Rare Diseases of the Retina: Present and Future


"The look is the mirror of the soul," dictates a popular saying, or "the eyes confess in silence the secrets of the heart," says another poetic phrase of St. Jerome. But there is much more: the eyes, with careful clinical analysis, often reflect a person's state of health or illness. The ophthalmologist can easily see, with clinical observation, the anterior segment of the eye, changes in colour of the retina, abnormalities in the shape or path of arterioles and venules, lesions that are part of general diseases and even primary intraocular tumours or related to a cancer of extraocular localization.

 What do we know today?

The retina is a highly specialized tissue with a very complex internal structure composed of multiple interconnected cell types. Light, after passing through the cornea and the inside of the eyeball, affects the photoreceptors of the retina (cones and canes) triggering a series of chemical and electrical phenomena, which finally translate into nerve impulses that are sent to the brain through the optic nerve. This complex anatomy can be altered by common processes (retinal detachment, degenerative diseases related to myopia or age, trauma and vascular lesions associated with hypertension or diabetes mellitus, to cite a few examples). Either of these situations is relatively easy to diagnose and can be approached with different treatment options that should be appropriately indicated in each case. Undoubtedly, in recent years, both the pharmaceutical industry as well as the technological and the new surgical instrumentation have collaborated very well in the progress of the treatment and the prognosis of these more common diseases. However, there are more unfortunate cases, because they present with a much lower incidence, their diagnosis is more difficult, they often require a highly specialized medical care - available only in reference centers - and often are intractable situations: they are rare diseases. This complex group includes congenital retinal malformations (uni or bilateral), heredodegenerative diseases and retinal dystrophies - which always affect both eyes - ocular manifestations of general illnesses - inflammation, metabolic disorders, neurological diseases , Mucopolysaccharidosis, blood dyscrasias, skin diseases, rheumatic diseases-, intraocular tumors and also retinopathies that appear due to toxicity of generally administered drugs, such as chloroquine.

Available Treatments

The current approach to these diseases is based on making a correct diagnosis, which is not always easy, and then assess which is the best medical or surgical option. For this, it is essential to have a well-prepared medical team, multidisciplinary, with a technical and human support of the first level to be able to carry out the assessment of the case, complementary tests and the most appropriate therapy. A correct diagnosis also allows the possibility of being able to inform the long-term prognosis and, possibly, in the case of a disease with a genetic component, to recommend the clinical study of the relatives. In many ways, the surprising progress that molecular biology and genetics have played in the last decade - and whose most visible result is the decoding of the human genome, allows us to augur the advent of new therapeutic and diagnostic tools.

What does the future hold?

Sketching an outlook on medicine in the future is not an easy task, because one runs the risk of confusing what is nourished by science with what comes from science fiction. However, there is a way to minimize this risk: tap into certain fields of medical research that are already beginning to show promising results. Therapies capable of correcting genetic defects that cause diseases in the retina, tissues created in vitro for transplantation, electronic microchips implanted inside the eyeball, personalised medecine, surgical maneuvers assisted by robotics, are some of the protagonist of the present and the near future of ophthalmology and medicine in general. These technological advances predict a very promising future for a multitude of diseases, not forgetting that, as the Barraquer school preaches, patient care should never be dehumanized.

Dr. Javier Elizalde