Barrett Rx Tool For Intraocular Lens Power Calculation In Pseudophakic Eyes Undergoing Intraocular Lens Exchange

To assess the accuracy of refraction prediction in eyes undergoing intraocular lens (IOL) exchange using a tool integrated into the software of a modern biometer with Scheimpflug technology.

Department of Ophthalmology, Goethe-University, Frankfurt, Germany, and University Eye Clinic Maastricht, Maastricht University Medical Center, Maastricht, Netherlands

In this consecutive case series, eyes that underwent uneventful bag-to-bag IOL exchange after lens extraction surgery were included. The calculation of IOL power was performed using the Barrett RX tool integrated into the Pentacam software (Oculus Optikgeräte GmbH, Wetzlar, Germany). The primary objective is to ascertain the prediction error (PE). The mean arithmetic prediction error (MPE), mean absolute prediction error (MAE), and median absolute prediction error (MedAE) are presented, along with the number of eyes within ±0.25, ±0.50, and ±1.00 diopters (D).

Twenty-five eyes of 25 patients (17 females) with a mean age of 60.2±11.4 years were included. The mean interval between primary IOL implantation and exchange was 25.3±31.5 weeks (range: 1.3 to 140.6 weeks). In 11/25 eyes, a different IOL model was implanted during the exchange. Before IOL exchange, the mean refractive error was ±0.62D. The MPE of the Barrett RX tool was 0.02±0.32D. MAE and MedAE was 0.27±0.17D and 0.22D, respectively. Across the eyes, 56.0% were within ±0.25D and 92.0% were within ±0.50D.

The Barrett RX formula has been demonstrated to be an efficacious method for calculating IOL power in eyes undergoing IOL exchange, with more than half of cases within ±0.25D of the predicted post-exchange refraction.