Color Vision as a Measure for Inherited Retinal Diseases



Status:Completed
Conditions:Healthy Studies, Ocular
Therapuetic Areas:Ophthalmology, Other
Healthy:No
Age Range:5 - Any
Updated:10/8/2017
Start Date:June 3, 2013
End Date:April 14, 2017

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Color Vision as an Outcome Measure for Clinical Trials of Inherited Retinal Degenerations

Background:

- The purpose of this study is to find out whether color vision measured with the Cambridge
Color Test is a good way to examine the severity of inherited retinal diseases (IRDs). IRDs
are a major cause of vision loss worldwide, but very little is known about how the diseases
affect color vision over time. This study will tell us if color vision may be used to track
changes in inherited retinal diseases over time.

Objectives:

- To improve understanding of color vision as a way to measure changes in inherited retinal
diseases.

Eligibility:

- People 5 years of age or older who have an IRD.

- Healthy volunteers at least 5 years of age.

Design:

- Participants will make at least one visit to the National Eye Institute clinic. If they
sign up for more tests, they may have up to three visits to the NEI clinic.

- Participants will be asked questions about their medical and eye history.

- Participants will be given an eye exam, including eye drops to dilate their pupils. They
will take the Cambridge Color Test, which includes looking at a monitor and pressing a
button, and arranging colored circles. Several other tests may be offered, but
participants can decline to take them.

- Treatment will not be provided as part of this study.

Objective: The aims of this study are to 1) examine the sensitivity of the Cambridge Color
Test (CCT) and the low vision CCT (LvCCT) to the severity of retinal disease in inherited
retinal degeneration (IRD) by comparing color vision status with changes in photoreceptor
structure and function, 2) examine the effects of eccentric fixation and reduction in visual
acuity on color discrimination thresholds obtained with the CCT and LvCCT, and 3) establish
normal ranges for the CCT and the LvCCT and determine the intra-session and inter-session
variabilities for these tests.

Study Population: Up to 59 healthy volunteers and 144 IRD participants age 5 or older will be
enrolled in this study.

Design: This study will be comprised of three related projects. For Aim 1, color
discrimination thresholds (CCT and LvCCT) and assessments of retinal structure (imaging) and
function (perimetry/microperimetry and electroretinogram) will be measured in 144 IRD
participants with varying retinal phenotypes and visual acuities. IRD participants will be
divided into four major categories: 1) cone & cone-rod dystrophies, 2) rod-cone dystrophies,
3) inherited maculopathies, and 4) inherited retinal dysfunction syndromes. The fourth
category will be used for IRDs that do not match the description for categories 1-3 (i.e.,
x-linked retinoschisis, congenital stationary night blindness). Degree of severity of retinal
dysfunction in IRD participants will be determined relative to the normal ranges obtained
from the healthy volunteers (see Aim 3a below). For Aim 2 color discrimination thresholds
(CCT and LvCCT) will be measured in one eye from 12 healthy volunteers in order to examine
the effects of eccentric fixation and reduced visual acuity on color thresholds independent
of retinal pathology. Between one and three study visits will be required for this aim. Aim 3
will be comprised of two parts. For Aim 3a, color thresholds will be collected from both eyes
(for intraocular variability) of 35 healthy volunteers age 5 or older. For Aim 3B, color
discrimination thresholds (CCT and LvCCT) will measured from 12 healthy volunteers twice in
one session and then again at a second visit occurring within two months of the initial visit
to determine intra-session and inter-session variability.

Outcome Measures: For both the CCT and LvCCT, an overall quantitative measure of color vision
will be obtained from the calculation of achromatic area. The sensitivity of CCT and LvCCT
will be examined by comparing achromatic area for IRD participants with varying levels of
phenotype severity defined by measures of retinal structure and function. Secondary outcomes
for this study include: 1) evaluation of sensitivity of the CCT and LvCCT to disease
severity,

2) evaluation of the effects of decreased visual acuity and eccentricity on color
discrimination thresholds (CCT and LvCCT), 3) establishment of the normal range of color
discrimination thresholds (CCT and LvCCT) as a function of age, and 4) determination of
intra- and inter-session variabilities of the two tests.

- INCLUSION CRITERIA:

1. Participants must be 5 years of age or older.

2. Participant (or legal guardian) must understand and sign the protocol s informed
consent document.

3. Participant must be able to cooperate with the testing required for this study.

4. Participant s eyes must have clarity of ocular media and degree of pupil dilation
sufficient to permit adequate fundus photography.

5. For IRD Participants only:

1. Participant must have IRD, defined as evidence of retinal rod- and
cone-mediated

dysfunction and degeneration established by standard clinical methods
including field tests, ERG, and imaging.

2. Participant must have a measurable visual acuity.

6. For Healthy Volunteers only:

1. Participant must have visual acuity of 20/20 or better.

EXCLUSION CRITERIA:

1. Participant is taking medications known to alter color vision, such as
hydroxychloroquine (Plaquenil ), sildenafil (Viagra ), ethambutol, chloroquine
amiodarone, and pamidronate disodium.

2. Participant has another ocular disease that may confound the study results, such as
diabetic retinopathy, vascular occlusions, retinopathy related to drug toxicity, optic
neuropathy, or central serous chorioretinopathy.
We found this trial at
1
site
9000 Rockville Pike
Bethesda, Maryland 20892
Phone: 800-411-1222
?
mi
from
Bethesda, MD
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