Refraction and anatomical lens position predictability in phacovitrectomy using a 7 mm optic with cutout haptics...

To evaluate the refractive and anatomical lens position (ALP) predictability of the Aspira aXA (7 mm optic, cutout haptics) and Sensar One AAB00 IOLs (6 mm optic, C-loop haptics) in phacovitrectomy in a prospective, non-randomized cohort study.

Preoperative biometry, 3-month subjective refraction, and swept-source optical coherence tomography were analyzed. ALP was the distance from the corneal endothelium to the IOL equator. Multivariate mixed-effects analysis was performed.

A total of 102 eyes from 97 patients were included (54 Aspira aXA; 48 Sensar One). The increase in the Aspira aXA lens thickness (LT) per diopter was 3.14 times greater than that of the Sensar One, yet showing a decrease from 1300 to 1100 μm at 23 D. The anterior chamber depth (ACD) increased from preoperatively to postoperatively-to a greater extent for the Sensar One (1.74 vs. 1.50 mm, p <0.0001)-while the axial length (AL) decreased, also to a greater degree for the Sensar One (p <0.05). Holladay 1 achieved the lowest mean absolute error (MAE) (Aspira aXA: 0.24; Sensar One: 0.23 D) and, with the SRK/T and Haigis formulas, the highest accuracy within ± 0.25 D. Preoperative ACD, AL, LT, and K_m influenced the mean numerical error (MNE) and MAE inconsistently. The IOL type affected the MNE and MAE only for Haigis, whereas the ALP significantly influenced the MNE, but not the MAE, in all formulas except Hill-RBF and SRK/T. Notably, the endotamponade type impacted the MNE and MAE in several modern formulas, but not in traditional vergence formulas. In contrast to AL and K_m, the ACD and LT were strong predictors of ALP (Aspira aXA: R² = 0.697, Sensar One: 0.881).

Preoperative ACD and LT reliably predict ALP. The Aspira aXA IOL introduces variability owing to its thickness profile. The endotamponade type exerts a significant influence. Traditional vergence formulas show greater robustness. Formula developments should integrate lens- and surgery-specific information.