Comparing Low-cost Handheld Autorefractors - a Practical Approach to Measuring Refraction in Low Resource Settings

February 11, 2020 updated by: David Bloom, Harvard School of Public Health (HSPH)

A Validation Study of Mobile Technologies for Assessing Visual Acuity and Eye Health Among Older Adults in India

Study compares four portable vision measurement and eye-imaging technologies in terms of accuracy and time and ease of use with older adult (ages 40-100) participants in a developing-country setting (India). Specifically, the five portable devices will be measured against the baseline of the traditional eye-examination techniques, including the use of eye charts and phoropters.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

Non-communicable diseases (NCDs) are a large and increasingly costly problem for India. Recent research estimates that NCDs could cost the Indian economy US$6.2 trillion from 2012-2030 if left unaddressed. For some NCDs, new solutions will need to be developed for diagnosis and treatment, while, for others, the necessary interventions exist but are not readily available to all who need them. Visual impairment is one area of health in which limited access to diagnostic and treatment technologies jeopardizes the health and economic well-being of the population. This is particularly true in India, where the population is rapidly aging and, despite the presence of some high-quality medical facilities, there remains a large burden of unaddressed visual impairment.

Loss of visual acuity can negatively impact individual and household income by reducing productivity or hours worked among the visually impaired; it can also affect economic wellbeing via the need for caretakers. There are two key tests that determine visual acuity and measure vision loss:

  1. Basic visual acuity (BVA), which is assessed using the naked eye or, when applicable, eyeglasses, and
  2. Best-corrected visual acuity (BCVA), which uses refraction to determine eyeglass/contact lens prescription.

In addition, diagnosing vision-hindering eye conditions requires specific medications or surgical procedures. Diagnosis of glaucoma, cataracts, or diabetic retinopathy typically requires a physician to examine a patient's retinas, corneas, and/or pupils at close range using specialized equipment, in conjunction with the visual acuity tests described above.

BCVA tests typically require heavy, cumbersome, and expensive equipment such as phoropters (instruments that measure the refractive state of the eye). Likewise, eye diseases typically require the use of specialized equipment such as slit lamp microscopes, ophthalmoscopes, and tonometers.

However, the recent and anticipated availability of affordable and lightweight portable technologies which can be used both by medical professionals and by trained laypeople has made eye testing easier and faster. This study will validate a number of new handheld devices developed for visual acuity measurement and retinal imaging.

This study explores testing for visual acuity and other impairments like diabetic retinopathy, glaucoma, age-related macular degeneration (AMD), and cataract without the use of traditional stationery and expensive instruments such as phoropters and conventional autorefractors and at a comparatively low cost. If the devices are proven able to accurately evaluate visual acuity and produce high-quality retinal images that can be used to aid diagnosis, it will be a breakthrough in reducing barriers of access to eye care facilities encountered by the majority of the rural population in India and other developing countries.

Also, since these devices are convenient and relatively easy to use, they can be easily used in household/community surveys involving vision measurement; the investigators are proposing to perform data collection for this study in India partially in order to investigate the potential for use of one or more of handheld devices in upcoming waves of the Longitudinal Aging Study in India (Protocol Number 16715), a nationally-representative aging and retirement study that collects data on multiple dimensions of aging, including socioeconomic, cognitive, and health indicators with the aim of informing national policy and practice relating to older adults. Specifically, the study involves an extensive biomarkers module which includes direct measurement of multiple medical and anthropometric indicators, such as blood pressure, grip strength, lung function, height, and weight. The current version of the biomarkers module calls for the use of a traditional eye chart to measure BVA; however, future versions of the study would greatly benefit from the use, if feasible, of portable and inexpensive devices which would allow researchers to collect richer and more accurate data on visual acuity and/or eye conditions and therefore provide a more detailed picture on older adults' eye health, as well as the predictors and correlates of eye health, on a national level.

Through the data gained from this study, the investigators hope to be able to develop useful recommendations for researchers, community health organizations, and health care professionals whose studies and patients would benefit from access to relatively low-cost portable vision measurement and retinal imaging devices. In particular, Indian consumers will have access to all devices pending market approval.

Study Type

Observational

Enrollment (Actual)

205

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

40 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

All

Sampling Method

Non-Probability Sample

Study Population

Individuals aged 40-100 coming to Sankara Eye Hospital for standard eyesight evaluation from surrounding urban/rural communities

Description

Inclusion Criteria:

- Individuals aged 40-100 coming to Sankara Eye Hospital from surrounding urban/rural communities.

Exclusion Criteria:

  • Individuals under the age of 40.
  • Blind individuals
  • Individuals with acute glaucoma, eye trauma/injury, infections such as conjunctivitis
  • Individuals physically/cognitively incapable of following basic instructions and sitting/standing still in order to use devices.

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

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
Vision device validation
In the single arm of this study, all members of this group were examined using a number of mobile eyesight assessment devices.
Group members had their vision tested with the following devices/methods: Eyenetra NETRA, PlenOptika Quicksee, Right Manufacturing Retinomax K Plus 3, and standard eyesight tests using eye charts, phoropters, and slit lens lamp imaging.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Accuracy of Assessment of Participants' Best Visual Acuity (in Diopters)
Time Frame: 1-2 hours
Measurements of participants' best visual acuity as measured by mobile devices compared to "gold standard" of subjective refraction
1-2 hours

Collaborators and Investigators

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

Collaborators

Investigators

  • Principal Investigator: David E Bloom, PhD, Harvard School of Public Health (HSPH)

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 (Actual)

August 15, 2016

Primary Completion (Actual)

September 1, 2016

Study Completion (Actual)

September 1, 2016

Study Registration Dates

First Submitted

July 20, 2017

First Submitted That Met QC Criteria

March 5, 2018

First Posted (Actual)

March 7, 2018

Study Record Updates

Last Update Posted (Actual)

February 24, 2020

Last Update Submitted That Met QC Criteria

February 11, 2020

Last Verified

February 1, 2020

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 22636

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

Yes

product manufactured in and exported from the U.S.

Yes

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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