Ocular allergy is an umbrella term used to capture a range of allergic inflammatory conditions that affect the eye. These conditions, like all allergic reactions, are the result of immune hypersensitivity to normally harmless substances, known as environmental antigens or allergens – typically pollen, dust, mould and animal dander.1 In patients attending optometric practice, the prevalence of ocular allergy is reported to be approximately 8%,2 but is likely to be higher due to underdiagnosis as a result of seasonal ocular allergies being conflated with hayfever symptoms3,4 – hence the true number of cases represents a significant figure that need to be managed in practice. Indeed, ocular allergies and conjunctival symptoms are present in 30–71% of patients with allergic rhinitis, yet the prevalence of ocular allergies alone ranges from 6% to 30% in the general population.3 This wide range is the result of studies including various ocular allergy subtypes. Subtypes of ocular allergy include allergic conjunctivitis (AC), vernal keratoconjunctivitis, atopic keratoconjunctivitis and giant papillary conjunctivitis.
Although symptoms are often mild to moderate in the majority of cases, ocular allergies can have significant impact on patients in their daily lives. In a study of patients suffering seasonal AC versus controls in cities across Spain, data from a range of validated questionnaires revealed sufferers had significantly reduced quality-of-life scores and increased healthcare costs to manage their symptoms, approaching 350 euros per annum.5 Likewise, in a UK setting with the same methodology, sufferers had significantly higher degrees of pain/discomfort and lower perception of health compared to controls, and increased costs for managing symptoms, ranging from over £60 per year for a pensioner to over double that for those in paid employment (>£120), while the latter also reported lower weekly earnings and lower working hours compared to controls.6 In a study of over 2500 participants diagnosed with nasal and/or ocular allergies, telephone questionnaires revealed that 29% reported their or their child’s daily life was impacted ‘a lot’ and workers reported their productivity was 29% lower during peak allergy symptoms compared to no symptoms.7