Eye Banking

Removal of eye balls from a dead body done either by an ophthalmologist or trained registered medical practitioner is known as Enucleation. Before removal, the eyes are made aseptic by standard surgical procedures. Maintaining aseptic conditions during and after removal of the eyes is extremely important.

Sterilized instruments, sterile gloves, etc., are used for enucleation. The time taken by an experienced doctor is about 20 to 30 minutes for both eyes. After the eyes have been removed, a ball of cotton wool is tightly packed in the empty eye socket or artificial eye balls are placed inside. The eye lids are sometimes stitched with a black thread. This gives an appearance as if the donor is asleep. There is absolutely no disfigurement of the face after eyes are removed. The enucleated eye balls are transported in a special glass bottle with a metal stand termed as Moist Chamber to the nearest processing and evaluation centre. The Moist Chamber is transported at 4 degrees centigrade.

According to the “Transplantation of Human Organs Act, 1994,” applicable to the States of Maharashtra, Goa and Himachal Pradesh and all Union Terrtories, only a registered medical practitioner is permitted to “enucleate” the eyes from a dead body. In Europe, U.S.A. and several other countries, a technician trained can enucleate or perform an in-situ corneal excision for the purpose of transplantation. This would bring down the time gap between death and enucleation. The registered medical practitioner would not have to rush to the location of death while there are many patients waiting in his own clinic for treatment.

The most common method used in Europe, USA and several other countries is In-situ corneal excision (direct removal of corneas from the dead body). This method not only saves time but also prevents the cornea from deterioration.

The cornea is cut and separated from the eyeball and stored in a suitable nutritive medium. The whole eye ball is not preserved. This medium helps in prolonging the life of a cornea by about 3-4 days. Known today as M.K. Medium it is now available from the L.V. Prasad Eye Institute, Hyderabad and all members of the Eye Bank Association of India at a nominal charge.

While using MK medium, adequate care and precaution needs to be taken while cutting and separating the cornea from the eye ball and storing it in the medium so as to avoid contamination. In other words, this must be done in a totally aseptic environment; as otherwise, the ingredients of the medium whilst being useful in prolonging the life of corneal tissue can also prove nutritive to the harmful bacteria which can damage the tissue itself.

When whole eye balls are collected from the donor, the corneas is cut and separated from the eyeball and stored in a suitable nutritive medium. Stringent aseptic conditions need to be maintained as in the case of In-situ corneal excisions. The time gap between death and cornea preservation in our country SHOULD NOT EXCEED 6 to 7 hours failing which the quality of the cornea is not suitable for optical penetrating keratoplasty (surgery for restoring vision).Similar observations have been made by the Santa Lucia Eye Bank in Manila, Philippines where similar climatic conditions prevail.

Despite the introduction of sophisticated equipment in Tissue Evaluation, the SLIT LAMP continues to remain the most important tool for corneal evaluation. It is very much a part & parcel of routine corneal evaluation, including both whole eyeball and the excised corneal button in the media.

A SLIT LAMP is an Ophthalmological tool consisting of a Microscope combined with a rectangular light source that can be narrowed into a Slit. Primarily it helps us to determine the suitability of tissue for surgical Use. It enables the technologists to study the layers of the cornea individually (Epithelium, Stroma & Endothelium), bringing to limelight the intricate flaws in the tissue and allowing us to inspect the Surface and the deeper layers thoroughly. Corneal defects can be examined with greater accuracy and more detail. It can reveal earlier stages of Corneal pathology much better than are visible grossly.

Last but not the least it is especially valuable in Qualitative Assessment of the health of the Endothelium, which is a critical factor for corneal transplant.

‘Endothelium’ is a single innermost layer of cornea and is primarily responsible for the quality of the vision after a cornea grafting surgery. Therefore, assessment of its integrity is critical in making a judgement about its utility for corneal grafting.

The structure can be studied by slit lamp examination which provides reliable information. This is performed in most eye banks by trained individuals. However, the technique of specular microscopy allows direct high magnification of the endothelial cells and consequently better judgement of its status by counting the number of cells mm square. .

Serology has been routinely perfomed to screen for infectious diseases such as AIDS (HIV), Hepatitis (HBsAg), Sexually transmitted Diseases (VDRL), etc. Auto-analysers have been implemented for the above tests in order to minimize human errors from time to time. .

Corneas are distributed on a first-cum-first-serve basis although priority is given to bilaterally blind recipients (blind in both eyes). Online eye banking can be a useful tool to maintain acountability and transparency at every level within every eye bank.