Descemet’S Membrane Endothelial Keratoplasty For Primary Graft Failure After Penetrating Keratoplasty

Penetrating keratoplasty (PKP) is an established technique used in the treatment of several corneal diseases. The endothelial rejection remains an important cause of graft failure in PKP. When a PKP graft fails to clear from the start, this complication is usually managed with a repeat PKP, which again exposes the patient to the inherent risks of an open-sky procedure and new additional antigens. The aim of this paper is to present a case of DMEK in a primarily failed PKP. This approach enables a safer procedure, faster visual acuity rehabilitation and less chance of endothelial rejection.

We report a case of Descemet’s membrane endothelial keratoplasty (DMEK) for the treatment of primary graft failure (PGF) following Penetrating Keratoplasty (PKP).

A 27-year-old female with advanced keratoconus, Kmax of 55.66D, with progressive decreased vision and contact lens intolerance. Uncorrected visual acuity (UCVA) was 20/400 in both eyes. There was no improvement in the right eye with refraction. She wore scleral contact lenses and visual acuity was limited to 20/50 in both eyes with them. She underwent PKP in the right eye. On the 1st POD, she presented a deepithelialized corneal graft, with diffuse edema associated with many Descemet folds. One week later, the cornea was re-epithelialized, but it maintained edema and visual acuity was worse than 20/800. Central corneal thickness was 785µm. Topical antibiotic was discontinued three weeks after surgery and dexamethasone sulphate was prescribed hourly. An empirical treatment for Herpes simplex keratitis was instituted with no response. With no clearing of the corneal edema, three months after the PKP, the patient underwent a phakic-DMEK for the treatment of primary graft failure. One month after surgery, UCVA was 20/40 improving to 20/20 with -0,50 x -2,25 x 70º. Corneal tomography performed 3 months after surgery showed a relatively regular anterior corneal surface.

DMEK is an alternative to a second PKP for the treatment of PGF. This technique is a less invasive option when compared to the standard PKP procedure. Besides it offers a faster visual rehabilitation and a reduced risk of rejection compared to repeat PKP. It is important to highlight that DMEK may have a relatively high incidence of primary graft failure by itself .Moreover, complications such as graft detachments or upside-down implantation may occur and may limit the use of this technique in these cases.Endothelial keratoplasty has revolutionized the field of corneal transplantation in the past few decades and it may significantly change the way primary failed PKP grafts are managed.