Search results for " Intraocular"
showing 10 items of 215 documents
Femtosecond laser for residual refractive error correction after refractive lens exchange with multifocal intraocular lens implantation.
2008
Purpose To assess visual and refractive outcomes of femtosecond laser for residual refractive error correction after refractive lens exchange (RLE) with multifocal intraocular lens (IOL) implantation. Design Prospective, nonrandomized, masked observational case series (self-controlled). Methods Fifty-three eyes of 31 consecutive patients were submitted to femtosecond laser surgery after RLE with multifocal IOL implantation. Patients showed an average manifest refractive error (D) of M , 0.200 ± 0.490; J 0 , −0.051 ± 0.532; and J 45 , −0.007 ± 0.371. Visual acuity (VA) was measured at distance and near vision before and six months after the surgery. Results At six months after surgery, mean …
Solvent for removing silicone oil from intraocular lenses: experimental study comparing various biomaterials.
2000
Abstract Purpose To evaluate the effectiveness of a perfluorocarbon—perfluorohexyloctane (PFHO)—in removing silicone oil from different intraocular lenses (IOLs) and determine whether any removal technique enhances the removal of silicone oil. Methods Six IOL materials were analyzed: standard poly(methyl methacrylate) (PMMA), heparin-surface-modified (HSM) PMMA, AcrySof, 2 polyHEMAs with different water contents, and a second-generation SLM-2 silicone. One or 2 μL of a highly viscous silicone oil (5700 cs) was applied to the center of each IOL optic. Perfluorohexyloctane (2 mL) was then used to remove the silicone oil by 1 of 3 techniques: immersion of the IOL in PFHO; irrigation of the sil…
Compression forces of haptics of selected posterior chamber lenses
1997
Abstract Purpose: To compare the compressive forces of the haptics of different intraocular lens (IOL) models and analyze the observed differences. Setting: Central Hospital of Central Finland and University of Jyvaskyla, Jyvaskyla, Finland. Methods: The haptics of 28 IOL models were compressed to a diameter of 9.0 mm. The compression forces were measured at 0.5 mm intervals. The conclusions were verified by numerical simulations of mechanical models of the lenses. Results: The measured forces varied between 100 and 601 mg at a diameter of 11.0 mm, 206 and 1057 mg at a diameter of 10.0 mm, and 315 and 2094 mg at a diameter of 9.0 mm. The slopes of the force curves of the three-piece lenses …
Compression forces of haptics of freely rotating posterior chamber intraocular lenses.
1998
Abstract Purpose: To measure the compressive forces of the haptics of 28 intraocular lens (IOL) models for different modes of compression and compare the results of two types of measurements. Setting: Department of Ophthalmology, Central Hospital of Central Finland, Jyvaskyla, Finland. Methods: The haptics of 28 types of IOLs were compressed to a diameter of 9.0 mm between curved anvils. The compression forces in the plane of compression (i.e., in the plane of the optics) were measured at 0.5 mm intervals. During compression, the optics and the haptics were free to rotate with respect to the anvils. The results were compared with those of earlier measurements in which the optics were held f…
Determination of scattering in intraocular lenses by spectrophotometric measurements.
2014
This study presents a method for measuring scattering in explanted intraocular lenses (IOLs). Currently, determining scattering in IOLs is usually performed by Scheimpflug cameras and the results are expressed in the units used by this apparatus. The method we propose uses a spectrophotometer and this makes it possible to measure the total transmission of the IOL by using an integrating sphere; the direct transmission is determined by the double-beam mode. The difference between these two transmissions gives a value of the scattering in percentage values of light lost. In addition, by obtaining the spectral transmission curve, information about the most scattered wavelengths is also obtaine…
Effect of Decentration on the Optical Quality of Two Intraocular Lenses
2016
To analyze the effect of decentration on the optical quality of two diffractive-refractive intraocular lenses, a bifocal and a trifocal, when displaced laterally (horizontal direction) from the center.The AT LISA 809M IOL (+3.75 D add) with two main foci and the AT LISA tri 839MP intraocular lens with three main foci (Carl Zeiss Meditec AG, Jena, Germany) were analyzed. The optical quality of the intraocular lenses was measured with the PMTF (power and modulation transfer function [MTF] measurement for refractive and diffractive intraocular lenses) optical bench (Lambda-X, Nivelles, Belgium). The optical quality of the lenses was evaluated by the MTF at different object vergences, the avera…
Agreement of predicted intraocular lens power using swept-source optical coherence tomography and partial coherence interferometry
2021
PURPOSE To analyze the agreement of the predicted intraocular lens (IOL) power obtained with ANTERION, IOLMaster 700 and Pentacam AXL biometers. METHODS We calculated the monofocal and trifocal IOL power using the SRK/T, Haigis, Barrett Universal II and Hoffer Q formulas for 106 eyes. IOL power agreement between devices was evaluated using the Bland-Altman method. RESULTS We found significant differences between biometers comparisons (p 0.05), with the same outcomes for medium- and long-eyes. No significant differences were found using the SRK/T, Haigis, or Hoffer Q formulas for short-eyes (p > 0.1). However, Barrett Universal II formula produced significant differences (p < 0.05) and thes…
Optical Quality Comparison between Spherical and Aspheric Toric Intraocular Lenses
2014
Purpose To measure and compare the optical quality of spherical and aspheric toric intraocular lenses (IOLs). Methods Wavefront aberrations of AcrySof Toric and IQ Toric IOLs (Alcon Laboratories) for different powers were measured at 3- and 5-mm pupils by Nimo TR0805 instrument. The Zernike coefficients of trefoil, coma, tetrafoil, secondary astigmatism, and spherical aberration were evaluated. The point spread functions (PSFs) of each IOL evaluated were calculated from the wavefront aberrations. The PSF images also were calculated from the IOL wavefront aberrations, adding the cornea's aberrations to simulate the optical quality after their implantation. Results Spherical toric IOLs showed…
A rapid method for measuring intraocular lens power in vitro with a focimeter.
2015
In this paper we describe a new method for measuring the intraocular lens (IOL) power using a focimeter, a negative ophthalmic lens and a saline solution (0.9% NaCl). To test this we measured the power of 58 different IOLs and we compared them with the power stated by the manufacturer. Despite the limitations, the results show a good correlation.