What is Retinitis Pigmentosa?
Retinitis pigmentosa is a genetic disorder that affects the photoreceptors layer of the retina specifically the rod photoreceptors and later on the involvement of the cones and causing its degeneration. It causes a gradual reduction in vision and eventually leads to blindness. It is also considered the most common hereditary fundus dystrophy. There is no permanent retinitis pigmentosa treatment however research is made to alleviate the symptoms and improve the lifestyle of the patients. The retinitis pigmentosa treatment is one of the challenges for recent science because the lost photoreceptors cannot be regenerated. The article will discuss inheritance patterns, causes, signs and symptoms, ocular complications, and syndromes associated with retinitis pigmentosa treatment options.
Retinitis Pigmentosa ICD 10
What is the ICD 10 code for retinitis pigmentosa?
It is the international coding used for different diseases. The ICD 10 code for retinitis pigmentosa is H35.52. It is important for documentation purposes of this disease.
What is the inheritance pattern of retinitis pigmentosa?
Retinitis pigmentosa can occur as a sporadic condition however autosomal dominance, autosomal recessive, and X-linked recessive inheritance patterns are also labeled. The sporadic cases occurring without a previous genetical history have a very favorable outcome. Autosomal dominant inheritance has the best prognosis. However, X-linked recessive inheritance, which is the least common inheritance pattern, has the worst prognosis. It is also believed that certain drugs may also be associated with causing retinitis pigmentosa, examples include quinine and phenothiazine.
CAUSES, SIGNS, AND SYMPTOMS
Retinitis Pigmentosa Causes
What are the causes of retinitis pigmentosa?
One of the most commonly established causes of retinitis pigmentosa includes the allelic variation or mutation of the rhodopsin gene that leads to the expression of the mutagenic gene and the phenotype of the disease.
Retinitis Pigmentosa Symptoms
What are the symptoms of retinitis pigmentosa?
- Nyctalopia: The most common symptom of retinitis pigmentosa is nyctalopia or night blindness. It is the first symptom observed by the patient. Other associated symptoms include
- Reduced peripheral vision and central vision may also be involved but in later stages. The reduced vision is usually labeled as “tunnel vision” to signify the peripheral visual field defect.
- Reduced color vision
Retinitis pigmentosa signs
What are the signs of retinitis pigmentosa?
The signs of retinitis pigmentosa include
- Contrast sensitivity: Visual acuity in retinitis pigmentosa may be normal however contrast sensitivity will be markedly reduced in the initial stages.
- Bone spicules retinal pigmentation: Bilateral and peripheral perivascular pigmentation may signify bone spicules.
- Disc pallor: The disc in RP appears as waxy in color labeled as “waxy disc pallor”
- Tessellated fundus: There is a gradual increase in pigmentation in the peripheral retina encroaching centrally. The unmasking of the choroidal vessels gives the tessellated fundus appearance.
- Arteriolar attenuation:
- Myopia: It is a common complaint in retinitis pigmentosa patients
- ERM: Epiretinal membrane formation is common in retinitis pigmentosa
- Cystoid macular edema
- Disc drusen occur more frequently in RP patients.
OCULAR COMPLICATIONS OF RETINITIS PIGMENTOSA
What are the ocular complications of retinitis pigmentosa?
Common ocular complications of retinitis pigmentosa include
- Posterior subcapsular cataract (most common)
- Open-angle glaucoma
- Intermediate uveitis
- Posterior vitreous detachment
- Exudative retinal detachment
SYNDROMES ASSOCIATED WITH RETINITIS PIGMENTOSA
What are the different types of syndromes associated with retinitis pigmentosa?
ATYPICAL RETINITIS PIGMINTOSA
The term atypical retinitis pigmentosa is used to combine a group of diseases having features common with typical retinitis pigmentosa. These include
Syndromic RP or atypical RP associated with systemic diseases
- Usher syndrome: It is an autosomal recessive disorder. The most common feature is deafness in children. Half of the cases have combined blindness and deafness.
- Kearns Sayre syndrome: It has a mitochondrial inheritance pattern and is characterized by CPEO (chronic progressive external ophthalmoplegia) with ptosis and cardiac problems. The fundus shows a typical appearance of salt and pepper retinopathy.
- Bassen Kornzweig syndrome: It is also known as abetalipoproteinemia. It is an autosomal recessive disorder. The disease is associated with dysfunction of fat- and fat-soluble vitamins D, E, A, and K. In children, there is failure to thrive and associated spinocerebellar ataxia.
- Refsum disease: It is an autosomal recessive disorder. It is a genetic condition associated with abnormal accumulation of phytanic acid accumulation in different regions of the body. It manifests as changes in skin such as skin thickening and other neurological and visceral changes. The fundus gives a salt and pepper appearance.
- Bardet Biedl syndrome: It is a genetically heterogenous entity and is associated with polydactyly, mental handicap and bulls-eye maculopathy.
DIAGNOSIS AND TESTS
How is retinitis pigmentosa diagnosis made?
The diagnosis of retinitis pigmentosa includes detailed ophthalmic examination by an ophthalmologist, followed by a series of investigations as followed
- Visual equity: Most of the patients have normal visual acuity in the initial stages however in advanced cases marked reduction in visual acuity will be observed.
- Contrast sensitivity: It is markedly decreased even in the initial stages of the disease.
- Perimetry: Initially perimetry signifies mid-peripheral changes in the visual field.
- Dark adaptation: It is prolonged in retinitis pigmentosa
- Full Field Electroretinography: It is one of the most sensitive tests for RP. It shows reduces scotopic rod and combined responses. The photopic response is reduced with the progression of the disease and in advanced cases ERG diminishes.
- Electrooculography: It is subnormal in RP
- Optical coherence tomography: OCT is used to identify the complications such as cystoid macular edema and epiretinal membrane formation.
- Genetic testing for Retinitis Pigmentosa: Genetical testing is a procedure to recognize the diseased gene in a particular person. It is useful in persons with a family history of retinitis pigmentosa. It helps in early recognition of the disease and to control the disease progression. It is also important in stopping the further transfer of the gene in the children by avoiding family marriages.
MANAGEMENT AND TREATMENT
Retinitis Pigmentosa Treatment
Current Treatment Options for Retinitis Pigmentosa
There is no retinitis pigmentosa treatment for permanent eradication of the disease, however, some medications and steps can be taken to control the progression and improve the lifestyle of the affected person and to avoid genetic transfer of the disease.
Regular follow-up: Regular check by ophthalmologist is crucial in the early detection of vision-treating diseases and their time management.
Gene therapy for retinitis pigmentosa:
Gene therapy is a recent advancement in dealing with retinitis pigmentosa. It consists of replacing the mutant gene with a normal gene. A normal cell is implanted into the retinal photoreceptors.
In 2017, the US Food and Drug Administration (FDA) approved the first gene therapy for an inherited retinal disease, Luxturna, which is used to treat RP caused by mutations in the RPE65 gene. The therapy involves injecting a viral vector carrying a functional copy of the RPE65 gene into the retina’s cells, restoring their ability to produce the necessary protein for vision.
One study was conducted successfully to treat dogs with RP caused by mutations in the PDE6B gene. The visual outcome was almost at the normal level.
Gene therapy for RP is still a relatively new field, and there are some challenges to overcome.
- CMO treatment: Cystoid macular edema in retinitis pigmentosa treatment with oral acetazolamide and sometimes topical carbonic anhydrous inhibitors can be used.
- High-dose vitamin A supplementation: palmitate of 15000 units per day is the standard dose of the therapy. Great care should be taken to avoid the adverse effects of vitamin A which includes lung cancer and hepatotoxicity. A person on vitamin A therapy should be closely monitored with blood tests and liver functions tests. It should not be used in pregnancy and ABCA4 gene mutations.
- Other drugs: Some other drugs such as calcium channel blockers have shown some promising benefits but the researchers are still going on to challenge the efficacy level of these drugs.
- Retinotoxic drugs: Retinotoxic drugs should be avoided in patients with retinitis pigmentosa. These include erectile dysfunction drugs, retinoids, isotretinoin, phenothiazine, and tamoxifen.
- Low vision aids: Patients with poor vision can use certain methods to aid in vision-dependent functions in daily life. These include the use of magnifying glasses, computer-based software, etc.
- Retinal prosthesis: Retinal prosthesis is a modality of treatment for severe vision loss. The technology is still under study
Advances in Retinitis Pigmentosa Treatment 2022
New research is going on for new treatment strategies for retinitis pigmentosa. The future prospects for retinitis pigmentosa and advances in retinitis pigmentosa treatment 2022 include the following options
- Retinal gene therapy: It consists of replacing the mutant gene with a donor normal gene at the level of retinal photoreceptors.
- Stem cell therapy: In this therapy, the transplanted cells are used as a replacement for degenerated cells. it is also postulated to increase the release of certain growth factors to enhance cell growth and function.
- CRISPR gene editing: It is considered a cheap procedure in which the genome of the living organism is modified.
- Neuroprotection therapy: Neuroprotection therapy aims to preserve and protect retinal cells from further damage in RP. This approach involves the use of pharmacological agents or lifestyle modifications to promote cell survival and reduce degeneration.
Retinitis pigmentosa is a genetic condition and no permanent treatment is developed so far. However, there are a few steps that can be followed to slow down the disease progression. These include
- Know your family history: As retinitis pigmentosa is a genetic condition, it is important to know your family history. The early you know, the better the progression control of the disease.
- Regular eye examination: It is crucial to have a regular examination by the ophthalmologist to know the ongoing disease condition. Any disease should be spotted well on time and treated accordingly for example if a patient develops a cataract. Early treatment has a good outcome on vision.
- Eye protection: Any patient with retinitis pigmentosa should take special care of the eyes by using a protective shield, especially during working hours. The profession should be chosen according to the patient’s eye condition. Any trivial injury can cause great loss to the eye.
- Sunglasses: Sunglasses should be used regularly by patients with retinitis pigmentosa. Yellow-tinted glasses have a protective role as well as giving a better view.
- Healthy food: Retina being a part of the human body needs good nourishment. A diet rich in antioxidants such as green leafy vegetables has a protective role.
- Quit smoking: smoking is known to be one of the risk factors for the progression of retinitis pigmentosa.
- Control of other diseases: other diseases having a direct or indirect impact on the retina should be promptly treated. These include hypertension, diabetes, cancers, etc. These diseases will add up to the already compromised eye.
Retinitis pigmentosa is a vision-threatening condition, however, the progression of the visual field loss can be reduced with medications and seeking regular checkups by the health care provider. People with retinitis pigmentosa need to learn living by their own and take certain steps to avoid major setbacks.
- Lifestyle modification: Patients with retinitis pigmentosa have problems with color vision and visual field, so inside the house should be properly managed to avoid any type of injuries for example making the house roomier, allowing light to enter the house, proper exposure of lights and installing bright colored lights. Furniture should be set in such a way as to avoid falls. The paint of the house should be made in such a way as to provide better contrast sensitivity.
- Going out alone: If a person with retinitis pigmentosa is living alone, then proper modifications should be made while going out. The person should be aware of the peripheral visual field loss. Special care should be taken to cross the roads. The use of a cane should be encouraged to avoid any falls and injury. The directions of the shops and neighborhood must be remembered properly. In case of weak memory written notes should be kept all the time and a hand band or necklace with a complete address should be worn all the time.
- Social welfare groups: It is important for persons with retinitis pigmentosa to seek help from social welfare groups. It includes having a helping hand while going out to shops or traveling. Besides that, their help should be taken to ensure regular follow-ups with the health professional.
- Support groups: Patients of retinitis pigmentosa should be encouraged to join the support groups. It will help them to grow psychologically and to share their feelings with people having the same problems. This will help in a healthy mental condition and avoid mental health conditions such as anxiety and depression.
- Software’s and other technologies: The new technology provides gadgets for persons with RP, these include magnifying glasses, screen readers, wristwatches with back lights (for use at night), mobile navigation to help find the destination, etc.
- Monetary help: Patients with retinitis pigmentosa can work like normal persons however in advanced diseases it is not possible to work normally. For this purpose, help should be taken by the welfare societies and government plans should be seek for disabled persons.
OUTLOOK / PROGNOSIS:
Retinitis pigmentosa being a genetical condition has a direct impact on vision however in this era retinitis pigmentosa treatment has led to better visual outcomes. It is not necessary that the person will become completely blind in his lifetime unless a certain protective measure is taken well on time. Special care should be taken by patients with retinitis pigmentosa such as regular checkups, protective shields and glasses use, a healthy diet, and avoid smoking. Eating a healthy diet and taking multivitamins regularly can have a dramatic impact.
People affected with retinitis pigmentosa can follow the new advances in retinitis pigmentosa treatment 2022. However, researches are still going on in this field. A person with advanced disease can seek treatment options like gene therapy, stem cell therapy, and neuroprotective therapy.
Can RP be cured?
It is not possible to cure retinitis pigmentosa completely, however measures should be taken to avoid the depilating condition. For this purpose, regular checkup by the health professional is crucial.
What are the treatment options for RP?
The treatment options for RP includes a regular checkup by the ophthalmologist to notify the ongoing complications associated with the disease and treat it accordingly. It includes using vitamin A supplementation, cataract extraction, treatment of cystoid macular edema, retinal implants, prosthesis, and avoiding retinotoxic drugs.
What are some of the latest advances in RP treatment?
The latest treatment options for RP include
Retinal gene therapy, Stem cell therapy, CRISPR gene editing, Neuroprotection therapy.
Is there hope for retinitis pigmentosa?
The patients will retinitis pigmentosa may have good vision throughout the life unless associated with complications. However timely recognition and treatment of any complication is important.
Are there glasses for retinitis pigmentosa?
Glasses can be used for the refractive error in retinitis pigmentosa patient. The most common refractive is myopia however astigmatism also common as keratoconus can be the associated ocular problem.
How soon will there be a cure for retinitis pigmentosa?
The treatment options for retinitis pigmentosa are still under study but the scientists are not sure about the final cure and outcome of the latest options.
- National Eye Institute. (2022). Facts about retinitis pigmentosa. Retrieved from https://www.nei.nih.gov/learn-about-eye-health/eye-conditions-and-diseases/retinitis-pigmentosa
- Sahel, J. A., Marazova, K., & Audo, I. (2021). Clinical characteristics and current therapies for inherited retinal degenerations. Cold Spring Harbor perspectives in medicine, 11(9), a038710.
- Bennett, J., & Maguire, A. M. (2020). Gene therapy for retinal disorders. Eye, 34(4), 689-693.
- Lopes, V. S., & Williams, D. S. (2020). Gene therapy for inherited retinal diseases: the state of the art. Human Gene Therapy, 31(11-12), 595-608.