Search results for "Lenses"
showing 10 items of 294 documents
Changes in higher-order aberrations after implantation of a foldable iris-claw lens in myopic phakic eyes
2006
Purpose To evaluate the change in higher-order aberrations (HOAs) after implantation of a foldable iris-claw phakic intraocular lens (pIOL) in myopic eyes. Setting Department of Ophthalmology, Johannes Gutenberg-University, Mainz, Germany. Methods This prospective nonrandomized comparative self-controlled trial included 41 eyes that had implantation of a foldable iris-claw pIOL between July 2003 and November 2004. All patient data for HOAs (Zernike coefficient) were measured and calculated using the same pupil size preoperatively and postoperatively, and the root-mean-square (RMS) wavefront error was calculated. Examinations were performed preoperatively as well as 1 week and 3, 6, and 12 m…
Impact of the pupil size – central optical zone diameter relationship on visual performance in aspheric multifocal contact lenses
2020
Abstract Purpose To determine the impact of different central optical zone diameters (COZDs), obtained from pupil size, on the visual performance of presbyopic subjects fitted with centre-distance simultaneous-image multifocal contact lenses (SIMCLs). Methods Thirty-two presbyopic volunteers, between 45–58 years of age, participated in this prospective, controlled, double-blind study. Subjects were fitted with 5 centre-distance SIMCLs of variable COZD, determined from the measurement of pupil size under photopic light conditions and corresponding to 60, 70, 80, 90 and 100 % of pupil diameter. Subjects visual performance was evaluated through the measurement of distance, intermediate and nea…
Reading ability with 3 multifocal intraocular lens models.
2006
Purpose To prospectively evaluate reading performance with of 3 types of multifocal intraocular lenses (IOLs) under different lighting conditions based on reading acuity and reading speed tests. Setting Augenklinik, Bad Hersfeld, Germany. Methods This randomized study comprised 60 cataract patients (120 eyes) randomly assigned to receive an SA40N IOL (AMO) (Group 1, 20 patients), Tecnis ZM001 IOL (AMO) (Group 2, 20 patients), or AcrySof ReSTOR SA60D3 IOL (Alcon) (Group 3, 20 patients). Pupil size and reading ability at near (visual acuity, reading speed) without correction, with best distance correction, and with best near correction were assessed 6 weeks postoperatively under low-light con…
Aspheric intraocular lenses enhance contrast sensitivity
2007
Evaluation of: Pandita D, Raj SM, Vasavada VA, Vasavada VA, Kazi NS, Vasavada AR. Contrast sensitivity and glare disability after implantation of AcrySof IQ natural aspherical intraocular lens: pro...
Postoperative Lens Position Preoperatively Determined by Scheimpflug Photography
1999
The position of the artificial lens has an important influence on refractive power calculation. We compared the position of the crystalline lens with that of the artificial lens after cataract surgery by means of Scheimpflug photography. A difference in position of approximately 0.8 mm in the anterior direction could be determined.
Lens implant selection with absence of capsular support.
2001
If contact lens or spectacle correction is not viable, little debate exists that the secondary placement of an intra-ocular lens (IOL) is the method of choice in the absence of capsular support. The choice of IOL mainly depends on the preoperative status of the eye (eg, aphakia in children) and the selected location for the implant. Theoretically, there are several IOL implantation approaches in cases without capsular support: an angle-supported anterior chamber (AC) IOL, an iris-fixated ACIOL, an iris-sutured or iris-fixated posterior chamber (PC) IOL and a transsclerally sutured PCIOL. No consensus exists, however, on the indications as well as on the relative safety and efficacy of these…
Validity of automated refraction after segmented refractive multifocal intraocular lens implantation
2017
Aim To evaluate the clinical utility of automated refraction (AR) and keratometry (KR) compared with subjective or manifest refraction (MR) after cataract or refractive lens exchange surgery with implantation of Lentis Mplus X (Oculentis GmbH) refractive multifocal intraocular lens (IOL). Methods Eighty-six eyes implanted with the Lentis Mplus X multifocal IOL were included. MR was performed in all patients followed by three consecutive AR measurements using the Topcon KR-8000 autorefractor. Assessment of repeatability of consecutive AR before and after dilation with phenylephrine 10%, and comparison of the AR and KR with MR using vector analysis were performed at 3mo follow-up. Results Ana…
Proclear EP vs placebo: visual outcomes and symptoms of asthenopia in nonpresbyopes and early presbyopes
2011
Purpose: Over the past 20 years, many studies have reported the success of multifocal contact lenses (MFCLs) compared to monovision (MV), with only partial success being reported for MFCLs. Chronologically it appears there has been a gradual improvement in the performance of MFCLs. This study investigated whether this change in success is reflected in clinical practice. Method: Lens fit data collected from 2005 to 2009 by the International Contact Lens Prescribing Survey Consortium was reviewed for patients over 45 years old. A similar survey conducted from 1988 to 1989 was also reviewed and compared. Twelve published (Pubmed.gov) reports of clinical trials involving MFCLs and MV were revie…
New Forceps and Spatula for Easy Retropupillary Implantation of Iris Claw Lenses in Aphakia: Experience in 4 Years of Use
2008
PURPOSE. Retropupillary implantation of an iris claw lens offers a rapid and atraumatic approach for rehabilitation of aphakic eyes. The difficulty in the implantation process arises because of the possibility of losing the intraocular lens (IOL) into the vitreous cavity and the need to change the hand holding the forceps during the enclavation. M ETHODS. The new forceps design radically changes the method of grasping an IOL. It contains an extendable supporting plate with a hook-like end. The instrument achieves a horizontal three-point fixation at the edge of the implant in the 6 and 12 o’clock position in order to prevent slippage into the vitreous cavity during the inclination. The supp…
New intraocular lens for achromatizing the human eye.
2007
To describe the design of a new intraocular lens (IOL) capable of correcting spherical and chromatic aberrations when implanted in the human eye.University of Murcia, Murcia, and University of Valencia, Valencia, Spain.A hybrid singlet achromatic IOL was designed. The IOL has a combination of a refractive and a diffractive surface, with 1 of the surfaces being aspherical. Optical simulations were used to model the polychromatic modulation transfer function (MTF) in pseudophakic eyes to explain the differences in optical quality afforded by the achromatic IOL. Parameters such as focus shift, optical path difference, through-focus, and robustness to tilt and decentering of achromatic IOLs wer…