Trifocal IOL Outcomes Show Minimal Dependence on Pupil Size

Visual performance and patient satisfaction after trifocal intraocular lens implantation are largely independent from pupil size (PS), according to results of a study published in the Journal of Cataract & Refractive Surgery. However, pupil size does appear to have a significant influence upon visual acuity at the extreme ends of defocus curve, as well as the need for near-vision spectacles and range-of-depth-of-field.

Researchers conducted a post hoc analysis of pooled data from 2 prospective single-center studies, including patients examined 3 months after successful bilateral PanOptix IOL implantation during cataract surgery or refractive lens exchange. Eligible participants had healthy eyes targeted within ±0.50 diopters (D) of emmetropia and expected postoperative astigmatism <0.70 D. 

All surgeries were performed by a single surgeon using either femtosecond laser–assisted or standard phacoemulsification techniques. Postoperative assessments included monocular and binocular visual acuity at multiple distances, defocus curve testing from -5.0 to +2.0 D, contrast sensitivity under photopic and mesopic conditions (with and without glare), and patient-reported satisfaction and spectacle independence.

A total of 52 patients (21 men; mean age, 68 years; range, 40-88) were evaluated 3 months after bilateral implantation of the PanOptix trifocal intraocular lens, representing 104 eyes, including 70 cataract surgeries and 34 refractive lens exchanges. 

Smaller photopic PS led to more near-spectacle independence, which also seemed to affect the intermediate-range.

Among implanted lenses, 54 were non-toric and 50 toric, and a femtosecond laser-assisted procedure was used in 102 cases. Binocular PS analysis classified patients under mesopic conditions into small (n=20), medium (n=25), and large (n=7) groups, and under photopic conditions into 4, 42, and 6 patients, respectively. Patient-reported outcomes demonstrated high satisfaction, with 86.5% willing to choose the same IOL again and spectacle independence achieved in 98.1% for distance, 96.2% for intermediate, and 92.3% for near vision.

Statistical analyses showed no significant association between photopic or mesopic pupil size and uncorrected or distance-corrected visual acuity at multiple distances, contrast sensitivity under photopic or mesopic conditions (with or without glare), overall satisfaction, or distance spectacle independence across Spearman correlation, ANOVA, point-biserial correlation, and chi-square testing. Continuous photopic pupil size demonstrated only borderline relationships with intermediate and near spectacle independence (r=-0.267, P =.056; r=-0.260; P =.063), while categorized photopic PS showed a modest association with near spectacle independence (P =.041) but not intermediate vision. Mesopic pupil size showed no significant correlations with visual or patient-reported outcomes, although weak trends toward significance were observed for newspaper-reading performance under photopic (r=0.268; P =.055) and mesopic (r=0.272; P =.051) conditions that were not confirmed in ANOVA analysis.

“Since most significant findings in the defocus curve were found between large and small pupils and -especially for RoF  0.2 logMAR- eyes with larger photopic PS demonstrated poorer outcomes, this characteristic may have influenced the results. Binocular VA in different distances, CS, spectacle independence for distance and IOL choice satisfaction were not associated with PS,” according to the research team. “In terms of daily activities, only newspaper reading showed a trend towards significance with larger PS in both conditions leading to worse grading. Smaller photopic PS led to more near-spectacle independence, which also seemed to affect the intermediate-range.”

Study limitations include an unequal distribution of PS categories, an unvalidated questionnaire, and inter-subject variability due to differences in individual perceptions and expectations.

Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.