Following a balanced diet that is rich in antioxidants and vitamin A (retinol), avoiding tobacco as well as alcohol and exercising can help prevent diseases of the retina or delay their onset and improve their prognosis, according to the ophthalmologists who gathered last weekend for the Retina Conference that took place in Barcelona.
According to the experts, leading a healthy lifestyle helps prevent systemic diseases, such as diabetes, hypertension and heart disease, which are all conditions that "eventually affect the retina." Consequently, experts stress the need to undergo annual eye examinations after the age of 40 or if major risk factors exist, such as family history, high myopia or chronic diseases of the central nervous system. "Early detection is essential to prevent the development of retinal diseases and improve the final functional prognosis," according to Dr Borja Corcóstegui, the director of IMO and coordinator of the Retina Conference, which was attended by more than 300 ophthalmologists from around the world.
This is one of the main conclusions of the meeting, organised by the Instituto de Microcirugía Ocular in Barcelona (IMO) and the European School for Advanced Studies in Ophthalmology (ESASO), in which experts explained that the most serious eye diseases are those that originate in the retina. Those that have the greatest impact are degenerative diseases, in particular, age-related macular degeneration (AMD); those that are associated with high myopia, those that are vascular in origin, mainly diabetic retinopathy; and those that are associated with biomechanical problems, such as retinal detachment or vitreo-macular traction.
During the conference, ophthalmologists were able to attend ten live operations that "demonstrated the great advances made in recent years in retina surgery, with improved techniques and the introduction of smaller instruments," according to Dr Carlos Mateo, a retina specialist at IMO. "All of this has facilitated the development of minimal incision surgery, which helps to improve visual outcomes and speed up patients’ recovery time," he explained.
The experts also analysed the possible complications related to certain techniques, for example, laser photocoagulation and vitrectomy (the most common retinal surgery today), which can produce reduced night vision or contrast sensitivity in the case of laser treatment and the appearance of cataracts or glaucoma associated with vitrectomy. Dr Stanley Chang, the father of modern vitrectomy, stressed the need for annual monitoring of patients who have undergone the procedure and described glaucoma as a complication of surgery, which can appear five years after the procedure.
Alternative treatments to surgery include intraocular injection of medication, which "will constitute a giant leap forward in the treatment of retinal diseases in the next decade," in particular, with the use of the so-called "slow-release" capsules, which, once inside the eye, can release the medication over a period of several weeks or months. In fact, this month, one of these drugs has been approved for the treatment of macular oedema, which uses an injectable and biodegradable long-acting corticosteroid implant (dexamethasone) for macular oedema in patients with retinal vein occlusion (RVO), the second most common retinal vascular disease after diabetic retinopathy and a significant and common cause of loss of vision, as presented to the conference. Another new treatment that was discussed is microplasmin, a drug that separates abnormal adhesion of the retina and membrane, which, according to experts, could preclude the need for surgery in cases of traction maculopathy.
According to the conference coordinator, "pharmacological treatments have made it possible, in the past five years, to reduce the number of retinal operations by 50%." Specialists predict that this percentage will drop even further in the coming years, due to the introduction of new genetic therapies, "which have already made significant advances in certain diseases, such as Stargardt disease," the most common of all degenerative retinal diseases, which appears at a young age and causes the degeneration of photoreceptors in the retina and vision loss, and originates from a mutation of the ABCR gene, according to Dr Stanley Chang.
Another disease, in which genetic studies are well advanced, is diabetic retinopathy. Dr José García-Arumí, a retina specialist at IMO, announced that he and his team are working, in vitro and in animals, on the induction of protective molecules in diabetic retinopathy cases. As he explained, "we are working on inducing the production of these molecules by retinal cells using viral vectors to change the genetic code of these cells." According to García-Arumí, this line of work seeks to "solve the imbalance of the retina protection systems that produce genes by introducing nanoparticles that change the genetic code of these cells, so that they increase protective factors and the balance is re-established."
At the same time, several specialists in different countries are working on the development of a microchip that electrically stimulates the retina in blind patients. The technique involves attaching a small camera to a pair of glasses, which is connected to a mini-processor that sends signals to a microchip located in the eye to stimulate the retina. In Spain, Dr Borja Corcóstegui has spent several years studying this implantation technique with nine completely blind patients, who could soon regain some of their sight. As he explained, "the microchip could be implanted very soon, after twenty years of research."