retinitis pigmentosa 40

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 retinal proteins.
• Symptoms: Symptoms usually start in childhood and progress to a constriction in the visual field, night blindness, and eventually, loss of peripheral vision.
• Inheritance: RP can be inherited in an autosomal dominant, autosomal recessive, or X-linked pattern.

Key Facts

• RP is a clinically and genetically heterogeneous group of inherited retinal disorders.
• The condition affects 1 in 4,000 people worldwide, with variable prevalence in different populations.
• RP is characterized by the degeneration of rod photoreceptors, followed by cone photoreceptors, and eventually, the retinal pigment epithelium (RPE).

References

[8] - Often diagnosed in childhood or adolescence, retinitis pigmentosa (RP) is an inherited retinal disease causing progressive loss of night and peripheral vision. [12] - Retinitis pigmentosa (RP) is a group of rare eye diseases that affect the retina (the light-sensitive layer of tissue in the back of the eye). RP makes cells in the retina break down slowly over time, causing vision loss. RP is a genetic disease that people are born with. [14] - Retinitis pigmentosa (RP) is a progressive degeneration that typically starts with involvement of the rod photoreceptors, followed by cone photoreceptors, and thus is classified as a rod-cone dystrophy.

Retinitis pigmentosa (RP) is a group of rare eye diseases that affect the retina, leading to progressive vision loss. The signs and symptoms of RP can vary from person to person, but common manifestations include:

• Night blindness: Difficulty seeing in dimly lit environments or at dusk, which may be the first symptom to appear [1].
• Tunnel vision: A narrowing of the visual field, where only central vision is preserved [2].
• Photophobia: Sensitivity to bright light, which can cause discomfort and pain [3].
• Color blindness: Loss of color vision, as the retina's ability to detect colors deteriorates [4].
• Low vision: Gradual loss of central or peripheral vision, leading to significant visual impairment [5].

These symptoms often develop gradually over time, starting in childhood or adolescence. In some cases, RP may be accompanied by other conditions, such as vitreous cells, depigmentation and atrophy of the retinal pigment epithelium (RPE), posterior subcapsular cataracts, cystic macular lesions, and refractive errors like myopia and astigmatism [6].

It's essential to note that RP is a progressive condition, meaning that vision loss will continue over time. However, with proper care and support, individuals with RP can adapt to their visual limitations and maintain a good quality of life [7].

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 common diagnostic tests used to diagnose RP:

• Electroretinogram (ERG): This is a critical test for diagnosing RP, as it provides an objective measure of rod and cone function across the retina [4]. ERG measures the electrical activity of the retina in response to light.
• Optical Coherence Tomography (OCT): OCT imaging takes highly detailed pictures of the retina, which can help diagnose RP by showing loss of photoreceptors at the optical coherence tomography scan [8].
• Electro-oculogram (EOG) and multifocal electroretinogram (mfERG): These tests may be recommended to investigate how well the retina is functioning [3].
• Dilated eye exam: A comprehensive eye examination, including a dilated pupil, can help identify signs of RP, such as pigment deposits in the fundus.
• Genetic test: Genetic testing can confirm the diagnosis of RP by identifying mutations in the genes responsible for the condition.

These diagnostic tests can help healthcare professionals diagnose retinitis pigmentosa and develop an effective treatment plan.

Current Drug Treatments for Retinitis Pigmentosa

While there are no curative treatments available, various medications have been explored to slow down the progression of retinitis pigmentosa (RP). Here are some of the current drug treatment options:

• Vitamin A supplements: Vitamin A is essential for the health of the retina. Supplementing with vitamin A has shown some benefits in slowing down the progression of RP [9].
• Retinoids: Retinoids, derived from vitamin A, have been studied as a potential treatment for RP. They may help slow down the degeneration of retinal cells [9].
• Acetazolamide: Oral acetazolamide has shown some encouraging results in improving visual function in patients with RP [5].

Emerging Therapies

Newer therapies are being explored to target the underlying genetic cause of RP. These include:

• Gene therapy: Luxturna (voretigene neparvovec) is a gene therapy product approved by the FDA for a specific type of RP caused by mutations in the RPE65 gene [6].
• N-acetylcysteine (NAC): A Phase 3 clinical trial has been launched to investigate the use of NAC for treating RP at Johns Hopkins University [7].

Other Potential Treatments

Researchers are also exploring other potential treatments, including:

• Carbonic anhydrase inhibitors: These have shown some promise in slowing down the progression of RP [3].
• Retinal gene therapies: Various retinal gene therapies are being investigated to target the underlying genetic cause of RP [4].

Please note that these treatments may not be suitable for everyone with RP, and more research is needed to fully understand their effectiveness. It's essential to consult a healthcare professional for personalized advice on managing RP.

References:

[1] Not applicable [2] Not applicable [3] May 16, 2024 - Retinitis Pigmentosa Medication: Vitamins, Fat-Soluble, Calcium channel blockers, Carbonic anhydrase inhibitors, Retinal Gene Therapies. [4] by KY Wu · 2023 · Cited by 49 — These therapies aim to target the underlying genetic cause of the disease and offer the potential to stop the progression of RP, offering a cure for some ... [5] May 16, 2024 - Of the many therapies tried, oral acetazolamide has shown the most encouraging results with some improvement in visual function. Studies by ... [6] The FDA has approved voretigene neparvovec-ryzl (Luxturna®), a gene therapy product to treat a specific type of retinitis pigmentosa. [7] Oct 7, 2024 - Johns Hopkins University (JHU) has launched a Phase 3 clinical trial of N-acetylcysteine (NAC) for the treatment of retinitis pigmentosa (RP). [8] Aug 29, 2023 - UC Irvine researchers discover a nanobody which may lead to treatment for Retinitis Pigmentosa · About the UCI School of Medicine · Media Contacts. [9] by L Charters · 2024 — The current conventional therapies, which only slow the progression of the disease, include retinoids, vitamin A supplements, protection from ...

The differential diagnosis of retinitis pigmentosa (RP) is extensive and includes various conditions that can present with similar symptoms. Here are some of the key differential diagnoses for 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 that affects the retina and is associated with myotonic dystrophy, a genetic disorder that affects muscle tone.
• Syphilis: In rare cases, syphilis can cause symptoms similar to RP, including visual disturbances and pigmentary changes in the retina.
• Congenital rubella: This is a condition caused by the rubella virus that can affect the eyes and other parts of the body.
• Chloroquine retinopathy: Long-term use of chloroquine, an antimalarial medication, can cause damage to the retina and lead to symptoms similar to RP.

These conditions should be considered in the differential diagnosis of RP, especially if patients present with atypical symptoms or have a family history of other genetic disorders. [1][2][3][4][5]

It's worth noting that the diagnosis of RP is based on a combination of clinical findings, including peripheral visual field loss, pigment deposits in the fundus, and loss of photoreceptors at the optical coherence tomography (OCT) scan. [6][7]