Recapping the Retinitis Pigmentosa

As unfortunate as it is, it is as true; with a few retinitis pigmentosa treatment options available in the market, currently the disease still lacks a viable cure.

(You can learn more about retinitis pigmentosa treatment options reading the article: Retinitis Pigmentosa – The Disease and Some Viable Treatment Options)

To have a better understanding regarding the cure of retinitis pigmentosa (RP), I find it quite imperative to recap the disease for you before going any further.

Frans Cornelis Donders, a renowned Dutch vision specialist, is credited for coining the term ‘Retinitis Pigmentosa’ in the middle 19th century.

He came up with these words to describe the appearance of the retinas of a specific group of people suffering from vision loss, whereby the term ‘retinitis’ implies the inflammation of the retina, which is in fact, somewhat misleading. Why? Because RP is not caused by inflammation of the eye, but it’s more of an inherited, gradual degeneration of the retina, whereas ‘pigmentosa’ attributes to the distinctive pigment clumping observed in many forms of the disease.

Currently, the term retinitis pigmentosa is commonly used to refer to a group of related eye disorders responsible of inducing progressive vision loss in the patients.

Retina, a layer constituted of the light-sensitive tissues lining the back of the eye, takes the brunt of this eye disease. This tends to be gradual process, where loss of vision occurs due to eventual deterioration of the light sensing cells of the retina.

RP initially starts affecting the patients through childhood, loss of night vision turning out to be one of its first signs, hampering the ability of the victims to navigate in low light conditions.

Later on, blind spots start developing in the peripheral vision, leading to peripheral vision loss. With the passage of time, these blind spots fuse together producing tunnel vision, restricting the visual field of a person. (You can learn more about tunnel vision here).

Central vision is the last area to be affected by retinitis pigmentosa taking years or even decades to develop sometimes, ultimately damaging your ability to perform detail-oriented tasks, such as reading, sewing, driving or the worst of all, recognizing faces. Many people suffering from RP end up as legally blind.

This disease is referred as ‘nonsyndromic’ when it occurs by itself and researchers have been able to identify various major types of nonsyndromic retinitis pigmentosa. These types are usually differentiated based on their respective inheritance pattern, i.e. autosomal dominant, autosomal recessive and X-linked.

Retinitis pigmentosa can also occur as part of syndromes that primarily affect other body organs and tissues, referred as ‘syndromic’ under such circumstances. Usher syndrome can be presented as one of the most common examples of syndromic retinitis pigmentosa, characterized by combination of hearing loss and vision loss taking effect during the early years of life.

Retinitis pigmentosa is known to affect its victims mostly during early childhood, affecting both eyes generally, and disturbing night vision with the possibility of narrowing down of field of vision as well.

Rods, the light sensing cells of the retina helpful for viewing in dim light, are the first one to take the brunt of RP, and their gradual deterioration leads to difficulty in seeing at night.

Expected Retinitis Pigmentosa Cure

The cure of retinitis pigmentosa, or other degenerative eye diseases for that matter, has always been a challenge, but it looks like the perseverance of researchers will finally come to fruition very soon. Thanks to the development of an ‘organ-on-a-chip’ type device to tackle the complex functionalities of ‘blood-retina barrier‘, researchers might have come closer than ever to develop a cure for RP.

Research scientists associated with the ‘Microelectronics Institute of Barcelona’, Universitat Autònoma de Barcelona and Vall d’Hebron Research Institute have successfully developed a ‘microfluidic chip’ capable of mimicking the complex human ‘blood-retina barrier’ of the eye. A recently published study elaborates on the fine details of how the device successfully does the job.

The layered natural structure of the retina is recreated in the device with the help of several compartments paralleled together. Each compartment contains a specifically grown cell type, thus replicating various layers naturally existing in the retina as closely as possible. For instance, capillaries are represented with endothelial cells, neuroretina are represented with neurons, whereas device’s external blood barrier is replicated with retinal pigmented epithelial cells (RPE).

These new advances with this device are based on a device previously developed and produced by Villa’s team aimed at emulating the blood-brain barrier. The development of these devices is expected to lead towards reduced animal testing and rapidly proceeding with the research and clinical trials for eye diseases like retinitis pigmentosa and diabetic retinopathy.

Gene therapy has also come up as a viable method of correcting gene mutations resulting in retinitis pigmentosa, and a number of biotechs have taken keen interest in advancing in this domain. For example, ‘Horama’ has done considerable work in development of gene therapy targeting the ‘PDE6β gene’. Similarly, ‘NightstaRx’ are working towards correcting the ‘RPGR gene’. Moreover, ‘GenSight’ have also shown significant progress by combining gene therapy with wearable device, specifically designed and developed to treat pigmentosa caused by 1 of up to 100 varying mutations.

Conclusion

Regular eye exam remain one of the best ways to make sure your eyes stay healthy and functional for as long as possible. Retinitis pigmentosa and many other eye diseases result in gradual deterioration of retinal cells and an early diagnosis helps you take preventive measures as soon as possible, significantly slowing down the deterioration.

The rapid progress geared towards innovative cures for retinitis pigmentosa and other degenerative eye diseases is surely a sigh of relief for scores of people suffering from such eye problems. Moreover, there are also some viable low vision aids like IrisVision, a wearable low vision solution designed to help you make the most of your leftover vision.

So, the future looks quite bright for some viable cures for diseases like retinitis pigmentosa, while low vision aids and other rehabilitative and assistive technologies help you live as independently as possible.