Corneal Transplantation & Keratoplasty (PKP, DALK, DMEK)
Surgical replacement of diseased, scarred, or ectatic cornea with donor tissue, spanning full-thickness PKP and advanced lamellar DALK and DMEK techniques.
Article Table of Contents
1. Comprehensive Overview
Corneal transplantation (Keratoplasty) is the most frequently performed and successful tissue transplantation worldwide, benefiting from ocular immune privilege and avascularity.
Evolving Surgical Modalities: 1. Penetrating Keratoplasty (PKP): Full-thickness replacement of host cornea with full-thickness donor graft, secured with 10-0 nylon microsutures. 2. Deep Anterior Lamellar Keratoplasty (DALK): Selective replacement of diseased epithelium and stroma while preserving the host's healthy native Descemet membrane and endothelium. Eliminates endothelial graft rejection risk; the gold standard for advanced keratoconus and stromal dystrophies. 3. Endothelial Keratoplasty (DSEK / DMEK): Selective transplantation of the endothelial-Descemet layer through a micro-incision without surface sutures, secured against the host stroma by an intracameral air/gas bubble. DMEK offers rapid visual recovery (often within weeks) and the lowest rejection rate (<1-2%) in organ transplantation.
2. Symptoms & Warning Signs
If you observe any of the following symptoms repeatedly, an eye exam is strongly recommended:
- Severe visual loss secondary to dense stromal opacities, bullous keratopathy, or advanced keratoconus
- Profound visual blur and distortion as if looking through frosted glass
- Graft Rejection Warning Signs (RSVP): Redness, Sensitivity to light, Vision drop, and Pain
3. Causes & Risk Factors
- 1Advanced keratoconus with extensive apical scarring or severe ectasia
- 2Pseudophakic / Aphakic Bullous Keratopathy from irreversible endothelial cell decompensation
- 3Fuchs' Endothelial Corneal Dystrophy (FECD)
- 4Dense corneal scars and leukomas following severe microbial keratitis or trauma
- 5Failed prior corneal graft requiring regrafting
4. Treatments & Medical Management
5. Prevention & Daily Eye Care Advice
- Strict compliance with postoperative topical steroid schedules without unauthorized self-discontinuation
- Wearing an eye shield during sleep and protective glasses during daytime activities
- Memorizing the RSVP graft rejection warning signs and presenting to the clinic within 24 hours of symptoms
- Strict avoidance of eye rubbing or direct trauma to the transplanted eye
6. When to Seek Emergency Eye Care
Visit an immediate eye emergency center if you experience any of the following critical indicators:
- ⚠Onset of any RSVP rejection sign: Redness, Sensitivity to light, Vision decline, or Pain
- ⚠Foreign body sensation indicating a loose, broken, or exposed suture
- ⚠New purulent discharge or blunt impact to the operated eye
7. Frequently Asked Questions
Q:Can a whole eye be transplanted?
Whole-eye transplantation for functional vision restoration is currently biologically impossible because severed optic nerve axons cannot regenerate back to the brain's visual cortex. Only anterior optical components (the cornea) can be successfully transplanted.
Q:What is the advantage of lamellar transplantation (DMEK/DALK) over PKP?
Lamellar surgeries selectively replace only the diseased tissue layer while preserving intact host layers, resulting in much faster visual recovery, superior structural integrity, and near-zero rejection rates.