View clinical trials related to Corneal Astigmatism.
Filter by:Abstract Purpose: To evaluate the visual performance and rotational stability of the Tecnis Toric one-piece IOL (AMO, USA) during the first 3 post-operative months Design: Prospective single center study Setting: VIROS - Vienna Institute for Research in Ocular Surgery, a Karl Landsteiner Institute, Hanusch Hospitel, Vienna, Austria Methods: In this prospective study patients with age-related cataract and corneal astigmatism of 1.0 to 3.0 D measured with the IOL-Master 500 (Carl Zeiss Meditec AG, Germany) were included. Pre-operatively, rotating Scheimpflug scans (Pentacam HR, Oculus, Germany) were performed and the cornea was marked in the sitting position at the slit lamp. Patients recieved a single-piece toric hydrophobic acrylic IOL (Tecnis Toric, AMO, USA). Immediately and 3 months after surgery retroillumination photographs were taken to assess the rotational stability of the IOL. Additionally, Autorefraction (Topcon, USA), subjective refraction, uncorrected and distance corrected visual acuity, keratometry, Scheimpflug and ocular wavefront (WASCA, Carl Zeiss Meditec AG, Germany) measurements were performed at the 3 months follow-up.
With increasing demands of patients concerning refractive outcome after cataract surgery, toric intraocular lenses (IOLs) that correct corneal astigmatism have been introduced more widely to cataract surgery. Originally toric IOLs were used mainly for patients with high degrees of astigmatism, especially after corneal surgical procedures such as penetrating keratoplasty. Since a couple of years, toric IOLs are available from numerous manufacturers to correct lower amounts of astigmatism which are much more prevalent with about 30% having a corneal astigmatism of 0.75D or more in the cataract population. This should result in less spectacle dependence of patients due to the astigmatic correction. The alternative method to reduce corneal astigmatism as part of cataract surgery is to make incisions on the steeper axis of the cornea such as limbal relaxing incisions or an additional clear corneal incision opposite (OCCI) to the main cataract opening. These techniques are in use since more than 2 decades and are widely used in clinical routine. As with toric IOLs, precise alignment of the cuts with the axis of astigmatism is essential. The disadvantage of the incisional techniques is the variability of the effect between patients since it depends on factors such as the extent of scaring of the cuts after surgery as well as corneal thickness. The main advantage is the simplicity of the technique and the lower cost. Aim of this study is to compare toric IOL implantation and opposite clear corneal incision during cataract surgery to correct corneal astigmatism.
To construct a computerized intraoperative keratometer to analyze the axis of corneal astigmatism accurately as well as rapidly by self-designed software during surgery.
To determine if arcuate incisions performed with the iFS femtosecond laser are safe and effective in reducing corneal astigmatism.
The main purpose of this study is to evaluate the use of limbal relaxing incision (LRI) for astigmatic correction. LRI is a procedure where a pair of incisions is made in the peripheral part of the cornea so as to alter its shape and improve the focusing power of the eye.
To assess visual performance in patients with low levels (0.5-0.75 Diopters) of corneal astigmatism.