Comparison of two optical biometers in intraocular lens power calculation

Evaluation of repeatability and agreement of two optical biometers for intraocular lens power calculation

The repeatability of two biometers (Lenstar-LS900 and Eyestar-900) to measure ocular parameters and intraocular lens (IOL) power calculation, and their agreement were evaluated. 134 eyes of 134 participants were measured thrice with each biometer. Axial length (AL), anterior chamber depth (ACD), lens thickness (LT) and keratometry (K) were evaluated. The IOL power was calculated using different formulas. The repeatability limit (RLimit), the mean differences (MD) and the limits of agreement (LoA) were calculated. The RLimits for all parameters were higher with Lenstar compared to Eyestar. RLimits were lower than 0.50 D except for Barrett Universal II (0.54 D) and Haigis (0.51 D) formulas with the Lenstar. Mean differences were lower than 0.01 mm for AL, ACD and LT, and lower than 0.03 D for K. MD ranged from 0 to 0.02 D for all formulas except for Barrett and Hill. When dividing the sample into subgroups (short, normal and long eyes), the MDs were similar for the IOL power and were lower than 0.03 D, except for the Barrett and Hill formulas. Both biometers provide repeatable biometry and IOL power calculations. The LoA interval for the IOL power calculation was between 0.75 and 1.50D, which was similar among the subgroups.

Comparison of measurements and calculated lens power using three biometers: a Scheimpflug tomographer with partial coherence interferometry and two swept source optical coherence tomographers

PURPOSE

To compare the biometric measurements obtained from the Pentacam AXL Wave, IOLMaster 700, and ANTERION and calculate the recommended intraocular lens power using the Barrett Formulae.

METHODS

This was a retrospective cross-sectional study of patients who underwent biometry using the Pentacam AXL Wave, IOLMaster 700, and ANTERION. Flat keratometry (K1), steep keratometry (K2), anterior chamber depth (ACD), and axial length (AL) from each device were measured and compared. These parameters were used to calculate the recommended IOL powers using the Barrett formula.

RESULTS

The study included 252 eyes of 153 patients. The IOLMaster had the highest acquisition rate among the two biometers. The Pentacam obtained the shortest mean AL, the IOLMaster measured the highest mean keratometry values, and the ANTERION measured the highest mean ACD. In terms of pairwise comparisons, keratometry and axial length were not significantly different between the Pentacam-IOLMaster and ANTERION-IOLMaster groups, while the rest of the pairwise comparisons were statistically significant. In nontoric and toric eyes, 35-45% of patients recommended the same sphere of IOL power. In another 30-40%, the Pentacam and ANTERION recommended an IOL power one step greater than that of the IOLMaster-derived data. 50% of the study population recommended the same toric-cylinder IOL power.

CONCLUSIONS

The Pentacam AXL Wave, IOLMaster 700, and ANTERION can reliably provide data for IOL power calculations; however, these data are not interchangeable. In nontoric and toric eyes, 35-45% of cases recommended the same sphere IOL power, and in another 30-40%, the Pentacam and ANTERION recommended one-step higher IOL power than the IOLMaster-derived data. In targeting emmetropia, selecting the first plus IOL power is advisable when using the Pentacam and ANTERION to approximate the IOL power calculations recommended by the IOLMaster 700.

Complications of foldable intraocular lenses requiring explantation or secondary intervention: 2022 survey with update of long-term trends

PURPOSE

To assess the complications that resulted in the explantation or secondary intervention with foldable intraocular lenses (IOLs).

SETTING

University setting, Salt Lake City, Utah.

DESIGN

Survey study.

METHODS

For the 25th consecutive year, surgeons were surveyed regarding complications associated with foldable IOLs requiring explantation or secondary intervention over the 2022 calendar year. These forms were made available online using the ASCRS and ESCRS websites and a fax-on-demand service. Surgeons completed 1 survey for each foldable IOL requiring explantation or secondary intervention. Further analysis determined complication trends related to specific IOL styles, materials, and types over the past 16 years (2007 to 2022).

RESULTS

103 completed surveys were returned in 2022 contributing to a total of 1627 tabulated surveys since 2007. In the 2022 survey, dislocation/decentration continued to be the most common complication overall. Glare/optical aberrations was a common complication associated with multifocal IOLs continuing a 16-year trend. In addition, hydrophilic acrylic IOLs as well as some silicone lenses in eyes with asteroid hyalosis demonstrated calcification as the most common complication necessitating explantation.

CONCLUSIONS

Dislocation/decentration remains the leading cause of explantation in most IOL types. Glare/optical aberrations continue to be an associated complication of multifocal IOLs suggesting this ongoing issue has yet to be resolved with this type of IOL. In addition, calcification of hydrophilic acrylic lenses and silicone lenses is a rare event but continues to occur.

Feasibility and repeatability of ocular biometry measured with IOLMaster 700 in a large population-based study

PURPOSE

To evaluate the feasibility and repeatability of IOLMaster 700 biometry measurements in an adult population. Furthermore, to assess the value of the Quality Indicators (QIs) provided by the device.

METHOD

As part of the large population-based Leipzig Research Centre for Civilization Diseases (LIFE) Adult-Study, randomly selected participants from Leipzig, Germany were evaluated with the ZEISS IOLMaster 700. Age range was 26-85 years, with 53% of participants above 70 years of age. Axial length (AL), central corneal thickness (CCT), anterior chamber depth (ACD), lens thickness (LT) and keratometry (K) were assessed in 1767 right eyes. Measurements were repeated twice and in a subset of 1331 eyes, three times. Measurement feasibility was evaluated for three levels; successful, with warnings and failed, using the inbuilt QIs. Repeatability was assessed as within-subject standard deviation (SD) and repeatability limits were calculated.

RESULTS

First measurement success rate for phakic eyes was over 99% for AL, CCT, ACD, over 98% for LT and over 97% for K. K had 16% eyes with warnings and the recommendation to repeat the measurement. Excluding the measurements with warnings resulted in a reduction of mean SD for AL from 48 to 4 μm and for mean K from 0.08 to 0.04 D. Repeatability for phakic eyes was 8 μm for AL, CCT, ACD and LT and 2.3 μm for CCT; 0.07 D and 0.12 D for mean K and delta K, respectively, for phakic cases without warnings (two measurements).

CONCLUSIONS

In our population-based sample, the IOLMaster 700 collected data for AL, CCT, ACD, LT and K from the vast majority of eyes. Considering the built-in QIs improved the measurement variability substantially. Repeatability measurements indicate that clinically meaningful changes can be detected reliably with this instrument.

Accuracy of the LaserArcs Femtosecond Cataract Surgery Arcuate Incision Nomogram in Patients Undergoing Cataract Surgery and Astigmatism Reduction

Purpose

The purpose of this study is to evaluate the efficacy and safety of the laserarcs.com nomogram in reducing astigmatism among cataract patients that underwent astigmatism reduction with laser arcuate incisions.

Methods

In this retrospective study, 50 patients who underwent uncomplicated cataract surgery with laser arc incisions for the reduction of astigmatism with a single surgeon between the dates of January 23, 2021 and February 10, 2022 were evaluated in a single eye. Preoperative astigmatism was determined on the basis of keratometry from biometry (IOLmaster, Carl Zeiss Meditec or LenStar LS900, Haag-Streit, Bern, Switzerland) and was compared to the postoperative manifest astigmatism. The percent change in the absolute magnitude of astigmatism was calculated along with the percent of patients with various levels of postoperative astigmatism.

Results

Mean cylinder was 0.97 ± 0.49 D pre-op and 0.21 ± 0.28 D postop. Mean reduction in cylinder was 81.4 ± 47.7% (P < 0.00001, one-sample t-test compared to a hypothetical 60% reduction in cylinder). Residual cylinder was ≤0.5 D in 90%, 0.25 D in 72%, and 0 D in 58%. Postoperative uncorrected visual acuity was 20/30 or better in 92% and 20/20 or better in 40%. Subgroup analysis showed that residual astigmatism was not affected by patient age, magnitude of preoperative astigmatism, preoperative spherical equivalent, or corneal curvature. No adverse events related to the laser arcuate incisions were noted.

Conclusion

Use of the LaserArcs nomogram yielded a significant reduction in preoperative astigmatism. Postoperative uncorrected visual acuity was substantially similar to best-corrected visual acuity, suggesting that many patients undergoing treatment will function without correction for distance tasks.

Agreement of predicted intraocular lens power using swept-source optical coherence tomography and partial coherence interferometry

PURPOSE

To analyze the agreement of the predicted intraocular lens (IOL) power obtained with ANTERION, IOLMaster 700 and Pentacam AXL biometers.

METHODS

We calculated the monofocal and trifocal IOL power using the SRK/T, Haigis, Barrett Universal II and Hoffer Q formulas for 106 eyes. IOL power agreement between devices was evaluated using the Bland-Altman method.

RESULTS

We found significant differences between biometers comparisons (p < 0.001). ANTERION and IOLMaster 700 did not produce significant IOL power differences (p > 0.05), with the same outcomes for medium- and long-eyes. No significant differences were found using the SRK/T, Haigis, or Hoffer Q formulas for short-eyes (p > 0.1). However, Barrett Universal II formula produced significant differences (p < 0.05) and these differences lay between the ANTERION and Pentacam AXL. ANTERION versus IOLMaster 700 comparison showed limits of agreement (LoA) varying from 1.1071D in SRK/T monofocal medium-eyes to 1.6828D in Hoffer Q trifocal all-eyes. The largest LoA (about 3.0D) was found for short-eyes when comparing the Pentacam AXL with the other two devices.

CONCLUSIONS

These devices provided statistically significant but clinically insignificant mean differences in predicted IOL power. However, wide LoA values suggest that for specific eyes these outcomes could be clinically significant.

To compare on-axis measurements of the axial length with off-axis measurements in the paracentral horizontal and vertical positions

Purpose: To compare on-axis measurements of the axial length (AL) with off-axis measurements in the paracentral horizontal and vertical positions using the Lenstar LS 900 biometer.Methods: In this, the samples were selected from patients scheduled for cataract surgery using a systematic randomization method. After applying the exclusion criteria, all subjects underwent optometric examinations and AL measurement using the Lenstar. Five consecutive, non-cycloplegic measurements were done on the right eye centrally, 10° temporally, 10° nasally, 10° superiorly and 10° inferiorly on the retina by the same examiner.Results: Two hundred and seven eyes were examined in this study, of which 126 (60%) were for female patients. The mean age of the participants was 64.32 ± 10.77 years (range: 34-91 years). The mean central, superior, inferior, temporal, and nasal axial AL was 23.22 ± 1.02, 23.21 ± 1.02, 23.21 ± 1.02, 23.21 ± 1.02, 23.20 ± 1.03, respectively. Comparison of these readings using repeated measures ANOVA showed a statistically significant difference in the AL value among these positions. According to the post-hoc results, superior and nasal AL was statistically significantly lower compared to the central AL.Conclusion: If on-axis biometry is not available, AL can be measured in an off-axis manner in the paracentral temporal, superior and inferior positions. Considering the marked difference in AL measurement between central and nasal positions, off-axis measurement is not recommended in the nasal part because it may be associated with a marked hyperopic shift after cataract surgery.

Feasibility and repeatability of ocular biometry measured with Lenstar LS 900 in a large group of children and adolescents

PURPOSE

To evaluate the feasibility and repeatability of Lenstar LS 900 biometry measurements in a paediatric population.

METHODS

Children were examined as part of the LIFE Child Study (Leipzig Research Centre for Civilization Diseases), a population-based study in Leipzig, Germany. Altogether, 1917 children, aged from 3.5 to 17.5 years, were assessed with the Haag Streit Lenstar LS 900. Three consecutive measurements of the right eye were analysed for axial length, central corneal thickness, anterior chamber depth, aqueous depth, lens thickness and flat and steep corneal radii. The number of successful measurements and repeatability were evaluated for each parameter and three age bands (3.5 to 6.5 years, 6.5 to 10.5 years and 10.5 to 17.5 years).

RESULTS

Best measurement feasibility was found for axial length and central corneal thickness (91% to 100%), followed by flat and steep corneal radii (86% to 100%), anterior chamber and aqueous depth (76% to 92%) and lens thickness (50% to 81%), with higher numbers for older children. Repeatability values (in mm) were: axial length 0.025 to 0.035; central corneal thickness 0.003 to 0.027; aqueous depth 0.024 to 0.058; anterior chamber 0.024 to 0.054; lens thickness 0.034 to 0.067. An overall trend showed better repeatability for older children, especially for central corneal thickness, aqueous depth and lens thickness.

CONCLUSIONS

For ocular biometry in the paediatric population, axial length, central corneal thickness, flat and steep corneal radii can be measured very reliably even in children from 4 years old onward using the Lenstar LS 900. Lens thickness can be quantified in a limited number of younger children. Repeatability was high for all variables investigated. Repeatability improved with age, reaching adult values in the adolescent age band. Established repeatability limits can be applied in future studies as a quality parameter.

Intraocular Lens Power Formulas, Biometry, and Intraoperative Aberrometry: A Review

The refractive outcome of cataract surgery is influenced by the choice of intraocular lens (IOL) power formula and the accuracy of the various devices used to measure the eye (including intraoperative aberrometry [IA]). This review aimed to cover the breadth of literature over the previous 10 years, focusing on 3 main questions: (1) What IOL power formulas currently are available and which is the most accurate? (2) What biometry devices are available, do the measurements they obtain differ from one another, and will this cause a clinically significant change in IOL power selection? and (3) Does IA improve refractive outcomes? A literature review was performed by searching the PubMed database for articles on each of these topics that identified 1313 articles, of which 166 were included in the review. For IOL power formulas, the Kane formula was the most accurate formula over the entire axial length (AL) spectrum and in both the short eye (AL, ≤22.0 mm) and long eye (AL, ≥26.0 mm) subgroups. Other formulas that performed well in the short-eye subgroup were the Olsen (4-factor), Haigis, and Hill-radial basis function (RBF) 1.0. In the long-eye group, the other formulas that performed well included the Barrett Universal II (BUII), Olsen (4-factor), or Holladay 1 with Wang-Koch adjustment. All biometry devices delivered highly reproducible measurements, and most comparative studies showed little difference in the average measures for all the biometric variables between devices. The differences seen resulted in minimal clinically significant effects on IOL power selection. The main difference found between devices was the ability to measure successfully through dense cataracts, with swept-source OCT-based machines performing better than partial coherence interferometry and optical low-coherence reflectometry devices. Intraoperative aberrometry generally improved outcomes for spherical and toric IOLs in eyes both with and without prior refractive surgery when the BUII and Hill-RBF, Barrett toric calculator, or Barrett True-K formulas were not used. When they were used, IA did not result in better outcomes.

Comprehensive Comparison of Axial Length Measurement With Three Swept-Source OCT-Based Biometers and Partial Coherence Interferometry

PURPOSE

To compare axial length measurements (and failure rate) of three swept-source optical coherence tomography (SS-OCT)-based biometers: IOLMaster 700 (Carl Zeiss Meditec, Jena, Germany), OA-2000 (Tomey, Nagoya, Japan), and Argos (Movu Inc., Komaki, Japan) to those provided by a partial coherence interferometry (PCI)-based optical biometer (IOLMaster v5.4 [Carl Zeiss Meditec]).

METHODS

A total of 119 patients (171 eyes) undergoing cataract surgery were enrolled. Axial length was measured with the four biometers in a random order. Chi-square analysis was used to determine whether statistically significant differences in success rates were found between biometers. Within-subject standard deviation (Sw), test-retest repeatability (TRT), coefficient of variation (CoV), and intraclass correlation coefficients (ICCs) were calculated to analyze the intraobserver repeatability. Bland-Altman plots were used for agreement assessment.

RESULTS

Axial length measurements were successfully measured in 166 eyes (97.08%) with the IOLMaster 700, 166 eyes (97.08%) with the OA-2000, 170 eyes (99.42%) with the Argos, and 138 eyes (80.70%) with the IOLMaster v5.4. Chi-square analysis indicated a significant difference in the failure rate between PCI- and SS-OCT-based biometers (P < .001). Intraobserver repeatability for the IOLMaster 700, OA-2000, and Argos showed excellent repeatability with low TRT (0.03, 0.06, and 0.05 mm, respectively), low CoV (0.04%, 0.10%, 0.07%, respectively), and high ICC (1.000, 0.999, and 1.000, respectively). The Bland-Altman 95% limits of agreement were as narrow as 0.09 mm, indicating excellent agreement among the three SS-OCT biometers and the PCI biometer.

CONCLUSIONS

The three SS-OCT biometers showed a significantly higher success rate for axial length measurement than the IOLMaster v5.4 in various lens opacities. These SS-OCT biometers are likely to become the gold standard for axial measurement. [J Refract Surg. 2019;35(2):115-120.].

Comparison of agreement and efficiency of a swept source-optical coherence tomography device and an optical low-coherence reflectometry device for biometry measurements during cataract evaluation

Purpose

To compare the agreement and efficiency of a swept source-optical coherence tomography biometer, IOLMaster 700 (IOLM700), and a low-coherence optical reflectometry biometer, LENSTAR LS 900 (LS900), when acquiring biometry measurements during cataract evaluation.

Methods

A retrospective chart review of biometry measurements that were performed in 64 eyes of 32 patients on the same day using the LS900 and the IOLM700. The total image acquisition time per subject was compared between the two machines using a Wilcoxon rank-sum test. Bland-Altman plots showing the mean difference and 95% limits of agreement were graphed. Intraclass correlation coefficients (ICCs) were calculated for the mean axial length (AL), anterior chamber depth (ACD), lens thickness (LT), and two keratometry mean values (K1 and K2) that were output from each device.

Results

The average time to complete biometry measurements in both eyes was significantly shorter for the IOLM700 compared with the LS900 (44.5±12.4 vs 168.8±67.2 seconds, P<0.001). The Bland-Altman analysis and ICCs showed high degrees of agreement for the mean biometry values (ICC: AL 0.9999, ACD 0.9993, LT 0.9571, K1 0.9922, K2 0.9926) generated by the two devices.

Conclusion

There was a high level of agreement between the mean biometry output measures for IOLM700 and LS900. However, it took ~73% less time on average to acquire the images when using the IOLM700 compared with the LS900. In a busy clinic setting, use of the IOLM700 for biometry measures may save time and prove more efficient.

Lenstar® LS 900 vs Pentacam®-AXL: Comparative study of ocular biometric measurements and intraocular lens power calculation

Purpose:

Comparison of biometric measurements and calculation of intraocular lens with a new biometer (Pentacam®-AXL, Oculus, Germany) and a reference biometer (Lenstar LS 900®, Haag-Streit AG, Switzerland), in order to assess the agreement between these two devices.

Setting:

Centro Hospitalar de Leiria, Portugal

Materials and methods:

Prospective, institutional study, in which measurements of axial length, anterior chamber depth from the corneal epithelium and endothelium to the anterior surface of the lens (anterior chamber depth ext and anterior chamber depth int), central corneal thickness and keratometry readings of the flattest and steepest meridians (K1 and K2) were obtained with the two systems. Intraocular lens calculation was also performed, using the Haigis, SRK/T and HofferQ formulas.

Results:

The study sample included 136 eyes of 79 patients. Of these, 42 were women and 37 were men. Statistically significant differences were found (p < 0.05, paired T test) in K1, K2 and central corneal thickness between the 2 biometers. Intraocular lens calculation with the Lenstar® and the Pentacam® with Haigis, SRK/T and HofferQ formulas showed statistically significant differences (p < 0.05 Paired T test).

Conclusion:

Axial length measurements obtained with the Pentacam® and Lenstar® appear to be interchangeable, while measurements of anterior chamber depth, K1 and K2, and central corneal thickness do not appear to be interchangeable between different devices. Statistically significant differences were found in the calculation of intraocular lenses in all formulas used.

Comparison of anterior segment parameters and axial lengths of myopic, emmetropic, and hyperopic children

PURPOSE

To compare the anterior segment parameters of myopic, hyperopic, and emmetropic children by using optical biometry.

METHODS

This prospective cross-sectional study included 150 eyes of 150 children between 6 and 16 years old. The eyes were divided into three groups according to their spherical equivalent (SE) refractive error values as myopic [between - 1.0 and - 6.0 diopter (D)], emmetropic (between + 0.50 and - 0.50 D), and hyperopic (between + 1. 0 and + 3.0 D). Axial length (AL), central corneal thickness, anterior chamber depth (ACD), lens thickness (LT), and mean keratometry (K mean) measurements were obtained by an optical biometry (LenStar LS 900, Haag Streit Diagnostics) were compared between the groups.

RESULTS

There were no statistically significant differences regarding the ages and genders of the participants between the groups (p > 0.05). The mean SE refractive error values were - 2.20 ± 0.71 D in myopic, - 0.08 ± 0.49 D in emmetropic, and + 2.06 ± 0.53 D in hyperopic eyes. The mean AL values were 24.50 ± 0.69, 23.41 ± 0.61, and 22.33 ± 0.61 mm, respectively, in myopic, emmetropic, and hyperopic eyes (p < 0.001). The mean ACD values were 3.94 ± 0.22, 3.78 ± 0.23, and 3.45 ± 0.20 mm, respectively, in myopic, emmetropic, and hyperopic eyes (p < 0.001). The mean LT values were 3.56 ± 0.20, 3.43 ± 0.17, and 3.31 ± 0.12 mm, respectively, in myopic, emmetropic, and hyperopic eyes (p < 0.001). There were no significant differences in the other parameters between the groups.

CONCLUSIONS

Refractive errors are the main factors those affect anterior segment parameters and AL in children and the most severely affected parameters were found to be the AL, ACD, and LT values.

Comparison of the biometric measurements calculated with Zeiss IOL-Master and WaveLight OB-820

Background

The primary objective of this study was to investigate the level of agreement between IOL-Master and OB-820 ocular biometers.

Materials and methods

In this prospective randomized case series, we measured the anterior chamber depth (ACD), the axial length (AL), the corneal radii (R1, R2), the ratio of mean corneal radius and spherical equivalent and the corneal astigmatism (cylinder [Cyl]) before and after cataract extraction surgery.

Results

Significant differences between pre- and postoperative data were observed for ACD for both biometric devices (P<0.01) and Cyl parameter in IOL-Master. Range and 95% limits of agreement (LoA) were clinically significantly different for AL parameter pre- and postoperatively and for R2 and radius and spherical equivalent postoperatively (P<0.001). The rest of the parameters presented sufficient 95% LoA, which imply good agreement.

Conclusion

In clinical practice, the IOL-master and OB-820 should not be used interchangeably due to discrepancy in the important AL parameter. Both biometers may provide consistent results regarding Cyl, ACD and R1.

Meta-analysis of optical low-coherence reflectometry versus partial coherence interferometry biometry

A meta-analysis to compare ocular biometry measured by optical low-coherence reflectometry (Lenstar LS900; Haag Streit) and partial coherence interferometry (the IOLMaster optical biometer; Carl Zeiss Meditec). A systematic literature search was conducted for articles published up to August 6th 2015 in the Cochrane Library, PubMed, Medline, Embase, China Knowledge Resource Integrated Database and Wanfang Data. A total of 18 studies involving 1921 eyes were included. There were no statistically significant differences in axial length (mean difference [MD] 0 mm; 95% confidence interval (CI) −0.08 to 0.08 mm; p = 0.92), anterior chamber depth (MD 0.02 mm; 95% CI −0.07 to 0.10 mm; p = 0.67), flat keratometry (MD −0.05 D; 95% CI −0.16 to 0.06 D; p = 0.39), steep keratometry (MD −0.09 D; 95% CI −0.20 to 0.03 D; p = 0.13), and mean keratometry (MD −0.15 D; 95% CI −0.30 to 0.00 D; p = 0.05). The white to white distance showed a statistically significant difference (MD −0.14 mm; 95% CI −0.25 to −0.02 mm; p = 0.02). In conclusion, there was no difference in the comparison of AL, ACD and keratometry readings between the Lenstar and IOLMaster. However the WTW distance indicated a statistically significant difference between the two devices. Apart from the WTW distance, measurements for AL, ACD and keratometry readings may be used interchangeability with both devices.

Axial Length Measurement Failure Rates with the IOLMaster and Lenstar LS 900 in Eyes with Cataract

PURPOSE

To evaluate axial length (AL) measurement failure rate with the IOLMaster (Carl Zeiss AG, Germany) and Lenstar LS 900 (Haag-Streit AG, Switzerland) in eyes with cataract.

METHODS

Two hundred and ninety-six eyes of 170 patients with cataract were enrolled. Cataract type and severity were graded using the Lens Opacities Classification System III (LOCS III) and AL measurements were attempted with IOLMaster (version 5.4) and Lenstar LS 900 (version 1.1). Chi-squared analysis was used to assess if the difference in AL measurement acquisition rate was statistically significant between the two devices. The association of the different cataract types and severity with the AL measurement acquisition rate was evaluated with logistic regression analysis.

RESULTS

AL measurements were obtained in 184 eyes (62.16%) using the IOLMaster and 191 eyes (64.53%) using the Lenstar, which corresponds to a failure rate of 37.84% and 35.47% respectively. Chi-square analysis indicated no significant difference between the Lenstar and IOLMaster for AL measurement failure rate (x2 = 0.356, P = 0.550). Logistic regression analysis indicated no association between acquisition rates and cortical or nuclear cataracts with either device. There was a statistically significant association between acquisition rates and increasing severity of posterior subcapsular cataracts with the IOLMaster (β = -1.491, P<0.001) and Lenstar LS 900 (β = -1.507, P<0.001).

CONCLUSION

The IOLMaster and Lenstar LS 900 have similar AL measurement failure rates (35-38%) for Chinese public hospital cataract patients. Increasing severity of posterior subcapsular cataracts was problematic for both devices.