Question

Enumerate the lamellar corneal surgeries and give indications for each.

Hint:

Lamellar corneal surgeries aim to treat corneal diseases while preserving corneal structures like the endothelium, improving postoperative recovery and reducing complications.

Answer 1

Lamellar corneal surgeries involve the partial thickness removal or replacement of corneal tissue. These surgeries preserve the underlying corneal structures, such as the endothelium and Descemet’s membrane, and are typically used in the management of corneal diseases that do not affect the entire corneal thickness. The main types of lamellar corneal surgeries and their indications are:
1. Deep Anterior Lamellar Keratoplasty (DALK):
- Indications:
- Corneal scarring from keratoconus, bullous keratopathy, and corneal dystrophies.
- For patients with healthy endothelium but severe anterior corneal pathology, DALK preserves the endothelium while removing the affected anterior corneal layers.
2. Anterior Lamellar Keratoplasty (ALK):
- Indications:
- Anterior corneal scarring, astigmatism, and focal corneal opacities.
- Used in cases where only the superficial layers of the cornea are affected, preserving the deeper stromal layers and endothelium.
3. Descemet’s Stripping Endothelial Keratoplasty (DSEK):
- Indications:
- Endothelial dysfunction such as Fuchs’ endothelial dystrophy or bullous keratopathy.
- It involves the removal of the diseased endothelium and Descemet’s membrane, followed by transplantation of a thin endothelial graft.
4. Descemet’s Membrane Endothelial Keratoplasty (DMEK):
- Indications:
- Fuchs’ dystrophy or post-surgical endothelial dysfunction.
- DMEK is a more advanced procedure than DSEK, involving the transplant of only the Descemet’s membrane and endothelial cells, offering faster recovery and better visual outcomes.
5. Limbal Stem Cell Transplantation:
- Indications:
- For patients with limbal stem cell deficiency due to conditions like chemical burns, congenital limbal stem cell deficiency, or ocular surface diseases.
- The surgery involves transplanting limbal stem cells from a donor or from the patient's own eye to restore corneal epithelial regeneration.