Management Of Epithelial Downgrowth After Penetrating Keratoplasty

To describe the medical and surgical management of a case of severe epithelial downgrowth following penetrating keratoplasty (PK).

All procedures were performed at a single center in Little Rock, Arkansas, USA.

A 58‑year‑old male with a past history of corneal ulcer in the right eye was referred for the evaluation of low visual acuity. The best corrected visual acuity (BCVA) was counting fingers at 1 meter in the right eye and 20/70 in the left eye (amblyopia). The intraocular pressure (IOP) was 16 mmHg in the right eye and 14 mmHg in the left eye. On slit‑lamp biomicroscopy corneal scar and nuclear sclerosis of the lens on the right eye were observed and a PK with a cataract extraction were performed. The surgery was uneventful, BCVA increased to 20/100 at 1 month after surgery and to 20/50 at 5 months after surgery.

At six-month follow-up BCVA was 20/70 and a membrane at the graft-host junction was noted. This was concerning for an epithelial downgrowth. It progressed centripetally for several weeks. In May 2024, the patient received intracameral Methotrexate (MTX, 400 mg/0.1 ml) weekly for 5 doses until the stabilization of the ingrowth was achieved.

Four weeks after the last injection, there was not a regrowth or progression of the membrane noted, but BCVA was 20/200 due to central corneal involvement. The patient subsequently underwent PK. The size of the corneal graft was chosen 1.5mm bigger (7.5 mm) than the previous graft (6 mm) in order to be able to remove the downgrowth in the graft-host junction completely.

By post-operative month six, BCVA was 20/100 (due to sutures / irregular astigmatism), IOP was 16 mmHg. Throughout this period no recurrence of the downgrowth was noted.

Epithelial ingrowth is an uncommon complication of intraocular surgeries and is characterized by the proliferation of corneal epithelial cells through the anterior segment. Many strategies have been proposed for the management, including irradiation, cryotherapy, laser photocoagulation, surgical removal. This article reports a case of successful treatment of epithelial ingrowth with intracameral MTX and PK. MTX is an antimetabolite agent that works by inhibiting dihydrofolate reductase in cells. Recently, MTX is proposed for the treatment of epithelial ingrowth. In our case, the stabilization of ingrowth successfully occurred after weekly intracameral MTX injection for a total of 5 doses. There was no recurrence in 6 month-follow‑up.