JPAC Joint United Kingdom (UK) Blood Transfusion and Tissue Transplantation Services Professional Advisory Committee

21.12: Ocular tissue retrieval, processing and storage

Update notice: Section 21.12.2 - Ocular tissue storage has been updated following the issue of Change Notification 23 - 2016

21.12.1: Eye retrieval

An ‘NHSBT Tissue Retrieval Site Risk Assessment’ form must be completed by the eye retriever to ensure the suitability of the retrieval site. This must be done for every eye retrieval as circumstances may change even within the same premises.

Eye retrieval must be carried out by a person who is trained and competent in enucleation. Either this individual must be employed by an HTA-licensed eye bank or there must be a third party agreement in place between the eye bank and the individual’s employing authority.

Enucleation should be carried out as soon as possible, but no longer than 24 hours after death. The eye retriever must be satisfied that lawful consent/authorisation has been obtained and that at the time of retrieval there is no known medical reason to suggest that the eyes should not be retrieved. Sterile, single-use instruments must be used and disposed of safely after the retrieval. The NHS Blood and Transplant (NHSBT) Human Tissue Transport Box contains all the required documentation, including an enucleation protocol, and a set of sterile, single-use instruments. All required documentation must be fully completed by the eye retriever, including the NHSBT Ocular Tissue Donor Information form and body map.

The NHSBT enucleation protocol must be followed.8 After enucleation a stump of optic nerve at least 5 mm long must remain attached to the eye, which is then secured in a plastic eye stand. The eye stand and eye (cornea uppermost) are placed on top of a moist cotton wool ball or gauze swab and placed in a sterile pot (moist chamber). The eye must not be immersed in any liquid in the moist chamber. The moist chambers are then packed in an NHSBT Human Tissue Transport box together with a plastic bag containing melting ice. At least 1 kg of ice is needed to keep the contents of the transport box below 5°C for up to 24 hours during transportation to the eye bank. The donor’s eye sockets should be packed with cotton wool and lids closed over plastic eye caps to restore the original profile of the lids. The final cosmetic appearance is of critical importance as family or friends may wish to view the body. Any bleeding or bruising resulting from the enucleation must be noted on the body map.

21.12.2: Ocular tissue processing and storage

Corneas should be excised and placed in an appropriate storage solution as soon as possible, but no longer than 24 hours after enucleation. Corneas may be stored for up to 2 weeks at 4°C in an appropriate hypothermic storage solution. Alternatively, the great majority of corneas in the UK are stored for up to 4 weeks in organ culture at 34°C. The corneal endothelium is examined by light microscopy a few days before use to ensure its suitability for transplantation in patients with corneal endothelial disease/deficiency. Organ-cultured corneas are delivered to hospitals in medium containing 5% dextran to reverse the stromal oedema that occurs during storage. Corneas with an inadequate endothelium may still be suitable for anterior lamellar grafts. These corneas may also be transferred to 70% ethanol and stored at room temperature for up to 12 months for use in glaucoma surgery. Sclera, which is also stored in 70% ethanol for up to 12 months, is used for glaucoma or other reconstructive surgery. Ocular surface stem cells may be isolated from the limbus and expanded in ex vivo culture for treating limbal stem cell deficiency.