Intraocular lens power calculation: Clinical comparison of 2 optical biometry devices
Presented at the XXVI Congress of the European Society of Cataract & Refractive Surgeons, Berlin, Germany, September 2008, and the ASCRS Symposium on Cataract, IOL and Refractive Surgery, San Francisco, California, USA, April 2009.
Received 10 June 2009; received in revised form 28 August 2009; accepted 9 September 2009.
Purpose
To evaluate intraocular lens (IOL) power calculation using a new optical low-coherence reflectometry (OLCR) biometer and compare the results with those obtained with a partial coherence interferometry (PCI) optical biometer.
Setting
International Vision Correction Research Centre, Department of Ophthalmology, University of Heidelberg, Heidelberg, Germany.
Methods
Biometry measurements in eyes of cataract patients were performed by the same examiner with an OLCR biometer (Lenstar LS 900/Allegro Biograph) and a PCI optical biometer (IOLMaster). After determination of axial length (AL), corneal radii values by keratometry (R1 and R2), and anterior chamber depth (ACD), power calculation for an AcrySof MA60AC IOL was compared between the 2 devices using 4 formulas and the corresponding IOL constants. The target was emmetropia.
Results
One hundred eyes of 100 cataract patients (mean age 70.0 years ± 10.6 [SD]) were measured. Of the biometry parameters, the only statistically significant differences between the 2 devices were in R2 (mean difference 0.02 ± 0.05 mm), (R1 + R2)/2 (mean difference 0.01 ± 0.04 mm), and ACD (mean difference 0.05 ± 0.11 mm) (P<.01, Wilcoxon test). The mean differences in IOL power calculations using the 4 formulas were not statistically significant between the 2 devices (P>.01, Wilcoxon test).
Conclusion
The OLCR biometry device provided precise and valid measurements and thus can be used for the preoperative examination of cataract patients.
Financial Disclosure
No author has a financial or proprietary interest in any material or method mentioned.
From the International Vision Correction Research Centre, Department of Ophthalmology, University of Heidelberg, Heidelberg, Germany
Corresponding author: Tanja M. Rabsilber, MD, Department of Ophthalmology, Ruprecht-Karls-University of Heidelberg, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany.
Supported by a research grant from Haag-Streit AG, Köniz, Switzerland.
ABSTRACT