Related Experiment Video
Updated: Jun 6, 2025
08:04
Cone-Enriched Cultures from the Retina of Chicken Embryos to Study Rod to Cone Cellular Interactions
Published on: March 20, 2021
3.5K
Retinal Sensitivity in Comparison to Cone Density in Choroideremia
Niamh Wynne1, Yu You Jiang1,2, Tomas S Aleman1,2
1Scheie Eye Institute, University of Pennsylvania, Perelman School of Medicine, Philadelphia, Pennsylvania, United States.
Investigative Ophthalmology & Visual Science
|December 3, 2024
Summary
In choroideremia (CHM), central vision loss is linked to cone cell density. Peripheral vision loss is associated with proximity to the degenerating retinal border.
Area of Science:
- Ophthalmology
- Genetics
- Neuroscience
Background:
- Choroideremia (CHM) is an X-linked inherited retinal degeneration.
- It leads to progressive loss of photoreceptors, retinal pigment epithelium, and choriocapillaris.
- Structural abnormalities exist even in functioning retinal areas.
Purpose of the Study:
- To investigate the relationship between cone density and visual sensitivity in the central retina of CHM patients.
- To understand the impact of structural changes on visual function in CHM.
Main Methods:
- Adaptive optics scanning light ophthalmoscopy (AOSLO) was used to image cone mosaics in 31 CHM patients (ages 10-57).
- Retinal sensitivity was measured using fundus tracking perimetry.
- Optical coherence tomography (OCT) assessed retinal structure; statistical analyses explored correlations between sensitivity and structural parameters.
Main Results:
- Cone density and retinal sensitivity were significantly reduced in CHM patients compared to controls.
- A significant correlation was found between cone density and visual sensitivity in the fovea and parafovea.
- Sensitivity correlated with distance to the atrophic border and ellipsoid zone extent.
Conclusions:
- Central visual sensitivity loss in CHM is primarily driven by cone photoreceptor loss.
- In peripheral regions, visual sensitivity is influenced by proximity to the atrophic border, indicating a functional transition zone.
Related Concept Videos
01:22Photoreceptors and Visual Pathways
5.7K
At the molecular level, visual signals trigger transformations in photopigment molecules, resulting in changes in the photoreceptor cell's membrane potential. The photon's energy level is denoted by its wavelength, with each specific wavelength of visible light associated with a distinct color. The spectral range of visible light, classified as electromagnetic radiation, spans from 380 to 720 nm. Electromagnetic radiation wavelengths exceeding 720 nm fall under the infrared category,...
5.7K
01:20Anatomy of the Eyeball
6.0K
The eye is a spherical, hollow structure composed of three tissue layers. The outer layer — the fibrous tunic, comprises the sclera — a white structure — and the cornea, which is transparent. The sclera encompasses some of the ocular surface, most of which is not visible. However, the 'white of the eye' is distinctively visible in humans compared to other species. The cornea, a clear covering at the front of the eye, enables light penetration. The eye's middle...
6.0K
01:32The Retina
67.6K
The retina is a layer of nervous tissue at the back of the eye that transduces light into neural signals. This process, called phototransduction, is carried out by rod and cone photoreceptor cells in the back of the retina.
67.6K