Allergic conjunctivitis is a disease with increasing prevalence that affects both children and adults and causes a significant deterioration in their quality of life and, on occasions, irreversible visual damage.
At the recent XX Annual Meeting of the Spanish Society of Ocular and Corneal Surfaces (SESOC), he highlighted the most outstanding developments in allergic conjunctivitis, a disease with increasing prevalence that affects both children and adults and causes significant deterioration of their quality of life and, sometimes, irreversible visual damage.
Allergic conjunctivitis is a disease with increasing prevalence that affects both children and adults and causes a significant deterioration in their quality of life and, on occasions, irreversible visual damage. This pathology consists of an intermittent or continuous inflammation of the conjunctiva (the transparent membrane that covers and protects the anterior segment of the eye and the interior of the eyelids) of allergic origin, affecting people sensitized to proteins from sources such as plant pollens and trees, dust mites, molds, animal dander, or substances in the work environment.
Specialists point out that it is often underdiagnosed (there are studies that estimate its prevalence at up to 40%) and, consequently, undertreated.
“Clinical evidence demonstrates the significant impact on the quality of life of patients and absenteeism from work and academics caused by allergic conjunctivitis. As an aspect to highlight, absenteeism from work means a decrease in productivity in adults and, in young people, learning difficulties that sometimes contribute to school failure ”, highlights the allergist Mª Cesárea Sánchez.
“Allergic conjunctivitis is the most frequent form of ocular allergy, and the most common of the non-infectious inflammatory processes of the anterior segment of the eye, representing around 35% of all conjunctivitis. If at least one in 4 people suffers from some type of allergic disorder, in the case of allergic conjunctivitis we are talking more of a prevalence of 30%”, adds the allergist Ignacio Jáuregui Presa.
Ruperto González, also an allergist, explains that “ocular allergy is closely related to allergic rhinoconjunctivitis (AR) in a percentage that exceeds 65%. RA is produced by inflammation of the nasal and conjunctival mucosa against environmental allergens in genetically susceptible patients”.
The binomial allergic conjunctivitis and dry eye can affect up to a third of Spaniards
At the same time that allergic conjunctivitis is related to RA, it is also related to dry eye syndrome. Specialists explain that this syndrome occurs when the tear film (the thin layer of liquid based on water, mucin and fat that hydrates and protects the cornea and conjunctiva) is unstable or of insufficient quality to keep the eyes well hydrated. And they affirm that ocular allergy and dry eye syndrome are the most frequent disorders of the surface of the eye (they can separately affect a third of Spaniards), both with a potentially serious impact on quality of life, and can coexist and overlap. In fact, the first condition may be a risk factor for the second.
“Dry eye encompasses a wide range of causes, among which we can find ocular allergy. The chronic or relatively persistent inflammation of the conjunctiva that ocular allergy causes in our patients, together with the unavoidable use of drugs for its symptomatic control (some of them toxic both due to their action and composition, as they require the use of preservatives), end up by altering the tissue structure and its secretion glands, giving rise to a dysfunction of the entire system that gives rise to what we call dry eye.
Its incidence in cases of patients with ocular allergy will increase progressively with age, resulting in almost 100% in atopics over 35 to 40 years if we use drugs with preservatives such as benzalkonium chloride and the type of mechanisms involved”, says the ocular surface specialist, Dr. Jesús Montero.
Focus of the new lines of treatment: eliminate preservatives, guarantee maximum sterilization, preserve eye hydration and facilitate coexistence with contact lenses
Currently, eye drops (such as antihistamines) are the most widely used pharmaceutical forms for the topical administration of active substances. The requirements of these preparations are sterility (ensuring the absence of microbial contamination), tolerance (that they are compatible with the ocular surface without causing damage to the eye) and permanence (that the therapeutic concentrations of the drug are maintained for the necessary time in the target tissues).
“Eye drops play a fundamental role in the treatment of anterior segment eye disorders. Drugs administered at the ocular topical level have shown greater efficacy and fewer adverse effects than any other route of administration”, points out Dr. Sánchez.
For the specialists participating in the symposium, the problem is that, in order to maintain sterility and tolerance, most of them need to contain in their composition a series of excipients, including preservatives with a surfactant effect that, in the long run, in chronic processes as usual be allergic conjunctivitis, can destabilize the tear film and eventually damage the eye, causing or aggravating a pre-existing dry eye syndrome.