Real-World Two-Year Outcomes of Diffractive Implantable Phakic Contact Lenses in Presbyopic Myopes: Functional Vision, Anatomical Findings, and Environmental Context.

Background and

Objectives

To evaluate two-year functional, anatomical, and patient-reported outcomes after bilateral implantation of a diffractive implantable phakic contact lens (IPCL) for presbyopia correction in myopic patients within a high-solar-radiation Atlantic island environment.

Methods

This retrospective observational study included 11 presbyopic myopic patients aged 40-50 years (22 eyes) who underwent bilateral diffractive IPCL implantation and completed a 2-year follow-up. Monocular defocus curves were recorded from +3.0 to -5.0 D and converted to logMAR. Functional visual range and area under the defocus curve (AUC) were calculated. Anatomical stability was assessed by central vault, pupil diameter, and crystalline lens rise measurements. Safety evaluation included slit-lamp examination for crystalline lens transparency and corneal integrity. Patient-reported outcomes were measured using the Quality of Vision (QoV) and Catquest-9SF questionnaires. Environmental parameters during implantation and follow-up were characterized using regional meteorological data.

Results

Mean visual acuity remained ≤0.14 logMAR up to -2.5 D of defocus, with functional vision (≤0.2 logMAR) extending to approximately -3.0 D in about half of the eyes. Median vault at 2 years was 546 µm (IQR 361.5-667.3 µm). No cases of clinically significant cataract or corneal compromise were observed. QoV scores were low (1.41 ± 0.43) and Catquest-9SF scores high (3.70 ± 0.18), with no strong correlations between subjective and anatomical metrics. Visual performance remained stable within a consistent high-solar-radiation and atmospheric light-scattering environment.

Conclusions

Diffractive IPCL implantation was associated with stable anatomical positioning, sustained functional visual performance across distances, and favorable patient-reported outcomes at 2 years. Within a consistent real-world environmental context, these findings provide a descriptive framework for understanding diffractive IPCL performance, while larger prospective studies are warranted.