Simultaneous Phakic Intraocular Lens Exchange – Indications And Results At 12-Month Follow-Up

To document indications and short-term results of simultaneous phakic intraocular lens exchange.

Phakic intraocular lens (pIOL) implantation represents the surgical procedure of choice for the management of moderate to high myopia and astigmatism, providing better visual and refractive results than corneal ablation refractive treatments. A clinical advantage associated with the pIOL is its reversibility and adjustability, as it can be removed and exchanged for another model according to certain clinical indications: incorrect lens size, refractive adjustment, or endothelial cell loss.

A retrospective study, including 21 eyes of 17 patients who underwent phakic lens explantation and simultaneous implantation of a new pIOL, either the same or a different model, at Braga Hospital between 2020 and 2024. The following parameters were assessed: cause for exchange, time between surgeries, explanted and re-implanted pIOL type, corrected and uncorrected visual acuity (VA), refractive error (RE), endothelial cell density (ECD) and rate of intra and post-operative complications.

The main causes for pIOL exchange were refractive error (38,0%), progressive endothelial cell loss (28,6%) and incorrect posterior pIOL sizing (23,8%); most of the pIOL explanted were anterior chamber pIOLs (61,90%). At 12 months follow-up, both corrected and uncorrected VA improved significantly after surgery (from 0.1 ± 0.28 to 0.7 ± 0.38; from 0.8 ± 0.38 to 0.9 ± 0.24, respectively). The RE decreased significantly (to 0.00 ± 0.81 D of sphere and -1.00 ± 1.17 D of cylinder). In the case of progressive ECD, 4 of 6 eyes (62,6%) had a preoperative mean ECD < 1500 cells/mm2; 5 of 6 eyes (83,3%) demonstrated a significant increase in mean ECD at 12 months. A single event of acute ocular hypertension was recorded.

Performing an exchange of a pIOL for a different model or dioptric power pIOL demonstrated to be safe and effective. At a short-term follow-up, most indications are residual refractive error or incorrect sizing of a posterior chamber pIOL. At mid or long-term, the main cause for pIOL exchange is progressive endothelial cell loss in a young patient with an anterior chamber pIOL; to implant a posterior pIOL demonstrated to be safe, avoiding the future risks of performing an early refractive lensectomy in a moderate-high myopic patient.