Retinitis Pigmentosa - Night Blindness

Night blindness is a retinal disease. The retina is the mesh layer that allows us to see and can be thought of as the wallpaper that fills the inside of our eyes. Night blindness is a disease that develops when the light-sensing layer of tissue cells in the retina is damaged due to genetic mutations. While it initially causes loss of night vision, it can also lead to loss of daytime vision in later ages. The incidence is known to be 1/3000 to 1/4000.

Night blindness is caused by damage to the cells in the retina. The disease is usually caused by genetic reasons. In addition, consanguineous marriages increase the risk of developing night blindness disease as it increases the likelihood of two recessive genes coming together.

 Difficulty seeing in dim light (at night) (nyctalopia), in progressive stages, difficulty seeing in daylight 

 Narrowing of the visual field

 Specific fundus signs (bone specules, attenuation of retinal arterioles, wax-like optic disc pallor)  

 Electroretinogram findings indicating photoreceptor cell dysfunction in the retina

 Night blindness may be accompanied by eye diseases such as cataracts, edema in the visual center, refractive errors such as myopia -astigmatism, keratoconus and glaucoma.

How is night blindness treated?

The course of the disease varies from patient to patient, even between different members of the same family.

Studies are still ongoing on the definitive treatment of night blindness.

The main aim of the treatment protocol is to slow down the progression of the disease and increase the adaptation of patients to social life.

A daily intake of 15.00 U of vitamin A has been shown to significantly slow the progression of the disease.

The carotenoids lutein and β-carotene have a limited effect on slowing the progression of night blindness.

In advanced stages, when photoreceptors are completely dead, gene therapy is pointless. It is more effective in cases detected at an early stage.

In 2017, the US Food and Drug Administration (FDA) approved voretigene neparvovec -rzyl (Luxturna), a gene therapy used to treat rare inherited blindness. While it is widely described by the media as a 'vision-saving' curative treatment, it is a very costly treatment. It is available for patients with mutations in the RPE65 gene on both chromosomes. Luxturna is given as a single injection under the retina at the back of each eye. Patients receiving this treatment have shown improved night vision, walking and adaptation to obstacles.

Researchers believe that transplanted stem cells can differentiate into retinal cells and integrate into patients' retina, and that differentiated stem cells will replace apoptotic or damaged retinal cells.

In this way, programmed cell death can be manipulated and healthy retinal cell life can be prolonged. Studies on this subject have shown positive results on visual prognosis in night blindness. In our clinic, subtenon PRP application, which contains abundant growth factors and is prepared from the patient's own blood, is performed by us, and its positive contributions on visual level and prognosis have been shown by studies.

Low-dose electrical impulses are sent to the retinal cells and these impulses increase the release of neuroprotective growth factors from the retinal cells. Thanks to these factors, the cells in the retina are protected and vision loss is stopped. The application should be performed once a week.

Blocking the blue light spectrum is recommended to reduce discomfort from light and increase contrast sensitivity, but has not been shown to have an effect on the course of the disease. 

Treatment of concomitant cataract and visual center edema improves the quality and level of vision. 

It emphasizes that it contributes to the stabilization of visual acuity, visual field and visual functions.

Protection from the sun, Mediterranean-type nutrition, walking outdoors for 30 minutes every day, never smoking, avoiding alcohol.

It is applied in very advanced stages of the disease, when vision is very reduced, and can provide silhouette vision through devices surgically implanted in various layers of the eye in order to reveal neural activity by detecting light in the remaining retinal neurons and converting it into electrical stimuli using artificial devices.

In patients with good peripheral vision, telescopic glasses, illuminated magnifiers or magnifiers with cameras respond particularly well to the reading needs of patients.