A lenticular astigmatism happens when there’s a distortion in the lens. Astigmatisms are sometimes also described as regular or irregular ... a laser to create a disc-shaped piece of tissue ...

The measure of corneal astigmatism magnitude and its meridian ... Strumenti Oftalmici), which uses the combination of a Placido disc and a rotating Scheimpflug camera to measure the anterior ...

With respect to the underlying imaging principles, corneal topography devices currently used clinically can be classified as placido-disk systems ... of against-the-rule astigmatism and inferior ...

Figure 1. OPD-Scan III of the axial topography of the left eye showing regular central astigmatism with distortion of the placido ring. Source: Lisa K. Feulner, MD, PhD Figure 2. OPD-Scan III of ...

In corneal refractive surgery, corneal topography is used preoperatively to detect irregular astigmatism ... integration into refractive surgery. Placido-disk systems have excellent accuracy ...