Comparison and Evaluation of Ocular Biometry Using a New Noncontact Optical Low-Coherence Reflectometer

doi:10.1016/j.ophtha.2009.04.019

Ophthalmology

Volume 116, Issue 11, November 2009, Pages 2087-2092

https://doi.org/10.1016/j.ophtha.2009.04.019 Get rights and content

Purpose

To evaluate a new high-resolution noncontact biometer (Lenstar; Haag-Streit AG, Koeniz, Switzerland) using optical low-coherence reflectometry and to compare the clinical measurements with those obtained from the IOLMaster (Carl Zeiss, Jena, Germany) and the Pachμmeter (Haag-Streit AG).

Design

Exploratory evaluation of diagnostic technology and nonrandomized, prospective clinical trial.

Participants

Eighty subjects (144 eyes) aged 20 to 90 years with cataractous, pseudophakic, aphakic, silicon oil–filled, or normal eyes.

Methods

Measurements of axial length (AL), anterior chamber depth (ACD), central corneal thickness (CCT), corneal radius (R1 [flattest radius of corneal curvature] and R2 [steep radius, 90° apart from R1]), and axis of the flattest radius (Ax1) obtained with the Lenstar were compared with those obtained with the IOLMaster or Pachμmeter. The results were evaluated using Bland-Altman analyses. The differences between both methods were assessed using the paired t test, and its correlation was evaluated by Pearson coefficient.

Main Outcome Measures

Axial length, CCT, ACD, R1, R2, and Ax1.

Results

The overall mean AL measured with the Lenstar and the IOLMaster was 24.1 mm (r = 0.999). Anterior chamber depth was 3.19 mm (Lenstar) and 3.17 mm (IOLMaster; r = 0.875). Excellent correlations also were found for the corneal radius and the axis of flattest radius (R1, r = 0.927; R2, r = 0.929; and Ax1, r = 0.938). Mean CCT was 0.557 mm (r = 0.978) for both Lenstar and Pachμmeter.

Conclusions

Measurements with the new Lenstar correlated well with those with the IOLMaster and Pachμmeter in cataractous, pseudophakic, aphakic, silicon oil–filled, and normal eyes. It is an accurate, fast instrument that provides additional information of interest to any cataract or refractive surgeon.

Financial Disclosure(s)

Proprietary or commercial disclosure may be found after the references.

Section snippets

Patients and Methods

One hundred forty-four eyes of 80 persons (34 men [42.5%]; mean age, 66.9 years; range, 20–90 years) were included in this evaluation of diagnostic technology and nonrandomized, prospective study. Eighty-three (57.6%) of the 144 eyes examined had cataracts. Of these, 58 eyes were classified as having nuclear (NUC) cataract grade 1, 17 had NUC cataract grade 2, and 8 cataracts were classified as NUC grade 3.⁶ Twenty-eight eyes (19.4%) were pseudophakic, 5 eyes (3.5%) were simply aphakic, and 14

Results

A total of 144 eyes were measured. This sample size proved statistically to be largely sufficient to determine and prove the relevant data for AL, ACD, CCT, R1, R2, and Ax1 with the desired precision and probability.

The mean values, SDs, measurement ranges, Spearman correlation coefficients, differences of the means, with their SDs and their 95% confidence intervals for AL, keratometry (R1 and R2), Ax1, ACD, and CCT are summarized in Table 2. Comparative measurements of AL were possible in 125

Discussion

Accurate measurement of AL, ACD, keratometry (R1 and R2), and Ax1 are important parameters for the calculation of the final IOL power and in achieving optimal postoperative results in patients undergoing cataract surgery. A less than satisfactory refractive outcome is a major reason for IOL explantation.⁹ The most common causes were described to be keratometry errors and incorrect AL determination.¹⁰

This study compared the new Lenstar biometer with the gold standard, the IOLMaster, for clinical

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: Manuscript no. 2008-1254.

: Financial Disclosure(s): The author(s) have made the following disclosure(s):

: Supported by a grant from the Haag-Streit Foundation, Bern, Switzerland. The funding organization participated in the design of the study, data analysis, and review of the manuscript.

: All authors had full access to all the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis.

: Kaspar Rohrer - Financial Support - Haag-Streit.

: Beatrice E. Frueh - Financial Support - Haag-Streit.

: Isabelle Clemetson - Financial Support - Haag-Streit.

: Rudolf Wälti - Employee - Haag-Streit Switzerland.

: David Goldblum - Consultant - Haag-Streit Switzerland.

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Original articleComparison and Evaluation of Ocular Biometry Using a New Noncontact Optical Low-Coherence Reflectometer

Purpose

Design

Participants

Methods

Main Outcome Measures

Results

Conclusions

Financial Disclosure(s)

Section snippets

Patients and Methods

Results

Discussion

Am J Ophthalmol

Am J Ophthalmol

J Cataract Refract Surg

J Cataract Refract Surg

Ophthalmology

Ophthalmology

J Cataract Refract Surg

Calculation of intraocular lens power: a review

Acta Ophthalmol Scand

A new non-contact optical device for ocular biometry

Br J Ophthalmol

A simplified cataract grading system

Ophthalmic Epidemiol

Original article
Comparison and Evaluation of Ocular Biometry Using a New Noncontact Optical Low-Coherence Reflectometer