Postoperative Comparison Of Patients With Bilateral Versus Unilateral Trifocal Intraocular Lens Implantation

This study aims to evaluate the visual outcomes and patient satisfaction when one eye is fitted with a monofocal intraocular lens and the other with a trifocal intraocular lens, comparing it to bilateral trifocal intraocular lens implantation. Key questions include: Is the combination of a monofocal intraocular lens and trifocal intraocular lens tolerable for distance, intermediate, and near vision? How do postoperative outcomes differ between these two groups in terms of vision, satisfaction, dysphotopsia, and contrast sensitivity?

This retrospective study included patients who attended the Ophthalmology Department of Prof. Dr. Cemil Taşçıoğlu City Hospital between March 20, 2021, and May 16, 2023, with a diagnosis of cataract in both eyes and who underwent uncomplicated phacoemulsification surgery in both eyes, receiving either bilateral trifocal intraocular lens implantation or a monofocal intraocular lens in the dominant eye and a trifocal intraocular lens in the non-dominant eye. 

The study analyzed 23 patients (Group 1) who received a bilateral trifocal intraocular lens (VSY Biotechnology GmbH, Acriva^UD Trinova Pro C) and 23 patients (Group 2) who had previously received a monofocal lens in one eye followed by a trifocal lens in the other. The postoperative findings were retrospectively evaluated. Postoperative examinations were performed at 1 day, 1 week, 1, 3 and 6 months. Visual acuities, spherical equivalan, manifest refraction, contrast sensitivity and defocus curves were recorded. Quality of life was evaluated with NEI-VFQ-25/TR. PCO rate, spectacle needs, positive and negative dysphotopsia were noted.

The study found no significant differences between groups in terms of binocular distance, intermediate and near vision acuities. However, Group 2 showed higher contrast sensitivity in high photopic environment, while no significant difference was found in mesopic conditions. Patients in Group 2 showed higher contrast sensitivity in monofocal eyes compared to trifocal eyes in glare situations. The posterior capsule opacification rate was 15.9% in the eyes with trifocal lenses. The quality-of-life questionnaire and defocus curve showed no significant differences between groups.

When the visual acuities, contrast sensitivities, defocus curves, and quality-of-life scores of patients who received bilateral trifocal intraocular lenses were compared with those who received unilateral monofocal and contralateral trifocal intraocular lenses, the results were similar. Trifocal intraocular lenses cause greater contrast sensitivity loss than monofocal lenses, but this does not appear to affect patient satisfaction or quality-of-life. According to the results, patients with a monofocal lens in one eye may be considered for trifocal intraocular lens implantation in the other.