(n.) A defect of the eye or of a lens, in consequence of which the rays derived from one point are not brought to a single focal point, thus causing imperfect images or indistinctness of vision.
Example Sentences:
(1) The authors have presented in two previous articles the graphic solutions resembling Tscherning ellipses, for spherical as well as for aspherical ophthalmic lenses free of astigmatism or power error.
(2) The high incidence of infant astigmatism has implications for critical periods in human visual development and for infant acuity.
(3) The most frequently occurring signs were: tilting of the disc (89%), oblique direction of the vessels (89%) and myopic astigmatism (96%).
(4) There was no evidence of glaucoma in any of the patients although two patients exhibited keratoconus and another one manifested moderate to high astigmatism.
(5) Of 809 eyes that underwent the Kelman phacoemulsification and aspiration (KPE) procedure, we report on 4 patients (0.49%) who developed sudden against-the-rule (AR) astigmatism after intraocular lens implantation.
(6) The two last methods are used for correction of astigmatism.
(7) The eyes were compared to 105 control eyes in which no astigmatic incisions were performed to assess the estimated effect of the TAK incisions.
(8) The choice of the method depends on the kind and degree of astigmatism and the degree of the spherical ametropia of the operated eye.
(9) The change in refractive astigmatism was as high as 1.50DC (diopter cylinder).
(10) The endpoint for the procedure is corneal astigmatism that will allow either spectacle or contact lens correction, depending on the patient's visual needs.
(11) A total of 527 astigmatic patients were examined for their axial distribution.
(12) Astigmatism greater than +1.25 diopters (as high as +5.50 diopters) was most commonly associated with dacryoceles (eight of 12 eyes) and with hemangiomas (14 of 17 eyes).
(13) In terms of the various keratometry values compared, mean K (corneal refractive power), flattest K, steepest K, astigmatism and the axis of astigmatism, 65% to 75% of the cases on automated keratometry were within 0.26 dioptres or 11 degrees of manually determined values; the difference was statistically significant (p < 0.001).
(14) Young adulthood myopia progression also appeared to be accompanied by a slight tendency toward a with-the-rule astigmatic shift.
(15) Forty-nine cases of primary keratophakia and 13 cases of secondary keratophakia were analyzed for postoperative astigmatism.
(16) A numerical example reveals some lesser known properties of the circle of least confusion of astigmatic pencils.
(17) Group II includes 10 patients with astigmatism due to circumscribed peripheral limbal corneal dystrophy.
(18) Amblyopia was due to anisometropia in 24 cases (50%), strabismus in 9 cases (18.7%), high astigmatism (meridional) in 7 cases (14.5%) and other causes or a combination of factors in 8 cases (16.7%).
(19) The differences between the 2 eyes were not statistically significant so far as the amount of astigmatism, final visual acuity, and peripheral anterior synechiae were concerned.
(20) Results showed that the wearing of spherical soft contact lenses, such as those used in this study, cannot be expected to predictably mask astigmatism.
Cataract
Definition:
(n.) A great fall of water over a precipice; a large waterfall.
(n.) An opacity of the crystalline lens, or of its capsule, which prevents the passage of the rays of light and impairs or destroys the sight.
(n.) A kind of hydraulic brake for regulating the action of pumping engines and other machines; -- sometimes called dashpot.
Example Sentences:
(1) Instead of later renal failure and, of course, mental retardation, it was the histological features of the fetus eyes which permit to diagnose and exhibit both congenital cataract and irido-corneal angle dysgenesis.
(2) Hyperopia was more common in younger persons, but senile cataract, macular degeneration and palpebral dermatochalasis or blepharochalasis were more common in older persons.
(3) Two patients developed cataract following tetracycline therapy.
(4) Eighteen cases (28 eyes) with congenital cataracts are analyzed.
(5) The evidence linking increased sorbitol pathway activity to diabetic complications, such as cataract and neuropathy in animal models, suggests that aldose reductase inhibitors will be useful therapeutic agents in human diabetics.
(6) This study of 47 patients from 11 families with neurofibromatosis type 2 (NF 2) confirms our previously reported association between posterior capsular cataract and NF 2.
(7) We examined 84 eyes with different lens opacities, the visual acuity was analysed in relation to the axial, cortical and capsular cataract.
(8) The most important ocular side effect of the systemic adiministration of corticosteroids is the formation of a posterior subcapsular cataract.
(9) About 7% of all Saudi Arabians, and 42% of those older than 40 years, have a cataract or its sequelae.
(10) A 60-year-old man developed periodic alternating nystagmus in association with decreased vision due to cataracts.
(11) We describe our technique of endocapsular cataract extraction and insertion of an intraocular lens and prospectively compare 93 eyes which underwent endocapsular cataract extraction with 83 which underwent a standard extracapsular procedure.
(12) I believe that 80% of all cataract surgery within the next 10 years will be performed with extracapsular extraction and lens implantation.
(13) The eye was subsequently enucleated and histopathology confirmed the diagnosis of retinoblastoma associated with anterior polar cataract.
(14) One hundred twenty-five patients were entered into a prospective investigation designed to assess the effect of intraoperative surface modification of PMMA, by coating with a 2% hydroxypropyl methylcellulose solution, on the incidence of fibrinous uveitis after extracapsular cataract surgery and lens implantation.
(15) Knowledge of the incidence of both short- and long-term elevation of intraocular pressure (IOP) after extracapsular cataract extraction (ECCE) and posterior chamber intraocular lens (PC-IOL) insertion is essential for the practicing ophthalmologist.
(16) The shortest latent period of cataract development was three years and the youngest subject was only 22 years old.
(17) Severe iritis which occurs within the first five days after cataract extraction may be categorized as (1) bacterial endophthalmitis, (2) toxic iritis, or (3) aseptic iritis.
(18) Cataracts accounted for 22% of bilateral and 6% of monocular blindness.
(19) After doing, over the past two years, 55 Copeland iris plane lenses combined with intracapsular cataract extraction, I find it to be a relatively simple procedure.
(20) Emory mice (EM) are genetically predisposed to late-onset cataract formation.