Choroideremia
A rare inherited retinal disease that causes progressive degeneration of the retina, retinal pigment epithelium, and choroid — the layers of the eye that support healthy vision.
Understanding Choroideremia
Choroideremia is a rare inherited retinal disease that causes progressive degeneration of the retina, retinal pigment epithelium, and choroid — the layers of the eye that support healthy vision.
The condition primarily affects males and typically begins with difficulty seeing in low light during childhood or adolescence. Over time, progressive loss of peripheral vision may occur, followed by increasing visual impairment.
Choroideremia is caused by changes in a single gene, making it an important condition in the development of gene-based therapies for inherited retinal diseases. Research into Choroideremia has helped advance understanding of genetic diagnosis, clinical trials, and potential approaches to preserving or restoring vision.
Retina International works with people affected by Choroideremia, patient organisations, researchers, clinicians, and partners worldwide to accelerate research, support meaningful patient involvement, and improve outcomes for people living with inherited retinal diseases.
What is Choroideremia?
Choroideremia is an inherited retinal disease characterised by progressive degeneration of the retina, retinal pigment epithelium (RPE), and choroid.
The retina contains photoreceptor cells that detect light and enable vision. The RPE supports retinal function, while the choroid provides blood supply and nutrients to the retina.
In Choroideremia, progressive loss of these layers affects the ability of the eye to process visual information, leading to gradual vision loss.
The condition usually begins with night blindness and narrowing of peripheral vision. As the disease progresses, the visual field may become increasingly restricted, although many people retain useful central vision into adulthood.
Choroideremia is sometimes referred to as:
- CHM-related retinal degeneration
- Choroideremia retinal dystrophy
The condition is rare and affects people worldwide.
1 gene
Caused by mutations in the CHM gene, making it a key condition for gene-based therapy research.
X-linked
Follows an X-linked inheritance pattern and primarily affects males.
Childhood or adolescence
Symptoms commonly begin with night blindness and loss of peripheral vision during childhood or adolescence.
How Choroideremia can affect vision
Night blindness
Difficulty seeing in dim light or adapting from bright to dark environments is often one of the earliest signs.
Loss of peripheral vision
Progressive narrowing of side vision may affect mobility and awareness of surroundings.
Reduced visual field
Over time, people may experience tunnel vision as peripheral vision decreases.
Reduced central vision
In later stages, central vision may become affected, impacting reading and detailed tasks.
Light sensitivity
Some individuals experience discomfort or difficulty in bright environments.
Identifying Choroideremia
Eye examination
An ophthalmologist examines the retina for characteristic changes associated with Choroideremia.
Visual field testing
This measures peripheral vision and tracks changes over time.
Retinal imaging
Imaging technologies may include:
- Fundus photography
- Optical coherence tomography (OCT)
- Fundus autofluorescence (FAF)
These can help assess retinal structure and monitor progression.
Electroretinography (ERG)
ERG evaluates retinal function and can support diagnosis.
Genetic testing
Genetic testing can identify mutations in the CHM gene and confirm the diagnosis.
A genetic diagnosis can help:
- Confirm the condition
- Identify affected family members
- Support genetic counselling
- Determine eligibility for clinical trials
Supporting vision and exploring emerging therapies
Low vision support
Specialist services can provide:
- Visual aids
- Assistive technologies
- Mobility training
- Strategies for adapting daily activities
Regular eye monitoring
Ongoing monitoring helps assess changes in vision and retinal health.
Genetic counselling
Genetic counselling can help individuals and families understand inheritance, family planning options, and testing decisions.
Emerging therapies
Because Choroideremia is caused by a mutation in a single gene, it has been a major focus for gene therapy research.
Research approaches include:
- Gene replacement therapy
- Retinal cell protection strategies
- Other approaches aimed at preserving retinal function
Adapting to progressive vision loss
Living with Choroideremia involves adapting to gradual changes in vision while maintaining independence, education, employment, and participation in daily life.
Support may include:
- Low vision rehabilitation
- Orientation and mobility training
- Assistive technology
- Workplace and educational adjustments
- Peer support networks
- Patient organisations
Because Choroideremia primarily affects males, families may also need support in understanding inheritance patterns and the potential impact on relatives.
The lived experiences of people affected by Choroideremia are essential in shaping research priorities and improving care.
Advancing the future of Choroideremia treatment
Gene therapy
Researchers are investigating whether delivering a functional copy of the CHM gene can preserve or improve retinal function.
Learn About Gene TherapyRetinal imaging advances
Improved imaging technologies allow researchers to monitor subtle changes in retinal structure and assess treatment effects.
Learn About Retinal ImagingClinical trials
Clinical trials are evaluating potential therapies designed to slow progression or restore aspects of retinal function.
Learn About Clinical TrialsInformation and community support
Take the Next Step
Choroideremia has played an important role in advancing gene therapy research and demonstrating the potential of precision approaches for inherited retinal diseases.
Through collaboration between patients, researchers, clinicians, and organisations worldwide, progress continues towards a future where people affected by Choroideremia have access to earlier diagnosis, improved support, and effective treatments.
