Descemet Membrane Endothelial Keratoplasty In Anterior Segment Dysgenesis

While Descemet membrane endothelial keratoplasty (DMEK) has been described in complex eyes, there is a scarce information on DMEK performed in eyes with anterior segment dysgenesis. The purpose of this report is to present a case in which a young patient with anterior segment dysgenesis with bullous keratopathy underwent staged cataract surgery followed by DMEK and to highlight the surgical considerations and challenges when performing DMEK in such an eye with complex anterior segment anatomy. 

This case was performed by a single surgeon in the Singapore National Eye Centre, a tertiary academic eye centre in Singapore. 

A 30 year old patient, with known history of anterior segment dysgenesis and glaucoma diagnosed in childhood, presented with bilateral progressive blurring of vision. On examination, her visual acuity was 6/30 and counting fingers in the right and left eye. There was bilateral microcornea with bullous keratopathy, worse in the left eye. There was extensive iris-corneal adhesion with limited view of the anterior segment in the right eye. In the left eye, the anterior chamber was shallow with nasal and temporal peripheral anterior synechiae, corectopia with a small pupil, thin hypoplastic iris and early lens opacity. Cataract surgery was first performed with specific measures taken to optimize visualization and surgical access, such as epithelial debridement, light pipe illumination, synechiolysis and iris hooks for pupil extension. During DMEK, a complete descemetorhexis and release of all iridocorneal adhesion was first performed. This was followed by insertion of a 6.0mm donor tissue using an endothelium-down pull-through technique. Full gas tamponade was accomplished despite challenges of a thin friable hypoplastic iris and significant iris defects not amenable to surgical closure. Postoperatively, the graft remained fully attached. Her best corrected visual acuity improved to 6/18 at 3 months. There were no other complications except late-onset intraocular pressure elevation which was medically controlled. 

DMEK is challenging in eyes with anterior segment dysgenesis due to the complex anatomy associated with microcornea, shallow anterior chamber, extensive peripheral anterior synechiae as well as iris hypoplasia and defects. Specific measures to enhance visualization and surgical access may be taken. Ensuring a complete descemetorhexis and release of any iris-corneal adhesion is important for graft attachment. Donor insertion using an endothelium down pull-through technique improves surgical control and reduces manipulation during graft unfolding in such complex eyes.