Impact of Glasses for Vision Problems on Cognitive Function in Rural Older Adults

Yuju Wu964 enrolled

Overview

The aim of this project is to explore whether vision correction can effectively slow cognitive decline in older adults. The primary question it seeks to answer is: Can providing free near and/or distance vision correction glasses to older adults with refractive errors or uncorrected vision, who have normal baseline cognition and hearing, reduce the rate of cognitive decline over 36 months in a cost-effective manner? Researchers will compare the rate of cognitive decline over 36 months between older adults who receive refractive correction and those who do not.

Exploratory subgroup analyses will be conducted to assess whether the intervention effect on cognitive decline differs according to baseline vision correction needs (near vision correction, distance vision correction, or both) and baseline cognitive function. These analyses will be interpreted cautiously due to their exploratory nature.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

PREVENTION

Masking

SINGLE

Enrollment

964

Conditions

Cognition Disorders

Interventions

Participants can choose from a variety of frames, and the research team will customize the glasses according to their pupillary distance and prescription. Once the glasses are ready, they will be provided to the participants following standard usage instructions. In case of loss or damage, participants should report it to the project team and will be provided with replacement glasses as needed. Each year, participants in the intervention group will undergo an eye exam to assess changes in vision, and their glasses prescription will be updated if necessary.

Eligibility

Sex: ALLMin age: 60 YearsMax age: 79 YearsHealthy volunteers:

Medical Language ↔ Plain English

Inclusion Criteria: * Older adults who meet all of the following criteria will be eligible to participate in this study: * Registered as a rural resident (holding rural household registration); * Age from 60 to 79 years at the time of enumeration; * Resident in the household for \> = 3 months and planning to reside in the local area for the trial duration; * Distance vision impairment (VI, presenting visual acuity \[VA\] \< 6/12 in the better-seeing eye and improving to ≥ 6/7.5 or better in either eye with spectacle correction) and/or near VI (presenting near VA \< 6/12 at 40 cm when measured binocularly and improving to ≥ 6/7.5 or better in either eye with near correction); * Independent mobility with or without the support of a walking stick; * Chinese version of the Mini-Mental State Examination (C-MMSE) score above the following cut-offs (out of 30): \>17 for illiterate participants, \>20 for those with primary school education, \>22 for those with junior high school education, and \>23 for those with high school education or above. * Willingness to participate, to be randomized to either study group, and to adhere to the protocol Exclusion Criteria: * Presence of glaucoma or visually significant cataract, or a history of surgical treatment for these or other major ocular conditions; * Consistent use of prescription spectacles and/or hearing aids; * Serious medical illness likely to result in loss to follow-up. Those less severely affected by conditions such as hypertension and/or diabetes will be eligible; * Failure on the whispered voice hearing screening test in the better ear (unable to repeat \> = 3 out of 6 words whispered from behind the participant at a distance of 50 cm);

Outcomes

Primary Outcomes

Change in global cognitive function

The primary outcome will be the change in global cognitive function from baseline to the 36-month follow-up, assessed by the total score of the Chinese version of the Montreal Cognitive Assessment Basic (MoCA-BC) . The MoCA-BC was selected because it minimizes reading and writing requirements and has been widely used in China, allowing for reliable cognitive assessment among individuals who are illiterate or have limited formal education.