Night Driving After Trifocal Versus Monofocal IOL Implantation

Inclusion criteria

• Adults aged 18 to 85 years.
• Scheduled to undergo bilateral phacoemulsification with in-the-bag intraocular lens implantation.
• Both eyes scheduled to receive the same type and model of either an Alcon trifocal intraocular lens or an Alcon monofocal intraocular lens.
• Possession of a valid motor vehicle driving license.
• Stable night-driving behavior during the previous 3 months, with night driving occurring at least twice per month.
• Lens Opacities Classification System III nuclear opalescence grade of 4 or lower in both eyes.
• Expected intraocular lens power between +10.0 D and +36.0 D, inclusive, in both eyes.
• Ability to understand the purpose and procedures of the study and independently complete the VND-Q and visual quality questionnaires.
• Willingness to provide written informed consent and complete the scheduled postoperative follow-up visits.

Exclusion criteria

• Corneal endothelial cell density below 1,500 cells/mm² in either eye.
• History of ocular trauma affecting visual function, previous intraocular surgery, or previous corneal refractive surgery in either eye.
• Strabismus, amblyopia, or nystagmus in either eye.
• Any ocular disease that may affect postoperative visual acuity, contrast sensitivity, mesopic visual function, or questionnaire assessment, including but not limited to irregular corneal astigmatism, corneal scar, corneal degeneration, keratoconus, keratitis, corneal dystrophy, uveitis, severe iris atrophy, intraoperative floppy iris syndrome, microphthalmos, macrophthalmos, color vision deficiency, active ocular inflammation, advanced glaucoma or uncontrolled intraocular pressure, macular disease, retinal pigment epithelial disease, diabetic retinopathy, retinal detachment, choroidal detachment, or optic atrophy.
• A high risk of zonular rupture or an contraindication to in-the-bag intraocular lens implantation, including zonular weakness, zonular dialysis, lens subluxation or dislocation, pseudoexfoliation syndrome, Marfan syndrome, posterior capsule rupture, or cyclodialysis.

Severe or unstable systemic disease, including systemic lupus erythematosus or Sjögren syndrome.

• Use of medication judged by the investigator to increase surgical risk or affect visual function, including amiodarone, chlorpromazine, ethambutol, digitalis, or chloroquine.
• Requirement for a combined ocular procedure, including limbal relaxing incisions, intraocular drug injection, retinal laser treatment, or another combined procedure judged inappropriate by the investigator.
• Severe anxiety, depression, or another significant psychiatric disorder.
• Any other condition judged by the investigator to make participation inappropriate.