Lisa Leishman

Prevention of capsular bag opacification with a modified hydrophilic acrylic disk-shaped intraocular lens

Purpose To evaluate the stability and capsular bag opacification with a modified disk‐shaped 1‐piece hydrophilic acrylic intraocular lens (IOL) suspended between 2 complete haptic rings connected by a pillar of the haptic material and with a commercially available 1‐piece hydrophilic acrylic IOL. Setting John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. Design Experimental study. Methods Study and control IOLs were implanted into the left eyes and right eyes of 5 New Zealand rabbits. Eyes were examined at the slitlamp from 1 through 4 weeks. At 4 weeks, the globes were enucleated and evaluated under a very‐high‐frequency ultrasound. Photographs were taken and capsular bag opacification scored from the posterior aspect (Miyake‐Apple view), and the eyes were processed for complete histopathology. Results At 4 weeks, the posterior capsule opacification score was 0.0 in the study group and 1.75 ± 0.5 (SD) in the control group (P=.005, paired t test). Ultrasound examination showed that 2 of the study IOLs had no contact between the posterior optic surface and the posterior capsule. Minimal proliferative cortical material was confined to the peripheral space between anterior and posterior rings of the study IOL haptics in localized areas at the equatorial region of the capsular bag. Anterior capsule opacification was absent in all eyes. Conclusions The study IOL is a modification of a previous design, incorporating haptic perforations between the peripheral rings. By maintaining an open capsular bag and enhancing endocapsular inflow of aqueous, this modified design appears to prevent capsular bag opacification. Financial Disclosure No author has a financial or proprietary interest in any material or method mentioned.

Light scattering and light transmittance in intraocular lenses explanted because of optic opacification

PURPOSE: To assess light scattering and light transmittance in intraocular lenses (IOLs) explanted because of optic opacification. SETTING: John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. DESIGN: Experimental study. METHODS: Poly(methyl methacrylate) (PMMA) IOLs with snowflake degeneration, hydrophilic acrylic IOLs with different calcification patterns, and 1 calcified silicone IOL explanted from an eye with asteroid hyalosis were studied with gross and light microscopy. Light scattering was measured with an EAS‐1000 Scheimpflug camera. Light transmittance was measured with a Lambda 35 UV/Vis spectrophotometer (single‐beam configuration with RSA‐PE‐20 integrating sphere). Analyses were performed at room temperature in the hydrated state and compared with controls. RESULTS: The study evaluated 8 PMMA IOLs, 22 hydrophilic acrylic IOLs, and 1 silicone IOL. Light scattering was as follows: 208 to 223 computer‐compatible tapes (CCTs) for PMMA IOLs with snowflake degeneration (control = 9 CCTs); 90 to 227 CCTs for calcified hydrophilic acrylic IOLs (controls = 12 to 23 CCTs); 223 CCTs for the calcified silicone IOL (control = 5 CCTs). The mean light transmittance in the visible light spectrum was 81.08% to 97.10% for PMMA IOLs (control = 98.80%); 78.94% to 97.32% for hydrophilic acrylic IOLs (controls = 97.32% to 98.66%); 94.68% for the silicone IOL (control = 97.74%). CONCLUSION: Intraocular lens opacification led to very high levels of light scattering and a potential for decreased light transmittance, which play a role in the development of symptoms such as glare and halos, decreased contrast sensitivity, and eventually decreased visual acuity. Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned.

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. Financial Disclosure Dr. Werner is a member of the Scientific Advisory Board of Powervision, Inc. No other author has a financial or proprietary interest in any material or method mentioned.

RNA interference targeting hypoxia-inducible factor 1α via a novel multifunctional surfactant attenuates glioma growth in an intracranial mouse model.

OBJECT High-grade gliomas are the most common form of adult brain cancer, and patients have a dismal survival rate despite aggressive therapeutic measures. Intratumoral hypoxia is thought to be a main contributor to tumorigenesis and angiogenesis of these tumors. Because hypoxia-inducible factor 1α (HIF-1α) is the major mediator of hypoxia-regulated cellular control, inhibition of this transcription factor may reduce glioblastoma growth. METHODS Using an orthotopic mouse model with U87-LucNeo cells, the authors used RNA interference to knock down HIF-1α in vivo. The small interfering RNA (siRNA) was packaged using a novel multifunctional surfactant, 1-(aminoethyl) iminobis[N-(oleicylcysteinylhistinyl-1-aminoethyl)propionamide] (EHCO), a nucleic acid carrier that facilitates cellular uptake and intracellular release of siRNA. Stereotactic injection was used to deliver siRNA locally through a guide-screw system, and delivery/uptake was verified by imaging of fluorescently labeled siRNA. Osmotic pumps were used for extended siRNA delivery to model a commonly used human intracranial drug-delivery technique, convection-enhanced delivery. RESULTS Mice receiving daily siRNA injections targeting HIF-1α had a 79% lower tumor volume after 50 days of treatment than the controls. Levels of the HIF-1 transcriptional targets vascular endothelial growth factor (VEGF), glucose transporter 1 (GLUT-1), c-MET, and carbonic anhydrase-IX (CA-IX) and markers for cell growth (MIB-1 and microvascular density) were also significantly lower. Altering the carrier EHCO by adding polyethylene glycol significantly increased the efficacy of drug delivery and subsequent survival. CONCLUSIONS Treating glioblastoma with siRNA targeting HIF-1α in vivo can significantly reduce tumor growth and increase survival in an intracranial mouse model, a finding that has direct clinical implications.

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. Financial Disclosure No author has a financial or proprietary interest in any material or method mentioned.

Anterior segment optical coherence tomography in the assessment of postoperative intraocular lens optic changes

PURPOSE: To evaluate the use of anterior segment optical coherence tomography (AS‐OCT) to assess postoperative intraocular lens (IOL) optic changes. SETTING: John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. DESIGN: Experimental study. METHODS: Intraocular lenses explanted because of various complications were used, including poly(methyl methacrylate) (PMMA) IOLs with snowflake degeneration, hydrophilic acrylic IOLs with calcification, a silicone IOL with calcification from an eye with asteroid hyalosis, and hydrophobic acrylic IOLs explanted because of decentration, subluxation, or uveitis–glaucoma–hyphema syndrome. After gross and light microscopy, the IOLs were examined in the dry and hydrated states using AS‐OCT. Selected hydrophilic acrylic IOLs were stained for calcium. In‐the‐bag IOLs in pseudophakic cadaver eyes were also evaluated by AS‐OCT before and after explantation to confirm correspondence with the clinical situation. RESULTS: Intraoptic changes, such as snowflake lesions in PMMA IOLs, calcification in hydrophilic acrylic IOLs, and glistenings in hydrophobic acrylic IOLs, could be imaged by AS‐OCT. The method was also helpful in analyzing the location and density. However, in cases of more superficial changes, unless the lesions/deposits were present on the optic surface with an extension to the optic substance of at least 0.1 mm, they could not be clearly differentiated from the overall outline of the IOL surface. CONCLUSIONS: Anterior segment OCT may be helpful in assessing the presence, location, and density of intraoptic changes, avoiding a misdiagnosis of IOL opacification and the performance of unnecessary procedures, such as posterior capsulotomy or vitrectomy. Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned.

Use of loteprednol for routine prophylaxis after photorefractive keratectomy

Background The purpose of this work is to report our experience using loteprednol 0.5% for routine prophylaxis after photorefractive keratectomy in an academic refractive surgery center. Materials and methods Photorefractive keratectomy was performed on 579 eyes from 316 patients in this retrospective chart review of patients treated postoperatively with either fluorometholone 0.1% (273 eyes) or loteprednol 0.5% (306 eyes). Primary outcome measures at 6 months included uncorrected distance visual acuity, corrected distance visual acuity, and manifest refraction spherical equivalent. Secondary outcome measures were incidence of corneal haze and increased intraocular pressure. Results There were no statistically significant differences in preoperative characteristics between the two groups when comparing age, sex, best-corrected visual acuity, spherical equivalent, or keratometry. Both groups achieved excellent visual outcomes, with a mean uncorrected distance visual acuity (logMAR) of 0.004 ± 1.4 in the fluorometholone group and −0.028 ± 1.1 in the loteprednol group (P = 0.013) at 6 months. Postoperative corneal haze and increased intraocular pressure were uncommon and not statistically different between the groups. Conclusion Loteprednol 0.5% performed similarly to fluorometholone 0.1% when used for prophylaxis following photorefractive keratectomy. The incidence of haze and increased intraocular pressure were similar between the two groups.

Pathologic Comparison of Asymmetric or Sulcus Fixation of 3-Piece Intraocular Lenses with Square Versus Round Anterior Optic Edges

OBJECTIVE To evaluate the pathologic findings of 3-piece intraocular lenses (IOLs) with asymmetric or sulcus fixation in pseudophakic cadaver eyes, comparing IOLs with square or round edges on the anterior optic surface. DESIGN Comparative case series with pathology. PARTICIPANTS A total of 661 pseudophakic cadaver eyes, obtained from eye banks within the United States, implanted with different IOLs. METHODS Anterior segment scanning of whole eyes with a high-frequency ultrasound system or high-resolution anterior segment magnetic resonance imaging followed by gross examination. Selected eyes were processed for complete histopathologic analysis. MAIN OUTCOME MEASURES Findings from imaging, gross, and histopathologic evaluation that could be related to out-of-the-bag fixation of the lenses. RESULTS Of 661 pseudophakic cadaver eyes obtained, 13 had 3-piece hydrophobic acrylic IOLs with anterior and posterior square optic edges, and 14 had 3-piece lenses with anterior round edges (13 silicone lenses and 1 hydrophobic acrylic lens) without symmetric in-the-bag fixation. These 27 selected eyes were processed for complete histopathologic analysis. Gross findings in both groups were composed of IOL decentration and tilt, pigmentary dispersion within the anterior segment and on the IOL surface, and iris transillumination defects. Histopathology of the 14 eyes with 3-piece IOLs with round anterior optic edges showed mild focal disruption of the iris pigmented layer and loop protrusion/erosion in the ciliary sulcus. Additional changes observed in the 13 eyes with square anterior optic edge IOLs included iris changes, such as vacuolization, disruption and loss of the pigmented epithelial layers, iris thinning and atrophy, synechiae, and pigmentary dispersion within the trabecular meshwork. One eye also exhibited initial signs of optic nerve disc cupping. CONCLUSIONS In this series, pathologic findings were more severe in eyes implanted with 3-piece IOLs with square anterior optic edges, suggesting that IOLs with round anterior edges are more suitable for sulcus fixation. FINANCIAL DISCLOSURE(S) Proprietary or commercial disclosure may be found after the references.

Calcification of a hydrophilic acrylic intraocular lens: Case report with laboratory analysis

We analyzed a single-piece plate-type hydrophilic acrylic posterior chamber intraocular lens (IOL) that was explanted due to a progressive loss of vision, which occurred 6 years after uncomplicated phacoemulsification. Gross and light microscopy, as well as anterior segment optical coherence tomography (OCT) revealed granular deposits below the IOL surface. Light scattering, as measured with Scheimpflug photography and densitometry analyses was found to be increased; spectrophotometry demonstrated a decrease in the light transmittance of the explanted lens. The granular deposits within the IOL material were found to be composed of calcium by histochemical methods (alizarin red and Von Kossa stains). To our knowledge this is the only report of calcification of this IOL design.

Long-term pathologic follow-up of obsolete design: Choyce Mark VIII anterior chamber intraocular lens

We analyzed an enucleated eye that was blind and painful from a 66-year-old patient implanted with a Tennant modification of the Choyce Mark VIII anterior chamber intraocular lens (IOL) as a secondary procedure in 1978. The eye developed glaucoma, with implantation of an Ahmed valve in 2006. Gross and light microscopic analyses showed corneal decompensation and vascularization, peripheral anterior and posterior synechiae, iris thinning, significant changes in the iris pigmented layer, fibrous tissue on the anterior surface of the iris, and Soemmerring ring formation in the periphery of capsular bag remnants. In addition, there was severe attenuation of the nerve fiber layer and extensive cupping of the optic disc. The IOL surface was overall smooth and regular, without warping of the footplates, and was partially covered by clumps of various cell elements, including giant cells intermixed with pigment. This study represents the longest clinicopathologic correlation report on this IOL.