The cornea is the eye's transparent front window — responsible for roughly two-thirds of the eye's total refractive power. When it becomes scarred, swollen, thinned, or irregularly shaped beyond what glasses, contact lenses, or lesser procedures can correct, a transplant becomes the only route back to vision. The major indications, in approximate order of frequency in India:

• Healed infectious keratitis (corneal scarring) — the leading indication for keratoplasty in Northern India. A corneal ulcer that has healed leaves behind permanent scar tissue in its place; if this scar sits over the visual axis, vision remains impaired long after the infection itself has resolved. This is a preventable cause — timely treatment of corneal ulcers and ocular surface infections reduces the eventual transplant burden. See our Corneal Ulcer guide for prevention.
• Advanced keratoconus — when the progressive corneal thinning and conical bulging of keratoconus reaches a stage where contact lenses no longer provide functional vision, or scarring/hydrops develops, keratoplasty (often DALK) restores a regular corneal surface. See our Keratoconus guide for the full disease progression and when cross-linking is no longer sufficient.
• Fuchs endothelial corneal dystrophy — a hereditary, progressive failure of the corneal endothelium (the innermost cell layer that pumps fluid out of the cornea to keep it clear). As endothelial cells die, the cornea swells and clouds — treated with DSEK/DMEK, which replace only this layer.
• Bullous keratopathy — corneal swelling and blister formation, most often following endothelial cell damage from complicated cataract surgery or long-standing glaucoma; corneal endothelial cell density has no capacity to regenerate once critically depleted.
• Corneal trauma and chemical injury — physical injury, chemical burns (acid or alkali), and thermal injury can cause irreversible scarring or perforation requiring tectonic (structural) or optical (vision-restoring) transplantation.
• Corneal dystrophies and degenerations — a group of inherited conditions causing progressive corneal clouding through abnormal material deposition within corneal layers.

India's corneal blindness burden is large, and the gap between need and supply has been documented for over two decades. Public health planning since the early 2000s has placed India's annual transplant requirement at approximately 100,000 procedures — which, accounting for a roughly 50% tissue utilisation rate (not every donated cornea is suitable or usable), translates to a need for around 200,000 donor corneas collected per year.

Actual collection has never come close. India's best-ever year was 71,700 donor eyes in 2017–2018 — and even that figure overstates usable supply, because voluntary donation tissue utilisation runs at only 22–28%, due to tissue quality issues, time delays in retrieval, and donor suitability screening. Hospital-based corneal retrieval programmes (where retrieval teams are embedded in hospitals to identify potential donors at the time of death) achieve a better utilisation rate of around 50%, which is why the National Programme has increasingly prioritised this model over passive voluntary donation drives.

The result is a current transplant rate that falls roughly four times short of the estimated 100,000/year need. The encouraging counter-data point: surveys of cornea surgeons and eye bankers have found that at well-run eye bank networks in India's major cities, over 60% report waiting times of less than one week for tissue availability once a patient is registered — suggesting the bottleneck is less about acute scarcity at registered centres and more about overall national capacity, regional distribution inequality, and the much larger pool of corneal-blind individuals who never reach a registered transplant centre at all.

Corneal transplant surgery is performed under local or general anaesthesia, typically as a day-case or with a single overnight admission, depending on the technique and the patient's overall health.

• Penetrating keratoplasty (PK): A circular trephine cuts out the diseased full-thickness central cornea of the patient's eye. A matching circular donor corneal button — cut slightly larger to account for tissue shrinkage — is sutured into place using fine, often nylon, sutures in a radial or running pattern. Surgery typically takes 60–90 minutes.
• DALK: The surgeon dissects down through the patient's diseased anterior stroma to the level just above Descemet's membrane, leaving the patient's own healthy endothelium intact, then sutures a donor anterior lamellar disc into the resulting bed. The "big bubble" technique — injecting air to separate stroma from Descemet's membrane — has made this dissection more reproducible.
• DSEK/DMEK: The patient's diseased Descemet's membrane and endothelium are stripped away through a small incision. A thin donor disc of stroma+Descemet+endothelium (DSEK) or Descemet+endothelium alone (DMEK) is folded, inserted through the small incision, unfolded inside the eye, and held in position against the posterior cornea using an air or gas bubble while it adheres — typically over 10–15 minutes of positioning.

Surgical instruments and materials relevant across all techniques include sharp, precise blades for the initial incisions (such as OP-BLADE surgical blades), ophthalmic viscoelastic devices to maintain anterior chamber stability and protect intraocular structures during manipulation (such as PURE-HYAL), and perioperative antibiotic prophylaxis to prevent post-surgical infection (such as MOXGUARD).

The cornea is one of the most immunologically privileged tissues in the body — it lacks blood vessels and has reduced lymphatic drainage, which is why corneal grafts have higher long-term survival rates than most other transplanted organs without requiring systemic immunosuppression. Survival rates at major Indian tertiary centres have been reported at approximately 79.6%, declining gradually over subsequent years for first-time grafts — figures that vary by indication, technique, and follow-up adherence. Despite this relative privilege, rejection remains the leading cause of graft failure, and recognising early signs is critical because rejection caught early can often be reversed with prompt treatment.

The mnemonic taught to patients: RSVP — any one of these symptoms after a corneal transplant warrants urgent ophthalmology review:

• R — Redness — new or worsening eye redness, particularly around the graft-host junction
• S — Sensitivity to light — new photophobia
• V — Vision change — any decrease in vision compared to the patient's post-operative baseline
• P — Pain — new or increasing eye discomfort

Rejection episodes are graded by which corneal layer the immune response targets — epithelial, stromal, or endothelial rejection (the most visually threatening, since destroyed endothelial cells cannot regenerate). Treatment is typically intensive topical corticosteroids, sometimes with adjunctive systemic immunosuppression for severe or recurrent episodes. Risk factors for rejection include prior graft rejection, corneal neovascularisation (blood vessel growth into the graft bed), large or eccentrically placed grafts, and younger recipient age.

Visual recovery speed differs dramatically by technique — a direct consequence of how much tissue is transplanted and how the wound heals.

All patients require long-term, often lifelong, follow-up with regular IOP checks (steroid-induced glaucoma is a recognised complication of prolonged post-operative steroid use), endothelial cell count monitoring (particularly after DSEK/DMEK), and vigilance for rejection signs even years after apparently successful surgery. Outcomes are consistently poorer in patients with bilateral corneal blindness compared to unilateral cases, and lower socioeconomic status has been independently associated with higher relative risk of transplant failure in Indian cohort studies — likely reflecting reduced access to the sustained follow-up care that long-term graft survival requires.

An eye bank is the regulated intermediary between donor and recipient — responsible for retrieval, evaluation, preservation, and allocation of donor corneal tissue.

• Retrieval — a trained technician retrieves the corneoscleral button (cornea plus a surrounding rim of sclera) or, less commonly today, the whole globe, within hours of death. Modern practice favours in-situ corneoscleral excision over whole-globe enucleation, as it is faster and less disfiguring.
• Screening — donor medical and social history is reviewed for transmissible disease risk (HIV, hepatitis B/C, rabies, sepsis, certain cancers, unknown cause of death). Serological testing is performed where required.
• Evaluation — the tissue is examined under a slit lamp and specular microscope to assess endothelial cell density and overall tissue quality, grading it for optical (vision-restoring) versus therapeutic/tectonic (structural, non-optical) use.
• Preservation — short-term storage uses McCarey-Kaufman (MK) medium (viable 3–4 days) or Cornisol/Optisol-GS medium (viable 10–14 days), refrigerated at 2–8°C. Glycerol preservation extends viability for tectonic use to weeks or months, but only non-optical grade, since it does not preserve endothelial cell viability.
• Distribution — many Indian eye banks now operate within networked systems with central distribution, allowing tissue collected in one city to reach a registered recipient anywhere within the network — improving overall national utilisation even where regional collection is uneven.

Modern lamellar splitting techniques mean that one donor cornea can, in suitable cases, be split to provide anterior tissue for one DALK recipient and posterior tissue for one DSEK/DMEK recipient — effectively doubling the number of people a single donation can help restore sight to.

• Who can donate — almost anyone, regardless of age, blood group, or prior eyesight (including people who wore glasses, had cataract surgery, or had one diseased eye — the unaffected eye may still be suitable). Final suitability is assessed by the eye bank at the time of donation, not pre-emptively by age or vision history alone.
• Who cannot donate — death from HIV/AIDS, viral hepatitis, rabies, septicaemia, certain leukaemias/lymphomas, and a small number of other conditions that pose infection transmission risk through the cornea.
• The time window — family or next of kin should contact the nearest eye bank within approximately 6 hours of death. Most city eye banks operate 24/7 retrieval helplines.
• What happens — a trained technician arrives, performs the retrieval (typically 15–20 minutes), and the body is released for funeral rites without delay or visible disfigurement to the face — the eyelids remain closed and the procedure is performed with care for the family's wishes.
• Pledging in advance — registering a pledge with a recognised eye bank in advance is straightforward (often available online) and signals intent — but family consent at the time of death remains legally and practically necessary in India, so informing close family of the wish to donate is the single most important step a prospective donor can take.