Descemet membrane endothelial keratoplasty and corneal biomechanics. / Queratoplastia endotelial de la membrana de Descemet y biomecánica corneal.

ABSTRACT

OBJECTIVE: To study the behaviour of the biomechanical properties of the cornea in DMEK (Descemet membrane endothelial keratoplasty). METHOD: Prospective longitudinal observational study. 21 pre and post-DMEK eyes. 3-month follow-up with the dynamic Scheimpflug Analyzer (Corvis ST, Oculus; Wetzlar, Germany). The following parameters were measured IOPnc non-corrected intraocular pressure (IOP), IOPb IOP corrected by biomechanics, maximum deflection amplitude (DefA), CCT central corneal pachymetry, flattening speed 1 and 2, peak distance, HC deformation amplitude deformation amplitude in maximum concavity, integrated inverse concave radius, DAR 1 and 2 deformation amplitude at 1mm and 2mm from the corneal apex, respectively. ARTh Ambrosial pachymetric ratio, SP1 stiffness parameter, CBI Corvis Biomechanical index and the maximum inverse radius. Pre-operative and post-operative measurements were performed with a 3-month follow-up and compared with a paired sample t-test. RESULTS: There was a significant decrease in the IOPnc of 1.54±3mmHg (p<0.05), a significant increase in the post-surgical IOPb of 3.79±3.18mmHg (p<0.001), a significant pachymetric decrease of 164.4±91.35µm (p<0.001) after the intervention. All dynamic parameters of the Scheimpflug analyzer changed significantly after surgery (p<0.05), except the ARTh and IWC variables. CONCLUSIONS: Variables indicate a decrease in corneal strength post-DMEK, with an increase in IOPb, at least the first 3 months after surgery. This finding is especially relevant in the follow-up of patients with coexisting glaucoma.