Brief Summary of the Study

The goal of this clinical study is to compare the quality of vision and patient satisfaction after cataract surgery using two different approaches to multifocal intraocular lenses (IOLs). These lenses replace the natural lens removed during surgery and are designed to allow clear vision at near, intermediate, and far distances, reducing or eliminating the need for glasses.

The study aims to understand whether using two different lens models-Mini Well in the dominant eye and Mini Well Proxa in the non-dominant eye-produces different levels of visual quality, glare, halos, or overall satisfaction compared with implanting the same trifocal lens model (FineVision POD F) in both eyes.

All lenses included in the study are approved medical devices already available on the market.

Who can participate? Adults scheduled to undergo cataract surgery in both eyes at the Ophthalmology Unit of the Policlinico of Verona may be eligible. A total of 36 participants will take part.

How does the study work?

Participation is voluntary. After informed consent, participants are randomly assigned (like flipping a coin) to one of two groups:

1. Experimental group: Mini Well lens in the dominant eye and Mini Well Proxa lens in the other eye.
2. Comparison group: FineVision POD F lens in both eyes.

Neither participants nor the clinical team conducting postoperative assessments will know which lenses were implanted (blinded study).

Before surgery, participants undergo a standard ophthalmic evaluation, including visual acuity tests and measurements of eye structure. After surgery in each eye, follow-up visits take place at approximately 1-2 days, 14 days, 1 month, and 3 months. During these visits, clinicians assess visual performance, eye health, and any symptoms. At the 3-month visit, participants also complete a questionnaire on vision quality and satisfaction, and undergo a specific test to measure perception of halos.

Participant responsibilities Participants are asked to attend all scheduled visits, follow medical instructions, use prescribed medications, and promptly report any symptoms or concerns.

Potential benefits Participants may experience improved vision at all distances with reduced dependence on glasses. However, personal benefit cannot be guaranteed. The study is expected to help determine whether combining two different lens models provides better visual outcomes than using the same lens in both eyes.

Risks and discomforts Risks are the same as those associated with standard cataract surgery and multifocal IOLs, including rare surgical complications and the possibility of visual disturbances such as glare or halos. These symptoms are common with multifocal lenses and often diminish over time, but in rare cases may require further intervention. All adverse events will be closely monitored.

Alternatives Patients may choose standard cataract surgery with monofocal lenses, which usually provide clear vision at one distance and may still require glasses for intermediate or near vision. Declining participation will not affect the quality of care.

Duration Each participant's involvement lasts about 4 months.

Voluntary participation Participants may withdraw at any time without affecting their medical care.

Confidentiality All personal and medical information will be handled confidentially and used only according to privacy regulations. Study results may be published anonymously in scientific reports.

This study is designed to evaluate patient-reported satisfaction and visual quality following bilateral cataract surgery with implantation of two different multifocal intraocular lens (IOL) strategies. The investigation compares a mixed-modality combination of complementary extended-depth-of-focus (EDOF) IOLs with a bilateral trifocal IOL approach. Although all lenses included in this research are CE-marked and commercially available, they differ in optical architecture and light-distribution profiles, offering an opportunity to assess whether pairing distinct optical designs between eyes can mitigate dysphotopsia while maintaining a full range of functional vision.

The scientific rationale derives from the known trade-offs associated with presbyopia-correcting IOLs. Trifocal designs distribute light to three focal points and provide distance, intermediate, and near performance, but may also induce photic phenomena such as halos or glare. EDOF platforms extend the depth of focus through controlled modulation of spherical aberration or wavefront shaping, with the goal of improving image continuity and contrast. The Mini Well and Mini Well Proxa lenses, which incorporate different wavefront-engineering profiles, are hypothesized to act synergistically when implanted contralaterally. This design may reduce dysphotopsia intensity by balancing light distribution asymmetrically across the visual system. In contrast, bilateral FineVision POD F implantation represents a uniform, widely adopted trifocal strategy.

The study is conducted at the Ophthalmology Unit of the Policlinico of Verona and enrolls 36 patients requiring routine bilateral cataract extraction. Participants are randomized 1:1 to one of the two treatment groups. The allocation sequence is computer-generated and concealed using a predefined method to ensure unbiased assignment. Masking is maintained at the patient level; patients are not informed of the IOL type they receive. Outcome assessors remain masked whenever feasible, although surgeons cannot be masked due to the nature of the intervention.

The protocol follows a standardized clinical workflow. Preoperative evaluation includes refraction, slit-lamp biomicroscopy, tonometry, retinal assessment, and biometric measurements using optical biometry to calculate IOL power. Cataract extraction is performed using a uniform phacoemulsification technique, with efforts to standardize incision size and capsulorhexis configuration. Postoperative care follows standard clinical practice and includes scheduled visits at early, intermediate, and late postoperative time points for both eyes.

Across follow-up, participants undergo routine ophthalmic assessments and standardized testing. At the final postoperative visit, patients complete structured questionnaires addressing visual function, satisfaction, spectacle independence, and visual disturbances. Objective quantification of dysphotopsia, including halo intensity and size, is also performed using validated halometry tools. These assessments provide combined subjective and objective characterization of visual quality.

The anticipated duration of participation is approximately four months, including preoperative evaluation, surgery for each eye, and postoperative follow-up through the three-month visit after the second eye procedure. Study data are collected in case report forms and stored under coded identifiers to ensure confidentiality. Data management follows applicable privacy legislation and good clinical practice guidelines. Quality assurance procedures include verification of source documents, consistency checks for questionnaire scoring, and calibration of devices used for optical quality measurements.

By comparing a contralateral EDOF-based strategy with bilateral trifocal implantation, this investigation seeks to clarify whether mixing complementary optical designs yields advantages in patient satisfaction, visual comfort, or dysphotopsia reduction. The findings are expected to contribute evidence relevant to presbyopia-correcting IOL selection, optimization of binocular optical planning, and patient counseling in cataract surgery.

Inclusion Criteria:

• Age 18 years or older.
• Diagnosis of age-related cataract in both eyes requiring bilateral cataract surgery.
• Corneal astigmatism 0.50 diopters or less in each eye.
• No other media opacities except cataract.
• Regular corneal shape without abnormal curvature or high-order aberrations on topography/aberrometry.
• Intraocular lens spherical power between +10.00 and +30.00 diopters according to biometry and IOL calculation.
• Willing and able to undergo surgery in the second eye within 7 days of the first-eye surgery.
• Willing and able to attend all scheduled follow-up visits, including the 3-month visit.
• Able to understand the study information and provide written informed consent.

Exclusion Criteria:

• Any prior ocular surgery in either eye.
• Any concomitant ocular disease that could affect visual outcomes (for example glaucoma, retinal disease, significant macular pathology, corneal dystrophy or degeneration, keratoconus, significant dry eye not controlled with treatment).
• Clinically significant irregular astigmatism or corneal scarring.
• Any intraoperative complication during cataract surgery that could compromise IOL position or visual outcome (such as posterior capsule rupture, zonular dialysis); such eyes will be excluded from the analysis set.
• Significant posterior capsule opacification before the 3-month outcome visit requiring YAG capsulotomy.
• Systemic disease or neurological condition that, in the investigator's opinion, may affect visual function, ability to complete testing (for example halometry, questionnaires), or study participation.
• Cognitive impairment or psychiatric condition that precludes giving informed consent or complying with study procedures.
• Participation in another interventional clinical study that could interfere with outcomes of this trial.

Deidentified individual participant data that underlie the main published results (including primary and secondary outcomes) will be shared. Data will be available beginning 12 months after publication of the primary manuscript and for 5 years thereafter. Data will be shared with qualified researchers for methods-sound proposals focused on cataract surgery, intraocular lenses, or visual outcomes, after approval by the sponsor and execution of a data use agreement. Requests should be sent to the corresponding investigator by email.

Data will be available beginning 12 months after publication of the primary manuscript and for 5 years thereafter.

Data will be shared with qualified researchers for methods-sound proposals focused on cataract surgery, intraocular lenses, or visual outcomes, after approval by the sponsor and execution of a data use agreement. Requests should be sent to the corresponding investigator by email.

Participants are masked to the intraocular lens (IOL) model implanted in each eye. Outcome assessors, including performing postoperative visual testing and halometry, remain masked to treatment allocation. Surgical staff cannot be masked due to required knowledge of lens type during the procedure. Postoperative data collection is structured to prevent assessors from accessing operative records or lens identifiers. Patients are instructed not to discuss perceived optical differences between eyes during masked assessments to preserve masking integrity.