Comparison of the treatment effect of preservative-free vs preserved eye drops in patients with dry eye syndrome

INTERVENTION: Permuted blocks were obtained using a computer‐based random code generator (Research Randomizer; http://randomizer.org/). 50 patients (Group 1) were treated four times with preservative‐free 0.1% sodium hyaluronate and 0.1% fluorometholone for the first month and preservative‐free 0.1% sodium hyaluronate and 0.05% cyclosporine for the second and third month. 50 patients (Group 2) were treated four times with preserved 0.1% sodium hyaluronate and preserved 0.1% fluorometholone for the first month and preserved 0.1% sodium hyaluronate and 0.05% cyclosporine for the second and third month. Following instillation of the eye drops, symptoms and signs of dry eye are measured. Total duration of treatment and follow‐up for each study arm: 3 months CONDITION: Dry eye syndrome ; Eye Diseases ; Dry eye syndrome PRIMARY OUTCOME: 1. Ocular surface disease index (OSDI); 2. Corneal fluorescein staining; 3. Schirmer tear test (without anesthesia); 4. Tear film break‐up time (tBUT); 5. Symptom score of dry eye; 6. Impression cytology; ; Measured at baseline, 1, 2 and 3 months. SECONDARY OUTCOME: Antioxidant and Inflammatory cytokine activities in tears measured by ELISA at baseline, 1, 2 and 3 months. INCLUSION CRITERIA: Eligible patients were at least 21 years of age and had a diagnosis of dry eye syndrome refractory to conventional management. Inclusion criteria were: 1. Schirmer test (without anesthesia) of 5 mm/5 minutes in at least one eye 2. Low tear film break‐up time (tBUT) (<5 seconds) 3. Mild superficial punctate keratitis, defined as a corneal punctate fluorescein staining score of =1 in either eye (scale 0 [none] to 3 [severe]); and one or more moderate (=2) dry eye related symptoms, including itching, burning, blurred vision, foreign body sensation, dryness, photophobia, soreness, or pain.