Double-C loop platform in combination with hydrophobic and hydrophilic acrylic intraocular lens materials.

PURPOSE: To analyze the behavior of a new double-C-loop quadripod symmetrical intraocular lens (IOL) platform combined with a hydrophilic lens material and a new hydrophobic glistening-free acrylic lens material, Ankoris and Podeye, respectively, in silico (computer simulation), in vitro (laboratory investigation), and in vivo (rabbit model). SETTING: John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA, and Physiol S.A., Liege, Belgium. DESIGN: Experimental study. METHODS: An in silico simulation investigation was performed using finite elements software, an in vitro investigation according to the International Organization for Standardization (ISO11979-3:2012), and an in vivo implantation in a rabbit model with 4 weeks of follow-up. Postmortem data were collected by Miyake-Apple gross examination and histopathologic analyses. Biocompatibility and IOL centration were tested. RESULTS: Both IOLs demonstrated statistically insignificant variations in posterior and anterior capsule opacification and Soemmerring ring formation. They were well biotolerated with no signs of toxicity, inflammation, or neovascularization. Axial and centration stability were noted in vitro and in vivo as a result of significant contact between surrounding tissues and haptics and the posterior portion of the optic. CONCLUSION: The results suggest suitability of the double-C loop IOL platform for the manufacturing of premium (ie, multifocal, toric, and multifocal toric) IOLs. FINANCIAL DISCLOSURE: Drs. Bozukova, Gobin, and Pagnoulle are employees of Physiol S.A., Liege, Belgium. Dr. Pagnoulle has a proprietary interest in the tested intraocular lenses. No other author has a financial or proprietary interest in any material or method mentioned.

Refractive index and its impact on pseudophakic dysphotopsia.

PURPOSE: It has been shown that the biggest dissatisfier for uncomplicated cataract surgery patients is pseudophakic dysphotopsia (PD). While edge design of an intraocular lens (IOL) impacts this problem, refractive index is still controversial as to its impact. This retrospective cohort study was designed to determine the role of increasing refractive index in PD. PATIENTS AND METHODS: This study was conducted at the John A. Moran Eye Center, University of Utah, USA. A retrospective chart review identified patients who received one of two hydrophobic acrylic single piece IOLs (AcrySof WF SP [SN60WF] or Tecnis SP [ZCB00]), which differed mainly by refractive index (1.55 versus 1.47). Eighty-seven patients who had received implantation of a one-piece hydrophobic acrylic IOL were enrolled. Patients were included if the surgery had been uncomplicated and took place at least a year before study participation. All eligible patients had 20/20 best corrected vision, without any disease known to impact visual quality. In addition to conducting a record review, the enrolled patients were surveyed for PD, using a modified National Eye Institute Visual Function questionnaire, as well as for overall satisfaction with visual quality. RESULTS: Statistical analysis demonstrated no difference between the two cohorts regarding PD, general visual function, and overall visual satisfaction. CONCLUSION: The study suggests that with the two IOLs assessed, increasing the refractive index does not increase incidence of PD or decrease overall visual satisfaction.

Light transmittance of 1-piece hydrophobic acrylic intraocular lenses with surface light scattering removed from cadaver eyes.

PURPOSE: To assess the potential effect of surface light scattering on light transmittance of 1-piece hydrophobic acrylic intraocular lenses (IOLs) with or without a blue-light filter. SETTING: John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. DESIGN: Experimental study. METHODS: Intraocular lenses were obtained from human cadavers (49 IOLs total; 36 with blue-light filter) and from finished-goods inventory (controls). The IOLs were removed from cadaver eyes and the power and model matched to unused controls. After surface proteins were removed, the IOLs were hydrated for 24 hours at room temperature. Surface light scattering was measured with a Scheimpflug camera (EAS-1000 Anterior Segment Analysis System). Light transmittance was measured with a Lambda 35 UV/Vis spectrophotometer (single-beam configuration; RSA-PE-20 integrating sphere). RESULTS: Hydrated scatter values ranged from 4.8 to 202.5 computer-compatible tape (CCT) units for explanted IOLs with blue-light filter and 1.5 to 11.8 CCT units for controls; values ranged from 6.0 to 137.5 CCT units for explanted IOLs without a blue-light filter and 3.5 to 9.6 CCT units for controls. In both groups, there was a tendency toward increasing scatter values with increasing postoperative time. No differences in light transmittance were observed between explanted IOLs and controls in both groups (IOLs with blue-light filter: P=.407; IOL with no blue-light filter: P=.487; both paired t test). CONCLUSIONS: Although surface light scattering of explanted IOLs was significantly higher than that of controls and appeared to increase with time, no effect was observed on light transmittance of 1-piece hydrophobic acrylic IOLs with or without a blue-light filter.

Light scattering and light transmittance of cadaver eye-explanted intraocular lenses of different materials.

PURPOSE: To evaluate light scattering and light transmittance in cadaver eye-explanted intraocular lenses (IOLs) manufactured from different materials. SETTING: John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. DESIGN: Experimental study. METHODS: Forty-nine pseudophakic cadaver eyes were selected according to IOL material/type and implantation duration, and the IOLs were explanted. Hydrophobic acrylic, hydrophilic acrylic, poly(methyl methacrylate) (PMMA), and silicone IOLs were included. Gross and light microscopy was performed for all IOLs. Light scattering was measured with an EAS 1000 Scheimpflug camera, and light transmittance was assessed using a Lambda 35 UV/Vis spectrophotometer (single-beam configuration with an RSA PE-20 integrating sphere). Analyses were performed at room temperature in the hydrated state and compared with analyses of controls. RESULTS: The highest levels of surface light scattering were measured for 3-piece hydrophobic acrylic, which was also the IOL type with the longest implantation duration among the Acrysof hydrophobic acrylic IOLs. Hydrophilic acrylic, PMMA, and silicone IOLs exhibited relatively low light-scattering levels. The lowest light-scattering levels were observed with PMMA IOLs (1-piece looped and 3-piece) and plate silicone IOLs, which represent the IOL types with the longest implantation duration in this series. Light transmittance values measured for all IOL types appeared to be similar to the values of the corresponding control IOLs. CONCLUSIONS: The phenomenon of surface light scattering (nanoglistenings) is more particularly related to hydrophobic acrylic IOLs and increases with implantation time. No significant effect of surface light scattering on IOL light transmittance was found.

Capsular bag opacification with a new accommodating intraocular lens.

PURPOSE: To evaluate the biocompatibility and capsular bag opacification of an accommodating intraocular lens (IOL) containing large haptic elements that separate the anterior and posterior capsules. SETTING: John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. DESIGN: Experimental study. METHODS: Bilateral phacoemulsification with IOL implantation was performed in 6 New Zealand rabbits. Each animal received a study (accommodating) IOL and a control (1-piece hydrophobic acrylic) IOL. Eyes were examined at the slitlamp from 1 day through 6 weeks postoperatively. The globes were then enucleated and evaluated grossly. Capsular bag opacification was scored from the posterior aspect (Miyake-Apple view). The eyes were then processed for complete histopathologic evaluation. RESULTS: At 6 weeks, the mean posterior capsule opacification (PCO) clinical score was 0.5 ± 0.3 (SD) in the study group and 3.0 ± 0.9 in the control group (P=.001, 2-tail paired t test). Anterior capsule opacification was practically absent in the study group and mild in the control group. Miyake-Apple posterior view showed a mean central PCO score of 0 ± 0 in the study group and 3.0 ± 1.1 in the control group (P=.001), peripheral PCO score of 0.7 ± 0.4 and 3.5 ± 0.8 (P=.0006), respectively, and Soemmerring ring score of 2.3 ± 0.8 and 7.0 ± 2.8 (P=.01), respectively. Histopathology showed no signs of toxicity in any eye. CONCLUSIONS: The study IOL maintained an expanded capsular bag secondary to the large size of the haptic elements, which appears to prevent capsular bag opacification.

Calcification of a hydrophilic acrylic intraocular lens after Descemet-stripping endothelial keratoplasty: case report and laboratory analyses.

We describe the case of an 83-year-old woman who had uneventful phacoemulsification with implantation of a tripod hydrophilic acrylic intraocular lens (IOL). Because of postoperative corneal decompensation, 2 Descemet-stripping endothelial keratoplasty (DSEK) procedures were performed within 2 years. After the second procedure, the graft was not well attached, requiring an intracameral injection of air on day 3. Approximately 9 months later, opacification was observed on the anterior surface of the IOL, with a significant decrease in visual acuity. The IOL was explanted within the capsular bag. Laboratory analyses revealed granular deposits densely distributed in a round pattern within the margins of the capsulorhexis. Granules were located at the anterior surface/subsurface of the IOL and stained positive for calcium (alizarin red and von Kossa method). Scheimpflug photography revealed high levels of light scattering from the opacified area. Surgeons should be aware of possible localized calcification following DSEK procedures in pseudophakic patients with hydrophilic acrylic IOLs.

Mucin deficiency causes functional and structural changes of the ocular surface.

MUC5AC is the most abundant gel-forming mucin in the ocular system. However, the specific function is unknown. In the present study, a Muc5ac knockout (KO) mouse model was subject to various physiological measurements as compared to its wide-type (WT) control. Interestingly, when KO mice were compared to WT mice, the mean tear break up time (TBUT) values were significantly lower and corneal fluorescein staining scores were significantly higher. But the tear volume was not changed. Despite the lack of Muc5ac expression in the conjunctiva of KO mice, Muc5b expression was significantly increased in these mice. Corneal opacification, varying in location and severity, was found in a few KO mice but not in WT mice. The present results suggest a significant difference in the quality, but not the quantity, of tear fluid in the KO mice compared to WT mice. Dry eye disease is multifactorial and therefore further evaluation of the varying components of the tear film, lacrimal unit and corneal structure of these KO mice may help elucidate the role of mucins in dry eye disease. Because Muc5ac knockout mice have clinical features of dry eye, this mouse model will be extremely useful for further studies regarding the pathophysiology of the ocular surface in dry eye in humans.