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Surgery of the cornea: corneal, limbal stem cell and amniotic membrane transplantation.

PURPOSE
To demonstrate surgical treatment options for complications of severe forms of dry eye at the cornea, limbus and conjunctiva.


METHODS
Corneal, limbal and conjunctival surgical treatment strategies are outlined.


RESULTS
Amniotic membrane transplantation, different forms of corneal transplantation and limbal stem cell surgery all are treatment options for complications of dry eye disease.


CONCLUSIONS
Nowadays a broad spectrum of surgical treatment options exists to treat corneal complications of severe forms of dry eye at the ocular surface. Currently available conservative therapy for patients with 'dry eye' is primarily focused on augmenting or stabilizing the tear film and reducing primary or secondary causative factors such as inflammation of the ocular surface. While most patients with 'mild' and 'moderate' forms of dry eye (accounting for more than 95% of all patients with dry eye) can be treated sufficiently with drug treatment as well as environmental measures, some patients with very severe forms of dry eye need surgical intervention. Corneal surgery in the context of dry eye has primarily the objective to correct surface pathologies of the cornea caused by severe dysfunctions of the precorneal tear film. This primarily means persistent epithelial defects of the ocular surface, corneal ulcerations and consecutive corneal scarring. Besides conservative approaches, the first can be treated by amniotic membrane transplantation. Lamellar or perforating corneal transplantations are used to treat stromal scarring or perforated ulcerations as a sequel of persistent epithelial defects and associated apoptotic degeneration of stromal keratocytes. Finally, limbal stem cell transplantation can correct limbal stem cell deficiency states associated with or caused by diseases leading to severe forms of dry eye (e.g. chemical burns leading to destruction of conjunctival mucus-producing cells). All three surgical approaches will be discussed below.