Choroideremia infographic showing a cross-section of the eye with the choroid layer labeled between the retina and sclera, the choroid's blood vessels feeding the retina, and a progression strip showing night blindness followed by shrinking peripheral vision leaving only central vision, with a banner noting it is a rare incurable condition that mostly affects men.

Choroideremia: The Inherited Eye Condition That Starts With Night Blindness and Why It Mostly Affects Men

Oct 13

9 min read

Updated: 3 days ago

Medically reviewed by Dr. Baraa Alnahhal, MD · Last reviewed: October 17, 2026

Quick Answer

Choroideremia is a rare, incurable inherited eye disease that damages the choroid's blood vessels, degrading the retina and leading to blindness. [7] It is an X-linked disorder, so severe disease mostly affects men. [1] [5] Night blindness often starts before age 10, followed by shrinking side vision. [2] There is no cure, but low-vision strategies, regular eye exams and gene therapy trials can help. [1]

What the research says

Choroideremia is rare and still has no approved treatment. A 2019 review estimates that it affects about 1 in 50,000 males and notes that no treatments are yet approved; early gene-therapy studies reported vision gains or maintained vision in some patients. (Pennesi et al., Retina, 2019) [7].
Genetic testing pinpoints the faulty CHM gene. Sequencing the CHM gene in 6 male patients from 5 unrelated Polish families found 5 disease-causing variants, 2 of which had never been reported before. (Skorczyk-Werner et al., Orphanet Journal of Rare Diseases, 2018) [6].

What Is Choroideremia?

Choroideremia (pronounced "kuh-roy-der-ee-me-ah") is a rare inherited disease that affects your eyes. It causes vision to get worse and then leads to blindness. [1] [3] Severe disease mostly affects men. [1] [5]

Key terms at a glance: The retina is the light-sensing tissue at the back of your eye; its photoreceptor cells capture light and turn it into electrical signals that travel along the optic nerve to your brain, where they're turned into images. The choroid is a layer between your retina and your sclera (the white protective covering of your eye). The choroid has blood vessels that feed your retina.

Term	What It Means
Choroid	The layer between your retina and sclera (the white protective covering of your eye)
Retina	The light-sensing tissue at the back of your eye
Photoreceptor cells	Retina cells that capture light and turn it into electrical signals
Optic nerve	The nerve that carries visual signals from the retina to your brain
Choroidal sclerosis	Another name for choroideremia

Choroideremia is an X-linked inherited condition that can lead to blindness. [2] [5] It's an incurable condition that's also known as choroidal sclerosis. The initial symptom is difficulty seeing at night. [2] [5] Then, you may have difficulty with peripheral vision (side vision). [2] [5]

Choroideremia is similar in some ways to retinitis pigmentosa, another condition that causes your retina to degrade. In fact, the two diseases have similar symptoms and sometimes have similar test results. Getting a genetic test is the best way to tell the difference between the two diseases. [3]

In your eye, your retina has photoreceptor cells that capture light and turn it into electrical signals. Those signals travel along your optic nerve to your brain where they're turned into images. The choroid is a layer between your retina and sclera, which is the white protective covering of your eye.

The choroid has blood vessels that feed your retina. Damage to your choroidal blood vessels leads to damage to your retina and peripheral sight.

How Common Is Choroideremia?

Choroideremia affects an estimated 1 in 50,000 to 1 in 100,000 people. [2]

Choroideremia symptoms infographic with five symptom cards — difficulty seeing at night (often before age 10), difficulty with peripheral side vision, lack of visual acuity sharpness, loss of the ability to see colors well, and increasing vision loss from the side that can progress to blindness — plus a horizontal progression strip showing peripheral vision narrowing from full sight down to a small central circle of vision. – rinnit.com

What Are the Signs and Symptoms?

The signs and symptoms of choroideremia include difficulty seeing at night (night blindness) — this often happens before the age of 10; difficulty with peripheral (side) vision; lack of visual acuity (sharpness); loss of the ability to see colors well; and increasing vision loss from the side that can progress to blindness. [1] [2]

What Causes Choroideremia?

Choroideremia is an X-linked genetic disorder. The gene that causes choroideremia is located on your X chromosome. [1] [2] Females have two X chromosomes, while males have one. [1]

Because there's only one X chromosome with the faulty gene related to choroideremia, females don't normally have the same vision problems that males with the faulty gene on their X chromosome have. Females may develop night blindness or glare issues later in life, but rarely go blind from choroideremia. [5]

But males have one X chromosome and one Y chromosome. They're more prone to developing X-linked genetic disorders. [1] Affected males pass on their X chromosome to their female children, who become carriers. Those female children have a 1 in 2 chance (50%) of passing the faulty X chromosome to their female children.

Choroideremia inheritance infographic with two sections. Section 1, "X-linked inheritance," shows how affected males pass the faulty X chromosome to female children who become carriers, with a 50% chance of passing it on, and why males are mostly affected while female carriers rarely go blind. Section 2, "How it's diagnosed," shows four test cards — electroretinogram, optical coherence tomography (OCT), fluorescein angiography, and genetic testing — each with a one-line description. – rinnit.com

How Is Choroideremia Diagnosed?

Choroideremia is diagnosed through an eye exam, and an eye care provider will examine your eyes if you report symptoms. They'll likely do these tests, as well as others.

Test	What It Does
Electroretinogram	Measures your retina's response to light — disks are placed on your face, eyes, head and scalp, thin wires go over the front of your eye above your bottom eyelid, and bright lights are flashed to measure your retina's activity [1] [2]
Optical coherence tomography (OCT)	A noninvasive imaging method that uses reflected light to create pictures of the back of your eye [1] [2]
Fluorescein angiography	Uses dye injected through your veins to show the blood vessels in your eye [2]
Genetic testing	A DNA test that identifies gene mutations (using blood, hair, skin, tissue or amniotic fluid samples) and can tell the difference between choroideremia and retinitis pigmentosa [1] [3]

How Is Choroideremia Treated?

Providers can't cure choroideremia. [1] [5] But you may receive treatment for other issues. For instance, as vision gets worse, you may find that you can use some strategies for coping with low vision. Coping tips range from devices like magnifiers to counseling for mental health and genetics. [1] [5]

What Can I Expect if I Have Choroideremia?

Generally, people with choroideremia can expect their peripheral vision to get worse over time, leaving only central vision. [2] [5] Eventually, the condition may progress to blindness. [1] There isn't a cure.

How Do I Take Care of Myself?

You can take care of yourself by following guidelines for a healthy life, including eating a healthy diet that includes green leafy vegetables, other vegetables, fruit and lean protein (while avoiding excess salt, sugar and unhealthy fats); getting enough physical activity; quitting smoking if you smoke; having regular eye exams; and getting enough sleep.

When Should I See My Healthcare Provider?

You should see a healthcare provider whenever you have a change in vision. [1] If any of the changes are sudden or painful, consider getting emergency care. See a provider if you find you're having difficulties with your daily activities. Ask for information on being eligible for gene therapy trials, too. [1]

What's the Difference Between Choroideremia and Gyrate Atrophy?

Gyrate atrophy of the choroid and retina is another genetic condition that may have similar signs and symptoms. But there are differences. You inherit gyrate atrophy in a different way — the pattern is autosomal recessive, which means both parents pass the gene to their child. [2] The pattern for inheriting choroideremia is X-linked; a parent with two X chromosomes passes the gene to their child. The mutated gene in choroideremia is also different from the mutated gene in gyrate atrophy.

Feature	Choroideremia	Gyrate Atrophy of the Choroid and Retina
Both are	Genetic conditions with similar signs and symptoms	Genetic conditions with similar signs and symptoms
Inheritance pattern	X-linked — a parent with two X chromosomes passes the gene to their child	Autosomal recessive — both parents pass the gene to their child [2]
Mutated gene	Different from the gyrate atrophy gene	Different from the choroideremia gene

What is the bottom line on choroideremia?

Choroideremia is a rare (1 in 50,000 to 1 in 100,000 people), incurable X-linked genetic eye disease in which a faulty gene on the X chromosome damages the choroid's blood vessels — the vessels that feed your retina — causing retina and peripheral sight to deteriorate. Because males have only one X chromosome, severe disease mostly affects men; female carriers usually have no or mild symptoms such as night blindness or glare issues later in life. It typically begins with night blindness before age 10, then side vision narrows, sharpness and color vision fade, and central vision alone may remain as the condition progresses toward blindness. Diagnosis uses eye exams, an electroretinogram, OCT imaging, fluorescein angiography, and genetic testing — the genetic test being the best way to distinguish it from similar conditions like retinitis pigmentosa or gyrate atrophy. While there is no cure, low-vision strategies, magnifiers, counseling, healthy-living habits, regular eye exams, and gene therapy trials offer meaningful support, and research into treatments is ongoing.

Frequently Asked Questions

What is choroideremia?

A rare inherited disease that affects your eyes. It causes vision to get worse and then leads to blindness. Severe disease mostly affects men. It's also known as choroidal sclerosis.

How do you pronounce choroideremia?

It's pronounced "kuh-roy-der-ee-me-ah."

How common is choroideremia?

It affects an estimated 1 in 50,000 to 1 in 100,000 people.

What causes choroideremia?

It's an X-linked genetic disorder. The gene that causes it is located on your X chromosome. Damage to the choroid's blood vessels leads to damage to your retina and peripheral sight.

What is the choroid?

A layer between your retina and your sclera (the white protective covering of your eye). The choroid has blood vessels that feed your retina.

Why does it mostly affect men?

Males have one X chromosome and one Y chromosome, so they're more prone to X-linked genetic disorders. Females have two X chromosomes, so a faulty gene on one is usually balanced by the other.

Can women be affected?

Females don't normally have the same vision problems as males with the faulty gene. Female carriers may develop night blindness or glare issues later in life, but rarely go blind from choroideremia.

How is it inherited?

Affected males pass their X chromosome to their female children, who become carriers. Those female children have a 1 in 2 chance (50%) of passing the faulty X chromosome to their female children.

What are the symptoms?

Difficulty seeing at night (night blindness — often before age 10), difficulty with peripheral (side) vision, lack of visual acuity (sharpness), loss of the ability to see colors well, and increasing vision loss from the side that can progress to blindness.

What is night blindness?

Difficulty seeing at night. In choroideremia, it's typically the first symptom and often happens before the age of 10.

How is choroideremia diagnosed?

With regular eye exams plus an electroretinogram (measures the retina's response to light), optical coherence tomography (OCT — pictures of the back of your eye using reflected light), fluorescein angiography (dye injected into your veins to show the eye's blood vessels), and genetic testing.

What is an electroretinogram?

A test that measures your retina's response to light. Disks are placed on your face, eyes, head and scalp, thin wires are placed over the front of your eye above your bottom eyelid, and a technician flashes bright lights to measure your retina's activity.

How is choroideremia different from retinitis pigmentosa?

The two diseases have similar symptoms and sometimes similar test results — both degrade the retina. Getting a genetic test is the best way to tell the difference between them.

How is choroideremia different from gyrate atrophy?

Both are genetic conditions with similar signs and symptoms, but gyrate atrophy is inherited in an autosomal recessive pattern (both parents pass the gene), while choroideremia is X-linked. The mutated genes are also different.

Is there a cure for choroideremia?

No. Providers can't cure choroideremia. There isn't a cure, but research into treatments and cures is ongoing.

How is choroideremia treated?

While it can't be cured, you may receive support for other issues — including strategies for coping with low vision, such as magnifiers and counseling for mental health and genetics.

What can I expect over time?

Generally, your peripheral vision will get worse over time, leaving only central vision. Eventually, the condition may progress to blindness.

How can I take care of myself?

Eat a healthy diet (green leafy vegetables, other vegetables, fruit, lean protein — avoid excess salt, sugar and unhealthy fats), get enough physical activity, quit smoking, have regular eye exams, and get enough sleep.

When should I see my healthcare provider?

Whenever you have a change in vision. If changes are sudden or painful, consider emergency care. Also see a provider if you're having difficulties with daily activities, and ask about eligibility for gene therapy trials.

Can I take part in gene therapy trials?

Ask your healthcare provider for information on being eligible for gene therapy trials — research into treatments and cures for choroideremia and other genetic diseases is ongoing.

Where can I find support?

Resources exist to help with your needs, and accepting help can make your life easier. A strong relationship with a healthcare team can help, and research into developing treatments and cures for choroideremia is going on right now.

References

Cleveland Clinic. Choroideremia: Causes & Diagnosis. Cleveland Clinic. Last updated September 21, 2026. https://my.clevelandclinic.org/health/diseases/24569-choroideremia
American Academy of Ophthalmology. Choroideremia. EyeWiki. Accessed October 30, 2026. https://eyewiki.aao.org/Choroideremia
Choroideremia Research Foundation. Home page. CureCHM. Accessed October 30, 2026. https://www.curechm.org/
MacDonald IM, Hume S, Zhai Y, Xu M. Choroideremia. GeneReviews® (NCBI Bookshelf). Last update March 4, 2021. PMID 20301511. https://www.ncbi.nlm.nih.gov/books/NBK1337/
National Organization for Rare Disorders. Choroideremia. NORD (National Organization for Rare Disorders). Last updated April 23, 2025. https://rarediseases.org/rare-diseases/choroideremia/
Skorczyk-Werner A, Wawrocka A, Kochalska N, et al. Novel CHM mutations in Polish patients with choroideremia - an orphan disease with close perspective of treatment. Orphanet J Rare Dis. 2018;13(1):221. PMID 30541579. https://doi.org/10.1186/s13023-018-0965-5
Pennesi ME, Birch DG, Duncan JL, et al. CHOROIDEREMIA: Retinal Degeneration With an Unmet Need. Retina. 2019;39(11):2059-2069. PMID 31021898. https://doi.org/10.1097/IAE.0000000000002553

Medical disclaimer

This article is for general informational purposes only and does not constitute medical advice, diagnosis, or treatment. Always seek the guidance of a physician or other qualified health provider with any questions you have about a medical condition. Never disregard professional medical advice or delay seeking it because of something you read here. See a healthcare provider whenever you have a change in vision — and seek emergency care if the change is sudden or painful.