgroup analysis was conducted based on the orientation and magnitude of anterior corneal astigmatism and axial length. When using SimK, the two calculators with predicted PCA showed comparable accuracy. When employing total corneal astigmatism, the Barrett toric calculator with measured PCA showed a lower centroid error (0.15 vs 0.38 D), a higher percentage of eyes with prediction errors within ±0.50 D (47.1% vs 32.9%, P = .018), and a lower mean prediction error (0.57 vs 0.71 D, P = .033) compared to the Z CALC2 calculator with TCRP in the 4-mm zone. In subgroup analysis, when employing total corneal astigmatism, the Barrett toric calculator with measured PCA exhibited superior accuracy, especially in the with-the-rule and anterior corneal astigmatism of 2.00 D or less subgroups. When using SimK, the Z CALC2 calculator and Barrett toric calculator yield comparable accuracy. The Barrett toric calculator with measured PCA may be more recommended when employing total corneal astigmatism. [J Refract Surg. 2024;40(10):e681-e691.].