Retinitis pigmentosa guide

What is retinitis pigmentosa?

Retinitis pigmentosa is a group of rare, genetic eye diseases. All these diseases affect the eye's retina and its light perception. The retina is the nerve layer that lines the back of the eye and is sensitive to light. Retinitis pigmentosa causes cells in the retina to slowly break down, causing a steady loss or deterioration of vision.

Most people are already born with this condition. But the disease may not manifest itself until adolescence. Over time, the symptoms become more noticeable, eventually leading to significant vision loss.

The disease affects about 1 in 4,000 people. Mutations cause it in any of the over 50 genes. But whatever the mutation, the result is irreparable damage to retinal cells.

Diagnostic tests

Symptoms of retinitis pigmentosa usually begin in childhood and involve:

• Problems with night vision.
• Vision problems in dim light.
• Blind spots in peripheral (lateral) vision.

Further, there are symptoms of tripping over objects and problems with bright light. In the future, the death of retinal cells leads to a more significant loss of visual field, visual acuity and colour vision.

Progression is different for all patients. For example, while some adults retain their central vision until age 50, others suffer more severe vision loss decades earlier.

Ophthalmologists can test for retinitis pigmentosa as part of a comprehensive eye exam. The examination is simple and painless - the doctor will give a few eyes drops to dilate the pupil and then check the eyes for retinitis pigmentosa and other eye problems. The tests include a visual field test to check peripheral (lateral) vision.

A deeper ophthalmic examination includes:

• Electroretinography (ERG) allows the ophthalmologist to check how well the retina responds to light.
• Optical coherence tomography (OCT) - this test uses light waves to take a detailed picture of the patient's retina.
• Fundus autofluorescence (FAF) imaging - in this test, the eye doctor uses blue light to take a picture of the retina.
• Genetic testing - allows you to learn more about the type of retinitis pigmentosa, which allows you to predict the further course of the disease.

Treatment methods

There is currently no cure for retinitis pigmentosa. Basically, help to the patient is reduced to symptomatic treatment. In addition, some treatments and lifestyle changes reduce the impact of the disease on the daily life of the patient:

• Regular check-ups at the ophthalmologist - the selection of glasses will help you see better.
• Supplementation – Including vitamin A, fish oil, or lutein helps keep your eyes healthy. However, consult a doctor before taking these supplements, as these supplements may increase your risk of liver disease or other side effects.
• Use of dimmable lighting - using light bulbs or fixtures with dimmable or dimmable lighting control creates a comfortable environment at work and home.
• Using a magnifying device is an aid in reading small print.
• Rearrangement of furniture - the optimal arrangement of furniture at home and work helps to obtain clean and vast spaces, significantly reducing the risk of collision with objects and preventing injury.

New treatments options

Research is currently being funded into retinitis pigmentosa to prevent the disease, treat it, and prevent vision loss. Although, to date, this can be considered an experimental treatment for retinitis pigmentosa, shortly, these are standard treatments:

• Restorative therapy is a multidisciplinary approach that combines the sciences of ophthalmology and neurology. In restorative therapy, positive results are achieved by applying weak electrical current pulses that stimulate partially damaged retinal nerve cells and improve the conduction of signals to the brain. Electrical stimulation increases the overall activity of the visual system and leads to functional recovery. The uniqueness of restorative therapy is that it is a non-surgical method performed by non-invasive electrical stimulation of various retinal cells (cones, rods, ganglion cells). The therapy does not replace damaged cells. However, it increases the functionality of the remaining ones.
• Stem cell treatment - the therapy involves the injection of retinal progenitor cells - stem cells that are in the process of becoming retinal cells. Donor stem cells or patient' ', obtained from the bone marrow or adipose tissue, are used. Stem cells generate proteins that maintain the patient's healthy cells and prevent their degeneration, thereby saving vision. The procedure is almost painless because it is performed under local anaesthesia—low chance of complications.
• Gene therapy is a method of treating diseases by correcting defective DNA in patients. The genetic analysis concludes mutations in specific genes that cause retinitis pigmentosa. Healthy copies of the gene are then delivered to the retina via an eye injection. Patients treated with this treatment experienced a significant improvement in the visual field, light sensitivity, and ability to navigate in a dark room.
• The bionic retina is implanted in the retina and attached to a video camera built into the glasses. The camera converts the images into electrical impulses that activate the remaining retinal cells. That is, the system bypasses faulty cells, stimulating capable ones. Electrical signals enter the brain, and the brain perceives them as a complete picture.

Statistics and prognosis

Retinitis pigmentosa is the most common retinal degeneration that leads to blindness. The disease develops over decades and leads a person to disability and hence to limitations—people with retinitis pigmentosa experience many quality of life problems.

From 2012 to 2020, Retina Australia conducted a global study of ophthalmic patients. Pigmentary retinitis was diagnosed in 1% of patients. A slight deterioration in central visual acuity or its absence was observed in 34.3%, signs of retinal damage - in 44.4%, followed by blindness - in 21.3%.

According to AiroMedical's analytics, most patients with retinitis pigmentosa severely decrease visual acuity in the third decade of life. Consequently, more than half of patients may be potential candidates for new treatments. Timely access to specialists is crucial for planning and choosing the upcoming treatment.

References:

1. Springer Nature Limited: Seeing through their eyes: lived experiences of people with retinitis pigmentosa
2. The University of Sydney: Bionic eye study progresses through trials
3. Foundation Fighting Blindness: Stem-Cell Therapy for Retinitis Pigmentosa Safe Thus Far in Early Human Study
4. The Johns Hopkins University: Retinitis Pigmentosa
5. American Academy of Ophthalmology: New Treatments for Retinitis Pigmentosa
6. NIH: At a glance: Retinitis Pigmentosa