Repeatability of Scheimpflug Tomography for Assessing Fuchs Endothelial Corneal Dystrophy

Reply

“…2 Recognizing that CCT can vary with the disease state, time of day, and observer interpretation, and, as Dr. Toprak points out, that such variation directly affects clinical validity, we recently reported on the repeatability of interpretation of Scheimpflug tomography for FECD under various conditions. 3 For repeated images of the same eyes over the course of a morning, we concluded that the overall tomography patterns were maintained such that clinical decision making would be consistent in most cases. The repeatability of objective parameters derived from Scheimpflug images, including CCT, improved after excluding eyes with clinically detectable edema (i.e., more advanced disease) based on narrower limits of agreement (see Figs 2 and 3 in our recent article 3 ).…”

“…3 For repeated images of the same eyes over the course of a morning, we concluded that the overall tomography patterns were maintained such that clinical decision making would be consistent in most cases. The repeatability of objective parameters derived from Scheimpflug images, including CCT, improved after excluding eyes with clinically detectable edema (i.e., more advanced disease) based on narrower limits of agreement (see Figs 2 and 3 in our recent article 3 ). This indicates there is less diurnal variation in eyes without clinically detectable edema (i.e., less advanced disease), for which Scheimpflug imaging is most helpful.…”

Predicting Corneal Improvement after Descemet Membrane Endothelial Keratoplasty for Fuchs Endothelial Corneal Dystrophy

“…In addition, because successful DMEK almost certainly results in the maximum change in CCT of any current intervention for FECD, this predicted outcome measure could serve as a benchmark against which the effect of novel medical and surgical interventions, including Descemet stripping only, 15 can be compared. The model might also be better than using differences in CCT to assess disease progression in clinical research (Figures 2 and 3) because pachymetry map patterns are minimally affected by diurnal variations 16 ; however, this determination requires significant further systematic investigation beyond the 2 cases shown with longitudinal data.…”

Essentials of the corneal endothelium for the cataract surgeon

“…[103][104][105] The thinnest point of healthy corneas is found within the central 3mm of tissue -which does not occur in cases with endothelial disease. [106,107] In corneas with more severe involvement, there is also an important diurnal fluctuation of values, with morning values invariably higher than those in the afternoon. [108,109] A choice of technique (extracapsular with greater endothelial loss than phacoemulsification depending on the scenario), substances and supplies used, procedure duration, type of IOLs (anterior chamber IOLs should be avoided) and surgeon's experience have a direct influence on the final outcome.…”