Effect of Photo‐Initiation Polymerization and Thermal‐Initiation Polymerization on the Reduction of Glistening in Hydrophobic Acrylic Intraocular Lens Materials

Glistening is the condensation of water that forms within the intraocular lens (IOL) materials. In this study, a new approach was attempted to reduce the glistening of IOL materials by introducing hydrophobic acrylic monomers with different alkyl side chain lengths into the IOL materials. Various hydrophobic acrylic monomers such as butyl acrylate (BA), 2‐ethylhexyl acrylate (EHA), and dodecyl acrylate (DA) were copolymerized with a hydrophobic acrylic monomer, 2‐phenoxyethyl acrylate, respectively. In this process, we investigated the effect of the alkyl side chain lengths of hydrophobic acrylic monomers on the glistening of hydrophobic acrylic IOL materials. As the content of hydrophobic acrylic monomers (BA, EHA, and DA) increased, the glistening of IOL materials decreased significantly for all hydrophobic acrylic monomers. At the same content of hydrophobic acrylic monomers, the IOL material showed the least content of glistening when copolymerized with DA. However, the IOL material obtained using BA exhibited the largest content of glistening, indicating that the glistening reduction effect was large in the order of DA>EHA>BA. These findings show that the glistening of IOL materials decreases with increasing alkyl side chain lengths of hydrophobic acrylic monomers.

Glistening is the condensation of water that forms within the intraocular lens (IOL) materials. In this study, a new approach was attempted to reduce the glistening using various types and content of crosslinking agents. Hydrophobic acrylic IOL materials were prepared from 2-phenoxyethyl acrylate using three different crosslinking agents: ethylene glycol dimethacrylate (EGDMA), 1,4-butanediol diacrylate (BDDA), and glycerol 1,3-diglycerolate diacrylate (GDGDA). The IOL material cross-linked with the GDGDA showed the least amount of glistening. However, the IOL materials exhibited the largest amount of glistening when cross-linked with the EGDMA, indicating that the glistening decreased in the order of GDGDA > BDDA > EGDMA.

Effect of types of hydrophilic acrylic monomers in reducing glistenings of hydrophobic acrylic intraocular lenses

Purpose: To compare the cost-effectiveness of different intra-ocular lens (IOL) materials (Hydrophobic acrylic, Polymethylmethacrylate (PMMA), Hydrophilic acrylic and Silicone) implanted after cataract surgery with reference to Nd:YAG laser capsulotomy and Nd:YAG-related complications in four European countries (France, Italy, Germany and Spain). Setting: A retrospective review of 1,525 patients (eyes), aged 50 to 80 years, operated with phacoemulsification for cataract in 1996 or 1997 in 16 surgical centres (4 per country). Methods: The study was conducted using a cost-effectiveness approach. Medical charts were reviewed to collect retrospective information during the 3-year period following cataract surgery in order to identify patients who underwent Nd:YAG laser capsulotomy post-operatively. Clinical data were combined with unit costs assessed by experts for Nd:YAG laser capsulotomy and their complications. A cost-effectiveness ratio (cost per patient without Nd:YAG laser capsulotomy intervention) was estimated in relation to each IOL material used in each of the four European countries. Results: Hydrophobic acrylic, specifically Acrysof ®, was the most cost-effective IOL material in all the countries except Germany where it was second. PMMA had the best ratio in Germany, was second in Spain and only third in Italy and France. Silicone was second in France and ranked third in the other countries, while hydrophilic acrylic had the worst ratio overall in all countries. Conclusions: Cost-effectiveness ratios of hydrophobic acrylic (Acrysof ®) were better than those of other types of IOL materials used in most of the countries. Sensitivity analyses were performed to vary the base case analysis to demonstrate the economic importance of the assumptions. In all cases, hydrophobic acrylic IOL material was shown to be a highly cost-effective option.

Neodymium:YAG capsulotomy rates associated with femtosecond laser–assisted versus manual cataract surgery

Zwitterionic sulfobetaine methacrylate (SBMA) coating on hydrophobic acrylic intraocular lens material to prevent the adhesion of lens epithelial cells: Effect of SBMA concentration

Influence of different acrylic intraocular lens materials on optical quality of vision in pseudophakic eyes

Purpose: To compare the chemotactic activity induced by polymethyl methacrylate (PMMA), acrylic, and silicone intraocular lens (IOL) materials, regardless of the surgical and host factors. Methods: The chemotactic effect of five different IOLs was studied using a modified multi-well Boyden chamber. Two different non-coated PMMA IOLs, a heparin-coated PMMA IOL, an acrylic IOL, and a silicone IOL were assessed. Each mean migration distance of the IOLs was compared with the others using Student's t test. Results: All IOLs induced some amount of leukocyte chemotaxis. There was no statistically significant difference between the chemotactic activity of PMMA IOLs. However, chemotactic activity was significantly higher in acrylic (p < 0.05) and silicone (p < 0.05) IOLs compared to one of the PMMA lenses. Conclusions: This limited study has proven that chemotaxis assay is a useful tool to assess the biocompatibility of IOLs. The IOL material itself might attract inflammatory cells to its surface in the absence of surgical and host factors. As PMMA IOLs do not cause an increase in inflammatory reaction, they may be considered safe to use. Further improvement in chemical composition and surface characteristics of IOLs should reduce the inflammatory reaction and increase the biocompatibility and safety of IOLs.

Role of vitrectomy with optic capture

Advances in cataract surgery have increased the demand for intraocular lens (IOL) materials. At present, the progress of IOL materials mainly contains further improving biocompatibility, providing better visual quality and adjustable ability, reducing surgical incision, as well as dealing with complications such as posterior capsular opacification (PCO) and ophthalmitis. The purpose of this review is to describe the research progress of relevant IOL materials classified according to different clinical purposes. The innovation of IOL materials is often based on the common IOL materials on the market, such as silicon and acrylate. Special properties and functions are obtained by adding extra polymers or surface modification. Most of these studies have not yet been commercialized, which requires a large number of clinical trials. But they provide valuable thoughts for the optimization of the IOL function.

Interaction with intraocular lens materials: Does heavy silicone oil act like silicone oil?

Purpose: To compare biofilm formation by Enterococcus faecalis on different intraocular lens (IOL) materials. Methods: E. faecalis biofilms were cultivated on disks of IOL material (silicone, PMMA [polymethylmethacrylate], or acrylic). Biofilms were stained with crystal violet (CV), which served as an index of biofilm formation. The bacterial population was enumerated after biofilm homogenization. Biofilms were also examined by confocal microscopy. Results: At 24 hr, there was no significant difference in biofilm formation, or the population within biofilms, among the three materials tested. However, after 48 and 72 hr, it was observed that silicone supported the least amount of biofilm formation (p < 0.05); biomass on PMMA and acrylic IOLs continued to increase, with acrylic demonstrating the greatest amount of stainable biofilm (p < 0.0005). The population on PMMA was significantly greater than the other IOL materials (p < 0.005). Confocal microscopy confirmed the lack of biomass on silicone. Conclusions: Among three IOL materials, E. faecalis biofilms formed more readily on PMMA and acrylic compared to silicone.

PurposeThe purpose of this study is to estimate and compare neodymium-doped yttrium aluminum garnet (Nd:YAG) capsulotomy rates for AcrySof ® and Clareon® intraocular lens (IOL) materials using historical data from the medical literature and Alcon-sponsored clinical studies.MethodsClinical trials that involved the implantation of AcrySof or Clareon monofocal IOLs in subjects with cataract or presbyopia were extracted from the literature and a company repository of clinical studies. The study duration, number of eyes, and cumulative percent of Nd:YAGs for posterior capsule opacification were extracted. Bayesian random effects meta-analyses were conducted to estimate and compare outcomes for the 2 different IOL materials.ResultsA Bayesian random effects, meta-analysis was performed that combined a literature review of published AcrySof Nd:YAG posterior capsulotomy rates and Nd:YAG rates observed in Alcon-sponsored clinical studies of AcrySof and Clareon. Sixteen Alcon studies contained Nd:YAG data suitable for meta-analysis. Three of these Alcon studies contained results for the Clareon material (2 one-year studies, and 1 three-year study). The literature review included 50 papers from 1998 to 2015. In combination, 30,891 eyes were available for analysis and 2040 Nd:YAG procedures were reported in studies with a follow-up duration ranging in length from 4 months to 10 years. The overall probability of performing a Nd:YAG capsulotomy within a year of implant for AcrySof was 1.44% (1.11% to 1.83%) and 0.62% (0.21% to 1.38%) for Clareon. There was small improvement in the probability of Nd:YAG within a year of implant for Clareon lenses of about 0.82% with a 95% credible interval of (0.07% to 1.36%) at 1 year. Results were similar for incidence rates per 100 surgeries in a year: 0.62 (0.21 to 1.40) for Clareon, 1.46 (1.12 to 1.87) for AcrySof, and the difference was 0.84 (0.07 to 1.39) favoring Clareon. At 3 years, the overall probability of performing a Nd:YAG capsulotomy for AcrySof was 4.19% (3.24% to 5.30%) compared with only 1.82% (0.63% to 4.02%) for Clareon.ConclusionA meta-analysis of Clareon multi-piece and single-piece clinical data predicts that the cumulative Clareon Nd:YAG probability will be ≤ AcrySof by 2.37% (0.18% to 3.91%) at 3 years. The results indicate that Clareon is likely to perform as well as, and possibly better than, AcrySof in terms of Nd:YAG capsulotomy rates.

Glistening on intraocular lenses: A review

El glistening de las lentes intraoculares: revisión de la literatura