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Corneal astigmatism as measured by anterior and total corneal power
Session Title: Assessment of Astigmatism
Session Date/Time: Saturday 05/10/2013 | 11:00-12:30
Paper Time: 11:18
Venue: Main Lecture Hall (Ground Floor)
First Author: : M.Goggin AUSTRALIA
Co Author(s): : T. Greenwell Z. Katherine A. Paul
To compare measurements of anterior and total corneal astigmatism to refractive astigmatic in patients with spherical IOL’s
Publicly funded hospital and private hospital
40 eyes of 27 patients underwent coaxial microincision cataract surgery receiving a spherical intraocular lens implant. Manifest subjective refraction was determined at least 6 weeks postoperatively. At the same visit corneal measurements were obtained using a Nidek keratometer (Nidek Co., Gamagori, Japan) and one of two rotating Scheimpflug cameras (Pentacam, Oculus Inc., Wetzlar, Germany; or Precisio, iVis Technologies, Taranto, Italy). Ocular residual astigmatism (ORA) was defined by comparing the refractive outcome and corneal power measurements using vector analysis.
The ORA using Scheimpflug total corneal power was 0.6 dioptres (D) (SD = 0.2) for Pentacam and 0.9 D (SD = 0.5) for Precisio. ORA using Nidek keratometry was 0.7 D (SD = 0.5). ORA using Scheimpflug anterior corneal power was 1.3 D (SD = 0.9) for Pentacam and 1.0 D (SD = 0.6) for Precisio.
Accounting for anterior and posterior surface curvature in calculating corneal power may provide more accurate prediction of ocular residual astigmatism compared with anterior corneal power alone.