Search results for "Lens"
showing 10 items of 948 documents
Bacterial Contamination of Anterior Chamber Fluid Following Non-complicated Cataract Surgery
1993
Objective: To study the anterior chamber contamination during non-complicated cataract surgery and its relationship with normal conjuctival organisms. Setting: Ophthalmology Department, La Fe Hospital, University of Valencia. Patients: Forty patients who had undergone cataract extraction using either ECCE, phacoemulsification or nucleus fracture methods. Results: Positive cultures of aqueous humour were obtained in 32.5% of cases. The most commonly isolated organism was Staphylococcus coagulase-negative. Only in 7.7% of cases was the microorganism found in the conjunctiva the same as that found in the anterior chamber. The inoculum size ranged between 20 and 160 colonies/ml. One of the case…
Tear Film Surface Quality in Modern Daily Disposable Contact Lens Wear
2021
Objectives As reported previously, tear film surface quality (TFSQ) should be considered in contact lens (CL) fitting. This study followed noninvasive keratograph tear film break-up time (NIKBUT) in CL wearers for 12 months to validate its clinical utility in predicting CL performance. Methods Fifty-five subjects (M/F=17/38) aged 26±4 years were prescribed silicone hydrogel or hydrogel CLs. The study included baseline measurements without CLs; 2 visits for CL fitting and control; follow-up after 3, 6, and 12 months of CL wear; and postwear visit without CLs. Ocular Surface Disease Index (OSDI), 8-Item Contact Lens Dry Eye Questionnaire (CLDEQ-8), first and mean NIKBUT (F/M-NIKBUT), fluoresc…
Implantable collamer lens with central hole: 3-year follow-up.
2018
Luis Fernández-Vega-Cueto,1 Carlos Lisa,1 José J Esteve-Taboada,2 Robert Montés-Micó,2 José F Alfonso1,3 1Department of Surgery, Fernández-Vega Ophthalmological Institute, Oviedo, Spain; 2Department of Optics and Optometry and Visual Sciences, University of Valencia, Valencia, Spain; 3School of Medicine, University of Oviedo, Oviedo, Spain Purpose: To evaluate the long-term predictability, stability, safety, and efficacy of the V4c Visian implantable collamer lens (ICL) with central hole to correct myopia.Patients and methods: One hundred and eighty-four eyes of 92 patients were evaluated during 3 years after implantation of …
Estimation of equivalent dose to the eye lens and hands in wrist surgery using OSL dosimetry
2016
The new recommendations of the International Commission on Radiological Protection (ICRP-2012 Publication 118) proposes reducing the limit of equivalent dose to the eye lens. For this reason, it is necessary to make estimates about received equivalent dose to the eye lens of medical staff. This study provides an alternative to dosimetry of the eye lens and hands, using dosimeters nanoDots based on optically stimulated luminescence (OSL) technology in wrist surgery procedure carried out with fluoroscopy.
Psychophysical and electrofunctional contrast sensitivity in cataractous patients treated with bendazac-lysine salt
1990
The clinical progression of the cataract may be influenced by drugs which reduce the denaturation of lens proteins. One of the most promising drugs is the bendazac-lysine salt. The drug was used in a double-blind study of a group of patients with initial cortical cataract in order to evaluate the changes in visual acuity and contrast sensitivity by means of a psychophysical and an electrophysiological method. After 6 months of treatment with bendazac the mean values of visual acuity showed a statistically significant increase in respect to baseline values, as well as an improvement of the threshold of contrast for most spatial frequencies. In the eyes treated with placebo there was no stati…
Prävention des früh-postoperativen IOD-Anstiegs nach Phakoemulsifikation
2001
Purpose. To compare the ocular hypotensive effect of different antiglaucomatous eye drops. Patients and methods. This double-blind, randomized study included 119 eyes of 119 patients without other ocular pathology undergoing standardized (one surgeon, Healon) small incision cataract surgery with foldable intraocular lens implantation.The patients were assigned to one of five groups: group 1:0.25% timolol in Gelrite (extended efficacy, n=23); group 2: 2% dorzolamide (n=24); group 3: combination of 0.5% timolol plus 2% dorzolamide (n=22); group 4: brimonidine (n=26); group 5: gentamicin (control, n=24). Intraocular pressure (IOP) was measured preoperatively and at 3±1,6±1,9±1,24±3, and 48±3 h…
Implantation of a custom intraocular lens with a 30-diopter torus for the correction of high astigmatism after penetrating keratoplasty.
2003
Abstract We present a 62-year-old woman who had implantation of an intraocular lens (IOL) with a torus of 30.0 diopters (D) in an eye after penetrating keratoplasty. The patient presented with cataract and a best corrected visual acuity of 20/400. Penetrating keratoplasty was performed in 1975 because of decompensated keratoconus. With a clear but inferiorly decentered corneal graft, visual acuity was limited because of keratoplasty-related high corneal astigmatism of 22.5@156 that could not be successfully treated with spectacles or contact lenses. A custom toric IOL with –30.0 D of cylindrical power was implanted in the capsular bag via a sclerocorneal tunnel incision. Additionally, a sph…
Spring constants of capsular tension rings.
2004
Purpose To determine the spring constants of several types of capsular tension rings (CTRs). Setting Department of Ophthalmology, Johannes Gutenberg-University, Mainz, Germany. Methods Fourteen models of CTRs provided by 9 companies were tested; all were 11.0 mm in diameter. The CTRs were positioned in a special retainer of a material-testing machine and compressed at a constant speed of 10.0 mm per minute. The distance and force values were recorded, and each CTR model was tested 3 times using a new specimen each time. The resulting measurements were used to calculate a mean spring constant for each CTR model. Results All tested CTRs showed linear proportionality between force and compress…
Optical quality of intraocular lenses after several years in the human eye
2013
The optical quality of explanted intraocular lenses (IOLs) was analysed to verify if their quality is maintained after having been in the human eye for several years. Twenty-five explanted IOLs were studied, 10 because of intraocular luxation and 15 from corneal donors. The dioptric power and modulation transfer function (MTF) were determined to discover the image quality of the IOLs. The spectral transmission was also established to ascertain whether the filter against ultraviolet (UV) radiation was still effective. The results show that the MTF of implanted IOLs is maintained and therefore so is the image quality they provide. Only decay in the MTF of some of the explanted IOLs was observ…
Influence of the tear film on optical quality of the eye
1997
The optical quality of the tear film of the eye was tested by measuring the retinal image before and after the break-up time (BUT). An objective method was used based on the evaluation of the retinal image of a point test projected onto the fovea. The loss of an entire tear film would result in a decrease in the optical quality because of corneal irregularities and the formation of an irregular tear lens after the BUT. Our results confirm the expected loss both of non-contact lens wearers and contact lens wearers. Also, the fact that the optical deterioration found after the BUT is greater for contact lens wearers confirms that soft contact lens wear produces a disruption of the tears.