Neural Compensation, Visual Function and Visual Quality After Monofocal or Multifocal Intraocular Lens Implantation

Neural Compensation, Visual Function and Visual Quality in Senile Cataract Patients After Monofocal or Multifocal Intraocular Lens Implantation

Multifocal intraocular lenses (MIOLs) provide enhanced far and near visual acuity, but they can bring about halos and glare, which are caused by design deficiencies of the IOLs. Compared to monofocal intraocular lens, pseudo accommodation in nonphysiological state may increase the difficulty of neural compensation reconstruction in patients with multifocal intraocular lens implantation. Patients enrolled into the study will be followed for 1 year and will have study visits preoperatively, at 1 week, 3 months, 6 months, 12 months postoperatively.In this trial, we aimed to specify the time of neural compensation reconstruction in patients and to explore the changes of visual function in senile patients with monofocal or multifocal intraocular lens implantation.

Cataract extraction and intraocular lens (IOL) implantation are the current standard treatments for age-related cataract (ARC). Cataract surgery increases visual acuity but may lead to complaints after surgery. Multifocal intraocular lenses (MIOLs) provide enhanced far and near visual acuity, but they can bring about halos and glare, which are caused by design deficiencies of the IOLs. Fortunately, most of the halos and glare diminish with time. Niels et al noted that neural adaptation (NA) may explain the lower incidence of glare and halos in their study. Compared to monofocal intraocular lens, pseudo accommodation in nonphysiological state may increase the difficulty of neural compensation reconstruction in patients with multifocal intraocular lens implantation.

In the present study, the investigators evaluated the activity of neurons in the visual cortex using fMRI both preoperatively and postoperatively. In addition, the investigators evaluated postoperative changes in VF, including visual acuity (VA), contrast sensitivity (CS), straylight values (SVs), and pattern visual evoked potential (PVEP), stereoscopic vision, wavefront aberrations at 1 week, 3 months, 6 months, 12 months postoperatively.In this trial, the investigators aimed to specify the time of neural compensation reconstruction in patients and to explore the changes of visual function in senile patients with monofocal or multifocal intraocular lens implantation.

Inclusion Criteria:

• visual acuity less than 0.3
• Cataracts in both eyes classified by the Lens Opacity Classification System III
• Corneal astigmatism less than 1.5 diopters (D)
• Capability of understanding and signing the informed consent

Exclusion Criteria:

• Corneal astigmatism ≥ 1.5D.
• History of neurological or psychiatric disorders; systemic disease such as severe hypertension or diabetes mellitus that might interfere with the visual outcomes.
• Associated ocular disease that could interfere with final results
• Previous anterior and posterior segment surgery and intraoperative or postoperative complications
• Driving at night frequently; excessive expectations for visual outcomes