The following is a summary of “New future perspective in corneal tissue utilisation – methods of preparation and preservation,” published in the June 2023 issue of Ophthalmology by Polachova et al.
The preparation and preservation of corneal stromal tissue is a complex and delicate process, but it is essential for ensuring the safety and effectiveness of corneal transplantation.
Researchers performed a retrospective analysis to optimize the preparation and preservation of corneal stromal tissue by comparing different methods, evaluating the possibility of using a single donor cornea for more than 1 patient and making more corneal lenticules. To compare different methods of preparing and preserving corneal lenticules and corneal stromal lamellae, morphological analysis (histology, scanning electron microscope) and microbiological analysis were performed. The study also conducted the surgical handling test to ensure safe tissue manipulation for surgical use.
Lenticule preparation was compared with 2 methods: microkeratome dissection and femtosecond laser. Tissue preservation was achieved through hypothermia, cryopreservation at -80 degrees Celsius in dimethyl sulfoxide (DMSO), and storage at room temperature in glycerol. Before study, some intrastromal lenticules and lamellae were exposed to 25 kilograys (kGy) of gamma radiation.
Microkeratome-created corneal stromal lamellae have smoother cut surfaces than femtosecond laser-created lamellae and have a sparser network. Femtosecond laser can create more than 5 corneal lenticules from a single donor cornea and have more surface irregularities and fiber conglomerates. Gamma irradiation damaged collagen fibrils in the cornea, causing irregular arrangement. Glycerol-stored cornea showed dehydrated fibrils with empty spaces. Cryopreserved cornea without irradiation showed regular fibrils similar to the hypothermia-stored cornea.
They concluded that Microkeratome-created corneal lenticules are smoother and cheaper, while gamma irradiation-damaged corneas and glycerol storage and cryopreservation are safe for clinical use.
Source: bmcophthalmol.biomedcentral.com/articles/10.1186/s12886-023-03048-3