Background and purpose: Allergic conjunctivitis has increased alarmingly in recent years. The objectives of the study are: 1) To establish the safety and efficacy of applying eyewashes in spray form as monotherapy on the symptoms and signs of allergic conjunctivitis; 2) To establish the comparative efficacy with other eye drops as antihistamines; 3) To measure the modification of immunoglobulin E (IgE) and matrix metalloproteinase 9 (MMP9) levels in the tears.

Material and methods: Prospective study. A total of 50 patients will be included. A scale from 0 to +3 will be established to quantify the intensity of the different parameters measured. A total of 8 symptoms will be studied - itching, tearing, mucous secretions, photophobia, foreign body sensation, redness, rubbing, palpebral swelling, and 3 signs - palpebral papillae, conjunctival hyperemia, and corneal involvement (dotted keratitis). Control at 30 minutes, 1 day, and 1 month after the application of the treatment. At the end of the treatment period, the degree of satisfaction with the treatment, the desire to continue or abandon it, and the need to associate other complementary treatments due to lack of control will also be evaluated. All patients will be treated exclusively with seawater isotonic solution in the form of a spray 5 times a day for 1 month. A second similar group of patients will be treated with antihistamine eye drops and a third group of patients with both antihistamine eye drops and seawater. Tears measurement of immunoglobulin E and matrix metalloproteinase 9 levels will be measured before and after treatment.

Inclusion Criteria:

The inclusion criteria were patients with mild or moderate allergic conjunctivitis as detailed in Table I. The minimum to be included in the study was the presence in both eyes of three symptoms and one sign (Table II). Among the symptoms, the presence of itching and two more of the following were essential: redness, tearing, foreign body sensation, rubbing, mucous secretion, and/or palpebral swelling sensation. Among the signs, conjunctival hyperemia, papillae in the palpebral conjunctiva, and/or corneal affectation in the form of dotted keratitis were evaluated.

Table 1 Degree of conjunctivitis I Mild II Moderate III Severe IV Blinding

Conjunctiva bulbar: congestion granuloma Conjunctiva tarsal: micropapillae 1mm giant >1 mm cobblestone Corneal staining : micro macro shield ulcer Limbal affectation: < 180 degrees >180 degrees insufficiency limbo/pannus/ vascularization corneal

Table 2 Signs and symptoms evaluated initially and at each visit

Symptoms Signs:

• Itching - Conjunctival Hyperemia
• Redness - Pads
• Foreign body sensation - palpebral swelling
• Photophobia
• Eyelid swollen sensation
• Mucous secretions
• Rubbing
• Tears

Exclusion Criteria:

• blepharitis
• meibomian gland dysfunction syndrome (MGS)
• dry eye disease
• topical eye drug such as cyclosporine, tacrolimus, interferon-alpha, mitomycin
• previous eye surgery
• corneal refractive surgery.
• use of contact lenses
• glaucoma
• pterygium
• ocular pemphigoid
• anti-allergic vaccines
• oral or subcutaneous drugs such as antihistamines, anti-leukotrienes (montelukast), corticoids, immunosuppressants or biological drugs.
• rhinitis and dermatitis

Allergic conjunctivitis patientes from 10 yeras old and older