Advances in Cataract Surgery

Majed Alkharashi; Walter J Stark; Yassine J Daoud


Expert Rev Ophthalmol. 2013;8(5):447-456. 

In This Article

Correction of Astigmatism During Cataract Surgery

Corneal astigmatism can be measured by multiple techniques including manual keratometry, autokeratometry, optical biometery and corneal topography. Topographic measurement of corneal astigmatism is currently the standard of care. Corneal topographic measurements identify irregular astigmatism that may limit optimum results.

Management of corneal astigmatism at the time of cataract surgery is an area of increasing importance and active research. Several approaches to correct corneal astigmatism have been successfully tried. These include main corneal incision-placement on the steep axis of the cornea, single or paired peripheral corneal relaxing incisions (PCRIs) and/or toric IOL implantation. Corneal incisions do not change the spherical equivalent power of the cornea enough to affect IOL power calculations. Because of the coupling effect, they flatten the meridian where they are placed and steepen the meridian 90° away.

For corneal astigmatism <1 D, placing the main corneal incision on the steep axis could be performed. With 1–1.5 D of astigmatism, peripheral corneal relaxing incisions may be utilized. Toric IOL is used for >1.5 D of astigmatism.[58]