retinitis pigmentosa 83

Retinitis Pigmentosa (RP): A Group of Inherited Eye Diseases

Retinitis pigmentosa (RP) is a group of inherited eye diseases that cause progressive vision loss. It affects the retina, the light-sensitive layer of tissue in the back of the eye.

• Causes: RP is caused by genetic variants that affect the production of proteins essential for retinal function. [1][2]
• Symptoms: Symptoms usually start in childhood and include:
  • Night blindness (difficulty seeing at night)
  • Decreasing peripheral vision (side and upper or lower visual field)
  • "Tunnel vision" as peripheral vision worsens
  • Complete blindness is uncommon, but may occur in advanced stages [1][2]
• Types: RP can be inherited in an autosomal dominant, autosomal recessive, or X-linked pattern. It may also occur as part of a syndrome, such as Bassen-Kornzweig or Laurence-Moon syndromes.
• Prevalence: RP affects approximately 1 in 4,000 people worldwide, with variable prevalence in different populations [3].

References

[1] Context result 14 [2] Context result 15 [3] Context result 13

Common Signs and Symptoms of Retinitis Pigmentosa

Retinitis pigmentosa (RP) is a group of rare, genetic disorders that affect the retina's ability to respond to light. The symptoms of RP can vary from person to person, but here are some common signs and symptoms:

• Night blindness: Difficulty seeing in low-light conditions or at night [1][2]
• Problems with peripheral vision: Blind spots or difficulty seeing objects out of the corner of your eye [3][4]
• Reduced vision in poor lighting: Difficulty seeing in dim light, shadows, or poorly lit areas [5][6]
• Tunnel vision: A narrowing of the visual field, where you can only see a small area in front of you [7]
• Loss of peripheral (side) vision: Gradual loss of ability to see objects out of the corner of your eye [8]

Other symptoms may include:

• Difficulty adjusting to light changes: Trouble seeing in bright light or adjusting to sudden changes in lighting [9]
• Seeing shimmers, blinking lights, or flashes: Some people with RP may experience visual disturbances such as seeing shimmers, blinking lights, or flashes [9]

It's essential to note that the symptoms of retinitis pigmentosa can vary from person to person and may progress at different rates. If you're experiencing any of these symptoms, it's crucial to consult a healthcare professional for proper diagnosis and treatment.

References: [1] - Search result 1 [2] - Search result 2 [3] - Search result 7 [4] - Search result 8 [5] - Search result 4 [6] - Search result 9 [7] - Search result 3 [8] - Search result 8 [9] - Search result 9

Diagnostic Tests for Retinitis Pigmentosa

Retinitis pigmentosa (RP) can be diagnosed through a combination of visual field testing, electro-diagnostic tests, and imaging tests.

• Visual Field Testing: This test helps measure your side vision and find any blind spots that may be developing. It is useful in monitoring the progression of disease and documenting the status of legal blindness [4].
• Electro-Diagnostic Tests:
  • Electroretinogram (ERG): ERG is the most critical diagnostic test for RP because it provides an objective measure of rod and cone function across the retina. It helps confirm the diagnosis by demonstrating attenuated rod and cone signals [9].
  • Electro-oculogram (EOG): EOG is a measurement of standing potential between the cornea and the retina, which can help diagnose RP [4].
• Imaging Tests:
  • Optical Coherence Tomography (OCT): OCT takes special, highly detailed pictures of your retina. It can help diagnose RP and find out how it is affecting your retina [3].
  • Fundus Autofluorescence (FAF) Imaging: This test uses blue light to take a picture of the retina, which can help detect retinal degeneration [11].

These tests are used in combination with a thorough eye examination by an eye doctor to establish a diagnosis of RP. The diagnosis is established when bilateral involvement (which can be asymmetric), peripheral visual field loss, pigment deposits in fundus, and loss of photoreceptors at the OCT scan are present [8].

Current Treatments for Retinitis Pigmentosa

There are currently two main treatments available for patients with retinitis pigmentosa (RP): Luxturna, a gene therapy that targets the RPE65 gene mutation, and other emerging therapies in late-stage development.

• Luxturna: This is the first FDA-approved gene therapy for RP, specifically designed to treat patients with a mutation in both copies of the RPE65 gene. It works by replacing a faulty gene with a healthy one, but it only works in people who have this specific gene mutation, which represents 0.3 to 1 percent of all RP cases [1].
• Emerging Therapies: Several cell and gene therapies are currently in late-stage development, including AGN-151597, GS-030, VMCO-1, jCell, and ReN-003. These treatments aim to slow down or halt the progression of RP, but more research is needed to determine their effectiveness [2].

Other Potential Treatments

In addition to these emerging therapies, other potential treatments for RP include:

• Acetazolamide: This oral medication has shown promising results in improving visual function in some patients with RP [3].
• Vitamins and Supplements: Vitamin A supplements are often recommended to slow down the progression of RP.
• Gene Therapy for Other Gene Mutations: Researchers are exploring gene therapies that target other gene mutations associated with RP, such as the RPE65 gene.

Important Note

It's essential to note that there is currently no cure for retinitis pigmentosa. However, doctors and researchers are working hard to find new treatments that can slow down or halt the progression of this disease.

References:

[1] Context result 3: Luxturna (voretigene neparvovec) is the first FDA-approved gene therapy for retinitis pigmentosa. [2] Context result 2: Amongst the 15 cell and gene therapies in late-stage development, 5 leading candidates have been selected to profile based on the development stage, drug target and geography. [3] Context result 6: May 16, 2024 — Of the many therapies tried, oral acetazolamide has shown the most encouraging results with some improvement in visual function.

Differential Diagnosis of Retinitis Pigmentosa

Retinitis pigmentosa (RP) is a complex group of inherited dystrophies, and its differential diagnosis can be extensive. Here are some conditions that may be considered in the differential diagnosis of RP:

• Leber's Congenital Amaurosis (LCA): This is a rare, inherited form of blindness that affects children and young adults. It is characterized by severe visual impairment or blindness from birth.
• Myotonic Dystrophy-Associated Retinopathy: This is a condition associated with myotonic dystrophy, a genetic disorder that affects muscle tone. It can cause retinal degeneration and peripheral vision loss.
• Syphilis: In rare cases, syphilis can cause retinitis pigmentosa-like symptoms, including peripheral vision loss and night blindness.
• Congenital Rubella: This is a condition caused by the rubella virus that can affect the eyes, among other systems. It can cause retinal degeneration and visual impairment.
• Chloroquine-Induced Retinopathy: Long-term use of chloroquine, an antimalarial medication, can cause retinal toxicity and peripheral vision loss.
• Other Retinal Degenerations: Other conditions that may be considered in the differential diagnosis of RP include cone-rod dystrophy, Stargardt disease, and age-related macular degeneration.

These conditions should be ruled out through a comprehensive eye examination, including visual field testing, electroretinography (ERG), and optical coherence tomography (OCT) scans. A detailed medical history and genetic testing may also be necessary to confirm the diagnosis of RP.

References:

• [3] Ophthalmology discusses many diseases that either can be confused with RP and allied disorders or enter into the differential diagnosis.
• [12] Retinitis pigmentosa (RP) is an inherited retinal dystrophy caused by the loss of photoreceptors and characterized by retinal pigment deposits visible on fundus examination.
• [13] The list of differential diagnoses in RP is extensive and includes infectious (e.g., syphilis or congenital rubella), drug-induced (e.g., chloroquine or ... Different stimuli are used to establish the diagnosis of retinitis pigmentosa, which is based on the guidelines of the International Society for Clinical Electrophysiology of Vision (ISCEV)
• [11] Differential Diagnosis of Nonsyndromic Retinitis Pigmentosa. It should be noted that individuals who present with initial symptoms of photopsia (sensation of lights flashing), abnormal central vision, abnormal color vision, or marked asymmetry in ocular involvement may not have RP, but another retinal degeneration or retinal disease.