PURPOSE To describe the prevalence of corneal astigmatism in infants and young children who are members of a Native American tribe with a high prevalence of refractive astigmatism. METHODS The prevalence of corneal astigmatism was assessed by obtaining infant keratometer (IK4) measurements from 1235 Tohono O'odham children, aged 6 months to 8 years. RESULTS The prevalence of corneal astigma...

BACKGROUND To use a Monte Carlo simulation to predict postoperative results with the AcrySof Toric lens, evaluating the likelihood of over- or under-correction using various toric lens selection criteria. METHODS Keratometric data were obtained from a large patient population with preoperative corneal astigmatism <= 2.50D (2,000 eyes). The probability distributions for toric marking accuracy,...

In modern cataract surgery, spectacle freedom is becoming more and more important. Emmetropia can be achieved for patients with myopic or hyperopic refractive errors by selecting the appropriate spherical lens power. However, approximately 20% of patients who undergo cataract surgery have 1.25 diopters (D) of corneal astigmatism or more. (FerrerBlasco, Montes-Mico et al. 2009; Hoffmann and Hutz...

Eyeglasses are a choice for correction for people with regular astigmatism and it doesn’t improve vision for irregular astigmatism. They will contain a cylindrical lens prescription for the astigmatism in a specific meridian of the lens which designates the axis of the lens power. Myopia or hyperopia can be associated to astigmatism. Generally, a single vision lens is prescribed so as to provid...

this study was conducted to define the prevalence and types of corneal astigmatism in relation with corneal optical power, axial length, sex and patient age. 641 cataract patients were included in a descriptive study. complete eye examinations were included in a descriptive study. complete eye examinations were performed. the data were analysed by standard procedures including analysis of varia...

Aim: We aimed to compare the results of photorefractive keratectomy (PRK) and femtosecond-assisted laser in situ keratomileusis (FS-LASIK) procedures treatment myopia myopic astigmatism.&#x0D; Material Method: Seventy eyes 35 patients with and/or astigmatism who had undergone PRK procedure were compared retrospectively 70 FS-LASIK procedure. &#x0D; Results: All completed 2-year follow-up period...

Aim: To determine the amount and type of surgically induced astigmatism (SIA),in superior and superotemparal sclera incisicion in small incision cataract surgery. Methods: A prospective randomized comparative clinical study. Study was done on a total number of 100 patients aged 40y and above with senile cataract. 50 cases were randomly assigned superior sclera group and other 50 cases were allo...

PURPOSE Our aim was to assess the corneal power, axis, and age dependence of the anterior and posterior corneal surfaces with Scheimpflug imaging. METHODS Patients older than 10 years without a history of ocular surgery, corneal diseases, contact lens wearing, or severe dry eye were enrolled. Data regarding the anterior and posterior cornea were analyzed by means of Scheimpflug imaging (Penta...

To determine if the involuntary contractions of eyelids may have any effects on the development of corneal astigmatism, we performed this prospective study which includes 19 patients with either essential blepharospasm or hemifacial spasm. In hemifacial spasm, the degree of corneal astigmatism was evaluated between two eyes. Then the topographic changes were checked using vector analysis techni...

PURPOSE To evaluate the agreement between total corneal astigmatism calculated by vector summation of anterior and posterior corneal astigmatism (TCAVec) and total corneal astigmatism measured by ray tracing (TCARay). METHODS This study enrolled a total of 204 right eyes of 204 normal subjects. The eyes were measured using a Galilei double Scheimpflug analyzer. The measured parameters include...