Refractive Outcomes after Cataract Surgery

Cataract Surgery in the Small Adult Eye: A Review

Modern cataract surgery continues to advance, yet intraocular lens (IOL) based surgery in the small adult eye remains challenging. Thorough preoperative assessment and surgical preparation optimise postoperative outcomes in these cases. Advances in IOL power calculation, including artificial intelligence-driven formulas, improve accuracy; however, careful consideration of biometry and IOL power selection is still necessary because inaccuracies can produce significant errors. Limited availability of high-powered IOLs to fully correct high refractive errors may necessitate further intervention. Surgical techniques have evolved to address the unique anatomical challenges of small eyes, improving safety and outcomes. Knowledge of the potential risks inherent in these cases can assist the surgeon in modifying the operative technique accordingly. This review discusses essential preoperative assessments, IOL power selection, surgical techniques, and potential complications, offering guidance for surgeons performing cataract surgery on small adult eyes.

Advanced Artificial-Intelligence-Based Jiang Formula for Intraocular Lens Power in Congenital Ectopia Lentis

Purpose

The purpose of this study was to develop an artificial intelligence (AI)-based intraocular lens (IOLs) power calculation formula for improving the accuracy of IOLs power calculations in patients with congenital ectopia lentis (CEL).

Methods

A total of 651 eyes with CEL that underwent IOLs implantation surgery were included in this study. An AI-based ensemble formula-the Jiang Formula, was developed using a training dataset of 520 eyes and evaluated on a testing dataset of 131 eyes. A five-fold cross-validation and a two-layer ensemble learning model were constructed. The formula was then tested in a test set and compared against five current classic formulas.

Results

The cohort included young patients (mean age = 14.38 ± 13.35 years). The Jiang Formula showed the lowest prediction error (PE; = 0.08 ± 1.01 diopters [D]), absolute error (AE; = 0.77 ± 0.65 D), median absolute error (MedAE; = 0.66 D), and root mean square error (RMSE; = 1.02 D) among six formulas (P < 0.001). Moreover, 68.00% of the eyes in the test set had AE within 1.0 D in the Jiang Formula.

Conclusions

AI-integrated two-layer ensemble learning model demonstrates promising applications in IOLs power calculations for patients with CEL, not only providing higher predictive accuracy than current classic formulas but also accommodating extreme values and variations in surgical techniques.

Translational Relevance

The Jiang Formula, an AI-integrated two-layer ensemble learning model, enhances IOLs power calculation accuracy in patients with CEL, ultimately improving surgical outcomes and supporting more effective, personalized treatment in this unique patient group.

Visual Performance and Patient Satisfaction of Bilaterally Implanted Extended Depth of Focus Intraocular Lens: Outcomes of a Multicenter Registry

PURPOSE

To evaluate visual performance, patient satisfaction, and spectacle independence in patients bilaterally implanted with AcrySof IQ Vivity intraocular lenses (IOLs) (Alcon Laboratories, Inc) during cataract or refractive lens exchange (RLE) surgery.

METHODS

This multicenter, ambispective, non-interventional registry study was conducted in Europe, Australia, and New Zealand. At the first follow-up visit, occurring between 3 and 6 months after IOL implantation, binocular uncorrected and corrected distance visual acuities at distance (UDVA/CDVA), intermediate (UIVA/DIVA 66 cm), and near (UNVA/DNVA 40 cm) were evaluated using the logarithm of the minimum angle of resolution (logMAR) chart. Patient satisfaction, spectacle independence, visual disturbances, and device deficiencies were also assessed.

RESULTS

The final analysis included 885 patients, with 790 (89.3%) and 82 (9.3%) patients who underwent cataract and RLE, respectively, where approximately 30% had one or more ocular comorbidity. Mean ± standard deviation logMAR (Snellen) UDVA, UIVA, and UNVA were 0.012 ± 0.102 (∼20/20), 0.088 ± 0.118 (∼20/25), and 0.256 ± 0.154 (∼20/40) for the cataract cohort and -0.005 ± 0.088 (∼20/20), 0.054 ± 0.141 (∼20/25), and 0.213 ± 0.151 (∼20/32) for the RLE cohort, respectively. The proportion of patients reporting spectacle independence at distance, intermediate, and near was 87.9%, 77.6%, and 46.1% for the cataract and 86.6%, 79.3%, and 59.8% for the RLE cohorts. The majority of patients among the cataract (92.1%) and RLE (85.4%) cohorts were satisfied with their postoperative sight, whereas 91.8% of the cataract and 84.1% of the RLE cohort reported no visual disturbances. No device deficiencies were reported.

CONCLUSIONS

In this real-world study, patients bilaterally implanted with AcrySof IQ Vivity IOLs demonstrated good visual performance and the majority reported spectacle independence for distance to intermediate, high visual satisfaction, and low levels of visual disturbances across both cohorts, despite approximately 30% who reported 1 or greater ocular comorbidity. [J Refract Surg. 2025;41(2):e131-e143.].

Capsular Bag Performance of a Novel Hydrophobic Single-Piece Intraocular Lens

INTRODUCTION

We conducted an evaluation of capsular bag performance of the Clareon CNA0T0 intraocular lens (IOL), focusing on postoperative anterior chamber depth (ACD), IOL tilt, and IOL decentration.

METHODS

Inclusion criteria were bilateral age-related cataract and the ability to provide informed consent. Exclusion criteria were prior surgeries, combined surgeries, and conditions posing a risk for postoperative capsular bag instability. Preoperative and 8-week postoperative assessments included optical biometry and high-resolution anterior segment optical coherence tomography (OCT). Subjective refraction was conducted only at 8 weeks postoperative visit.

RESULTS

In the first analysis, 49 right eyes of 49 patients were included. Mean preoperative and postoperative ACD were 3.10 and 4.69 mm, respectively. Mean preoperative tilt was 4.77°, increasing to 5.06° postoperatively. Preoperative decentration was 0.16 mm, increasing to 0.26 mm postoperatively. Absolute refractive error (ARE) was + 0.31D, with 81% of eyes within ± 0.5D limits. In analysis II (98 eyes of 49 patients), both eyes showed a moderate correlation in IOL tilt (Pearson correlation coefficient: 0.27, p = 0.061) and a low correlation in IOL decentration (Pearson correlation coefficient: 0.02, p = 0.892) and ARE (Spearman: 0.15, p = 305) between right and left eyes of the same patient.

CONCLUSIONS

The Clareon CNA0T0 IOL demonstrated high mechanical stability, with low postoperative tilt and decentration values, resulting in excellent refractive outcomes and visual acuity. These findings confirm the IOL's high stability within the capsular bag and effectiveness in minimizing postoperative refractive error, requiring only minor A-constant adjustments for optimal cataract surgery outcomes.

TRIAL REGISTRATION

NCT06595693.

Screening for Occult Macular Pathology Prior to Cataract Surgery Using Optical Coherence Tomography

Purpose

To study the prevalence of occult macular pathology using optical coherence tomography (OCT) during the preoperative evaluation for cataract surgery and associated risk factors.

Methods

A retrospective analysis of patients' medical records and imaging. Adult patients who underwent cataract extraction who had normal preoperative fundoscopic examination and available preoperative OCT imaging were included.

Results

The analysis included 121 eyes belonging to 121 patients. The prevalence of occult macular pathology was 21.5%, with the most common being interface abnormalities (8.3% of the eyes), drusen (4.1%), and diabetic macular edema (4.1%). Visually significant pathologies were noted in 6.6% of the eyes. Occult macular pathology was rare in patients aged less than 50 years (4.5%) and common among patients 70 years of age or older (43.3%). The most significant predictors of occult macular pathology were advanced age (OR: 1.06, p = 0.033) and diabetes mellitus (OR: 6.79, p = 0.002).

Conclusion

Relying on fundoscopic evaluation alone would miss 1 in 5 eyes with occult macular pathology and 1 in 15 with pathologies that would alter the visual outcome. Preoperative OCT screening prior to cataract surgery should be considered, especially in patients with advanced age and diabetes mellitus.

Refractive Outcomes After Cataract Surgery-The Impact of Preoperative Visual Acuity, the Intraocular Lens Model, and the Surgeon's Experience: An Empirical Analysis of Hungarian and Kosovan Patients

Background/Objectives: Phacoemulsification and intraocular lens (IOL) implantation comprise a standard procedure for cataract treatment. However, minimal refractive error remains a determinant of postoperative results. Our study aimed to evaluate the refractive outcomes and the impact of the surgeon's experience and the IOL model on Kosovan and Hungarian patients after cataract surgery. Methods: This study included the preoperative and postoperative data of 1417 patients scheduled to undergo cataract surgery with IOL implantation at two centers: the Ophthalmology Department of Semmelweis University, Budapest, Hungary, and the Ophthalmology Department of the University Clinical Center of Kosovo, Prishtina, Kosovo. STATA and SPSS were used for statistical analysis. Results: The data of 1001 Hungarian and 416 Kosovan patients were included in this study. There was a statistically significant difference between the groups in the 1-month postoperative best-corrected distance visual acuity (BCDVA) (p = 0.001); in the Hungarian patients, the 1-month BCDVA was 85.2%, while in the Kosovan patients, it was 49.6%. Of the 14 different IOLs implanted in the Hungarian patients, the AcrySof IQ toric SN6AT, FineVision HP (POD F GF), and 677MTY IOLs resulted in a statistically significant positive impact on the 1-month postoperative visual acuity (p < 0.05). The AcrySof SA60AT and Akreos ADAPT AO, implanted in the Kosovan patients, had a statistically significant positive impact on the 1-month postoperative visual acuity (p < 0.05). More extensive surgeon experience had a statistically significant positive impact on postoperative outcomes (p < 0.00). Conclusions: Multifocal and toric IOLs showed superiority in terms of postoperative outcomes in our study; therefore, we conclude that greater surgeon experience, the availability of premium IOLs, and appropriate IOL selection have a considerable impact on refractive outcomes after cataract surgery.

Comparison of ocular biometric measurements and intraocular lens power calculation using different methods in eyes with implantable collamer lenses

This prospective cohort study included 80 healthy candidates for Implantable Collamer Lens (ICL) implantation who underwent biometric assessments with Scheimpflug imaging (the Pentacam-AXL) and swept-source optical coherence tomography (SS-OCT; the IOLMaster-700), both before and 3 months after surgery. The main outcome measures were mean keratometry, anterior chamber depth, axial length, and various intraocular lens (IOL) calculation formulas (Haigis, SRK/T, Hoffer Q, Holladay 1, Barrett Universal 2, and Olsen). The interchangeability of the devices was assessed by generating 95% limits of agreement (95% LoA) and associated Bland-Altman plots. The average age of the participants was 31.5 ± 5.4 years (22-43), with 58 (72.5%) being female. Among the cases analyzed, 11 (13.4%) had incorrect anterior lens surface segmentation using the IOLMaster-700, and 1 case (1.2%) had inappropriate segmentation using the Pentacam-AXL. Postoperative IOL power calculation resulted in readings that were, on average, 0.15 to 0.30 D higher compared to preoperative measurements. The 95% LoAs could differ by up to 0.85 D higher after surgery, indicating weak agreement between pre- and postoperative measurements. There was poor agreement between the IOLMaster-700 and Pentacam-AXL in IOL power calculation for eyes with post-ICL implantation, with a difference of more than 1 D in the 95% LoAs. In conclusion, Scheimpflug imaging was found to be less susceptible than the SS-OCT technique to segmentation errors of the anterior lens surface after ICL implantation. Neither device showed interchangeable results for pre- versus postoperative IOL power calculation. The determination of IOL power by the IOLMaster-700 versus Pentacam-AXL was not interchangeable in eyes with ICL implantation.

Polypseudophakia: from "Piggyback" to supplementary sulcus-fixated IOLs

Polypseudophakia, the concept of using a second intraocular lens (IOL) to supplement an IOL that has already been placed in the capsular bag, was first used as a corrective measure where the power requirement was higher than that of available single IOLs. Subsequently, the technique was modified to compensate for post-operative residual refractive errors. In these early cases, an IOL designed for the capsular bag would be implanted in the sulcus.  Although these approaches were less than ideal, alternative means of correcting residual refractive errors were not without their limitations: IOL exchange can be traumatic to the eye and is not easily carried out once fibrosis has occurred, while corneal refractive surgical techniques are not suitable for all patients. Piggyback implantation was the term first coined to describe the use of two IOLs, placed together in the capsular bag. The term was later extended to include the procedure where an IOL designed for the capsular bag was placed in the sulcus. Unfortunately, the term piggyback has persisted even though these two approaches have been largely discredited. Intraocular lenses are now available which have been specifically designed for placement in the ciliary sulcus. As these newer IOLs avoid the many unacceptable complications brought about by both types of earlier piggyback implantation, it is time to employ a new terminology, such as supplementary IOL or secondary enhancement to distinguish between the placement of an unsuitable capsular bag IOL in the sulcus and the implantation of an IOL specifically designed for ciliary sulcus implantation. In addition to minimising possible complications, supplementary IOLs designed for the sulcus have expanded the options available to the ophthalmic surgeon. With these new IOLs it is possible to correct presbyopia and residual astigmatism, and to provide temporary correction of refractive errors in growing, or unstable, eyes. This article aims to review the literature available on supplementary IOL implantation in the ciliary sulcus and to summarise the evidence for the efficacy and safety of this intervention. KEY MESSAGES: What is known Polypseudophakia has been used for over 30 years to correct hyperopia or residual refractive error, but early techniques were associated with significant complications. What is new The development of specially designed sulcus-fixated supplementary IOLs significantly reduces the risks associated with these procedures, and has also opened up new opportunities in patient care. The reversibility of the procedure allows patients to experience multifocality, and to provide temporary and adjustable correction in unstable or growing eyes. The terms "secondary enhancement" or "DUET" to describe supplementary IOL implantation are preferential to "piggyback".

Comparative Analysis of Refractive Outcomes Following Cataract Surgery Using IOL Master 500 and IOL Master 700 Biometry Devices: A Retrospective Analysis

Background: This study aims to compare the refractive outcomes of cataract surgery using two different biometry devices, the IOL Master 500 and IOL Master 700, and to investigate the influence of patient-related factors on these outcomes. Methods: In this retrospective study, we analyzed data from 2994 eyes that underwent cataract surgery. Multiple linear regression analyses were performed to examine the impact of the biometry device (IOL Master 500 or IOL Master 700), patient age, time elapsed between biometry and surgery, gender, and insurance status, as well as biometric parameters (anterior chamber depth, axial length, and corneal curvature), on postoperative refractive outcomes, specifically the deviation from target refraction. Results: The choice of the IOL Master device did not result in a statistically significant difference between the two devices (p = 0.205). Age (p = 0.006) and gender (p = 0.001) were identified as significant predictors of refractive outcomes, with older patients and males experiencing slightly more hyperopic outcomes compared to younger patients and females, respectively. The time elapsed between biometry and surgery and insurance status did not significantly influence the refractive outcomes. Conclusions: Our study, supported by a large cohort and a diverse group of patients representing typical anatomical variants seen in cataract surgery, supports the thesis that the IOL Master 500 and IOL Master 700 can be regarded as equivalent and effective for biometry in cataract surgery. The differences between the devices were negligible. Therefore, switching between the devices is safe for bilateral patients.

Comparison of Safety and Efficacy of Four-Point Scleral Intraocular Lens Fixation and the Yamane Technique

INTRODUCTION

The purpose of our study was to compare the safety and efficacy of two scleral fixation intraocular lens (IOL) methods of four-point scleral fixation (Akreos AO60) and the Yamane technique (AcrySof MA60AC).

METHODS

This prospective, randomized study was conducted at the Military Institute of Medicine-National Research Institute in Warsaw between 2021 and 2023. We compared both groups for cause of aphakia, ocular history, refractive status, and complication.

RESULTS

Our study included 50 eyes from 47 patients. Four-point fixation was performed in 25 eyes (group 1), and the Yamane technique was used in 25 eyes (group 2). Surgical time was 24.1 min ± 8.9 in group 1 and 25.1 min ± 9.9 in group 2 (p > 0.05). The postoperative BCVA (best-corrected visual acuity) for group 1 and group 2 at 1 year's observation was 0.10 ± 0.15 and 0.09 ± 0.17 logMAR, respectively (p > 0.05). Postoperative total refractive error (RE) was - 0.06 ± 0.71 diopters (D) for four-point scleral fixation and 0.83 ± 0.70 D for Yamane technique (p < 0.05). Endothelial cell density (ECD) loss was 0.9% in group 1 and 3.5% in group 2 (p > 0.05). Bleeding into the anterior chamber and vitreous body was more frequent in the group of patients operated on with the use of the Yamane technique (10 cases, 20%, p = 0.01). IOL displacement was found in one case (2%) in group 2.

CONCLUSIONS

Both analyzed techniques are well tolerated and ensure good refractive results (extremely predictable in four-point scleral fixation) and have a similar safety profile. Four-point scleral fixation of IOL would appear to be safe, effective and beneficial for young, active patients, especially after trauma or recurrent subluxation.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov identifier NCT06389643.

Intraocular lens selection in diabetic patients: How to increase the odds for success

The incidence of cataracts is significantly higher in diabetic individuals, particularly in younger age groups, with rates quadrupled in those under 65 and doubled in those over 65 compared to non-diabetics. Cataract surgery in diabetic patients poses many challenges: Poor epithelial healing, decreased corneal sensitivity, increased central corneal thickness, decreased endothelial cell count, variable topography, poor pupillary dilatation, anterior capsular phimosis, posterior capsular opacification (PCO), chances of progression of diabetic retinopathy (DR), zonular weakness, and vitreous prolapse and diabetic macular edema. Selection of an appropriate intraocular lens (IOL) is crucial for visual rehabilitation and monitoring DR. The choice of IOL in diabetic cataract patients is a challenging scenario. Square-edge IOLs are favored for their capacity to mitigate PCO, whereas hydrophilic counterparts may incur calcification in the setting of proliferative DR. The advisability of premium IOLs for achieving spectacle independence warrants judicious evaluation, particularly in the presence of advanced retinopathy. Optimal IOL placement within the capsular bag is advocated to minimize postoperative complications. Rigorous preoperative assessment and informed patient counseling regarding IOL options are indispensable for optimizing surgical outcomes. This review article covers various aspects regarding the choice of IOLs in different case scenarios and complications in the diabetic population.

Intraocular Lens Power Calculation in Eyes After Myopic Laser Refractive Surgery and Radial Keratotomy: Bayesian Network Meta-analysis

PURPOSE

To compare the accuracy of formulas for calculating intraocular lens power in eyes after myopic laser refractive surgery or radial keratotomy.

DESIGN

Bayesian network meta-analysis.

METHODS

PubMed, Embase, the Cochrane Data Base of Systematic Reviews, and the Cochrane Central Register of Controlled Trials databases were searched for retrospective and prospective clinical studies published from January 1, 2012, to August 24, 2022. The outcome measurement was the percentage of eyes with a predicted error within the target refractive range (±0.50 diopter [D] or ±1.00 D).

RESULTS

Our meta-analysis includes 24 studies of 1172 eyes after myopic refractive surgery that use 12 formulas for intraocular lens power calculation. (1) A network meta-analysis showed that Barrett true-K no history, the optical coherence tomography (OCT) formula, and the Masket formula had a significantly higher percent of eyes within ±0.50 D of the goal than the Haigis-L formula, whereas the Wang-Koch-Maloney formula showed the poor predictability. Using an error criterion of within ±1.00 D, the same 3 formulas performed slightly better than the Haigis-L formula. Based on performance using both prediction error criteria, the Barrett true-K no history formula, OCT formula, and Masket formula showed the highest probability of ranking as the top 3 among the 12 methods. (2) A direct meta-analysis with a subset of 4 studies and 5 formulas indicated that formulas did not differ in percent success for either the ±0.5 D or ±1.0 D error range in eyes that had undergone radial keratotomy.

CONCLUSIONS

The OCT, Masket, and Barrett true-K no history formulas are more accurate for eyes with previous myopic laser refractive surgery, whereas no significant difference was found among the formulas for eyes that had undergone radial keratotomy.

Impact of thermo-mechanical skin treatment on refraction and keratometry in patients with dry eye disease and the implications for cataract surgery

PURPOSE

To determine the changes in keratometry measurements and refraction in patients having the thermo-mechanical periorbital skin treatment, Tixel®, to treat dry eye disease (DED).

METHODS

A multi-centre, prospective, non-masked study was conducted. DED patients were recruited in 3 international centres and were evaluated in 5 visits separated by an interval of 2 weeks except for the last visit which took place after 18 weeks from visit 1. The same clinical examination was performed at all visits: OSDI questionnaire, tear stability, keratometry, best corrected visual acuity and refraction. Tixel® treatment was applied at the first 3 visits.

RESULTS

89 participants (24 males/65 females; mean age: 55.0 ± 14.2 years) were included: 20 presented moderate DED symptoms and 69 severe DED symptoms. Significant differences were found for the spherocylindrical refraction (vector analysis) between visit 1 and visits 2 and 3. Following cumulative analysis, 11.86 % and 16.94 % of participants had more than 0.5 dioptre (D) change in mean keratometry and keratometric astigmatism, respectively, at 3 months post-treatment. A total of 5.40 % had a sphere and cylinder change greater than 0.50D and 16.21 % had the axis changed more than 10 degrees (vector analysis). These changes were particularly significant in patients with severe DED symptoms.

CONCLUSIONS

Keratometry readings and refraction can change following thermo-mechanical skin treatment for DED, especially in those patients with severe DED symptoms. This should be considered as potential errors in intraocular lens calculations may be induced.

The Development of a Thick-Lens Post-Myopic Laser Vision Correction Intraocular Lens Calculation Formula

PURPOSE

To describe the development of the post-myopic laser vision correction (LVC) version of the PEARL-DGS intraocular lens (IOL) calculation formula and to evaluate its outcomes on an independent test set.

DESIGN

Retrospective, single-center case series.

METHODS

A modified lens position prediction algorithm was designed along with methods to predict the posterior corneal curvature radius and correct the corneal power measurement error. A different set of previously operated eyes that underwent LVC was used to evaluate the prediction precision of the post-LVC formula.

RESULTS

Post-LVC PEARL-DGS formula significantly reduced mean absolute error of prediction in comparison to Haigis-L, Shammas, and American Society of Cataract and Refractive Surgery (ASCRS) average formulas (P < .001). It exhibited similar postoperative refractive precision as the Barrett True-K No History formula (P = .61).

CONCLUSION

The post-LVC formula development process described in this article performed as well as the state-of-the-art post-LVC formula on the present test set. Further studies are required to assess its efficacy in other independent sets.

Effect of residual sphere on uncorrected visual acuity and satisfaction in patients with monofocal and multifocal intraocular lenses

PURPOSE

To assess the effect of residual sphere on vision and satisfaction in pseudophakic patients.

SETTING

Private clinics, United Kingdom.

DESIGN

Retrospective case series.

METHODS

A multivariate model evaluated the effect of 1-month residual sphere on outcomes of pseudophakic patients. Odds ratios (ORs) were calculated to assess the relative risk of not achieving ≥20/20 monocular uncorrected distance visual acuity (UDVA), ≥20/50 uncorrected near visual acuity (UNVA), and not being satisfied with vision. ORs were assessed for residual sphere -1.00 to +1.00 diopter (D) in quarter-diopter steps, using 0.00 D as a reference.

RESULTS

The analysis included 38 828 multifocal and 11 571 monofocal intraocular lenses (IOLs). The residual myopic sphere ≤-0.25 D and hyperopic sphere ≥+0.50 D had a clinically meaningful effect on UDVA. Although monofocal IOLs had an improvement in UNVA with every additional 0.25 D of myopia, the change in ORs with increasing myopia was not significant for multifocal IOLs. The mean improvement in UNVA comparing eyes with 0.00 D and -1.00 D sphere was 0.26 logMAR for monofocal and 0.03 logMAR for multifocal IOLs. Low near-addition IOLs had a slightly higher gain in UNVA with increasing myopia, but the gain was not as substantial as with monofocal IOLs. The effect of ametropia on satisfaction was more pronounced for multifocal IOLs. For every 0.25 D of residual myopia, there was >25% increase in dissatisfied patients.

CONCLUSIONS

Although myopia improved UNVA in eyes with monofocal IOL, multifocal IOLs did not benefit from residual myopia. Multifocal IOL patients desiring distance vision should be targeted closest to emmetropia, even if it means targeting slight hyperopia.

Prevalence and associated factors of refractive error among adults in South Ethiopia, a community-based cross-sectional study

INTRODUCTION

The increasing prevalence of refractive error has become a serious health issue that needs serious attention. However, there are few studies regarding the prevalence and associated factors of refractive error at the community level in Ethiopia as well as in the study area. Therefore, providing updated data is crucial to reduce the burdens of refractive error in the community.

OBJECTIVE

To assess the prevalence and associated factors of refractive error among adults in Hawassa City, South Ethiopia, 2023.

METHOD

A community-based cross-sectional study was conducted on 951 adults using a multistage sampling technique from May 8 to June 8, 2023, in Hawassa City, South Ethiopia. A pretested, structured questionnaire combined with an ocular examination and a refraction procedure was used to collect data. The collected data from the Kobo Toolbox was exported to a statistical package for social sciences for analysis. Binary and multivariable logistic regression analyses were performed. A P-value of less than 0.05 was considered statistically significant in the multivariable analysis.

RESULT

A total of 894 study participants were involved in this study with a 94.1% response rate. The prevalence of refractive error was 12.3% (95% CI: 10.2, 14.5%). Regular use of electronic devices (adjusted odds ratio = 3.64, 95% CI: 2.25, 5.91), being diabetic (adjusted odds ratio = 4.02, 95% CI: 2.16, 7.48), positive family history of refractive error (adjusted odds ratio = 2.71, 95% CI 1.59, 4.61) and positive history of cataract surgery (adjusted odds ratio = 5.17, 95% CI 2.19, 12.4) were significantly associated with refractive error.

CONCLUSION AND RECOMMENDATION

The overall magnitude of refractive error in our study area was high. Regular use of electronic devices, being diabetic, positive family history of refractive error, and a positive history of cataract surgery were associated with refractive error.

Does the Difference in Axial Length Affect the Refractive Outcome?

Background

The purpose of this study is to compare axial length (AL) and the refractive outcome after phacoemulsification surgery from 2014 to 2019 at Hospital Sultanah Nur Zahirah, Terengganu, Malaysia.

Method

This was a retrospective record review of all cataract patients who met the inclusion criteria and underwent uneventful superior wound phacoemulsification with nontoric intraocular lens (IOL) by a single surgeon from 2014 to 2019. Using optical biometry or immersion technique, the preoperative AL determined solely via the Sanders, Retzlaff and Kraff 2 (SRK2) formula was selected. The postoperative spherical equivalent (SE) at 6 weeks-12 weeks was retrieved. Using Statistical Package for the Social Sciences version 24.0, the mean differences between targeted and actual postoperative SE were analysed based on the AL.

Result

In this study, 490 eyes of 472 patients aged 25 years old-88 years old (mean age 65.72 years old [SD 8.83]) were involved. There were 162 eyes (33%) in Group A (< 23 mm), 189 eyes (39%) in Group B (23.01 mm-24.0 mm) and 139 eyes (28%) in Group C (> 24.0 mm). The mean AL was 23.63 mm (SD 1.19). The mean differences between the targeted and actual postoperative SE were: -0.09 D (SD 0.60) in Group A, -0.07 D (SD 0.53) in Group B and -0.16 D (SD 0.52) in Group C. No significant difference was found between these groups (P = 0.327).

Conclusion

There was no significant difference in the refractive outcome using the SRK2 formula in different ALs after phacoemulsification surgery. Hence, there is no reason to modify or adjust the targeted SE based on AL.

Intra-Observer and Inter-Observer Variability of Intraocular Lens Measurements Using an Interferometry Metrology Device

The NIMO TEMPO (Lambda-X, Nivelles, Belgium) is a novel, user-friendly and compact device designed for in vitro optical analysis of refractive and diffractive intraocular lenses (IOLs). This device analyzes the IOL wavefront and generates a synthetic eye model for numerical computation. The objective of this study was to evaluate the precision of this innovative device. Intra- and inter-observer variability were calculated using a two-way analysis of variance (ANOVA) after conducting ten measurements of eight different IOL models, with each measurement being repeated by three distinct operators (resulting in a total of 30 measurements for each IOL). The device demonstrated satisfactory intra- and inter-observer variability in evaluating IOL power and modulation transfer function (MTF) profiles, with values of 0.066 and 0.078 diopters for IOL power and 0.018 and 0.019 for MTF measurements, respectively. Furthermore, this hybrid optical and numerical in vitro IOL wavefront analyzer appears to have several advantages over conventional optical bench devices. It reduces the need for operator manipulation, and allows for numerical modeling of various optical environments, including cornea models and apertures. In conclusion, this novel metrology device designed for refractive and diffractive IOLs appears to provide a satisfactory precision, making it a promising tool in the field of IOL metrology.

Online intraocular lens calculation

PURPOSE OF REVIEW

To showcase the majority of online intraocular lens (IOL) calculation tools and highlight some of their characteristics.

RECENT FINDINGS

Online tools are available for preoperative and postoperative IOL-related calculations, including IOL power and toricity selection for standard patients, patients who underwent prior refractive surgery, keratoconus, limbal relaxing incisions for astigmatism management, realignment of a misplaced or rotated toric IOL, surgical induced astigmatism (SIA), formulae comparison, and other tools.

SUMMARY

As there are new online developments and technology is advancing rapidly, we hope that this review will assist ophthalmologists in becoming acquainted with a large variety of online tools.

Bibliometric analysis of research relating to refractive cataract surgery over a 20-year period: from 2003 to 2022

AIM

To investigate the research trend on refractive cataract surgery, compare the contributions of different countries, institutions, journals, and authors in the past 20y, and explore its potential research hotspots.

METHODS

All publications were extracted relating to refractive cataract surgery from 2003 to 2022 from Web of Science. Document types were limited to original articles and reviews, and the language was limited to English. Quantitatively and qualitatively of the publications were analyzed through Microsoft Excel and GraphPad Prism. VOSviewer and CiteSpace were used for bibliometric and visualized analysis.

RESULTS

A total of 2090 publications were enrolled. The United States contributed the most publications (434, 20.8%), followed by China (345, 16.5%) and England (163, 7.80%). Publications from the United States were cited more frequently (9552 citations) with the highest H-index of 48. China ranked second in the total number of publications, the papers were not cited that frequently (3237 citations), and the H-index ranked sixth (H-index=29). Journal of Cataract and Refractive Surgery published the most papers (333, 15.9%), and the University of London had the highest number of publications (75, 3.59%). Dick HB from Germany published the most papers. Corneal astigmatism-related research, cataract surgery method-related research, postoperative visual-quality relate to research, and postoperative complications-relate research are the hotspots in this field. The most significant limitation was that the database was updated frequently and the latest publications were not included.

CONCLUSION

The bibliometric analysis shows a brief summarization of the contribution of the authors, institutions, countries, and journals. Corneal astigmatism, cataract surgery method, postoperative visual-quality and postoperative complications related researches have become the emerging hotspots, which can give a direction in the future researches.

Influence of the CleaRing intraocular open capsule device on refractive predictability in cataract surgery

BACKGROUND

The marked improvement in cataract surgery and intraocular lens (IOL) quality has led to a decline in posterior capsular opacification (PCO) incidence; however, PCO remains a common complication of cataract surgery. The CleaRing intraocular capsule open device (IOCD) decreases PCO incidence. We aimed to investigate the influence of the CleaRing IOCD on refractive predictability in cataract surgery.

METHODS

We conducted this prospective pilot study at the Wolfson Medical Center, Holon, Israel. Ten eyes of patients who underwent cataract surgery and insertion of an IOL after IOCD implantation into the capsular bag were included. All patients completed 12 months of follow-up, including refraction, measurement of uncorrected (UDVA) and best-corrected distance visual acuity (CDVA), slit-lamp biomicroscopy, and ultrasound biomicroscopy.

RESULTS

All the surgeries were uneventful, with no postoperative complications. The IOL was centred in the device and bag in all cases. The mean prediction error at 1 and 12 months postoperatively was +0.28 ± 0.32 D and +0.50 ± 0.32 D, respectively. The mean UDVA was 0.17 ± 0.13 and 0.15 ± 0.11 logMAR, and the mean CDVA was 0.04 ± 0.10 and 0.04 ± 0.06 logMAR, respectively. The manifest refractive cylinders at 12 months postoperatively were compatible with corneal astigmatism.

CONCLUSIONS

Implantation of the IOCD resulted in a slight, predicted, and stable hyperopic shift with a low standard deviation. The standard deviation of the prediction error demonstrated excellent refractive accuracy and predictability using the IOCD, which was as low as 0.32 D at the 12-month follow-up.

Efficacy of cataract surgeries performed during blindness prevention programs in Chongqing, China: a multicenter prospective study

OBJECTIVE

To determine the efficacy of cataract surgeries in blindness prevention programs in Chongqing.

METHODS

During February-December 2019, we prospectively enrolled 487 patients (592 eyes) undergoing cataract surgery during blindness prevention programs in 6 Chongqing district/county hospitals (experimental group) and 481 patients (609 eyes) undergoing cataract surgery in the First Affiliated Hospital of Chongqing Medical University (controls). Uncorrected visual acuity (UCVA), refractive status, best corrected visual acuity (BCVA), slit lamp examination, and visual function/quality of life (VF-QOL) questionnaire scores were evaluated preoperatively, and at 1 and 6 months postoperatively.

RESULTS

In the experimental group, UCVA, BCVA, and VF-QOL scores at 1 and 6 months were better than the preoperative values (P < 0.05), but lower than the control-group values (P < 0.05). Rates of good UCVA and BCVA outcomes (≤ 0.5 logMAR) in the experimental group were 76.2% and 87.6%, respectively, at 1 month and 68.9% and 83.1%, respectively, at 6 months. Most eyes in the experimental (82.1%) and control (89.5%) groups had refractive errors within ± 1 D at 1 month. At 6 months, posterior capsule opacification (PCO) was more common in the experimental group (20.9% vs. 15.0%, P < 0.05). At 6 months, the main causes of visual impairment (UCVA > 0.5 logMAR) in the experimental group were uncorrected refractive errors (33.0%), PCO (29.5%), and fundus diseases (33.9%).

CONCLUSION

Cataract surgeries in blindness prevention programs in Chongqing significantly improved visual acuity, VF, and QOL, but underperformed compared to surgeries in the tertiary teaching hospital.

Diagnostic Techniques to Increase the Safety of Phakic Intraocular Lenses

Preoperative and postoperative diagnostics play an important role in ensuring the safety of patients with phakic intraocular lenses (pIOLs). The risk of endothelial cell loss can be addressed by regularly measuring the endothelial cell density using specular microscopy and considering the endothelial cell loss rate and the endothelial reserve in accordance with the patient's age when deciding whether to explant a pIOL. The anterior chamber morphometrics, including the anterior chamber depth and the distance between the pIOL and the endothelium, measured using Scheimpflug tomography and anterior segment optical coherence tomography (AS-OCT), can help to assess the risk of the endothelial cell loss. In patients undergoing posterior chamber pIOL implantation, accurate prediction of the vault and its postoperative measurements using AS-OCT or Scheimpflug tomography are important when assessing the risk of anterior subcapsular cataract and secondary glaucoma. Novel approaches based on ultrasound biomicroscopy and AS-OCT have been proposed to increase the vault prediction accuracy and to identify eyes in which prediction errors are more likely. Careful patient selection and regular postoperative follow-up visits can reduce the complication risk and enable early intervention if a complication occurs.

A data-driven approach to evaluate factors affecting resident performance in cataract surgery

PURPOSE

To evaluate the operative duration and clinical performance of ophthalmology residents performing standard phacoemulsification cataract surgeries using information available from electronic health records (EHR).

METHODS

This is a retrospective cohort study. De-identified surgical records of all standard phacoemulsifications performed in a tertiary institution between 1st January 2015 and 8th August 2018 were retrieved from the hospital EHR. The main outcome measures were improvement in operative duration with case experience, corrected distance visual acuity (CDVA) improvement, and intra-operative complication rates.

RESULTS

Twelve ophthalmology residents performed a total of 1427 standard phacoemulsifications. The median operative duration was 27 min (interquartile range, 22-34 min), which improved from 31 to 24 min (before the 101st case [Group 1] versus 101st case onwards [Group 2], p < 0.001). Gradient change analysis (non-linear regression) showed significant reduction until the 100th case (p = 0.043). Older patients (0.019), worse pre-operative CDVA (0.343), and surgery performed by Group 1 (1.115) were significantly associated with operative duration above 30 min. LogMAR CDVA improved from a mean of 0.57 ± 0.52 pre-operatively to 0.10 ± 0.18 post-operatively (p < 0.001). Posterior capsule rupture (PCR) rate decreased from 4.0% [Group 1] to 2.1% [Group 2] (p = 0.096), while overall complication rate decreased from 8.9% to 3.1% (p < 0.001).

CONCLUSION

The median operative duration reduced consistently with surgical experience for the first 100 cases. Older patients, poorer pre-operative VA, and surgical experience of less than 100 cases were significantly associated with an operative duration above 30 min. There was a statistically significant decrease in complication rate between Group 1 and 2.

Technical failure rates for biometry between swept-source and older-generation optical coherence methods: a review and meta-analysis

PURPOSE

Precise ocular measurements are fundamental for achieving excellent target refraction following both cataract surgery and refractive lens exchange. Biometry devices with swept-source optical coherence tomography (SS-OCT) employ longer wavelengths (1055-1300 nm) in order to have better penetration through opaque lenses than those with partial coherence interferometry (PCI) or low-coherence optical reflectometry (LCOR) methods. However, to date a pooled analysis showing the technical failure rate (TFR) between the methods has not been published. The aim of this study was to compare the TFR in SS-OCT and in PCI/LCOR biometry.

METHODS

PubMed and Scopus were used to search the medical literature as of Feb 1, 2022. The following keywords were used in various combinations: optical biometry, partial coherence interferometry, low-coherence optical reflectometry, swept-source optical coherence tomography. Only clinical studies referring to patients undergoing routine cataract surgery, and employing at least two (PCI or LCOR vs. SS-OCT) optical methods for optical biometry in the same cohort of patients were included.

RESULTS

Fourteen studies were included in the final analysis, which presented results of 2,459 eyes of at least 1,853 patients. The overall TFR of all included studies was 5.47% (95% confidence interval [CI]: 3.66-8.08%; overall I² = 91.49%). The TFR was significantly different among the three methods (p < 0.001): 15.72% for PCI (95% CI: 10.73-22.46%; I² = 99.62%), 6.88% for LCOR (95% CI: 3.26-13.92%; I² = 86.44%), and 1.51% for SS-OCT (95% CI: 0.94-2.41%; I² = 24.64%). The pooled TFR for infrared methods (PCI and LCOR) was 11.12% (95% CI: 8.45-14.52%; I² = 78.28%), and was also significantly different to that of SS-OCT: 1.51% (95% CI: 0.94-2.41%; I² = 24.64%; p < 0.001).

CONCLUSIONS

A meta-analysis of the TFR of different biometry methods highlighted that SS-OCT biometry resulted in significantly decreased TFR compared to PCI/LCOR devices.

A systemic review and network meta-analysis of accuracy of intraocular lens power calculation formulas in primary angle-closure conditions

BACKGROUND

For primary angle-closure and angle-closure glaucoma, the fact that refractive error sometimes deviates from predictions after intraocular lens (IOL) implantation is familiar to cataract surgeons. Since controversy remains in the accuracy of IOL power calculation formulas, both traditional and network meta-analysis on formula accuracy were conducted in patients with primary angle-closure conditions.

METHODS

A comprehensive literature search was conducted through Aug 2022, focusing on studies on intraocular lens power calculation in primary angle-closure (PAC) and primary angle-closure glaucoma (PACG). A systemic review and network meta-analysis was performed. Quality of studies were assessed. Primary outcomes were the mean absolute errors (MAE) and the percentages of eyes with a prediction error within ±0.50 diopiters (D) or ±1.00 D (% ±0.50/1.00 D) by different formulas.

RESULTS

Six retrospective studies involving 419 eyes and 8 formulas (Barrett Universal II, Kane, SRK/T, Hoffer Q, Haigis, Holladay I, RBF 3.0 and LSF) were included. SRK/T was used as a reference as it had been investigated in all the studies included. Direct comparison showed that none of the involved formula outperformed or was defeated by SRK/T significantly in terms of either MAE or % ±0.50/1.00 D (all P>0.05). Network comparison and ranking possibilities disclosed BUII, Kane, RBF 3.0 with statistically insignificant advantage. No significant publication bias was detected by network funnel plot.

CONCLUSIONS

No absolute advantage was disclosed among the formulas involved in this study for PAC/PACG eyes. Further carefully designed studies are warranted to evaluate IOL calculation formulae in this target population.

TRAIL REGISTRATION

Registration: PROSEPRO ID: CRD42022326541.

Theoretical Relationship Among Effective Lens Position, Predicted Refraction, and Corneal and Intraocular Lens Power in a Pseudophakic Eye Model

Purpose

To ascertain the theoretical impact of anatomical variations in the effective lens position (ELP) of the intraocular lens (IOL) in a thick lens eye model. The impact of optimization of IOL power formulas based on a single lens constant was also simulated.

Methods

A schematic eye model was designed and manipulated to reflect changes in the ELP while keeping the optical design of the IOL unchanged. Corresponding relationships among variations in ELP, postoperative spherical equivalent refraction, and required IOL power adjustment to attain target refractions were computed for differing corneal powers (38 diopters [D], 43 D, and 48 D) with IOL power ranging from 1 to 35 D.

Results

The change in ELP required to compensate for various systematic biases increased dramatically with low-power IOLs (less than 10 D) and was proportional to the magnitude of the change in refraction. The theoretical impact of the variation in ELP on postoperative refraction was nonlinear and highly dependent on the optical power of the IOL. The concomitant variations in IOL power and refraction at the spectacle plane, induced by varying the ELP, were linearly related. The influence of the corneal power was minimal.

Conclusions

The consequences of variations in the lens constant mainly concern eyes receiving high-power IOLs. The compensation of a systematic bias by a constant increment of the ELP may induce a nonsystematic modification of the predicted IOL power, according to the biometric characteristics of the eyes studied.

Translational Relevance

Optimizing IOL power formulas by altering the ELP may induce nonsystematic modification of the predicted IOL power.

Saving of Time Using a Software-Based versus a Manual Workflow for Toric Intraocular Lens Calculation and Implantation

Background: To determine whether there is a significant saving of time when using a digital cataract workflow for digital data transfer compared to a manual approach of biometry assessment, data export, intraocular lens calculation, and surgery time. Methods: In total, 48 eyes of 24 patients were divided into two groups: 24 eyes were evaluated using a manual approach, whereas another 24 eyes underwent a full digital lens surgery workflow. The primary variables for comparison between both groups were the overall time as well as several time steps starting at optical biometry acquisition until the end of the surgical lens implantation. Other outcomes, such as toric intraocular lens misalignment, reduction of cylinder, surgically induced astigmatism, prediction error, and distance visual acuity were measured. Results: Overall, the total diagnostic and surgical time was reduced from 1364.1 ± 202.6 s in the manual group to 1125.8 ± 183.2 s in the digital group (p < 0.001). The complete time of surgery declined from 756.5 ± 82.3 s to 667.3 ± 56.3 (p < 0.0005). Compared to the manual approach of biometric data export and intraocular lens calculation (76.7 ± 12.3 s) as well as the manual export of the reference image to a portable external storage device (26.8 ± 5.5 s), a highly significant saving of time was achieved (p < 0.0001). Conclusions: Using a software-based digital approach to toric intraocular lens implantation is convenient, more efficient, and thus more economical than a manual workflow in surgery practice.