Optical low–coherence reflectometry useful for biometric measurements

The Lenstar LS 900 and applanation ultrasound can be used interchangeably for biometric measurement in cataract patients, according to a study published in Graefe's Archive for Clinical and Experimental Ophthalmology.

A team led by Dr Damir Bosnar, University Eye Clinic, University Hospital Sveti Duh, Croatia, compared the innovative non-contact optical low-coherence reflectometry (OLCR) method by the Lenstar LS 900 with applanation ultrasound to see if there was sufficient agreement in results of biometric measurements for intraocular lens (IOL) power calculations to warrant a replacement method.

Five consecutive measurements were performed on 32 eyes of 22 cataract patients. Applanation ultrasound and Lenstar IOL power calculation was based on both their automated keratometry and axial length measurements. Interobserver repeatability of applanation ultrasound and Lenstar was assessed by Bland-Altman analysis.

Predicted refractive error in 95%of observations was 0.26 ± 0.62 D with applanation ultrasound and 0.01± 0.20 D with Lenstar. The Lenstar demonstrated excellent repeatability and the applanation ultrasound showed acceptable repeatability.

The study suggested that OLCR could become an alternative method for biometric measurement for IOL power calculation in cataract patients.