Descemet membrane endothelial keratoplasty (DMEK): intraoperative and postoperative complications and clinical results / Queratoplastia endotelial da membrana de Descemet (DMEK): complicações intraoperatórias e pós-operatórias com resultados clínicos

ABSTRACT Purpose: To evaluate the complications and clinical results of Descemet membrane endothelial keratoplasty (DMEK) in patients with endothelial failure that occurred during the learning curve of a surgeon. Methods: Fifty eyes of 50 patients with DMEK and ≥6 months of follow-up were included. The patients were divided into the first 25 (group 1) and the second 25 (group 2) procedures performed by the surgeon. Best corrected visual acuity (BCVA), central corneal thickness (CCT), unfolding time of the Descemet membrane (DM) graft, and intraoperative and postoperative complications were compared between groups. Results: The differences in postoperative increase of BCVA (p=0.595) and decrease of CCT (p=0.725) in the two groups were not significant. The unfolding time of the DM was longer in group 1 than in group 2 (p=0.001). Primary graft failure occurred in three patients in group 1 and none in group 2. At the last visit, 42 (85.7%) of patients' corneas were clear, with significant difference between groups (p=0.584). A patient in group 1 with a history of pars plana vitrectomy, inferior iridectomy, and fluid as a tamponade experienced drop of the DM graft into the iridectomy space. All other intraoperative complications occurred in group 1. Conclusions: Occurrence of intraoperative and postoperative complications was increased in patients with coexisting ocular pathology or complicated endothelial dysfunction and during the surgeon's learning curve of DM endothelial keratoplasty procedures.

RESUMO Objetivo: Avaliar as complicações e os resultados clínicos da queratoplastia endotelial da membrana de Descemet (DMEK) em indivíduos com insuficiência endotelial, durante a curva de aprendizado de um cirurgião. Métodos: Cinquenta olhos de 50 pacientes submetidos ao procedimento queratoplastia endotelial da membrana de Descemet com pelo menos 6 meses de acompanhamento foram incluídos neste estudo. Os pacientes foram divididos em dois grupos: como os primeiros 25 casos do cirurgião (grupo 1) e como os 25 casos seguintes (grupo 2). A melhor acuidade visual corrigida (MAVC), a espessura corneana central (ECC), o tempo de desdobramento do enxerto da membrana de Descemet (MD), as complicações intraoperatórias e pós-operatórias foram apresentadas e comparadas entre os grupos. Resultados: Os grupos não diferiram estatisticamente em relação ao aumento pós-operatório de melhor acuidade visual corrigida (p=0,595) ou à diminuição da espessura corneana central (p=0,725). O tempo de desdobramento dos enxertos de membrana de Descemet no grupo 1 foi maior do que no grupo 2 (p=0,001). Falha do enxerto primário foi observada em 3 pacientes do grupo 1 e em nenhum do grupo 2. Na última visita, 42 (85,7%) das córneas dos pacientes estavam claras e não foram observadas diferenças estatisticamente significativas entre os grupos (p=0,584). Na cirurgia de um paciente do grupo 1, com história de vitrectomia pars plana (PPV) com iridectomia inferior e fluido como tamponamento, observou-se queda do enxerto de membrana de Descemet no local da iridectomia. Além disso, todas as demais complicações intraoperatórias ocorreram no grupo 1. Conclusões: As complicações intraoperatórias e pós-operatórias foram maiores em pacientes com coexistência de outra patologia ocular ou com disfunção endotelial complicada durante as curvas de aprendizado dos cirurgiões no procedimento queratoplastia endotelial da membrana de Descemet.

Pérdida celular endotelial corneal asociada a facoemulsificación y experiencia del oftalmólogo: análisis prospectivo de datos secundarios individuales / Corneal endothelial cell loss associated to phacoemulsification and ophthalmologist experience: prospective analysis of individual secondary data

Resumen Introducción La facoéresis es el procedimiento en que se extrae quirúrgicamente el cristalino para tratar las cataratas. La pérdida endotelial corneal es una complicación reconocida. Si bien se han descrito diversos factores asociados a este daño, la experiencia del cirujano ha sido poco explorada. Objetivos Evaluar la asociación entre la experiencia del cirujano y otras variables asociadas a la pérdida celular endotelial en el contexto de la facoéresis. Métodos Se analizaron registros clínicos de 198 cirugías de cataratas, evaluando el efecto de la experiencia del cirujano y otras variables asociadas: energía disipada acumulada, tipo de viscoelástico empleado, uso de azul tripán, cantidad de fluídica, tiempo de ultrasonido, energía de facoemulsificación combinada y recuento celular endotelial pre y postoperatorio. Resultados No se observaron diferencias en el conteo postoperatorio de células endoteliales. Los oftalmólogos con más de cinco años de experiencia presentaron menor uso de azul tripán pero mayor cantidad de energía disipada acumulada en cada procedimiento, mientras que los oftalmólogos con menor experiencia utilizaron mayor cantidad de fluídica. Conclusiones Aunque hubo diferencias en el manejo de algunos factores influyentes sobre la pérdida endotelial cornal según la experiencia de los oftalmólogos, no se hallaron diferencias en relación a dicha pérdida como resultado final.

Abstract Introduction Phacoeresis is the procedure through which the lens is surgically removed to treat cataracts. A corneal endothelial loss is a recognized sequel. Although several factors associated with this harm have been described, the surgeon's prior experience has been scarcely evaluated. Objectives To assess the association between the surgeon's experience and other variables associated with a corneal endothelial cell loss in the context of phacoeresis. Methods Clinical records of 198 patients undergoing cataract operations were prospectively reviewed. The experience of the surgeon and other variables were recorded, including cumulative dissipated energy, viscoelastic type, the use of trypan blue, amount of fluidics, ultrasound time, combined phacoemulsification energy, and pre- and postoperative corneal endothelial cell counts. Results No differences were observed in the postoperative corneal endothelial cell count between surgeons with more or less than five years of experience. Nevertheless, ophthalmologists with more than five years' experience used less trypan blue, but more cumulative dissipated energy in each procedure, while less experienced ophthalmologists used less fluidics. Conclusions Although there were differences in the surgical management regarding the surgeons' experience in factors known to influence corneal endothelial cell loss, no differences in endothelial cell loss were observed as an outcome.

Central Corneal Thickness and Corneal Endothelial Cell Changes Caused by Contact Lens Use in Diabetic Patients

PURPOSE: To analyze the effects of soft contact lenses on central corneal thickness and morphologic characteristics of the corneal endothelium in diabetic patients. MATERIALS AND METHODS: Ultrasound pachymetry and noncontact specular microscopy were performed on 26 diabetic patients who regularly use soft contact lenses (group 1), 27 diabetic patients who do not use soft contact lenses (group 2) and 30 normal subjects (group 3). We compared the values in each group using the Mann-Whitney test. RESULTS: The central cornea was found to be thicker in diabetic patients, both those who use and do not use contact lenses, than in the normal control group. The central corneal thickness was significantly higher in group 1 (564.73 +/- 35.41 microm) and group 2 (555.76 +/- 45.96 microm) than in the control group (534.05 +/- 27.02 microm), but there was no statistically significant difference between groups 1 and 2. Endothelial cell density was significantly different between the groups, and was smallest in the group of diabetic patients using contact lenses. The coefficient of variation of cell size was significantly higher and the percentage of hexagonal cells was significantly lower in contact lens using diabetic patients than in non-contact lens using diabetic patients and in the control group. CONCLUSION: Central corneal thickness and endothelial cell density is more affected by diabetes mellitus, and corneal endothelial cell morphology is more affected by contact lens use, when compared with normal subjects.

Risk Factors for Endothelial Cell Loss after Phacoemulsification: Comparison in Different Anterior Chamber Depth Groups

PURPOSE: To assess the risk factors for endothelial cell loss after phacoemulsification with implantation of intraocular lens according to anterior chamber depth (ACD). METHODS: This prospective study included 94 eyes of 94 patients undergoing phacoemulsification cataract surgery. To assess the risk factors for corneal endothelial cell loss, we examined seven variables at 1 day, 1 week, 6 weeks, and 12 weeks postoperatively in each ACD-stratified group. RESULTS: Multiple linear regression analysis showed that the only variable influencing the percentage decrease in corneal endothelial cell density throughout the postoperative follow-up period in the long ACD group (ACD III) was nucleosclerosis. The variables influencing the percentage decrease in corneal endothelial cell density in the short ACD group (ACD I) at one day and one week postoperatively were corneal incisional tunnel length and nucleosclerosis. CONCLUSIONS: Risk factors for endothelial cell loss after phaoemulsification were different according to ACD. Long corneal tunnel length can be one of the risk factors for endothelial cell loss in short ACD eyes.