Mini-DMEK for the Treatment of Chronic Focal Corneal Endothelial Decompensation

The purpose of the study was to evaluate the feasibility of mini-descemet membrane endothelial keratoplasty ("Mini-DMEK," graft diameter <5 mm) for the treatment of chronic focal corneal endothelial decompensation for reasons other than acute hydrops in patients with keratoconus.

Of the 3010 patients registered in the prospective Cologne DMEK database, 16 patients with focal corneal endothelial decompensation treated with Mini-DMEK were identified. After exclusion of patients with acute hydrops in keratoconus (n = 9), indications for focal corneal endothelial decompensation were either defects in Descemet membrane after intraocular surgeries (n = 5) or corneal edema in the area of Haab striae in buphthalmus (n = 2). Best spectacle-corrected visual acuity, corneal thickness in the affected area, and rebubbling rates served as main outcome measures.

All patients showed a postoperative increase in the best spectacle-corrected visual acuity from preoperative logarithm of the minimum angle of resolution (logMAR) 1.1 (±0.7) to logMAR 0.3 (±0.2) after the first month (P = 0.046) and to logMAR 0.3 (±0.2) after half a year (5-7 months) (P = 0.025). The corneal thickness decreased from preoperative 757 μm (±125) to 603 μm (±121) after the first month (P = 0.031) and to 593 μm (±131) after half a year (5-7 months) (P = 0.031). Rebubbling was necessary in 43% of patients (3 of 7 eyes). In 2 patients, Mini-DMEK was performed as triple Mini-DMEK including cataract surgery.

Mini-DMEK is an effective treatment option for focal chronic corneal endothelial decompensation caused by tears in Descemet membrane or other defects such as Haab striae. Mini-DMEK can also be performed as a triple procedure including cataract surgery (triple Mini-DMEK).