Autologous serum eye drops (ASED) are an established therapy for ocular surface diseases; however, their preparation can be costly and may not be available due to the need for germ-free conditions. This pilot trial assesses the feasibility of collecting ASED in a closed-circuit system for patients with chronic ocular surface diseases.

Autologous Serum exhibits characteristics very similar to those of tears, such as pH, osmolarity, vitamins, and Immunoglobulin A. It also contains growth factors, nutritional factors, and antibacterial components that are necessary for the maintenance of cellular viability in the epithelial repair process. The use of autologous serum eye drops was first described in 1984 by Fox et al., in research for a preservative-free tear substitute. Subsequently, in 1999, Tsubota et al. found that, due to the presence of growth factors and vitamins, autologous serum could have a true epithelial trophic potential for the ocular surface. The autologous serum eye drops are not only a lubricant for the ocular surface but also provide various essential substances for the reconstruction of epithelial damage, including vitamin A, epithelial growth factor, fibronectin, and a variety of cytokines. With these epithelial trophic factors, autologous serum facilitates proliferation, migration, and differentiation of the ocular surface epithelium. Moreover, it is known for its anti-catabolic properties, inhibiting the inflammatory cascade triggered by interleukin-1, which prevents tissue destruction. Therefore, autologous serum eye drops have been effective in the treatment of persistent epithelial defects, neurotrophic ulcers, superior limbic keratoconjunctivitis, dry eye conditions, graft-versus-host disease (GVHD), or after refractive surgeries, such as LASIK (Laser Assisted In Situ Keratomileusis). In 2020, Wang et al. published an article with 7 randomized controlled trials comparing the use of autologous serum versus artificial tears in patients with dry eye syndrome. In the meta-analysis, all 7 studies evaluated subjective symptoms and showed that autologous serum eye drops were superior to ocular lubricants in alleviating and remitting symptoms. It was shown that autologous serum eye drops significantly improved parameters such as OSDI (Ocular Surface Disease Index), tear break-up time, and Bengal Rose staining when compared to the control group using ocular lubricants. Given the numerous properties of autologous serum eye drops, there is no doubt about their benefit and effectiveness in treating several ocular surface diseases, including ocular GVHD. However, the difficulty in accessing production and the substantial cost of autologous serum eye drops are the main challenges, and their use is often limited to more severe dry eye cases and those refractory to conventional treatment.

Inclusion Criteria:

• ≥ 18 years
• Dry eye and/or chronic epithelial defects of the ocular surface with indication for autologous serum according to the evaluation of ophthalmologists specialized in Cornea and Ocular Surface;
• Peripheral venous access or PICC that allows the collection of whole blood.

Exclusion Criteria:

• Active ocular infection;
• Hemoglobin < 11 g/dL;
• Angina, MI, or stroke in the last 30 days;
• Significant pulmonary or cardiac disease that contraindicates autologous serum collection in the investigator's opinion;
• Active ocular or systemic infection at the time of collection;
• Inability to attend follow-up visits at 6 and 12 weeks;
• Active hematological malignancy (except measurable residual disease) or solid malignancy (except non-melanoma skin cancer);
• Positive for HIV, HCV, HBV, HTLV, Chagas disease, or syphilis;
• Life expectancy < 6 months;
• Not pregnant (as reported by the participant).