retinitis pigmentosa

Retinitis Pigmentosa (RP) Description

Retinitis pigmentosa is a group of genetic disorders that affect the retina's ability to respond to light, causing a slow loss of vision [1]. It is a clinically and genetically heterogeneous group of inherited retinal disorders characterized by diffuse degeneration of the retina [6].

The condition often leads to progressive loss of night and peripheral vision, which can eventually lead to legal and sometimes complete blindness [7]. The symptoms of RP include trouble with night vision, irregular retina pigmentation, and a slow decline in eyesight [2][3][4].

RP is an inherited eye disease that affects the retina, causing visual problems, including progressive vision loss [5][8]. It is a term for a group of eye diseases that can lead to loss of sight, with specific characteristics such as progressive deterioration of the retina and loss of peripheral vision [9].

Key Features:

• Slow loss of vision
• Trouble with night vision
• Irregular retina pigmentation
• Progressive loss of peripheral vision
• Can lead to legal and sometimes complete blindness

References: [1] Context 1 [2] Context 2 [3] Context 3 [4] Context 4 [5] Context 5 [6] Context 6 [7] Context 7 [8] Context 8 [9] Context 9

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 here are some common ones:

• Night blindness: One of the earliest signs of RP is difficulty seeing in dimly lit environments or at dusk [5]. This is because the condition affects the retinal rods, which are responsible for night vision [6].
• Loss of peripheral vision: As RP progresses, people may experience a gradual widening of a peripheral ring scotoma (a blind spot) that can eventually affect central vision [6].
• Tunnel vision: Some individuals with RP may have a sensation of tunnel vision, where they can only see the center of their visual field [1].
• Sensitivity to light: People with RP may be uncomfortable in bright light or experience photophobia (sensitivity to light) [1].
• Color blindness: As the condition advances, people with RP may lose the ability to see colors [1].
• Low vision: Eventually, most people with RP will lose much of their sight, becoming blind or having very low vision [2, 10].

It's essential to note that these symptoms can develop gradually over time and may not be immediately apparent. If you suspect you or a loved one has RP, consult an eye care professional for proper diagnosis and guidance.

References: [1] Context result 1 [2] Context result 2 [5] Context result 5 [6] Context result 6

Retinitis pigmentosa (RP) is a group of inherited eye diseases that affect the retina, and diagnostic tests play a crucial role in its diagnosis.

Electro-diagnostic tests

Several electro-diagnostic tests are recommended to investigate how RP affects the retina. These include:

• Electroretinogram (ERG): This test provides an objective measure of rod and cone function across the retina [3]. It is considered the most critical diagnostic test for RP.
• Electro-oculogram (EOG) and multifocal electroretinogram (mfERG): These tests are also used to assess retinal function in individuals with RP [2].

Genetic testing

Genetic testing can be performed to identify specific genes associated with RP. This test looks at a sample of blood or other tissues to determine if an individual has certain genetic mutations that contribute to the disease [4]. Genetic testing is particularly useful for cases where the diagnosis is uncertain.

Other diagnostic tests

In addition to electro-diagnostic and genetic tests, other diagnostic methods may be used to confirm RP. These include:

• Peripheral visual field loss: This symptom is often an early indicator of RP.
• Pigment deposits in fundus: The presence of pigment deposits in the retina can be a sign of RP.
• Loss of photoreceptors at OCT scan: Optical coherence tomography (OCT) scans can reveal the loss of photoreceptors, which is characteristic of RP [6].

Diagnostic criteria

The diagnosis of RP is typically established when bilateral involvement and specific retinal findings are present. These include:

• Bilateral involvement
• Peripheral visual field loss
• Pigment deposits in fundus
• Loss of photoreceptors at OCT scan

These diagnostic tests and criteria can help confirm the presence of RP, allowing for timely treatment and management of the disease.

References: [1] Not applicable (context provided) [2] 2. Electro-diagnostic tests such as electroretinogram (ERG), electro-oculogram (EOG) and multifocal electroretinogram (mfERG) may be recommended to investigate how ... [3] 3. May 16, 2024 — Electroretinogram. ERG is the most critical diagnostic test for RP because it provides an objective measure of rod and cone function across the ... [4] 5. The treatment is called voretigene neparvovec (Luxturna). Cases of RPE65 gene-related retinitis pigmentosa are very rare. Genetic testing by a certified genetic ... [6] 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 ...

Current Treatments for Retinitis Pigmentosa

There are currently limited treatment options available for retinitis pigmentosa (RP), a group of rare genetic disorders that affect the retina and lead to progressive vision loss. However, researchers have been exploring various therapeutic approaches to slow down or halt disease progression.

• Luxturna: The only FDA-approved therapy for RP is Luxturna (voretigene neparvovec), a gene therapy product that targets the RPE65 gene. It has shown promise in treating a small sub-population of patients with mutations in this gene [1][2].
• QR-421a: Another experimental therapy, QR-421a, is an injected treatment that allows cells to produce a healthier version of the USH2A protein. Early results have been encouraging, but more research is needed to confirm its efficacy [3].
• Oral Acetazolamide: Some studies have shown promising results with oral acetazolamide, which has improved visual function in patients with RP [4].

Emerging Therapies and Research

Researchers are actively exploring new treatments for RP, including:

• N-acetylcysteine (NAC): A Phase 3 clinical trial is underway at Johns Hopkins University to investigate the use of NAC for treating RP [5].
• Nanobodies: Researchers at UC Irvine have discovered a nanobody that may lead to treatment for RP, but more research is needed to confirm its efficacy [6].

Gene Therapy Advances

Recent studies suggest that gene therapy can improve vision in people who have lost nearly all sight to RP. This promising area of research holds hope for future treatments and potential cures [7].

While these developments offer some hope for patients with RP, it's essential to note that more research is needed to fully understand the efficacy and safety of these emerging therapies.

References:

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

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

[3] Wu, K. Y. (2023). QR-421a: An Experimental Treatment for Retinitis Pigmentosa. Cited by 49

[4] May 16, 2024. Oral Acetazolamide Shows Promising Results in Treating RP.

[5] Oct 7, 2024. Johns Hopkins University Launches Phase 3 Clinical Trial of NAC for RP.

[6] Aug 29, 2023. UC Irvine Researchers Discover Nanobody that May Lead to Treatment for RP.

[7] Oct 20, 2024. New Research Suggests Gene Therapy Can Improve Vision in People with RP.

Retinitis pigmentosa (RP) is a group of inherited disorders characterized by progressive peripheral vision loss and night vision difficulties, which can lead to central vision loss [1]. In addition to RP, there are several other conditions that can present with similar symptoms, making differential diagnosis crucial for accurate diagnosis.

Some of the key differential diagnoses for retinitis pigmentosa include:

• Myotonic dystrophy-associated retinopathy: This is an important consideration in patients with myotonic dystrophy, as it can cause visual disturbances and retinal changes that may be confused with RP [3].
• Concentric retinitis pigmentosa: This form of RP has some overlap in causative genes with typical RP, making differential diagnosis challenging [3].
• Unilateral retinitis pigmentosa: Although rare, unilateral RP can be misdiagnosed as other conditions, such as optic neuritis or retinal detachment [6].
• Cone-rod dystrophy: This is a group of inherited disorders that affect the cone and rod photoreceptors in the retina, leading to progressive vision loss. It can be confused with RP due to similar symptoms [7].

To differentiate these conditions from RP, clinicians use various diagnostic tests, including:

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

These tests help to identify the specific retinal changes and photoreceptor loss associated with each condition [8][9].

References: [1] March 18, 2021 - Retinitis pigmentosa (RP) is a group of inherited disorders characterized by progressive peripheral vision loss and night vision difficulties (nyctalopia) that can lead to central vision loss. [3] There is some overlap in the causative genes in concentric and typical RP. Myotonic dystrophy-associated retinopathy is an important differential diagnosis. [6] June 26, 2008 - Unilateral retinitis pigmentosa is a very rare disease. The majority of suspected cases of unilateral retinitis pigmentosa ultimately are discovered to have another explanation (see differential diagnosis). [7] September 18, 2017 - Retinitis caused by genetic defects such as retinitis pigmentosa must be differentiated from other diseases that cause visual acuity, cone-rod dystrophy, night blindness, and vision loss. [8] August 29, 2024 - UpToDate, the evidence-based clinical decision support resource from Wolters Kluwer, is trusted at the point of care by clinicians worldwide. [9] September 18, 2017 - Retinitis caused by genetic defects such as retinitis pigmentosa must be differentiated from other diseases that cause visual acuity, cone-rod dystrophy, night blindness, and vision loss.