AMD, Retinitis Pigmentosa
Conditions
Keywords
microperimetry, rod visual fields
Brief summary
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.
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.
Interventions
DIAGNOSTIC_TESTRod sensitivity
diagnostic test for rod loss in central retina
Sponsors
Retina Foundation of the Southwest
Study design
Observational model
CASE_ONLY
Time perspective
PROSPECTIVE
Eligibility
Sex/Gender
ALL
Age
10 Years to 85 Years
Healthy volunteers
Yes
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Rod Sensitivity Within the Central Retina as Measured on the Nidek MP-3S | 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 |
Countries
United States
Participant flow
Recruitment details
patients recruited from medical clinic (Texas Retina Associates)
Participants by arm
| Arm | Count |
|---|---|
| Patients With a Diagnosis of Retinitis Pigmentosa patients with a diagnosis of retinitis pigmentosa
Rod sensitivity: diagnostic test for rod loss in central retina | 20 |
| Patients With a Diagnosis of Intermediate AMD patients with a diagnosis of intermediate AMD
Rod sensitivity: diagnostic test for rod loss in central retina | 20 |
| Total | 40 |
Baseline characteristics
| Characteristic | Patients With a Diagnosis of Retinitis Pigmentosa | Patients With a Diagnosis of Intermediate AMD | Total |
|---|---|---|---|
| Age, Categorical <=18 years | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical >=65 years | 0 Participants | 15 Participants | 15 Participants |
| Age, Categorical Between 18 and 65 years | 20 Participants | 5 Participants | 25 Participants |
| Ethnicity (NIH/OMB) Hispanic or Latino | 2 Participants | 0 Participants | 2 Participants |
| Ethnicity (NIH/OMB) Not Hispanic or Latino | 18 Participants | 20 Participants | 38 Participants |
| Ethnicity (NIH/OMB) Unknown or Not Reported | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) American Indian or Alaska Native | 2 Participants | 0 Participants | 2 Participants |
| Race (NIH/OMB) Asian | 3 Participants | 2 Participants | 5 Participants |
| Race (NIH/OMB) Black or African American | 2 Participants | 1 Participants | 3 Participants |
| Race (NIH/OMB) More than one race | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 1 Participants | 0 Participants | 1 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) White | 12 Participants | 17 Participants | 29 Participants |
| Region of Enrollment United States | 20 participants | 20 participants | 40 participants |
| Sex: Female, Male Female | 12 Participants | 15 Participants | 27 Participants |
| Sex: Female, Male Male | 8 Participants | 5 Participants | 13 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | 0 / 20 | 0 / 20 |
| other Total, other adverse events | 0 / 20 | 0 / 20 |
| serious Total, serious adverse events | 0 / 20 | 0 / 20 |
Outcome results
Primary
Rod Sensitivity Within the Central Retina as Measured on the Nidek MP-3S
Number of participants with rod sensitivity measured in decibels at multiple retinal locations within the central retina
Time frame: through study completion, an average of 1 year
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| Patients With a Diagnosis of Retinitis Pigmentosa | Rod Sensitivity Within the Central Retina as Measured on the Nidek MP-3S | 7 Participants |
| Patients With a Diagnosis of Intermediate AMD | Rod Sensitivity Within the Central Retina as Measured on the Nidek MP-3S | 20 Participants |
p-value: <0.05t-test, 2 sided