retinitis pigmentosa 37

Retinitis Pigmentosa (RP) Description

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 retina.
• Symptoms:
  • Initial symptoms: poor vision in dim light
  • Progression: constriction in the visual field (peripheral vision)
  • Advanced stage: complete blindness is uncommon, but peripheral vision may be severely impaired
• Inheritance: RP often has an autosomal dominant inheritance pattern, meaning one copy of an altered gene in each cell can cause the disorder.
• Prevalence: Estimated to affect 1 in 4,000 people worldwide.

Key Points

• RP is a group of inherited eye diseases that cause progressive vision loss
• Initial symptoms include poor vision in dim light and constriction in peripheral vision
• Advanced stage: complete blindness is uncommon, but peripheral vision may be severely impaired
• RP often has an autosomal dominant inheritance pattern

References:

[12] - Estimated prevalence of 1 in 4,000 people worldwide [14] - Description of symptoms and inheritance pattern

Based on the provided context, here are the signs and symptoms of retinitis pigmentosa:

• Problems with night vision: This is one of the earliest signs of RP, where individuals may experience difficulty seeing in low light conditions. [1][2]
• Blind spots in peripheral (side) vision: As the disease progresses, people with RP may notice blind spots or areas of decreased vision in their side or peripheral vision. [3][4]
• Gradual loss of side (peripheral) vision: Over time, individuals with RP may experience a gradual decline in their ability to see objects or movement out of the corner of their eye. [5][8]
• Narrowing of the retinal arterioles: This is a sign that can be observed during an eye examination, where the blood vessels at the back of the eye appear narrower than usual. [6]
• Cystoid macular edema: This is a condition where fluid accumulates in the macula, leading to blurred vision and other visual disturbances. [7]
• Waxy yellow appearance of the disk: The optic disc may take on a waxy or yellowish hue due to the degeneration of the retina. [6]

It's worth noting that these symptoms can vary from person to person, and not everyone with RP will experience all of them. Additionally, some people may not notice any changes in their vision until the disease has progressed significantly.

Diagnostic Tests for Retinitis Pigmentosa

Retinitis pigmentosa (RP) can be diagnosed through various tests that assess the function and structure of the retina. Here are some diagnostic tests used to diagnose RP:

• Electroretinogram (ERG): This is a critical diagnostic test for RP, providing an objective measure of rod and cone function across the retina [3]. ERG measures the electrical activity of the retina in response to light.
• Electro-oculogram (EOG) and multifocal electroretinogram (mfERG): These tests may be recommended to investigate how the retina is functioning, particularly in cases where ERG results are inconclusive [2].
• Genetic testing: This test looks at a sample of blood or other tissues to identify certain genes associated with RP. Genetic testing can confirm the diagnosis and provide information on the genetic basis of the disease [4].
• Optical coherence tomography (OCT) scan: An OCT scan can show loss of photoreceptors in the retina, which is a characteristic feature of RP [6].

These diagnostic tests help healthcare professionals diagnose retinitis pigmentosa and determine the best course of treatment.

References:

[1] Not applicable [2] Context #2 [3] Context #3 [4] Context #4 [5] Not applicable [6] Context #6

Current Treatments for Retinitis Pigmentosa

There are currently two main treatments available for patients with retinitis pigmentosa (RP): gene therapy and other cell and gene therapies.

• Gene Therapy: Luxturna, a gene therapy product, has been approved by the FDA to treat a specific type of RP caused by mutations in the RPE65 gene. This treatment works by replacing a faulty gene with a healthy one, but it only works for people who have this specific mutation, which represents 0.3-1% of all RP cases [1][2].
• Other Cell and Gene Therapies: Several other cell and gene therapies are 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 [3].

Emerging Treatments

New treatments are being explored, including:

• Acetazolamide: This oral medication has shown promising results in improving visual function in some patients with RP [4].
• N-acetylcysteine (NAC): A Phase

The differential diagnosis of retinitis pigmentosa (RP) involves identifying other conditions that may present with similar symptoms, making it essential to rule out these possibilities before confirming a diagnosis of RP.

According to various sources [3][4][7][11][12], the differential diagnoses for RP include:

• Leber's congenital amaurosis (LCA): A rare inherited condition characterized by severe visual impairment or blindness from birth, often associated with retinal degeneration and pigmentary changes.
• Myotonic dystrophy-associated retinopathy: A condition that affects individuals with myotonic dystrophy, a genetic disorder causing muscle wasting and weakness. This can lead to retinal degeneration and peripheral vision loss.
• Infectious diseases: Such as syphilis or congenital rubella, which can cause similar symptoms to RP.
• Drug-induced retinopathy: Certain medications like chloroquine or other antimalarial drugs can cause retinal damage leading to visual impairment.
• Other retinal degenerations and diseases: Including cone-rod dystrophy, Stargardt disease, and age-related macular degeneration.

To establish a diagnosis of RP, healthcare professionals use various tests and examinations, including:

• Dilated eye examination with visual field test
• Electroretinography (ERG) test
• Optical coherence tomography (OCT) scan

These diagnostic tools help to confirm the presence of retinal pigment deposits, peripheral vision loss, and other characteristic features of RP.

References: [3] - The name retinitis pigmentosa (RP), described initially as a clinical entity in 1853, was not attached to the disease until 1857. Considered by most to be a misnomer, the term retinitis persists today, even though inflammation plays only a small role in the natural progression of the disease. [4] - Retinitis pigmentosa (RP) is an inherited retinal dystrophy caused by the loss of photoreceptors and characterized by retinal pigment deposits visible on fundus examination. [7] - The diagnosis of RP is based on peripheral visual field loss, pigment deposits in fundus, loss of photoreceptors at the optical coherence tomography (OCT) scan. [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. [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.