Evaluation of Total Corneal Power Calculations for Intraocular Lens Selection Using the Optovue OCT in Descemet's Stripping Automated Endothelial Keratoplasty (DSAEK) Patients

Many patients with endothelial dysfunction also present with cataracts. It is therefore common practice to perform cataract extraction and intraocular lens (IOL) implantation during the same operation and immediately prior to Descemet's Stripping Automated Endothelial Keratoplasty (DSAEK), in order to minimize trips to the operating room and the associated risks of ocular surgery. However, the unique posterior corneal anatomy of the DSAEK recipient makes it difficult to predict pre-operatively the proper power of IOL to place, and some patients end up with a mismatched lens that requires spectacle correction. The current gold standard for IOL power calculation (A-Scan optical biometry) takes measurements of the anterior surface of the cornea and makes assumptions about the posterior surface that are violated by the unique hourglass shape of the donor DSAEK graft. New optical coherence tomography (OCT) technology provides us with the ability to measure curvature in both the anterior and posterior aspects of the cornea in order to generate an IOL calculation that has the potential to give more accurate results for our DSAEK patients.

The investigators will be using the Optovue to perform corneal power analysis on patients who have already received DSAEK and cataract surgery, in order to compare the post-op Optovue power calculations to the pre-operative power calculations provided by the A-Scan. If the OCT is shown to provide accurate IOL power calculations, then some patients might be better served by a two-stage procedure where DSAEK is performed and then followed six months later by cataract surgery using the OCT to calculate IOL power.