Abstract

The development of biomaterials for ocular applications has advanced considerably, driven by the need for safe and effective devices such as intraocular lenses, corneal scaffolds, and contact lenses. A critical step in this process is the biological evaluation of materials, which ensures biocompatibility and predicts clinical performance. In vitro assays, including cytotoxicity tests such as MTT and MTS, provide essential insights into cell viability and material interactions with ocular tissues. Complementary methods, such as the HET-CAM assay, offer ethical and efficient alternatives to traditional animal testing by assessing irritation potential in a vascularized membrane model. In vivo studies remain indispensable for evaluating longterm stability, optical clarity, and tissue integration, although their use is increasingly complemented by advanced in vitro and tissue-engineered models. Emerging approaches, including alternative assays such as HET-CAM, smart polymers responsive to ocular microenvironments, nanocomposite scaffolds, and microfluidic ocular-on-chip systems, represent innovative strategies to accelerate the safe translation of biomaterials into ophthalmic practice. This mini review discusses conventional and alternative assays for ocular biomaterials, including recent sensitive in vitro protocols designed to evaluate acute irritation and phototoxicity of medical devices and ophthalmic drugs, as well as organ-on-chip platforms that recreate dynamic ocular environments for predictive testing. Together, these approaches form a comprehensive framework for the characterization of ocular biomaterials, supporting innovation while reducing reliance on animal experimentation.

Keywords:Ocular biomaterials; Biocompatibility; Cytotoxicity assays; Het-cam; In vivo evaluation; Smart polymers; Epioculatm; Microfluidic ocular-on-chip