Abstract:AIM: To compare outcomes of applying preservative free artificial tears (PFAT) with and without hyaluronic acid (HA) in early postoperative course following photorefractive keratectomy (PRK). METHODS: In this triple-blinded randomized clinical trial, PRK procedure was performed on both eyes of 230 patients. Following PRK, patients were divided into three groups: the HA+ group, 44 patients PFAT containing HA; the HA- group, 71 patients PFAT without HA were administered 5 times per day (every 4h); the third group, 115 patients received no PFAT before lens removal. On the 1st and 4th postoperative day, Visual Analogue Score (VAS) was utilized to evaluate patient’s level of pain. Participants were asked to complete a questionnaire about the severity of eye discomfort ranked from 0 to 10 (0=no complaint; 10=most severe complaint experienced). RESULTS: In eyes receiving PFAT with or without HA (Drop group), mean scores for epiphora, foreign body sensation, and blurred vision on the 1st postoperative day were statistically lower (P<0.05). Filamentous keratitis (FK) was detected in 11 (4.7%) eyes, and recurrent corneal erosion (RCE) was observed in 5 (2.1%) eyes. In the control group, FK was noted in 16 (6.9%) eyes while 13 (5.6%) eyes had RCE and 5 (2.1%) eyes had corneal haze. The rate of complications was statistically lower in Drop group (P=0.009). However, the aforementioned scores were not statically different between HA+ and HA- group one and two (P=0.29). CONCLUSION: Following PRK, applying PFAT with and without HA yields faster visual recovery, decreases postoperative ocular discomfort and haze formation; however there is no additive effect for HA.