PURPOSE We report the surgical management of a patient with glaucoma undergoing cataract surgery with high preexisting astigmatism. A combination of techniques was employed for her astigmatism management. METHODS A 76-year-old female with 5.5 dpt of corneal astigmatism underwent surgery in her left eye consisting of one-site trabeculectomy, phacoemulsification, toric intraocular lens implanta...

In the first part of this chapter, the optical condition of astigmatism is defined. The main causes and available classifications of ocular astigmatism are briefly described. The most relevant optical properties of image formation in an astigmatic eye are analysed and compared to that of an emmetropic eye and an eye with spherical ametropia. The spectacle prescription and axis notation for asti...

SEPTEMBER 2010 CATARACT & REFRACTIVE SURGERY TODAY EUROPE 25 A stigmatism is an optical defect that may lead to shadowing, loss of contrast sensitivity, distortion, blurred vision, and ghosting. There are two types of astigmatism, regular and irregular. Irregular astigmatism is often caused by a corneal scar or scattering in the crystalline lens. It is estimated that astigmatism of more than -0...

We report on our investigation into astigmatism in 40 eyes following a corneal cataract incision closed with a continuous 10/0 nylon monofilament suture (Ethilon). Immediately after surgery there was astigmatism caused by the nylon suture (suture-induced astigmatism), its severity depending on the tightness of the suture. It ranged from 1 to 10-5 dioptres, the mean value 4-09 dioptres with a st...

In astigmatism variations in the curvature of the cornea or lens along different meridians prevent the light rays from focusing onto a single point. Corneal refraction depends on the corneal curvature. If the cornea is more curved, the power of refraction is higher and vice versa. Corneal and lenticular astigmatism can complement or cancel each other. Their summation represents the so called “t...

We report on our investigation into astigmatism in 40 eyes following a corneal cataract incision closed with a continuous 10/0 nylon monofilament suture (Ethilon). Immediately after surgery there was astigmatism caused by the nylon suture (suture-induced astigmatism), its severity depending on the tightness of the suture. It ranged from 1 to 10 5 dioptres, the mean value 4 09 dioptres with a st...

PURPOSE To evaluate the influence of astigmatism in terms of its amount and direction on the results of Humphrey Matrix perimetry. METHODS A total of 31 healthy volunteers from hospital staff were consecutively recruited to undergo repeat testing with Humphrey Matrix 24-2 full threshold program with various induced simple myopic astigmatism. All subjects had previous experience (at least twic...

We studied the role of native astigmatism and ocular aberrations on best-focus setting and its shift upon induction of astigmatism in 42 subjects (emmetropes, myopes, hyperopes, with-the-rule [WTR] and against-the-rule [ATR] myopic astigmats). Stimuli were presented in a custom-developed adaptive optics simulator, allowing correction for native aberrations and astigmatism induction (+1 D; 6-mm ...

OBJECTIVE To analyze the effectiveness and safety of corneal relaxing incisions (CRI) in correcting keratometric astigmatism during cataract surgery. METHODS A prospective study of two groups: control group and treatment group. A treatment group included 25 eyes of 25 patients who had combined clear corneal phacoemulsification, IOL implantation and CRI. A control group included 25 eyes of 25 ...