Rod Sensitivity in Age-related Macular Degeneration (AMD) and Retinitis Pigmentosa (RP)

December 11, 2019 updated by: Retina Foundation of the Southwest
A new fundus-guided microperimeter (MP-3S) has been developed by Nidek, Inc. to track the fundus of the patient and present stimuli in specific anatomically-defined locations. Furthermore, this tracking means that exactly the same locations can be tested on subsequent (follow-up) visits. The investigators will use a method called two-color perimetry to map rod and cone sensitivity on this device. With this technique, the sensitivity difference (blue-red) to chromatic test stimuli can be used to determine whether rods, cones or both photoreceptor systems mediate the threshold at a given location in the macula.

Study Overview

Status

Completed

Intervention / Treatment

Detailed Description

Despite recent advances in understanding the pathogenesis of retinitis pigmentosa (RP) and age-related macular degeneration (AMD), precise characterization of the disease phenotype remains elusive. In both diseases, much of the focus has necessarily been on the loss of cone function, since visual fields, acuity and contrast sensitivity are typically measured under photopic conditions. In RP, we need a greater understanding of patterns of rod loss since most disease-causing mutations affect primarily rods. In AMD, recent findings have shown that scotopic sensitivity can be much more affected than conventional photopic measurements such as visual acuity. For patients, however, it is difficult to maintain stable fixation, especially when central vision is compromised. A new fundus-guided microperimeter, the MP-3S, has been developed by Nidek, Inc. to circumvent this problem. The investigators will evaluate the value of this device for following rod and cone loss in patients with either RP or AMD.

Study Type

Observational

Enrollment (Actual)

40

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

    • Texas
      • Dallas, Texas, United States, 75231
        • Retina Foundation of the Southwest

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

10 years to 85 years (Child, Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

All

Sampling Method

Non-Probability Sample

Study Population

50 subjects with retinitis pigmentosa 50 patients with AMD 10 normal volunteers ages 18 to 40 and 10 normal volunteers ages over age 55 years

Description

Inclusion Criteria:

  • clear media
  • diagnosis of RP or non neovascular AMD
  • normal volunteers

Exclusion Criteria:

  • exudative AMD
  • other eye diseases that could cause vision loss
  • physical ailments that would preclude comfortable testing
  • unable to provide informed consent

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
Retinitis Pigmentosa
patients with a diagnosis of retinitis pigmentosa and reduced rod function on baseline testing
diagnostic test for rod loss in central retina
Age-related Macular Degeneration
patients with a diagnosis of intermediate AMD and reduced rod function on baseline testing
diagnostic test for rod loss in central retina

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Rod Sensitivity Within the Central Retina as Measured on the Nidek MP-3S
Time Frame: through study completion, an average of 1 year
Number of participants with rod sensitivity measured in decibels at multiple retinal locations within the central retina
through study completion, an average of 1 year

Collaborators and Investigators

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

Investigators

  • Principal Investigator: David G Birch, PhD, Retina Foundation of the Southwest

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

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)

October 1, 2017

Primary Completion (Actual)

March 1, 2019

Study Completion (Actual)

March 1, 2019

Study Registration Dates

First Submitted

October 24, 2017

First Submitted That Met QC Criteria

October 24, 2017

First Posted (Actual)

October 26, 2017

Study Record Updates

Last Update Posted (Actual)

December 23, 2019

Last Update Submitted That Met QC Criteria

December 11, 2019

Last Verified

December 1, 2019

More Information

Terms related to this study

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

IPD Plan Description

anonymized rod visual fields

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

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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