Ectoine, a novel natural osmoprotectant, protects bacteria living in extreme environments. This study aimed to explore the therapeutic effect of ectoine for dry eye disease. An experimental dry eye model was created in C57BL/6 mice exposed to desiccating stress (DS) with untreated mice as controls (UT). DS mice were dosed topically with 0.5–2.0% of ectoine or a vehicle control. Corneal epithelial defects were detected via corneal smoothness and Oregon Green dextran (OGD) fluorescent staining. Pro-inflammatory cytokines and chemokines were evaluated using RT-qPCR and immunofluorescent staining. Compared with UT mice, corneal epithelial defects were observed as corneal smoothness irregularities and strong punctate OGD fluorescent staining in DS mice with vehicle. Ectoine treatment protected DS mice from corneal damage in a concentration-dependent manner, and ectoine at 1.0 and 2.0% significantly restored the corneal smoothness and reduced OGD staining to near normal levels. Expression of pro-inflammatory cytokines (TNF-α, IL-1β, and IL-6) and chemokines CCL3 and CXCL11 was significantly elevated in the corneas and conjunctivas of DS mice, whereas 1.0 and 2.0% ectoine suppressed these inflammatory mediators to near normal levels. Our findings demonstrate that ectoine can significantly reduce the hallmark pathologies associated with dry eye and may be a promising candidate for treating human disease.

Introduction Involved site radiation therapy (ISRT) is a widely used treatment for primary ocular adnexal mucosa-associated lymphoid tissue (MALT) lymphoma with control rates over 85%; however, its complications could reach 30%–50%. Intralesional rituximab injection has shown promising results with remission rates between 65% and 100% and minimal complications. This study aimed to conduct a multicentre randomised controlled clinical trial to compare the safety and efficacy of intralesional rituximab injection versus ISRT on primary ocular adnexal MALT lymphoma. Methods and analysis This is a multicentre randomised controlled trial and will be conducted at eight ophthalmic departments and institutes in China. 108 patients with primary ocular adnexal MALT lymphoma will be enrolled and randomised to undergo intralesional rituximab injection or ISRT. Comprehensive examinations will be performed before and after the treatment. The primary outcome is the cumulative occurrence rate of complications of grade ≥2 within 5 years after treatment commencement. The main secondary outcome is overall response rate, and progression-free survival, time to next treatment and overall survival will also be compared between the groups. Ethics and dissemination Ethical approval has been obtained from the Ethics Committee of the Zhongshan Ophthalmic Center (ID: 2023KYPJ125-3; V.20240818) and the ‘5010 Plan’ evaluation committee at Sun Yat-sen University, Guangzhou, China, and all subcentres. All the participants will be required to provide written informed consent. The results will be disseminated through scientific meetings and published in peer-reviewed journals. Trial registration number NCT06190301.