Cataract Surgery Has Benefits in Patients With Dementia

Megan Brooks

November 19, 2015

BARCELONA — Cataract surgery improves not only vision but also cognitive function and neuropsychiatric symptoms in patients with dementia, preliminary results of an ongoing National Institutes of Health (NHI)–sponsored study suggest.

"Memory is profoundly dependent on perception, and if you don't perceive something, it's really hard to remember it," Alan J. Lerner, MD, professor of neurology, Case Western Reserve University School of Medicine, and director, University Hospitals Neurological Institute of Brain Health & Memory Center, Cleveland, Ohio, noted in an interview with Medscape Medical News.

"People are sometimes reluctant to do cataract surgery in patients with dementia, and I think these people may be being denied a chance to have a better quality of life," he added.

The findings were reported at the recent 8th Clinical Trials Conference on Alzheimer's Disease (CTAD).

"Our findings suggest the need to aggressively address dementia-related comorbidities, such as cataract-related visual impairment, while balancing safety and medical risks," the authors say.

The analysis reports outcomes for 61 individuals with dementia (clinical dementia rate [CDR], 0.5 to 3.0) and at least one visually significant cataract. Forty-three patients had immediate cataract surgery following baseline testing (intervention group). The remaining 18 either declined surgery or had surgery delayed 6 months and underwent repeat baseline testing at that time (control group).

Results "Heartening"

Cataract surgery led to an improvement (from baseline to 6 months) in the primary outcome measures of visual acuity (Early Treatment Diabetic Retinopathy Study Chart [ETDRS], Snellen-equivalent), cognitive function (Mini-Mental Status Exam [MMSE]), and Neuropsychiatric Inventory (NPI).

Average changes in ETDRS visual acuity (logMAR) for the right eye and left eye for the cataract surgery group were –0.26 and –0.24, respectively, indicating improvement, the researchers report.

In contrast, the control group did not show a change in vision. The corresponding Snellen-equivalent denominator values indicated a change of –5 lines in both eyes in the surgery group while the control group values remain static. "Vision got better with surgery, which is not a trivial thing," Dr Lerner noted.

Mean MMSE scores held steady in the surgery group and declined about 2.2 points in the delayed surgery group.

"The biggest changes were in behavior," Dr Lerner said. NPI scores in the surgery group improved (mean change, –4.6) and worsened in the control group (mean change, 4.0). Surgery also led to a reduction in NPI caregiver distress ratings (mean change, –2.47), whereas caregiver distress increased in the control group (mean change, 0.87).

"We recognize this is a very small study, but the results are very heartening," Dr Lerner said. On the basis of these findings, the authors think cataract removal "should be studied in a larger phase 3 clinical trial, and clinically considered regardless of dementia status."

David B. Glasser, MD, a clinical spokesperson for the American Academy of Ophthalmology and practicing ophthalmologist specializing in cataract surgery and treatment, was not surprised by the study findings.

"Many clinicians have made similar observations on a case-by-case basis, so the concept is not new and the findings are not surprising. This study validates those anecdotal observations by systematically evaluating cognition and behavioral indices, albeit in a small group of patients and with modest improvements in functionality," Dr Glasser told Medscape Medical News.

"The take-home message," he added, "is that cataract surgery can improve cognition and quality of life in patients with dementia by increasing visual sensory input. A diagnosis of dementia should not automatically disqualify these patients from surgery when a visually significant cataract is present. Although patients with dementia may have difficulty cooperating during surgery with topical or local anesthesia, the surgery can be completed safely under general anesthesia."

The study is supported by the National Institutes of Health/National Institute on Aging. The authors have disclosed no relevant financial relationships.

8th Clinical Trials Conference on Alzheimer's Disease (CTAD). Poster P1-35. Presented November 5, 2015.


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