Difference between total and corneal astigmatism in degrees and astigmatic axis.

Total Corneal Astigmatism and Posterior Corneal Surface.

Total Corneal Astigmatism Measurement.

We read with interest the article by Tonn et al. on corneal astigmatism. At the beginning of the article, the authors indicated that: ‘‘Scheimpflug tomographers provide a map of the anterior chamber and therefore a more accurate model of the cornea, its thickness, and posterior surface.’’ Since the anterior chamber is really a space, and not a structure, it is probably clearer to say that Schei...

Contribution of posterior corneal astigmatism to total corneal astigmatism.

PURPOSE To determine the contribution of posterior corneal astigmatism to total corneal astigmatism and the error in estimating total corneal astigmatism from anterior corneal measurements only using a dual-Scheimpflug analyzer. SETTING Cullen Eye Institute, Baylor College of Medicine, Houston, Texas, USA. DESIGN Case series. METHODS Total corneal astigmatism was calculated using ray trac...

Corneal topographic astigmatism (CorT) to quantify total corneal astigmatism.

PURPOSE To evaluate the performance of corneal topographic astigmatism (CorT) based on total corneal power measurements. METHODS Anterior, posterior, and total corneal power measurements of 526 virgin eyes obtained using the CSO Sirius tomographer (Costuzione Strumenti Oftalmici, Scandicci, Florence, Italy) were analyzed. Individual CorTs were created from each set of data. These CorTs were a...

Total Corneal Astigmatism Measurement Precision.

We read with interest the article by Savini and Naeser on refractive astigmatism following toric intraocular lens (IOL) implantation. In the group of 40 eyes phacoemulsification was performed through a 2.75-mm temporal incision. In Table 1 it was indicated that surgical-induced corneal astigmatism along the surgical meridian (mean 6 SD) was -0.15 6 0.40 diopters (D; range, -0.81 to þ0.79 D) in ...