Rod and Cone Mediated Function in Retinal Disease

Overview

Background: Retinal diseases cause the loss of rod and cone photoreceptors. Symptoms include vision loss and night blindness. Researchers want to learn about rod and cone function in healthy people and people with retinal disease. They want to know if how well a person sees in the dark can test the severity of retinal disease. Objectives: To find out if how well a person sees in the dark can test the severity of retinal disease. To find out if this can help detect retinal disease and track its changes. Eligibility: People ages 5 and older with: Retinal disease OR 20/20 vision or better with or without correction in at least one eye Design: Participants will be screened with medical and eye history and eye exam. Those with retinal disease will also have: Eye imaging: Drops dilate the eye and pictures are taken of it. Visual field testing: Participants look into a bowl and press a button when they see light. Electroretinogram (ERG): An electrode is taped to the forehead. Participants sit in the dark with their eyes patched for 30 minutes. Then they get numbing drops and contact lenses. Participants watch lights while retina signals are recorded. Visit 1 will be 3-8 hours. Participants will have up to 6 more visits over 6-12 months. Visits include: Eye exam and imaging Time course of dark adaptation: Participants view a background light for 5 minutes then push a button when they see colored light. Dark adapted sensitivity: Participants sit in the dark for 45 minutes. They push a button when they see colored light. For participants with retinal disease, ERG and visual field testing ...

Objective: The objective of this protocol is to investigate local changes in rod and cone photoreceptor function across the retina in healthy volunteers and participants with retinal disease. Study Population: Up to 250 healthy volunteers and 250 participants, age five or older, with retinal disease. Design: This single-center, observational, case-control study will be comprised of three related Aims that assess rod and cone function with commercial perimeters and/or a commercial Cambridge Research Systems computer monitor (Display++) specialized for displaying stimuli at low light intensities. For Aim 1 the normal retinal sensitivity ranges will be established for both fundus-guided and non-guided perimeters. For Aim 2, the normal range for describing the kinetics of dark adaptation following bleaching of retinal rhodopsin will be established for the fundus-guided and non-guided perimeters. For Aim 3, local changes in rod and cone photoreceptor function across the retina in participants with retinal disease will be examined from measurement of the kinetics of dark adaptation, scotopic and photopic retinal sensitivity, and/or Radial Frequency (RF) hyperacuity on the Display++ monitor. Testing may also include patient reported outcome (PRO) questionnaires to assess vision problems under low luminance conditions. Outcome Measures: The primary outcome for this study is to establish normal ranges for A) the kinetics of dark adaptation (time), B) retinal sensitivity (dB) for the fundus-guided and non-guided perimeters, and C) RF hyperacuity on the Display++ monitor. The secondary outcomes will be to examine changes in the kinetics of dark adaptation, scotopic and photopic retinal sensitivity, and/or RF hyperacuity in participants with retinal disease and potentially correlate these clinical measures with patients self-reported evaluation of their vision under low luminance conditions.