Analysis Of The Refractive Accuracy With A Novel Swept-Source Optical Coherence Biometer In Eyes With Nonstandard Axial Lengths

To analyze the refractive accuracy of a new swept-source optical coherence biometer in short and long eyes implanted with monofocal intraocular lenses (IOL).

Clínica Rementería, Madrid, Spain.

This retrospective study considered eyes with short axial length (AL) (< 22.5mm) or long AL (>26mm) bilaterally implanted with the Acrysof® IQ monofocal IOL. All eyes were analyzed with the ARGOS® biometer and IOL calculations were made with the same device using the Barrett Universal II (BUII). One month after the surgery, visual outcomes and refractive prediction errors were calculated. Then, a back calculation of the prediction errors based on the novel optimized Barret True Axial Length (BTAL) formula was performed and results with both formulas were compared.

Fifty eyes of 50 patients (25 with AL < 22.5mm (short) and 25 with AL > 26mm (long)) were included. Monocular UDVA was 0.02±0.05 and 0.10 ± 0.15 logMAR for short-eye and long-eye groups, respectively. For short-eyes, mean prediction error (MPE) was 0.18±0.32 D with BUII and 0.01 ± 0.33D with BTAL (p<0.001). Mean absolute error (MAE) was 0.31 ±0.20 and 0.27 ±0.19D with BUII and BTAL, respectively (p=0.16). The percentage of patients with prediction error ≤ 0.50Dwith BUII was 76% and 80% with BTAL For long eyes, MAE was -0.12±0.35D with BUII and -0.11±0.36D with BTAL (p=0.21). MAE was 0.30±0.22 with BUII and 0.31±0.21D with BTAL (p=0.15). For both formulas, 80% of patients were within a prediction error of ≤ 0.50D.   

The novel swept-source optical coherence biometer showed good overall refractive accuracy using the BUII. With the BTAL, the refractive accuracy was similar for long eyes and better for short eyes. Therefore, formulas purposely designed for biometric measurements with this novel technology seem to be a promising tool for eyes with nonstandard anatomies.