Search results for "Lens capsule"
showing 10 items of 11 documents
Closed foldable capsular rings
2004
A new foldable capsular tension and bending ring system with a sharp-edged design is described. The closed foldable capsular rings (CFCR) consist of 8 hydrophobic and 8 hydrophilic ring segments. The CFCRs have a 9.2 mm minimum overall diameter. The CFCRs were inserted using various cartridge systems or a two-folded technique with a forceps. The CFCRs were implanted after phacoemulsification through a small (1.6 to 3.2 mm) incision in 104 human adult eyes without intraoperative complications. No postoperative complications such as capsule folds or inward bending were observed over a 6-month follow-up. Posterior capsule opacification was minimal or absent in all eyes.
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…
Effect of large positioning holes on capsule fixation of plate-haptic intraocular lenses
2000
Abstract Purpose To compare the centration and fixation of silicone plate-haptic intraocular lenses (IOLs) with different-sized positioning holes. Setting Eye Clinic of the Johannes Gutenberg-University Mainz, Mainz, Germany. Methods In a prospective randomized study, 51 Chiroflex C10 and 56 Chiroflex C11 IOLs were implanted under standardized conditions by the same surgeon. The IOL position was documented at the end of surgery and by retroillumination on the first day and 5 months postoperatively. The positioning-hole area was evaluated by ultrasound biomicroscopy (50 MHz) 5 months postoperatively. Results One day postoperatively, no IOL in either group was decentered more than 1.0 mm. Aft…
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…
Capsule measuring ring to predict capsular bag diameter and follow its course after foldable intraocular lens implantation
2003
Purpose: To evaluate the extent of capsular bag shrinkage after cataract surgery with intraocular lens (IOL) implantation and develop a regression formula to predict postoperative capsular bag size. Setting: Eye Hospital, Johannes Gutenberg-University, Mainz, Germany. Methods: The axial length (AL), anterior chamber depth, and corneal radius in 58 eyes were measured preoperatively. Cataract surgery was by phacoemulsification followed by implantation of a 3-piece, acrylic, posterior chamber IOL. The capsular bag diameter and anterior capsulorhexis were measured intraoperatively and 1 day and 1, 3, and 6 months postoperatively using a Koch capsule measuring ring (HumanOptics). Results: The me…
Effect of a closed foldable equator ring on capsular bag shrinkage in cataract surgery.
2005
To evaluate the effect of a closed foldable equator ring (CFER) versus a conventional capsular tension ring (CTR) on capsular bag shrinkage.Department of Ophthalmology, Johannes Gutenberg-University, Mainz, Germany.In this prospective study, 70 eyes of 70 patients were randomized to 2 groups using a 1:1 block scheme. After uneventful cataract surgery, a capsular measuring ring was implanted in all eyes to measure the capsular bag diameter in vivo. In Group 1, a CTR was implanted in the capsular bag. In Group 2, a CFER was inserted. Biometric characteristics such as axial length and the horizontal and vertical corneal radii were measured preoperatively. The capsular bag diameter and capsulor…
Effect of trypan blue on the elasticity of the human anterior lens capsule.
2007
Purpose To evaluate the effect of trypan blue (VisionBlue) staining on the elastic properties of the human anterior lens capsule. Setting Center for Vision Science, Ruhr University Eye Hospital, Bochum, Germany. Methods Nineteen anterior capsules were obtained from 19 human eyes at the time of cataract operation. Two same-size strips were prepared from each capsule; 1 was exposed to trypan blue staining for 10 seconds, and the other was a control. The elasticity measurements were performed on both specimens using a modified rheometer. Results The mean age of the patients was 75.3 years ± 13.3 (SD) (range 35 to 89 years). Sixty-three measurements of 19 suitable specimen pairs were performed.…
Implantation of the modified endocapsular bending ring in pediatric cataract surgery using a viscoadaptive viscoelastic agent.
1999
Cataract surgery and intraocular lens (IOL) implantation in pediatric eyes remain controversial. Using a viscoadaptive viscoelastic agent, we implanted a modified capsular bending ring (CBR) as well as an acrylic IOL with a sharp-optic-edge design in the capsular bag. All operated eyes demonstrated a low postoperative inflammatory reaction and a clinically well-centered IOL. The band-shaped, sharp-edged CBR facilitates the creation of a sharp, discontinuous bend in the equatorial capsule, which prevents anterior and posterior capsule opacification. Combining the viscoadaptive viscoelastic agent and the CBR enhances the safety of primary and secondary posterior chamber IOL implantation in pe…
Capsular bag shrinkage after implantation of a capsular bending or capsular tension ring.
2005
To evaluate the influence of a capsular bending ring (CBR) or tension ring (CTR) on capsular bag shrinkage.Department of Ophthalmology, Johannes Gutenberg-University, and Department of Medical Biometry, Epidemiology and Informatics, University of Mainz, Mainz, Germany.In 92 eyes of 92 patients, a capsular measuring ring (CMR) was implanted after phacoemulsification to measure capsular bag size in vivo. Patients were randomized into 3 groups: The first received a CMR and CBR, the second received a CMR and CTR, and the third received a CMR alone. Measurements were performed preoperatively, intraoperatively, during the first 3 postoperative days, and after 1 and 3 months. Preoperative biometri…
Accommodative intraocular lenses: current status
2005
Purpose of review The possibility of using a monofocal IOL with accommodative ability allows refractive cataract surgery with a clearly decreased potential of photic phenomena. Three IOLs of different designs and materials have demonstrated accommodative ability, but the degree of accommodative amplitude has been reported to different extents and variabilities. The plate-haptic CrystaLens has a hinged design that might permit forward movement of the optic as a result of pressure changes in the vitreous cavity. The 1CU has modified haptics that bend in the bag as the lens capsule contracts, which are supposed to cause anterior displacement of the lens optic. With the dual-optic one-piece Syn…