What Are Inherited Retinal Diseases?
Inherited retinal diseases (IRDs) are a family of over 300 genetic conditions in which mutations in specific genes cause progressive degeneration of the retina, the light-sensitive tissue at the back of your eye. Unlike conditions such as age-related macular degeneration or diabetic retinopathy, which develop due to aging or other health conditions, IRDs are caused by gene mutations you are born with.
Different mutations damage different parts of the retina and cause different patterns of vision loss. Some IRDs primarily affect the rod photoreceptors (cells responsible for night and peripheral vision), while others affect the cone photoreceptors (cells responsible for central vision and color vision) or the retinal pigment epithelium (RPE), a support layer that nourishes the photoreceptors. IRDs affect approximately 1 in 3,000 people, and the first gene therapy for any genetic disease was approved in 2017 for one form of IRD.
Common Types of Inherited Retinal Diseases
Retinitis Pigmentosa (RP)
RP is the most common inherited retinal disease, affecting an estimated 100,000 people in the United States. It is a rod-cone dystrophy, meaning the rod photoreceptors degenerate first, followed by the cones. The earliest symptom is typically night blindness, often noticed in adolescence or young adulthood. Over years to decades, peripheral vision progressively narrows — often described as “tunnel vision.” Over 100 genes have been identified as causes of RP, and severity varies widely, but most patients are classified as legally blind by around age 40. Total blindness is uncommon.
Stargardt Disease
Stargardt disease is the most common inherited macular dystrophy, affecting approximately 1 in 10,000 people. Caused by mutations in the ABCA4 gene, it typically presents in the first two decades of life with difficulty reading or recognizing faces. The disease primarily damages the macula, leading to progressive central vision loss while peripheral vision is usually preserved. There is no FDA-approved treatment as of early 2026, though a promising oral medication (tinlarebant) met its Phase 3 primary endpoint and may be submitted for approval in 2026.
Leber Congenital Amaurosis (LCA)
LCA is the most severe form of IRD, presenting at birth or within the first year of life with profound vision loss. At least 23 genes have been identified as causes. LCA caused by RPE65 gene mutations is the most clinically significant subtype because it is treatable with Luxturna, the first and only FDA-approved gene therapy for an inherited retinal disease.
Choroideremia
Choroideremia is an X-linked condition (primarily affecting males) caused by mutations in the CHM gene. Symptoms begin with night blindness in childhood, followed by progressive peripheral vision loss and severe tunnel vision by the thirties and forties. Central vision is typically preserved until later in the disease. Choroideremia is often misdiagnosed as retinitis pigmentosa; genetic testing is the definitive way to distinguish them.
Best Disease
Best disease (vitelliform macular dystrophy) is caused by mutations in the BEST1 gene and affects the macula. It typically presents in childhood with a characteristic “egg yolk” lesion visible on examination. Progression is variable — many patients maintain useful central vision for decades, while others progress to significant central vision loss. Peripheral vision is preserved.
Common Symptoms
Symptoms vary depending on the specific type of IRD, but most share common patterns. Many patients have no obvious symptoms in the earliest stages, and historically the average time from symptom onset to diagnosis was over 20 years — though this has improved significantly with better access to genetic testing.
- Night blindness: Difficulty seeing in dim environments, such as trouble driving at night, navigating restaurants or theaters, or adjusting when moving from bright to dark rooms. This is the hallmark early symptom of RP and choroideremia.
- Peripheral vision loss: A gradual narrowing of your side vision over years to decades, often described as looking through a narrow tube. Affects mobility, driving, and spatial awareness.
- Central vision loss: Difficulty reading, recognizing faces, or seeing fine detail. This is the primary symptom in Stargardt disease and Best disease.
- Color vision changes: Difficulty distinguishing certain colors, particularly in conditions that affect the cone photoreceptors.
- Light sensitivity: Discomfort or difficulty seeing in bright environments, common in cone-involved dystrophies.
Important note: If you have a known IRD and experience any sudden change in vision — new flashes of light, a sudden increase in floaters, a curtain or shadow across your vision, or sudden worsening of central vision — contact us promptly. These symptoms may indicate a treatable secondary complication such as retinal detachment or macular swelling, not the underlying progressive disease.
Causes and Genetics
IRDs are caused by mutations in genes that are essential for normal retinal function. These genes encode proteins involved in converting light into electrical signals, maintaining photoreceptor structure, recycling visual pigments, and supporting the RPE. When a gene is mutated, the protein it produces is absent or dysfunctional, and the affected retinal cells gradually die.
IRDs follow several inheritance patterns:
- Autosomal recessive (most common): Both parents are typically unaffected carriers. Each child has a 25% chance of being affected. This includes Stargardt disease, most forms of LCA, and many forms of RP.
- Autosomal dominant: One copy of the mutated gene causes disease. Each child has a 50% chance of inheriting it. Some forms of RP and Best disease follow this pattern.
- X-linked: Males are primarily affected; females are usually carriers. This includes choroideremia and X-linked RP, the most severe form of RP.
Why genetic testing matters: Identifying your specific gene mutation is critical for three reasons. First, it determines your prognosis — different genes cause different rates of progression. Second, it clarifies the risk to your family members and informs family planning decisions. Third, it determines whether you are eligible for gene therapy or clinical trials, nearly all of which require a confirmed genetic diagnosis for enrollment.
How Are Inherited Retinal Diseases Diagnosed?
Diagnosing an IRD requires clinical examination, specialized retinal testing, and genetic analysis. At Retina Vision Consultants, we use a comprehensive approach to characterize your disease and identify the underlying gene mutation.
- Dilated Fundus Examination: A thorough examination of the retina to identify characteristic patterns of degeneration specific to each IRD type.
- Optical Coherence Tomography (OCT): High-resolution cross-sectional imaging of the retina that reveals photoreceptor layer thinning and loss of the ellipsoid zone, a marker of remaining viable photoreceptors. The integrity of this layer helps determine prognosis and gene therapy candidacy.
- Fundus Autofluorescence (FAF): Non-invasive imaging that maps the health of the RPE. FAF is particularly important in Stargardt disease, where it is the primary tool for tracking progression, and in RP, where a characteristic bright ring around the macula marks the border of surviving photoreceptors.
- Electroretinogram (ERG): The most important functional test for IRDs. ERG measures the electrical activity of your retina’s photoreceptors in response to light, providing objective data about rod and cone function. A severely reduced or absent ERG is a hallmark of conditions like LCA and advanced RP.
- Visual Field Testing: Maps the extent and pattern of peripheral vision loss over time, particularly important for monitoring RP and choroideremia.
Genetic Testing: The definitive confirmatory step. Next-generation sequencing of retinal dystrophy gene panels (testing 200–400+ known IRD genes) identifies the specific causative mutation. Current diagnostic yield ranges from approximately 49–75%, and patients without an initial result may benefit from retesting as databases expand. The Foundation Fighting Blindness offers free genetic testing through its My Retina Tracker program.
Treatment Options at RVC
The treatment landscape for inherited retinal diseases has changed dramatically. A decade ago, there were no approved treatments for any IRD. Today, gene therapy is a reality for one form, and the clinical trial pipeline is expanding rapidly.
Luxturna Gene Therapy (For RPE65-Mediated Disease)
Luxturna (voretigene neparvovec) is the first and only FDA-approved gene therapy for an inherited retinal disease. Approved in December 2017, it treats patients with vision loss caused by confirmed mutations in both copies of the RPE65 gene who have sufficient remaining viable retinal cells. Luxturna uses a harmless viral vector to deliver a working copy of the RPE65 gene directly to the retina through a surgical injection. In clinical trials, 93% of treated patients gained functional vision, and improvements have been sustained for up to 7.5 years.
Clinical Trials and Emerging Therapies
Multiple gene therapies are in development for other forms of IRD, including RPGR gene therapy for X-linked RP and CHM gene therapy for choroideremia. A gene-agnostic optogenetic therapy (MCO-010), which can potentially restore some vision regardless of the specific mutation, is currently under FDA review for RP. Tinlarebant, an oral medication for Stargardt disease, met its Phase 3 primary endpoint and may be submitted for approval in 2026. Your retina specialist can evaluate whether you may be eligible for any active trials.
Stem Cell Therapy Research
Retina Vision Consultants’ Dr. Steven Schwartz pioneered the first FDA-approved clinical trials of human embryonic stem cell-derived RPE transplantation at UCLA, demonstrating safety and vision improvements in patients with Stargardt disease and dry AMD. Research continues to advance toward autologous stem cell therapy using a patient’s own cells.
Managing Symptoms and Complications
For patients with RP, vitamin A palmitate supplementation (15,000 IU/day) has been shown to slow the rate of cone function decline. Vitamin A is contraindicated in Stargardt disease. Cystoid macular edema, a treatable complication in some RP patients, can be managed with carbonic anhydrase inhibitors. Low vision aids, adaptive technology, and rehabilitation services are an essential part of comprehensive IRD care.
Living With an Inherited Retinal Disease: What to Expect
Will I go blind? The answer depends on your specific condition and gene mutation. Most patients with RP retain some functional vision for decades — total blindness is uncommon, though most are classified as legally blind by middle age. Stargardt disease causes central vision loss while preserving peripheral vision and mobility. LCA causes severe impairment from infancy, but gene therapy can now help those with RPE65 mutations. Best disease has the most variable course.
How often will I need to be seen? Most stable IRD patients are seen annually for a comprehensive evaluation including OCT, visual field testing, and FAF. Younger children, newly diagnosed patients, or those with active progression may need visits every 6–9 months. Regular monitoring ensures you remain eligible for clinical trials as new therapies emerge.
Family considerations: Genetic counseling is strongly recommended. Other family members may benefit from evaluation and carrier testing to inform family planning decisions.
Even when no treatment is currently available for your specific mutation, ongoing specialist care matters — secondary complications can be caught early, the pipeline is advancing rapidly, and maintaining current evaluation data keeps you ready for emerging therapies.
When to See a Retina Specialist
If you have noticed progressive changes in your night vision, peripheral vision, or central vision — especially if similar symptoms run in your family — a comprehensive evaluation including genetic testing is an important first step. An accurate diagnosis opens the door to prognosis information, family planning guidance, and potential eligibility for gene therapy or clinical trials.
Call Retina Vision Consultants at (310) 269-8565 to request an appointment. Early and accurate diagnosis gives you the best chance of accessing emerging treatments while you still have viable retinal cells that can respond to therapy.
