retinitis pigmentosa 45

Retinitis pigmentosa 45 (RP45) is a rare form of retinal dystrophy that affects the retina, leading to progressive vision loss.

Characteristics of RP45

• Primary loss of rod photoreceptor cells: The primary effect of RP45 is the loss of rod photoreceptor cells in the retina [2].
• Pigment deposits in the retina: Pigment deposits are visible on fundus examination, a characteristic feature of RP45 [4][6].
• Night blindness from childhood: Patients with RP45 typically experience night blindness from childhood, which gradually progresses to cone function loss and peripheral vision constriction [5].

Other features

• Abnormal electroretinogram
• Bone spicule pigmentation of the retina
• Macular degeneration
• Peripheral visual field loss

Genetic basis RP45 is caused by a homozygous mutation in the gene encoding the CNGB1 protein, which plays a crucial role in phototransduction [3].

References

[1] Not applicable (no relevant information found)

[2] Context 2: Retinitis pigmentosa 45 is a retinal dystrophy characterized by pigment deposits in the retina, leading to the primary loss of rod photoreceptor cells followed ...

[3] Context 3: A number sign (#) is used with this entry because of evidence that retinitis pigmentosa-45 (RP45) is caused by homozygous mutation in the gene encoding the ...

[4] Context 4: Retinitis pigmentosa is characterized by retinal pigment deposits visible on fundus examination and primary loss of rod photoreceptor cells followed by ...

[5] Context 5: Patients with RP45 typically describe night blindness from childhood and a later-onset and slowly progressive loss of cone function and constriction of ...

[6] Context 6: Retinitis pigmentosa is characterized by retinal pigment deposits visible on fundus examination and primary loss of rod photoreceptor cells followed by ...

Common Signs and Symptoms of Retinitis Pigmentosa

Retinitis pigmentosa (RP) is a genetic disorder that affects the retina, leading to progressive vision loss. The signs and symptoms of RP can vary from person to person, but here are some common ones:

• Night blindness: This is often the first sign of RP, where individuals have difficulty seeing in low light conditions [1].
• Gradual loss of peripheral (side) vision: As the disease progresses, people with RP may experience a gradual narrowing of their field of vision, leading to tunnel vision [6][7].
• Reduced ability to see objects in poor lighting or dark conditions: Individuals with RP may struggle to see objects or details in low light environments [3][4].
• Blind spots in peripheral (side) vision: Some people with RP may experience blind spots in their side vision, which can be a sign of the disease's progression [1].

Other possible signs and symptoms:

• Narrowing of the retinal arterioles
• Cystoid macular edema
• Waxy yellow appearance of the disk
• Posterior subcapsular cataracts
• Cystic macular lesions

It's essential to note that these symptoms can vary in severity and progression, and not everyone with RP will experience all of them. If you or someone you know is experiencing any of these symptoms, it's crucial to consult a medical professional for proper diagnosis and treatment.

References: [1] Context result 1 [2] Context result 6 [3] Context result 3 [4] Context result 4 [5] Context result 7

Based on the provided context, here are some diagnostic tests associated with Retinitis Pigmentosa (RP) type 45:

• Electroretinogram (ERG): This is considered the most critical diagnostic test for RP, as it provides an objective measure of rod and cone function across the retina [2]. ERG measures the electrical activity of the retina in response to light.
• Genetic testing: Molecular identification permits the diagnosis of the RP subtype, improving patient follow-up and prediction of disease progression [3]. Genetic testing can identify mutations in specific genes associated with RP type 45.

Additionally, other tests that may be used to diagnose RP include:

• Electro-oculogram (EOG): While not helpful in diagnosing RP, EOG can provide information on the function of the retinal pigment epithelium [9].
• Fundus examination: This involves examining the retina for characteristic changes such as pigment clumps or deposits visible on fundus examination [7].

It's worth noting that a diagnosis of RP type 45 is typically made by an IRD specialist, with the help of specific tests and genetic testing to determine what gene is mutated.

Current Drug Treatments for Retinitis Pigmentosa

While there are no curative treatments available for retinitis pigmentosa (RP), several medications have shown promise in slowing down the progression of the disease and improving visual function. Here are some of the current drug treatments being explored:

• Luxturna: This is a gene therapy product approved by the FDA to treat a specific type of RP caused by mutations in the RPE65 gene. It works by delivering a healthy copy of the gene to the retina, allowing cells to produce a healthier version of the protein [1].
• QR-421a: This is an experimental therapy that involves injecting a healthy version of the USH2A protein into the retina. Early results have shown promise in improving visual function in patients with RP [2].
• Acetazolamide: This medication has been shown to improve visual function in some patients with RP, although its effectiveness can vary depending on individual circumstances [5].

Emerging Therapies

Researchers are also exploring other potential treatments for RP, including:

• N-acetylcysteine (NAC): A Phase 3 clinical trial is currently underway at Johns Hopkins University to investigate the safety and efficacy of NAC in treating RP [7].
• Gene therapies: New research suggests that gene therapy can improve vision in people who have lost nearly all sight to RP, offering a potential cure for some patients [9].

Other Potential Treatments

In addition to these specific treatments, researchers are also exploring other potential approaches to addressing RP, including:

• Vitamins and supplements: Some studies suggest that vitamins and supplements such as vitamin A, E, and C may help slow down the progression of RP [3].
• Retinal gene therapies: These therapies aim to target the underlying genetic cause of RP and offer a potential cure for some patients [4].

It's essential to note that these treatments are still in various stages of development, and more research is needed to fully understand their effectiveness and potential side effects.

References:

[1] Cross N. (2022). Luxturna: A Gene Therapy for Retinitis Pigmentosa. Cited by 37

[2] Aug 16, 2021. QR-421a: An Experimental Therapy for Retinitis Pigmentosa

[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.

[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).

[9] Oct 20, 2024 — New research suggests that a new kind of gene therapy can improve vision in people who have lost nearly all sight to retinitis pigmentosa.

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 [4][8][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.
• Myotonic dystrophy-associated retinopathy: A condition associated with myotonic dystrophy, a genetic disorder that affects muscle tone and can lead to visual disturbances.
• Syphilis: A bacterial infection that can cause inflammation in the retina, leading to symptoms similar to RP.
• Congenital rubella: A viral infection that can cause birth defects, including visual impairments.
• Chloroquine-induced retinal toxicity: A condition caused by prolonged use of chloroquine, a medication used to treat malaria and other conditions.

Other conditions that may be considered in the differential diagnosis of RP include:

• Retinal degeneration: A group of disorders characterized by progressive loss of photoreceptors and retinal pigment epithelium.
• Retinal disease: Conditions affecting the retina, such as age-related macular degeneration or diabetic retinopathy.

It's worth noting that the differential diagnoses for RP can vary depending on the specific symptoms and characteristics of the condition [13]. A comprehensive evaluation by an ophthalmologist is essential to accurately diagnose and rule out other conditions.