Clinical Outcomes of a Novel Customized Multifocal Corneo-Scleral Contact Lens With Spherical Aberration Control

PURPOSE: To evaluate the objective and subjective clinical outcomes of a customized multifocal corneo-scleral contact lens (CLs) with spherical aberration (SA) control in presbyopic patients. METHODS: A pilot observational clinical study was conducted in 27 presbyopic subjects (54 eyes). All participants were fitted with a customized multifocal corneo-scleral rigid gas-permeable (RGP) CLs designed to induce controlled SA. Binocular visual acuity (VA) was assessed under photopic conditions for distance, intermediate (67 cm), and near (40 cm) vision after a minimum wear period of 2 months and binocular defocus profile was constructed by plotting mean visual acuity (logMAR) as a function of induced defocus from +2.00 to -2.50 D. Ocular aberrations with the lens in situ were measured using a Hartmann-Shack aberrometer. Subjective visual quality and comfort were evaluated using the Quality of Vision (QoV) questionnaire and the eight-item Contact Lens Dry Eye Questionnaire (eCLDEQ-8). Spearman correlation analyses were performed to explore relationships between visual outcomes and optical parameters. RESULTS: Mean binocular VA was 0.03±0.06 for distance vision, 0.10±0.12 for intermediate vision, and 0.32±0.17 for near vision. The binocular defocus profile showed preserved visual performance from distance to intermediate defocus levels, with a marked reduction at-2.50 D. A weak but statistically significant positive correlation was found between the sign of induced SA and distance VA (ρ=0.303, P=0.026), indicating poorer distance vision with positive SA induction. Near VA was weakly and positively correlated with mean pupil diameter (ρ=0.301, P=0.027). No significant associations were observed between VA and total higher-order aberration (HOAs) magnitude. Subjective symptoms were generally mild, with difficulty focusing being the most frequently reported complaint. CONCLUSIONS: The customized multifocal corneo-scleral CLs with SA control evaluated can provide good distance and intermediate visual performance in presbyopic patients, but limited near visual performance and symptom tolerance. The sign of induced SA and pupil size seem to influence visual outcomes, supporting the value of individualized optical design. Further controlled studies with larger samples and extended follow-up are warranted.