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

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.

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Key information

Conditions

Retinitis Pigmentosa AMD Congenital, Hereditary, and Neonatal Diseases and Abnormalities Eye Diseases Eye Diseases, Hereditary Genetic Diseases, Inborn Retinal Degeneration Retinal Diseases Retinal Dystrophies

Age range

10 year–85 year

Sex eligibility

All sexes

Study type

Observational

Primary location

Retina Foundation of the Southwest

Dallas, Texas, 75231, United States

About this study

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.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

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

Treatment and study plan

Rod sensitivity

Diagnostic Test

diagnostic test for rod loss in central retina

Primary outcomes

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

Sponsors and collaborators

Lead sponsor

Retina Foundation of the Southwest

Other

Registry information

Important dates

Study start: 2017
Primary completion: 2019
Study completion: 2019
First posted: Oct 26, 2017
Registry last updated: Dec 23, 2019

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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