Retinitis pigmentosa (RP) is one of a group of rare, progressive inherited retinal diseases (IRDs) that can cause severe vision loss and eventual blindness. Individual IRDs are caused by at least one dysfunctional gene. IRDs affect people of all ages, manifests as various types of damage to the retina (a light-sensitive layer of tissue at the back of the eye), and can progress at different rates in different people, even within the same family.

The term RP itself covers several disease variants that cause the breakdown of retinal cells over time. The condition affects about 100,000 people in the U.S.. Symptoms generally start appearing in childhood or adolescence, and most people with RP are considered legally blind before the age of 50.

The loss of night vision, and difficulty navigating in dim lighting, is one of the earliest symptoms of RP, along with blind spots in your peripheral (side) vision. Not being able to see objects out of the corners of your eyes may lead you to bump into things or trip over objects that are right in front of you. Over time, your field of vision narrows until you only have a small amount of central, or forward, vision, also referred to as “tunnel vision”.

Other symptoms of RP often include eventual loss of color vision, and severe sensitivity to bright light. 

RP is primarily caused by genetic mutations passed from parent to child through one of three genetic inheritance patterns: autosomal recessive, autosomal dominant, or X-linked. 

Autosomal recessive. Both parents carry one mutated gene and one normal gene and have no symptoms themselves. In these cases, the parents are called unaffected carriers. Each of their children has a 25% chance of being affected. A child who inherits a mutated gene from only one parent will be an unaffected carrier.

Autosomal dominant. Only one parent is usually affected and is the only parent with a mutated copy of the gene. A child has a 50% chance of being affected by inheriting the mutated gene. The role the genes of the unaffected parent play in disease inheritance is unclear.

X-linked. The mutated gene is located on the X chromosome. Females have two X chromosomes and can carry the disease gene on one X chromosome. Women who are carriers are less commonly affected than male carriers but have a greater chance of passing that mutation to both their daughters and sons. Men won’t pass an X-linked disease to a male child.

(The way people with RP sees can vary depending on the stage and severity of the disease. Over time, some people with RP experience a gradual loss of peripheral (side) vision. This leads to “tunnel vision,” where the central vision remains, but the peripheral vision narrows. Image from Shutterstock)

People with retinitis pigmentosa (RP) experience progressive vision loss due to the degeneration of the retina, the light-sensitive tissue at the back of the eye. The way they see can vary depending on the stage and severity of the disease. Here are some common visual symptoms and how they affect vision:

1. Night Blindness (Nyctalopia): Difficulty seeing in low light or darkness is often one of the first symptoms of RP. People with RP may struggle to navigate in dimly lit environments, such as at dusk or in poorly lit rooms.
2. Loss of Peripheral Vision (Tunnel Vision): Over time, RP often causes a gradual loss of peripheral (side) vision. This leads to “tunnel vision,” where the central vision remains, but the peripheral vision narrows. Individuals may not see objects or people outside their direct line of sight, making activities like driving or walking in crowded places challenging.
3. Blurred or Distorted Vision: As RP progresses, vision may become blurry or distorted. This can make it difficult to read, recognize faces, or perform tasks that require detailed vision.
4. Loss of Central Vision: In the advanced stages of RP, central vision can also be affected. This central vision loss can make it hard to perform activities that require fine detail, such as reading or recognizing faces, even though some peripheral vision might still remain.
5. Photophobia: Increased sensitivity to light (photophobia) is common. Bright lights can cause discomfort or glare, making it hard to see in bright environments.
6. Difficulty with Color Vision: Some people with RP may experience changes in color vision, finding it harder to distinguish between different colors.

These symptoms can vary widely among individuals with RP. Some may retain a degree of functional vision for many years, while others may experience rapid progression of the disease. Adaptive strategies, assistive technologies, and visual aids can help people with RP manage their daily activities and maintain their quality of life.

Eye doctors diagnose RP using a comprehensive eye exam that involves dilating your pupils, conducting a chart test, taking retinal photographs, and assessing your field of vision. These  are all painless and non-invasive. 

Other tests that may be performed to determine and confirm an RP diagnosis include:

• Electroretinography,
• ­Optical coherence tomography (OCT),
• Autofluorescence imaging, and 
• Genetic testing.

Since there are more than 100 genes that can contribute to the development of RP, there is no single therapy that treats all cases of it. Assessing your symptoms and accurately identifying which gene is causing your particular case of RP can help you and your ophthalmologist determine which treatments and/or support aids and services may be most useful to you.

Research is ongoing to develop therapies to treat the various forms of RP. Here are some existing treatment options, along with just a few of the experimental therapies being explored.

Current Treatments

Current medical treatments available to help manage specific symptoms of RP include:

• Medicated eye drops or oral medications to reduce retinal swelling
• Cataract surgery for patients whose eye lens become clouded by protein deposits
• An artificial retina (the ARGUS II implant) for people with severe RP-related vision loss
• Gene therapy, in the form of injection during eye surgery to at least partially correct a defect in a specific RP-related gene [OE5] [YS6] 

Certain dietary supplements such as fish oil, lutein, and vitamin A have also been shown to help slow vision, but taking too much can be dangerous. Excessive vitamin A, for instance, can potentially harm your liver and worsen certain eye conditions.

The Need for New Solutions

Chronic, progressive vision loss can significantly impact a person’s ability to:

• Complete basic daily tasks, 
• Maintain employment and
• Live independently.

According to the American Academy of Ophthalmology, the available treatments help only a fraction of the estimated 100,000 Americans living with RP and more than a million people worldwide. This is due to both effectiveness and accessibility.

The one treatment with some curative properties, the gene therapy using voretigene neparvovec (Luxturna®), costs approximately $850,000 per injection, making it available to only 1–6% of patients.

This is why new, innovative, and widely accessible therapies are necessary.

Upcoming Innovations

Just a few of the other potential treatments for RP currently being investigated around the world include:

• Optogenetic therapies
• Photoswitch therapy
• XLRP gene therapy
• RP gene therapy
• Oral antioxidant therapy
• Protein therapy
• NR2E3 gene therapy
• RNA therapy
• Drug therapy

Clinical trials are key to finding preventions, treatments, and cures for both chronic and acute conditions. Participating in clinical trials empowers you to:

• Receive tests and medical care before and during the trial period,
• Obtain information about support groups and other resources,
• Play a significant role on behalf of existing and future patients and
• Play a more active role in your own healthcare.

Managing daily life with RP can be challenging, but with the right strategies, you can maintain independence and improve your quality of life. Here are some daily management tips to help navigate the challenges of RP.

Daily Management Tips

Maximize Use of Your Remaining Vision

• Lighting. Ensure your living spaces are well-lit. Use adjustable lamps and task lighting to focus on specific activities.
• Contrast. Increase contrast in your environment. For example, use white plates on a dark tablecloth or brightly colored tape on stairs.
• Magnification. Utilize magnifying glasses, large-print books, and devices with screen magnifiers to read and perform detailed tasks.

Organize Your Environment

• Declutter. Keep your living and working spaces organized and free of unnecessary clutter to prevent tripping and falling.
• Consistent placement. Always place items in the same location. This helps you find them easily and reduces frustration.
• Labeling. Use tactile labels or high-contrast labels to identify objects, especially in the kitchen and bathroom.

Use Assistive Technology

• Screen readers. Invest in screen readers or text-to-speech software for computers and smartphones.
• Navigational aids. GPS-based apps and talking maps can assist in navigating both familiar and unfamiliar areas.
• Smart home devices. Voice-controlled devices can help manage tasks such as setting reminders, turning on lights, or adjusting thermostats.

Safety Precautions

• Night vision aids. Wear hats with brims and use sunglasses or photochromic lenses to reduce glare and improve vision in varying light conditions.
• Home modifications. Install handrails, grab bars, and non-slip mats in key areas like the bathroom and stairs.
• Emergency preparedness. Keep a flashlight and a phone with large buttons or voice-activated dialing close by.

Healthy Lifestyle

• Regular eye exams. Regular check-ups with your ophthalmologist can monitor the progression of RP and keep you updated about new treatments.
• Balanced diet. Eat a diet rich in vitamins and nutrients that support eye health, such as leafy greens, fish, and nuts.
• Exercise. Engage in regular physical activity to maintain overall health and well-being. Adapt exercises to suit your vision needs.

Emotional Support

• Join support groups. Connect with others who have RP. Sharing experiences and tips can be comforting and empowering.
• Counseling. Consider counseling or therapy to manage the emotional impact of progressive vision loss.
• Highlight your abilities and triumphs. Focus on what you can do rather than what you can’t. Celebrate small victories and maintain a positive outlook.

Support Resources

Though RP is a rare disease, there is actually a wide array of resources available to help people with low vision and blindness. These range from low-vision counselors who can help you find assistive devices, recommend adjustments for your home and workspace and connect you with rehabilitation services and vocational retraining. 

Some online organizational resources include:

•   https://nfb.org/resources/braille-resources
•   https://www.ncsab.org
•   https://visionservealliance.org/vision-loss-resources/lost-your-vision/
•   https://www.asharedvision.com (for genetic testing)
•   https://lowvision.preventblindness.org 

Guide dog services in the U.S. can be found through:

•   https://www.guidedogsofamerica.org, and
•   https://www.guidedog.org.

Living with RP requires adjustments and proactive management, but it doesn’t have to mean giving up your independence or quality of life. By adopting these daily management tips and leveraging available resources, you can navigate the challenges of RP with greater ease and confidence.

Despite the rare and highly specialized nature of retinitis pigmentosa (RP), there are quite a few myths and misconceptions floating around about it. Understanding the truth about RP can help you and your loved ones navigate its challenges. Read on as we set the record straight.

Myth 1: Retinitis pigmentosa is a single disease

Fact: Retinitis pigmentosa is not a single disease but rather a group of inherited disorders. These disorders share similar characteristics, such as the progressive degeneration of the retina, but they can vary significantly in terms of

•     Severity,
•     Age of onset, and
•     Rate of progression.

RP can be caused by mutations in over 100 different genes, leading to a wide range of symptoms and experiences.

Myth 2: RP causes total blindness quickly

Fact: While retinitis pigmentosa does lead to progressive vision loss, the rate of degeneration can vary widely among individuals. Some people may retain partial vision well into adulthood, while others may experience more rapid progression. Total blindness is not guaranteed for everyone with RP. Many individuals maintain some degree of vision for many years.

Myth 3: RP only affects peripheral vision

Fact: RP typically begins with the loss of peripheral vision, often leading to “tunnel vision,” but can also affect central vision as the disease progresses. Night blindness and difficulty adjusting to low light are common early symptoms. Over time, individuals may experience a reduction in central vision, impacting activities such as reading and recognizing faces.

Myth 4: There is no hope for treatment

Fact: While there is currently no cure for retinitis pigmentosa, there are promising treatments and ongoing research aimed at managing the condition. Gene therapy, retinal implants, and stem cell therapy are just some of the areas being explored. As we mentioned in an earlier email, vitamin A supplementation has been shown to slow the progression of certain forms of RP. Regular check-ups with your retinal specialist can help you stay informed about the latest advancements, treatment options, and clinical trial opportunities.

Myth 5: People with RP can’t lead independent lives

Fact: Many people with retinitis pigmentosa lead independent and fulfilling lives. With the help of adaptive technologies, mobility training, and support networks, individuals with RP can pursue careers, hobbies, and social activities. Tools such as screen readers, magnification devices, and orientation and mobility training enable people with RP to navigate their environments and maintain their independence.

References:

• American Academy of Ophthalmology (AAO): https://www.aao.org/eye-health/diseases/what-is-retinitis-pigmentosa
• National Eye Institute (NEI): https://www.nei.nih.gov/learn-about-eye-health/eye-conditions-and-diseases/retinitis-pigmentosa
• Foundation Fighting Blindness: https://www.fightingblindness.org/diseases/retinitis-pigmentosa
• American Optometric Association (AOA): https://www.aoa.org/healthy-eyes/eye-and-vision-conditions/retinitis-pigmentosa?sso=y
• Mayo Clinic: https://www.mayoclinic.org/medical-professionals/ophthalmology/news/diagnosis-clinical-trials-and-treatments-for-inherited-retinal-diseases/mac-20556115
• MedlinePlus (National Library of Medicine): https://medlineplus.gov/ency/article/001029.htm
• National Organization for Rare Disorders (NORD): https://rarediseases.org/rare-diseases/retinitis-pigmentosa/