Effect of Pre and Post Operative PRK and PRK Stream Light on Tear Film Stability

Background: Tear film instability can lead to dry eye disease, which is a common complication following refractive surgeries such as Photorefractive Keratectomy (PRK) and Transepithelial PRK (Trans-PRK).Objective: This study aimed to evaluate the effects of PRK and Trans-PRK on tear film stability using the Tear Break-Up Time (TBUT) test and Schirmer II test.Methods: A quasi-experimental study was conducted at the National Eye Center, Lahore, including 100 patients aged 18-30 years undergoing PRK or Trans-PRK. Tear film stability was assessed before and after surgery using TBUT and Schirmer II tests. Data were analyzed using SPSS version 25, applying paired t-tests to compare pre- and post-surgery outcomes.Results: Significant reductions were observed in TBUT and Schirmer II test values after PRK (mean difference: 4.80, p < 0.001; 4.86, p < 0.001) and Trans-PRK (mean difference: 3.06, p < 0.001; 2.96, p < 0.001), indicating increased eye dryness post-surgery.Conclusion: Both PRK and Trans-PRK significantly reduced tear film stability, increasing the risk of dry eye symptoms. Proper patient assessment and post-operative care are essential to mitigate these risks.