Safety and efficacy of intense pulsed light in the treatment of severe chronic ocular graft-versus-host disease

Objective: To investigate the safety and efficacy of intense pulsed light (IPL) in the treatment of severe chronic ocular graft-versus-host disease (coGVHD). Methods: A prospective cohort study. Seventeen patients with severe coGVHD were selected for inclusion in this study. All subjects were treated with IPL every fortnight together with conventional treatment, observation time points were pre-treatment (W0), 4 weeks post-treatment (W4), 8 weeks post-treatment (W8) and 12 weeks post-treatment (W12). Dry eye related examinations include Tear meniscus height (TMH), Non-invasive break-up time (NIBUT), Schirmer I test, Tear film lipid layer thickness (LLT), Ocular surface staining (OSS) and assessment of meibomian gland. Corneal epithelial cell morphology and inflammatory cell infiltration were analyzed by corneal confocal microscopy, while goblet cell density and squamous epithelial grade were assessed by conjunctival imprinted cytology. Results: Patients did not experience any adverse reactions during the follow-up period. All subjects showed significant improvement in clinical symptoms and most signs after IPL treatment. The corneal confocal micro-scopy showed that the number of dendritic cells infiltrates in the corneal stroma was significantly reduced after IPL treatment (p < 0.001). Conjunctival blot cytology suggested an increase in the number of conjunctival goblet cells from 5.12 +/- 2.71 cells/mm(2) before treatment to 22.00 +/- 4.58 cells/mm(2) after treatment, with a statistically significant difference (p < 0.001). An improvement in conjunctival epithelial cell morphology and a decrease in squamous epithelial grade was also observed. Conclusions: IPL treatment can effectively increase tear film stability in patients with severe coGVHD without significant side effects.