Late Epithelial Downgrowth Following Penetrating Keratoplasty

To present a case of delayed epithelial downgrowth in an eye following penetrating keratoplasty for acanthamoeba keratitis.

Tertiary eye centre in London, UK. 

A 62-year-old female presented with a one-year history of decreased vision in her left eye. She had undergone penetrating keratoplasty in the same eye 20 years ago due to acanthamoeba keratitis. On examination, her visual acuity was reduced to 6/60, with pinhole correction improving it to 6/9. The cornea showed signs of graft failure, with sectoral clouding. Additionally, a mild cataract was noted. Cataract surgery was performed initially, followed by Descemet's membrane endothelial keratoplasty. Histological examination of the excised endothelium revealed folded Descemet’s membrane lined by epithelial cells, confirming epithelial downgrowth. The visual outcome was excellent, with a follow-up at four months showing a visual acuity of 6/7.5 and no signs of graft failure.

Epithelial downgrowth is a rare complication following penetrating keratoplasty, where epithelial cells invade the anterior chamber and may spread across the posterior cornea, iris, and anterior chamber angle. This condition can lead to corneal decompensation, intractable glaucoma, and, in severe cases, phthisis bulbi, negatively affecting visual acuity and graft survival. While most cases present with symptoms within the first year after surgery, this case illustrates that epithelial downgrowth can develop even decades after intraocular procedures. Surgical intervention may be an effective management option in such instances.