Describe corneal blindness and eye banking in India.

Corneal Blindness as a Public Health Problem

• Corneal blindness differs from cataract blindness in every respect that matters to a programme, and the differences explain why it is so much harder to address:
• It affects the young, so each case costs far more blind-years; it is frequently unilateral, so it is under-reported in surveys that measure the better eye; it is largely preventable rather than curable; and its treatment requires donor tissue, which is a supply problem rather than a surgical one
• Causes in India — corneal ulcer, particularly fungal keratitis following agricultural trauma.

Eye Banking

• An eye bank is an organisation that retrieves, evaluates, preserves and distributes donor corneal tissue. An eye donation centre retrieves and transports tissue to an eye bank but does not evaluate or distribute it
• The hospital cornea retrieval programme (HCRP) transformed Indian eye banking, and the reason is instructive. The older model relied on voluntary pledges and telephone calls after a death at home.
• The key insight is that most people agree when asked, and the limiting factor is that nobody asks. Pledging cards are far less effective than a trained person making a request at the right moment
• Legal framework — the transplantation OF human organs and tissues act (1994, amended 2011) governs donation in India. Consent is from the next of kin; no payment may be made; and tissue must be allocated without regard to the donor family’s wishes about the recipient
• Retrieval — within about 6 hours of death (longer if the body is refrigerated); by IN-situ corneoscleral excision in preference to whole-globe enucleation, since it leaves the globe intact and is far more acceptable to families; with the lids closed, the head elevated and the eyes cooled beforehand
• Preservation — McCAREY-kaufman medium for up to 4 days; optisol-GS for up to 14 days, which is the standard; and organ culture for up to 4 weeks
• Evaluation — donor screening for transmissible disease; slit-lamp examination; and specular microscopy for the endothelial cell count, which should exceed 2,000 to 2,400 cells per square millimetre for optical grafting. Tissue below that may still be used for tectonic or therapeutic purposes
• Absolute contraindications to donation — death of unknown cause; HIV, hepatitis B and C, active syphilis, rabies; creutzfeldt-JAKOB disease and other prion disease; septicaemia; leukaemia and lymphoma; and retinoblastoma and other ocular malignancy
• What are not contraindications, and this matters because useful corneas are declined unnecessarily: age; refractive error and spectacle wear; the colour of the eyes; diabetes and hypertension; most cancers not involving the eye or blood; and previous cataract surgery in the distant past
• The limiting factor IN INDIA remains the supply OF tissue, not the availability of surgeons — and a substantial proportion of collected tissue is not used because of poor quality, positive serology or delay. Improving the utilisation rate matters as much as increasing collection