Search Results

Abstract

PURPOSE: The study aimed to measure the scientific production in Ophthalmology and Vision (O&V) in Argentina, Brazil, Chile, Paraguay and Uruguay over a period of 10 years (1995-2004), in order to find out temporal evolution and variations in this field of research. METHODS: PubMed / Medline was used to retrieve records on O&V research literature. The search strategy included keywords, country in the affiliation field and publication date. Data were extracted from each citation and recorded in a spreadsheet. Subsequent analysis focused on type and main topic of publication, journals where articles had been published, and evolution of research done on animals and humans. RESULTS: A total of 1,216 citations were retrieved. Brazil had the largest number of authored publications with an average annual production of 82.4, followed by Argentina with 31.0, Chile 6.4, Uruguay 1.6, and Paraguay 0.2. The ratio of articles on O&V relative to publications involving Health Science ranged from 1.0 to 2.3. The frequency of publications almost tripled from 1995 to 2004. Research on humans showed a significant increase in Argentina and Brazil. CONCLUSIONS: Results provide initial benchmarks on O&V publication rates in countries in South America that may be useful to follow research trends.

Keywords: Bibliometrics; Research; Comparative study; Ophthalmology; South America

Abstract

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Abstract

Corneal blindness affects more than 12 million individuals worldwide; however, the availability of human donor corneas meets only a small fraction of the demand. Porcine corneal xenotransplantation represents a promising alternative because of the cornea's immune privilege and the anatomical similarities between human and porcine corneas. However, the galactose-α1,3-galactose antigen expressed on porcine cells induces hyperacute rejection through the activation of human anti-Gal antibodies, complement pathways, and innate immune cell infiltration. This review summarizes the mechanisms underlying corneal immune privilege and contrasts them with galactose-α1,3-galactose-mediated rejection pathways. In addition, it evaluates five major mitigation strategies: GGTA1-knockout pigs, enzymatic α-galactosidase treatment, RNA interference, decellularization, and immunosuppressive approaches, including CD40-CD154 blockade and topical tacrolimus. Preclinical studies have demonstrated that GTKO corneas can maintain transparency for longer than 1 year, whereas decellularized matrices preserve corneal architecture while exhibiting low antigenicity. These findings support the future clinical translation of porcine corneal xenotransplantation.

Keywords: Corneal transplantation; Xenotransplantation; Graft rejection; Galactose; Immunosuppressive agents.