Combined Intense Pulsed Light and Low-Level Light Therapy for the Treatment of Dry Eye: A Retrospective Before-After Study with One-Year Follow-Up

Purpose: To assess the effectiveness of a combination of intense pulsed light and low-level light therapy (IPL/LLLT) for the treatment of dry eye. Study Design: Retrospective before-after single-center clinical study. Materials and Methods: Patients diagnosed with dry eye, refractory to conventional treatment, underwent four sessions of combined IPL/LLLT over 3 months. The Ocular Surface Disease Index (OSDI) questionnaire, non-invasive breakup time (NIBUT), tear film osmolarity and meniscus height were measured 6 months before intervention, at baseline, post-intervention (3 months), 9 and 15 months. Results: NIBUT, osmolarity and meniscus height significantly worsened during the 6 months before treatment, whereas symptoms did not change. OSDI scores significantly improved at post-intervention (MD = -44.0, 95% CI -38.1, -50.0), and then increased again until the at last follow-up, but still significantly different from baseline (MD = -30.0, 95% CI -23.4, -36.8). The three clinical signs showed a similar pattern, with one-year improvements of 3.6 seconds for the NIBUT (95% CI 3.1, 4.2, p < 0.001), 28 mOsm/L for osmolarity (95% CI 23.6, 32.4, p < 0.001) and 0.03 mm for meniscus height (95% CI 0.02, 0.04, p < 0.001). No adverse effects were observed. Conclusion: IPL/LLLT is safe and produces an important reduction in symptoms and signs of dry eye disease, still relevant one year after the end of treatment in a sample with high symptoms' severity. Therefore, it represents a promising treatment option for patients who do not improve with conventional treatment. Randomized trials are needed to determine the added benefit provided by LLLT.