DMEK leads to mild hyperopic shift, long-term refractive stability
AMSTERDAM — Corneal deturgescence following Descemet’s membrane endothelial keratoplasty leads to a mild hyperopic shift, probably caused by changes in the posterior surface of the cornea.
“After these minor changes, refraction remains stable in the long term,” Marina Rodriguez, MD, said at the European Society of Cataract and Refractive Surgeons meeting.
The mean spherical equivalent changed by +0.4D from preoperative to 3 months. The mean shift from preoperative to 2 years was +0.3D. The average change in cylinder was -0.2D at 3 months and -0.3D at 2 years. For both sphere and cylinder the refractive change was within 1D in more than 70% of the patients.
“Between 3 months and 2 years, refraction remained substantially stable. Pentacam outcomes showed no change in the corneal front and a change of -1D in corneal back,” Rodriguez said.
The small hyperopic shift after DMEK might result from a reversal of a preceding myopic shift induced by stromal swelling in endothelial disease, she explained.
“The preoperative stromal edema of the decompensated cornea, with consequent flattening of the posterior corneal curvature, leads to an increase of the corneal back power and to a myopic shift. Surgery reduces corneal swelling, leading to steepening of the posterior corneal curvature and to a hyperopic shift,” Rodriguez said.
Since no change in the anterior corneal curvature is induced, normal intraocular lens power nomograms can be used for cataract surgery prior to, during or after DMEK, she concluded.
Diclosure: Rodriguez has no relevant financial disclosures.