Cataract Removal and Alzheimer's Disease

November 7, 2017 updated by: Grover C. Gilmore, PhD., University Hospitals Cleveland Medical Center

Therapeutic Effects of Cataract Removal in Alzheimer's Disease

Two very common aging-related diseases in older adults are Alzheimer's disease (AD) and cataracts. In elderly adults, these two diseases frequently occur in the same person. Although a cure for AD is currently unavailable, cataracts can be effectively treated with surgery in most people. The removal of cataracts has documented benefits for visual performance and for reducing accidents and falls. However, it has been the experience of the ophthalmologists, and others in the field, that patients, caregivers, and primary care doctors are reluctant to proceed with cataract surgery once an individual is given the diagnosis of AD. It is thought that cataract surgery will not improve the AD patient's quality of life, vision, and cognition. The investigators have designed this study to determine whether or not this is true.

Study Overview

Status

Completed

Detailed Description

In this project, we propose to test the following clinical hypothesis, while addressing the primary and two secondary Specific Aims:

Hypothesis: Cataract removal produces measurable benefits in vision, perception, independent function, and quality of life in patients with co-morbid Alzheimer's disease.

Primary Specific Aim: To determine the effects of cataract removal on visual acuity, spatial contrast sensitivity, vision dependent functions, visual information processing, and quality of life in patients with Alzheimer's disease.

Secondary Specific Aims.

  1. To delineate the baseline characteristics of those patients who benefit most from the surgical intervention.
  2. To assess the thickness of the retinal nerve fiber layer (RNFL) with optical coherence tomography (OCT) in large samples of AD patients classified with mild or moderate dementia to determine if the thickness of the RNFL is associated with dementia severity, visual performance measures, and other patient characteristics.

The study is designed as a Randomized Controlled Trial (RCT) with two cohorts of AD patients in a longitudinal investigation. Each person will be evaluated periodically over a 6 month period. All participants will be diagnosed with visually significant bilateral cataractous lens. The cohorts will be established by randomly assigning patients to either the immediate or the (optional) delayed surgery group. Patients will be stratified by AD severity (CDR mild or moderate) and cataract severity prior to being randomized. Comparisons between and within groups will test the change over time in vision, visual information processing, and quality of life associated with or without the removal of cataracts. The RNFL thickness of each person will be evaluated with optical coherence tomography (OCT). The thickness of the RNFL will be compared across dementia severity levels. Each consented participant will have a consenting study partner who may be referred to as a Research Partner, and who will often be the participant's caregiver. The latter will help to assure protocol adherence by the AD participants and will provide information about behavioral symptoms, activities of daily living, and amount of resources used. The study will demonstrate the clinical efficacy of cataract removal as a direct intervention to potentially improve the visual and cognitive functions, and the quality of life in persons diagnosed with AD.

Study Type

Interventional

Enrollment (Actual)

122

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

    • Ohio
      • Cleveland, Ohio, United States, 44109
        • MetroHealth Medical Center
      • Cleveland, Ohio, United States, 44106
        • University Hospitals Case Medical Center

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

50 years to 90 years (ADULT, OLDER_ADULT)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • age 50 and older
  • clinical diagnosis of possible/probable Alzheimer's disease, or other type of dementia, mild (CDR-1), moderate (CDR-2), or severe (CDR-3)
  • at least 1 visually significant cataract
  • no ocular pathology
  • psychotropic drug must be with stable dosage for 30 days

Exclusion Criteria:

  • history of cataract removal
  • history of visually significant retinal, or optic nerve abnormalities
  • informed consent cannot be obtained from either subject or their research partner
  • subject shows evidence (in preoperative testing) of unstable cardiac or pulmonary function
  • history of uncontrolled diabetes or hypertension
  • history of stroke in areas known to affect cognition
  • life expectancy of less than 1 year
  • Down's Syndrome

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: OTHER
  • Allocation: RANDOMIZED
  • Interventional Model: PARALLEL
  • Masking: NONE

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
ACTIVE_COMPARATOR: Immediate Cataract Surgery
Subjects randomly selected into the Immediate Surgery group will have their cataract surgery scheduled one month from the time their initial study visits are completed. The subjects will be followed monthly for a period of 6 months for surgical and non-surgical adverse events. At the 6-month point, subjects will receive a final comprehensive eye exam and neuropsychological testing. The research partners will complete final activities of daily living and resource utilization questionnaires.
Cataract surgery, as part of standard of care, will be performed on 1/2 of the group under investigation.
NO_INTERVENTION: Delayed Cataract Surgery
Subjects selected into the Delayed Surgery group will be asked to delay their surgery for 6 months after their initial study visits. At 6 months, this group will also undergo the same testing as the Surgery Group.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
Visual acuity, spatial contrast sensitivity, visual perception and cognition
Time Frame: Baseline and Month 6
Baseline and Month 6

Secondary Outcome Measures

Outcome Measure
Time Frame
Independent function
Time Frame: Baseline and Month 6
Baseline and Month 6
Quality of Life
Time Frame: Baseline and Month 6
Baseline and Month 6
Retinal Nerve Fiber Layer
Time Frame: Baseline, Months 2,4, & 6
Baseline, Months 2,4, & 6

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Investigators

  • Principal Investigator: Grover C. Gilmore, PhD., Case Western Reserve University
  • Study Director: Sara Debanne, PhD., Case Western Reserve University
  • Study Director: Julie Belkin, M.D., University Hospitals Cleveland Medical Center
  • Study Director: Jonathan Lass, M.D., University Hospitals Cleveland Medical Center
  • Study Director: Alan Lerner, M.D., University Hospitals Cleveland Medical Center
  • Study Director: Thomas Steinemann, M.D., MetroHealth Medical Center

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

June 1, 2009

Primary Completion (ACTUAL)

March 30, 2017

Study Completion (ACTUAL)

March 30, 2017

Study Registration Dates

First Submitted

June 15, 2009

First Submitted That Met QC Criteria

June 15, 2009

First Posted (ESTIMATE)

June 16, 2009

Study Record Updates

Last Update Posted (ACTUAL)

November 9, 2017

Last Update Submitted That Met QC Criteria

November 7, 2017

Last Verified

November 1, 2017

More Information

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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