Vault Prediction Accuracy Of An Online Calculator For Posterior Chamber Phakic Intraocular Lens Implantation In Filipino Eyes

To evaluate the predictability of postoperative vault following posterior chamber phakic intraocular lens implantation in Filipino eyes using an online calculation tool and to assess early safety and visual outcomes.

St. Luke’s Medical Center, Philippines

This retrospective chart review included eyes undergoing posterior chamber phakic intraocular lens implantation (Eyecryl Phakic IOL, Biotech Vision Care, India) for myopia with or without astigmatism at St. Luke’s Medical Center, Philippines. Preoperative parameters including anterior chamber depth, white-to-white, axial length, and crystalline lens rise (CLR) were obtained; CLR was measured with ultrasound biomicroscopy. Predicted vault was calculated using the Biotech online calculator. Postoperative vault at 1 month was measured using anterior segment OCT (Cirrus, Carl Zeiss Meditec). Agreement was evaluated using Bland–Altman analysis. Prediction accuracy and visual outcomes were assessed.

Seventeen eyes of 9 patients were included. Mean predicted vault was 485.8 µm and mean achieved vault was 463.5 µm. The mean difference was −22.3 ± 114.9 µm. Bland–Altman analysis showed 95% limits of agreement from −247.4 to +202.8 µm. Mean absolute prediction error was 94.2 µm (median 68 µm). Prediction accuracy showed 58.8% of eyes within ±100 µm, 88.2% within ±200 µm, and 100% within ±300 µm of predicted vault. A moderate correlation was observed between predicted and achieved vault (r = 0.42). At 1 month, mean UDVA was 0.08 ± 0.14 logMAR and mean CDVA was 0.03 ± 0.12 logMAR. The efficacy index was 1.08 and safety index was 1.16, with no loss of CDVA lines.

The Biotech online vault prediction calculator demonstrated acceptable agreement between predicted and achieved vault in Filipino eyes undergoing posterior chamber phakic intraocular lens implantation. Favorable early visual and safety outcomes, along with good prediction.