Corneal Transplant — How It Works, Benefits & Recovery — Procedure Guide, Recovery & Risks | MyMedicPlus

A corneal transplant (keratoplasty) is an ophthalmic surgical procedure that replaces a diseased, scarred, or structurally abnormal cornea with healthy donor corneal tissue to restore visual function. The cornea is the clear outer dome of the eye; its optical clarity and curvature are essential for sharp vision. When the cornea is irreversibly damaged, transplantation is the only means of restoring sight. Several distinct surgical techniques exist, and the choice depends on which layers of the cornea are diseased. Penetrating keratoplasty (PK) replaces the entire corneal thickness; this was the traditional approach but is now reserved for cases where all layers are affected. Modern partial-thickness or lamellar techniques have largely replaced PK for many indications. Deep anterior lamellar keratoplasty (DALK) replaces only the stromal layers while preserving the patient's own endothelium, eliminating rejection of the endothelial layer (the main cause of graft failure). Descemet membrane endothelial keratoplasty (DMEK) and Descemet stripping endothelial keratoplasty (DSAEK/DSEK) replace only the innermost endothelial layer — ideal for Fuchs' dystrophy and bullous keratopathy. DMEK achieves superior visual outcomes compared to DSAEK and PK due to the thinner transplanted tissue and more anatomically precise replacement.

Corneal transplantation is indicated when corneal disease causes significant visual impairment that cannot be corrected by spectacles, contact lenses, or topical medication. The leading indications in high-income countries are: keratoconus — progressive corneal thinning and ectasia causing irregular myopia and astigmatism, typically requiring DALK when contact lenses no longer provide adequate correction; Fuchs' endothelial dystrophy — the most common indication for DMEK, where progressive endothelial cell loss causes corneal oedema and reduced vision; pseudophakic bullous keratopathy — endothelial decompensation following cataract surgery; corneal scarring from bacterial keratitis (e.g., Pseudomonas, Acanthamoeba), herpes simplex keratitis, or trachoma; posterior polymorphous corneal dystrophy and other inherited endothelial dystrophies; chemical burns causing corneal opacification; and previously failed corneal grafts. The decision to transplant requires demonstration of visual disability attributable to corneal disease rather than co-existing retinal or optic nerve pathology — macular and retinal function must be adequate for the patient to benefit. Systemic conditions (immunosuppression, uncontrolled diabetes) and ocular surface disease (dry eye, lid abnormalities) are addressed before surgery to optimise graft survival.

Surgery is typically performed under local anaesthesia with intravenous sedation or, in children and anxious patients, general anaesthesia, as a day-case or overnight procedure. For penetrating keratoplasty: a trephine (circular cutting tool) removes the entire diseased corneal button. The donor cornea — preserved in Optisol or dextran-based storage medium at 4°C and used within 14 days of harvest — is cut to the same or slightly larger diameter and sutured in place with 16–24 interrupted 10/0 nylon sutures, or a running suture. For DMEK: the diseased endothelium is stripped from the patient's cornea (descemet membrane stripping, DSAEK). The donor endothelial graft (a thin 10–15 micron scroll of Descemet membrane and endothelium) is folded, loaded into an injector, and introduced through a 3 mm incision into the anterior chamber, where it is unrolled and positioned against the corneal stroma with an air bubble injected to hold the graft in contact with the posterior cornea during the healing period. The patient is positioned face-up for 1 hour post-operatively to allow the air bubble to press the graft against the cornea. Sutures are not required for DMEK, enabling faster and more predictable visual recovery. The total operative time is typically 60–90 minutes under operating microscope visualisation.

Corneal transplantation restores functional vision in the majority of carefully selected patients. Five-year graft survival rates are 80–90% for most indications, with keratoconus showing the best long-term outcomes (90–95% at 10 years). DMEK for Fuchs' endothelial dystrophy achieves excellent visual outcomes: 70–80% of patients attain 6/6 (20/20) best-corrected visual acuity, compared to approximately 30–50% with DSAEK. DMEK also has significantly lower rejection rates (approximately 1–2% at 5 years) compared to penetrating keratoplasty (10–20% at 5 years), because the transplanted tissue volume is minimal and predominantly non-vascularised. DALK for keratoconus avoids endothelial rejection entirely while providing optical correction comparable to penetrating keratoplasty. Beyond visual acuity, quality of life improvements are substantial: patients with advanced keratoconus or Fuchs' dystrophy are often unable to drive or work effectively before surgery; most return to these activities within months. Corneal transplantation is one of the most successful solid organ transplant procedures globally, reflecting the immune privilege of the cornea due to its avascularity and limited lymphatic drainage.

Corneal transplant carries specific risks that patients must understand and monitor for lifelong. Graft rejection is the most important risk — it occurs in 10–20% of penetrating keratoplasty grafts by 5 years and presents with the 'RISDV' signs: Redness, Irritation, Sensitivity to light, Decreased Vision. Rejection is often reversible with urgent intensive topical steroid treatment if recognised early; patient education about these warning signs is essential. Primary graft failure (graft that never clears, due to inadequate donor endothelial cell density or surgical trauma) occurs in under 2% of cases at accredited eye banks with strict donor criteria. Raised intraocular pressure (secondary glaucoma) from topical steroid use or from surgical trauma occurs in approximately 10–20% of patients and requires anti-glaucoma therapy. Suture-related complications in penetrating keratoplasty include loose or broken sutures (causing astigmatism or infection), requiring suture removal or adjustment over 12–18 months. High post-keratoplasty astigmatism is common and may require rigid contact lenses, relaxing incisions, or repeat surgery to optimise visual outcomes. Endophthalmitis (intraocular infection) is rare but devastating. DMEK-specific risks include primary graft detachment requiring re-bubbling (occurs in 20–30% of DMEK cases, managed endoscopically under local anaesthesia in most cases).

An eye shield is worn for 2–4 weeks post-operatively to protect the eye from inadvertent trauma. Topical steroid drops (prednisolone or dexamethasone) are prescribed to prevent rejection and continued long-term — DMEK patients often taper steroids over 12–24 months; penetrating keratoplasty patients may require indefinite low-dose steroids. Antibiotic eye drops are used for 4 weeks. Vision after DMEK often begins to improve within 2–8 weeks as the donor endothelium actively pumps the oedema from the corneal stroma; full visual stabilisation takes 3–12 months. After penetrating keratoplasty, visual recovery is slower: sutures distort the cornea and are removed selectively between 12–18 months; best vision is not achieved until all sutures are removed and refraction has stabilised. Spectacles or rigid contact lens fitting follows once refraction is stable at 12–18 months post-PK. Patients are advised to avoid eye rubbing, contact sports without protective eyewear, and swimming in untreated water for the first 3 months. Regular follow-up is scheduled at 1 week, 1 month, 3 months, 6 months, and annually thereafter for life, as late rejection and graft failure can occur many years after transplantation.