Anterior segment angle changes, vault, and intraocular pressure after phakic intraocular lens implantation: An anterior segment optical coherence tomography study

Abstract

Objective: This study aimed to evaluate 6-month changes in iridocorneal angle morphology, central vault, and intraocular pressure after toric phakic intraocular lens implantation, using anterior segment optical coherence tomography.

Methods: This retrospective single-surgeon cohort included 21 right eyes of 21 patients who completed 1- and 6-month follow-up after toric phakic intraocular lens implantation. Angle opening distance and trabecular–iris space area at 500 and 750 µm, and trabecular–iris angle, were measured nasally and temporally. Anterior chamber depth, anterior chamber width, vault, intraocular pressure, and spherical equivalent were also recorded.

Results: Spherical equivalent improved from −8.06 ± 2.43 D to −0.32 ± 0.32 D at 6 months (p < 0.001). Vault was 578 ± 89 µm at 1 month and 559 ± 81 µm at 6 months (p = 0.006); all eyes remained within 250–750 µm. Trabecular–iris angle decreased by 42.3%, and angle opening distance and trabecular–iris space area by 52–59% (all p < 0.001), with no further narrowing after month 1. Intraocular pressure was 14.5 ± 2.4, 20.9 ± 3.7, and 17.8 ± 3.3 mmHg at the three visits. Six-month vault correlated with preoperative anterior chamber width (r = 0.47; p = 0.030) and axial length (r = 0.44; p = 0.046).

Conclusion: Toric phakic intraocular lens implantation was associated with early angle narrowing followed by stabilization through month 6. Vault remained within 250–750 µm. Associations between postoperative vault, anterior chamber width, and axial length were exploratory.