retinitis pigmentosa 38

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 retinal proteins. Several genes have been identified as responsible for the condition.
• Transmission: The transmission pattern of RP can be autosomal recessive, autosomal dominant, or X-linked. In some cases, it may occur as part of a syndrome, such as Bassen-Kornzweig or Laurence-Moon syndromes.
• Symptoms: Symptoms usually start in childhood and progress to night blindness and peripheral vision loss. The condition is characterized by the breakdown of rod photoreceptors, followed by cone photoreceptors.

Key Statistics

• RP affects 1 in 4,000 people worldwide.
• The prevalence of RP varies among different populations.

References

[12] The name retinitis pigmentosa (RP), described initially as a clinical entity in 1853, was not attached to the disease until 1857.[1] 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. RP is not a single entity but rather a group of disorders that produce a gradual loss of vision ...

[13] Retinitis pigmentosa (RP) is a progressive degeneration that typically starts with involvement of the rod photoreceptors, followed by cone photoreceptors, 1,2 and thus is classified as a rod-cone dystrophy. The condition is estimated to affect 1 in 4,000 people worldwide, with variable prevalence in different populations.

[14] Abnormal gene coding for retinal proteins appears to be the cause of retinitis pigmentosa; several genes have been identified. Transmission may be autosomal recessive, autosomal dominant, or, infrequently, X-linked. It may occur as part of a syndrome (eg, Bassen-Kornzweig, Laurence-Moon). One of these syndromes includes congenital hearing loss ...

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 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 or at night [1].
• Gradual loss of peripheral (side) vision: As the disease progresses, people with RP may experience a gradual narrowing of their field of vision, which can lead to tunnel vision [6][7].
• Reduced ability to see objects in poor lighting: Individuals with RP may struggle to see objects or details in dimly lit environments [3].
• Blind spots in peripheral (side) vision: Some people with RP may experience blind spots or areas of reduced vision in their side (peripheral) vision [1][6].

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 suspect you or a loved one may have RP, consult an eye care professional for proper diagnosis and guidance.

References: [1] Context result 1 [3] Context result 3 [6] Context result 6 [7] Context result 7

Diagnostic Tests for Retinitis Pigmentosa

Retinitis pigmentosa (RP) is a group of inherited eye diseases that affect the retina, and diagnostic tests play a crucial role in its diagnosis. Here are some common diagnostic tests used to investigate RP:

• Electro-diagnostic tests: These tests include electroretinogram (ERG), electro-oculogram (EOG), and multifocal electroretinogram (mfERG). They provide an objective measure of rod and cone function across the retina [3].
• Genetic testing: This test looks at a sample of your blood or other tissues to see if you have certain genes that are associated with RP. Genetic testing can identify specific genetic mutations that cause RP, such as the RPE65 gene mutation [4].
• 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 [3]. It helps confirm the diagnosis by demonstrating attenuated rod and cone signals [8].
• Optical Coherence Tomography (OCT) scan: An OCT scan can show loss of photoreceptors in the retina, which is a common finding in RP patients [6].

These diagnostic tests help healthcare professionals diagnose RP and rule out other conditions that may cause similar symptoms. Early diagnosis and genetic testing can also provide valuable information for family planning and genetic counseling.

References: [3] May 16, 2024 — Electroretinogram. [4] Nov 11, 2024 — Genetic testing. [6] 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 ... [8] Sep 21, 2023 — Electroretinograms help confirm the diagnosis by demonstrating attenuated rod and cone signals.

Current Drug Treatments for Retinitis Pigmentosa

While there are no definitive cures for retinitis pigmentosa (RP), various drug treatments have shown promise in slowing down the progression of the disease or improving visual function. Here are some of the current drug treatments being explored:

• Luxturna: The FDA has approved Luxturna, a gene therapy product, to treat a specific type of RP caused by mutations in the RPE65 gene. This treatment involves injecting a healthy copy of the RPE65 gene into the retina.
• QR-421a: Another gene therapy, QR-421a, is being investigated for its potential to treat USH2A-related RP. This treatment involves injecting a healthy version of the USH2A protein into the retina.
• Acetazolamide: Oral acetazolamide has shown some encouraging results in improving visual function in patients with RP. However, more research is needed to confirm its effectiveness.

Emerging Therapies

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

• N-acetylcysteine (NAC): A Phase 3 clinical trial of NAC has been launched by Johns Hopkins University to investigate its potential in treating RP.
• Nanobodies: Researchers at UC Irvine have discovered a nanobody that may lead to the development of a treatment for RP.

Gene Therapy

Gene therapy holds promise as a potential cure for some forms of RP. This approach involves introducing healthy copies of the genes responsible for the disease into the retina, allowing cells to produce a healthier version of the protein.

These emerging therapies and treatments offer hope for patients with retinitis pigmentosa, but more research is needed to confirm their effectiveness and safety.

References:

• [1] by N Cross · 2022 · Cited by 37 — Currently, Luxturna® (voretigene neparvovec) is the only approved therapy for RP and is only authorised for the treatment of a small sub-...
• [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...
• [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.

The differential diagnosis of retinitis pigmentosa (RP) is vast and can be challenging due to its complex clinical presentation.

Possible Differential Diagnoses:

• Traumatic retinopathy [8]
• Retinal inflammatory diseases [8]
• Autoimmune paraneoplastic retinopathy [8]
• Drug-induced retinal toxicity [8]

These conditions can present with similar symptoms and findings as RP, making accurate diagnosis crucial. A thorough medical history, physical examination, and diagnostic tests are essential to rule out these differential diagnoses.

Key Diagnostic Features:

• Peripheral visual field loss
• Pigment deposits in the fundus
• Loss of photoreceptors at optical coherence tomography (OCT) scan [6]

These features can help differentiate RP from other conditions. However, a comprehensive evaluation by an ophthalmologist or retinal specialist is necessary to confirm the diagnosis.

Genetic Testing:

• Genetic testing can also be used to diagnose RP and rule out other genetic disorders that may present with similar symptoms [7].

References: [8] - Traumatic retinopathy, Retinal inflammatory diseases, Autoimmune paraneoplastic retinopathy, Drug-induced retinal toxicity [6] - Key diagnostic features of RP [7] - Genetic testing for RP