Refractive Predictability Of A Combined Optical Coherence Tomography (Oct) And Reflection Biometer

To compare the refractive predictability of a combined OCT/reflection biometer with an optical low coherence reflectometry (OLCR) biometer and a Swept-Source-OCT biometer. 

Private eye clinic in Haugesund, Norway.

This was a retrospective study of refractive and visual outcomes after successful cataract surgery. Biometry was performed with combined OCT/reflection device (Alcon Argos), an OLCR device (Haag-Streit Lenstar 900) and a swept source OCT device (Heidelberg Anterion).  IOL calculations were based on the Barret II universal formula. Initial IOL selection were based on the OLCR biometry. The primary outcome measure was the Refractive Prediction Error (RPE) and MedAE (median absolute error with the arithmetic mean error reduced to zero) 4-6 weeks after surgery. Secondary measures included subjective spherical equivalent (SE) refraction, uncorrected (UCVA) and best corrected distance visual (BCVA) acuity. 

124 eyes of 124 patients were included. 57% were female and the mean age was 74,8 years. The mean logMAR UCVA and BCVA was 0.09 and -0.02, respectively. The mean refractive SE was -0.04 D. The mean RPE was 0.06 ± 0.42 D, -0.14 ± 0.42 D  and 0.18 ±0.40 D (p < 0.01) for the Argos, Anterion and Lenstar, respectively. The MedAE was 0.28 D (range 1.22 D), 0.30 D (range 1.17 D) and 0.28 D (range 0.96) for the Argos, Anterion and Lenstar, respectively. The RPE for the Argos, Anterion and Lenstar was within ±0.5 D in 76%, 70% and 77%, respectively, within ±0.75 D in 94%, 93% and 90% respectively, and within 1D in 98% for all devices. The difference in percentages between devices was not statistically significant (p<0.2)

The Argos showed the lowest RPE compared to the other two biometers. However the MedAE (which represents results with optimal lens constants for the sample) was not significantly different and showed a lower range for the Lenstar. The results of this study indicate that the refractive predictability of the Argos combined OCT/reflection biometer is comparable with the swept source OCT biometer and OLCR biometer.