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

Study Overview
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Brief Summary
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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.

Detailed Description
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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.

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

Conditions
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Cataract

Intervention / Treatment
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* Procedure: multifocal intraocular lens implantation
* Procedure: monofocal intraocular lens implantation
* Drug: Dexamethasone
* Device: multifocal intraocular lens (IOL) (Tecnis ZMB00)
* Device: monofocal intraocular lens (IOL) (Tecnis ZCB)


Participation Criteria
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Eligibility Criteria
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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

Ages Eligible for Study
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Minimum Age: 45 Years
Maximum Age: 75 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: multifocal intraocular lens group<br> | Procedure: multifocal intraocular lens implantation<br>* In this group, the surgery was performed with cataract extraction and multifocal intraocular lens (IOL) (Tecnis ZMB00). The standard technique in all patients consisted of sutureless phacomulsifacation using the Legacy 2000 Series and Infinity phacoemulsification machine (Alcon Laboratories Inc., Fort Worth, Texas, USA), with clear corneal incisions up to 3.2 mm and 5.0 to 5.5 mm capsulorhexis. Surgery in the fellow eye was performed 1 month later in each patient.<br>Drug: Dexamethasone<br>* All patients received subconjunctival dexamethasone (2 mg) during surgery<br>Device: multifocal intraocular lens (IOL) (Tecnis ZMB00)<br> <br> |
| Active Comparator: monofocal intraocular lens group<br> | Procedure: monofocal intraocular lens implantation<br>* In the group, the surgery was performed with cataract extraction and monofocal intraocular lens (IOL) (Tecnis ZCB). The surgery technique was same as the multifocal intraocular lens group<br>Drug: Dexamethasone<br>* All patients received subconjunctival dexamethasone (2 mg) during surgery<br>Device: monofocal intraocular lens (IOL) (Tecnis ZCB)<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change from contrast sensitivity | Contrast sensitivity (CS) was tested with a Contrast Glare Tester 1000 | 1 week, 1 month, 3 month, 6 month,1 year after surgery | 
| Change from functional magnetic resonance imaging |  | 1 week, 1 month, 3 month, 6 month,1 year after surgery | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change from best corrected visual acuity |  | 1 week, 1 month, 3 month, 6 month,1 year after surgery |