Vol. 7, Issue 1, Part A (2025)

Background: Allergic conjunctivitis is one of the main and most common allergic manifestations, affecting 20% of the global population. Elevated tear levels of metalloproteinase 9 (MMP-9) have been correlated with the severity and chronicity of clinical manifestations of the disease. All current treatments, especially the most effective ones like corticosteroids, are associated with side effects upon chronic administration. A natural treatment alternative without side effects that reduces pharmacodependence, such as seawater, would be an excellent therapeutic option.
Purpose: This prospective study aims to evaluate the anti-inflammatory efficacy of isotonic seawater solution on MMP-9 levels in the tears of patients with allergic conjunctivitis.
Methods and Study Design: This is a registered prospective study (Clinical Trial Gov/USA NCT 04695795). A total of 50 patients and 100 affected eyes were included. Initial inclusion criteria were: positive InflammaDry® test in both eyes + grade I, II, and III allergic conjunctivitis - Bonini-Gokhale scale. Tear MMP-9 levels were measured using the commercial InflammaDry® test before and after treatment. All patients were treated exclusively with Quinton® isotonic seawater six times a day for four weeks.
Results: The InflammaDry test was positive in 100% of patients (n = 50) and 100% of eyes (n = 100) before treatment as an obligatory inclusion criterion. After seawater treatment, 100% of patients and eyes with grade I conjunctivitis tested negative with undetectable MMP-9 levels in both eyes, 89% with grade II conjunctivitis, and 80% of patients with grade III. These changes are statistically significant (p< 0.0087).
Conclusion: Seawater washes are a safe and highly effective treatment in reducing ocular surface inflammation in allergic conjunctivitis, being able to negate previously positive MMP-9 tear levels in an average of 89% of cases.