[Show abstract][Hide abstract] ABSTRACT: To evaluate the effect of the iPad as a low vision aid in improving the reading ability of low vision patients (LVPs).
In this study, 228 consecutive patients that came for their routine eye care examination at the University of Florida, Jacksonville eye clinic, were enrolled. Patients met inclusion criteria if they had best-corrected visual acuity (BCVA) of 20/100 or worse in the best corrected eye and were willing to participate in the study. The patient's reading ability was assessed both with the patient's own spectacles and an iPad. Patients were encouraged to enlarge the reading material as well as change the contrast until they could read comfortably. The number of patients able to read the text comfortably was recorded.
Out of the total 228 participants who qualified, 103 (45%) were male and 125 (55%) were female. Only 22% could read standard newsprint-sized text (N8) without the help of an iPad. With the help of an iPad, 94% participants with impaired vision were able to read standard newsprint-sized text (N8) or smaller text (P<0.01).
The iPad, a new portable electronic media device, can be adapted by LVPs to improve their reading ability.
[Show abstract][Hide abstract] ABSTRACT: This study determines 'correlation constants' between the gold standard histological measurement of retinal thickness and the newer spectral-domain optical coherence tomography (SD-OCT) technology in adult C57BL/6 mice.
PLoS ONE 10/2014; 9(10):e111203. · 3.53 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Ocular ischemic microenvironment plays a critical role in the progression of diabetic retinopathy (DR). In this study, human CD34(+) cells were incubated with vitreous or aqueous of subjects with PDR and evaluated for cell migration with CXCL12. Intracellular levels of nitric oxide (NO) was measured with DAF-FM. Tube formation assay used to evaluate the effect of treated-CD34(+) cells on in vitro angiogenesis. Angiogenic protein array and mass spectrometry (MS) was performed to ascertain factors secreted by healthy non diabetic CD34(+) cells exposed to diabetic vitreous or aqueous. PDR vitreous/aqueous reduced migration of CD34(+) cells (672.45±42.1 AFU / 736.75±101.7 AFU; p<0.01) and attenuated intracellular NO levels (182±1.4 AFU / 184.5±6.3 AFU; p=0.002). Pretreatment with PDR vitreous suppressed tube formation of human retinal endothelial cells (64±1.6 Vs 80±2.5). CD34(+) exposed to PDR vitreous resulted in the increased expression of CXCL4 and serpin F1 whereas CD34(+) exposed to PDR aqueous showed increased expression of CXCL4, serpin F1 and endothelin-1 (ET-1). MS analysis of CD34(+) (exposed to PDR vitreous) expressed J56 gene segment, isoform 2 of SPARC-related modular calcium-binding protein 2, isoform 1 of uncharacterized protein c1 orf167, integrin alpha-M, and 40s ribosomal protein s21. Exposure of healthy non diabetic CD34(+) cells to PDR vitreous and aqueous resulted in decreased migration, reduced generation of NO and altered paracrine secretory function. Our results suggest that the contribution of CD34(+) cells to the aberrant neovascularization observed in PDR is driven more by the pro-angiogenic effects of the retinal cells rather than the influence of the vitreous.
AJP Endocrinology and Metabolism 08/2014; · 4.09 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Retinal ischemia-induced upregulation of vascular endothelial growth factor (VEGF) leads to endothelial proliferation of the anterior segment, resulting in neovascular glaucoma.
[Show abstract][Hide abstract] ABSTRACT: Understanding measurement variability and relationships between measurements obtained on different optical coherence tomography (OCT) machines is critical for clinical trials and clinical settings.
[Show abstract][Hide abstract] ABSTRACT: Abstract Purpose: To assess the cytotoxicity of varying concentrations of Brilliant Blue Green (BBG) on Human Retinal Pigment Epithelial cells (HRPE) exposed to metal halide surgical endoilluminator (SE) at varying distances of illumination. Methods: HRPE (ARPE-19) were exposed to 2 concentrations (0.25 and 0.5 mg/mL) of BBG and illuminated with SE for 1, 5, and 15 min. Illumination (measured with light meter) was positioned at varying distances (1 and 2.5 cm) to mimic surgical distance of illumination. Cell viability (WST-1 assay) as well as structural changes in cells was quantified. Results: At 1 cm distance of illumination, 0.25 mg/mL BBG decreased viability of HRPE to 89.6%±4.3%, 83.9%±10.9%, and 38.9%±5.1% of controls after 1, 5, and 15 min of exposure, respectively. Similarly, 0.5 mg/mL BBG at 1 cm distance of illumination reduced the viability of HRPE to 93.7%±2.8%, 59.6%±16%, and 34.7%±3.5% of controls. At the distance of 2.5 cm, HRPE showed improved viability; cells exposed to 0.25 mg/mL BBG maintained 98.85%±3.3%, 95.31%±7.12%, and 62.07%±3.0% of viability compared with controls after 1, 5, and 15 min of exposure. Morphometric evaluation of RPE cells showed increased width (swelling) of HRPE. Conclusion: BBG at its clinically used concentration (0.25 mg/mL) during vitreoretinal surgery is safe and not toxic to HRPE for up to 5 min under focal illumination (1 cm) and up to 15 min under diffuse illumination (2.5 cm) from the commonly used SE. Translational Relevance: Results of our study are useful in establishing safety parameters for the use of BBG dye in vitreoretinal surgery.
Journal of Ocular Pharmacology and Therapeutics 07/2014; 30(8). · 1.42 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Objective. To prospectively evaluate the effect of intravitreal bevacizumab on aqueous levels of interleukin-6 (IL-6) and vascular endothelial growth factor (VEGF) in patients with exudative age-related macular degeneration (AMD) and correlate clinical outcomes with cytokine levels. Methods. 30 eyes of 30 patients with exudative AMD underwent intravitreal injection of bevacizumab three times at monthly intervals. The aqueous samples prior to the 1st injection (baseline) and 3rd injection were analyzed for VEGF and IL-6 levels. Subjects were subgrouped based upon change in the central subfield (CSF) macular thickness on SD-OCT at 8 weeks. Group 1 included patients (n = 14) with a decrease in CSF thickness greater than 10% from the baseline (improved group). Group 2 included patients (n = 16) who had a decrease in CSF thickness 10% or less (treatment-resistant). Results. In subgroup analysis, in both groups 1 and 2 patients, compared to aqueous VEGF, aqueous IL-6 levels showed a better correlation with CSF thickness on SD-OCT (r = 0.72 and 0.71, resp.). Conclusions. Aqueous IL-6 may be an important marker of treatment response or resistance in wet macular degeneration. Future therapeutic strategies may include targeted treatment against both VEGF and IL-6, in patients who do not respond to anti-VEGF treatment alone.
Journal of Ophthalmology 01/2014; 2014:502174. · 1.94 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: IMPORTANCE Sickle cell disease (SCD) is characterized by vaso-occlusive crisis. In the eye, central retinal artery occlusion (CRAO) is a rare complication in SCD, with only 1 previous report of bilateral, concurrent CRAO. We report a case of bilateral, concurrent CRAO in a patient with SCD, possibly precipitated by the use of phosphodiesterase 5 inhibitors. OBSERVATIONS A 37-year-old African American woman with a known medical history significant for SCD and pulmonary arterial hypertension who was receiving treatment with tadalafil, a phosphodiesterase 5 inhibitor, developed bilateral, concurrent CRAO that persisted after exchange transfusion. CONCLUSIONS AND RELEVANCE Bilateral CRAO secondary to SCD is extremely rare, with only 1 previous case report in the literature. The use of phosphodiesterase 5 inhibitors is an additional risk factor and may have contributed to the development of concurrent CRAO in this patient.
[Show abstract][Hide abstract] ABSTRACT: Abstract Context: Lutein (LUT) and zeaxanthin (ZEA) are currently under investigation in clinical trials as prophylactic nutritional agents for age-related macular degeneration (AMD). However, dose used in these trials is empirical and not been investigated in in vitro studies. Objective: In this study, we investigated the dose-response effect of LUT and ZEA in protecting retinal pigment epithelium (RPE) from oxidative stress, a common underlying pathology in AMD. Methods: Three thousand cultured human retinal pigment epithelial cells (ARPE-19) were plated in 72-well plate and after 24 h were exposed to increasing concentrations of hydrogen peroxide (H2O2). ARPE-19 cells were exposed to four different concentrations of LUT (0.5, 1, 2 and 4 µg/mL) and ZEA (0.1, 0.2, 0.4 and 0.8 µg/mL). After 24 h incubation, cells were subjected to oxidative stress induced with H2O2. Cultures containing saline solution and dichloromethane served as controls. Cell viability was assessed using the WST-1 assay. Pathophysiological pathways were evaluated by measuring caspase-3 levels as an indicator of apoptosis induction. Reactive oxygen species (ROS) levels were measured using dihydrorhodamine-123. Results: Cell viability as a percentage of control was 81.3%, 81.1%, and 88.8% at 0.5, 1, and 2 µg/ml, respectively of LUT (p < 0.001). The maximum cytoprotective effect was seen with LUT at 2 μg/mL. ZEA did not show any cytoprotective effect at all concentrations used in the study. Caspase-3 showed a corresponding decrease in levels with LUT (1 and 2 µg/ml). Significant decrease in ROS levels were measured only with LUT at 4 µg/ml (p = 0.02). Discussion and conclusions: Results from our study provide in vitro data to support the epidemiologic studies, which are currently underway to provide evidence that lutein may act as cofactor that modulates processes implicated in AMD pathogenesis.
Cutaneous and Ocular Toxicology 07/2013; 33(2). · 0.92 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To report normative data for retinal thickness in wild-type C57BL/6 mouse utilizing a miniature SD-OCT system.
THIRTY ADULT MICE (RANGE: 3-5 months) were anesthetized and secured into the Bioptigen Spectral Domain Ophthalmic Imaging System. Right eye SD-OCT images were standardized by centralizing the optic nerve head (ONH) prior to image acquisition. Global and quadrant total retinal thickness (TRT) values were measured from retinal nerve fiber layer to retinal pigment epithelial layer. Posterior segment analyses also included the outer retinal layer (ORL) and inner retinal layer (IRL). Further sublayer analyses of four layers from the ORL and three layers comprising the IRL were also performed.
The overall mean±SD global TRT in a C57BL/6 mouse model was 204.41±5.19 µm. Quadrant mean TRT values were 204.85±5.81 µm inferiorly, 204.97±6.71 µm nasally, 205.08±5.44 µm temporally, and 202.74±4.85 µm superiorly. Mean±SD thickness for ORL, and IRL were 126.37±10.01 µm, and 107.03±10.98 µm respectively. The mean±SD estimates for the four layers of the ORL were 18.23±2.73 µm, 26.04±4.21 µm, 63.8±6.23 µm, and 19.22±4.34 µm. Mean±SD values for the three IRL sublayers were 27.82±4.04 µm, 59.62±6.66 µm and 19.12±3.71 µm.
This study established normative values for the total retinal thickness and sublayer thickness for the wild-type C57BL/6 mice. Moreover, it provides a standard of retinal morphology, in a commonly used animal model, for evaluating therapeutic interventions and retinal disease pathophysiology.
PLoS ONE 06/2013; 8(6):e67265. · 3.53 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: PURPOSE: To evaluate the differential sensitivity of choroidal endothelial, retinal pigment epithelial, and retinal ganglion cells to escalating doses of proton beam radiation and to establish a safe dose range for the management of choroidal neovascularization associated with age-related macular degeneration (AMD). DESIGN: Laboratory investigation. METHODS: Proliferating simian choroidal endothelial cells (RF/6A), differentiated rat retinal ganglion cells (RGC-5), and serum-starved human retinal pigment epithelial cells (ARPE-19) were exposed to 2, 4, 8, and 12 cobalt gray equivalent of proton beam radiation and cell viability was quantified on day 9. Reactive oxygen species levels were analyzed. RESULTS: Significant decline of choroidal endothelial cell viability was noted as dose escalated from 4 to 8 cobalt gray equivalent with maximum effect observed at 12 cobalt gray equivalent. RGC-5 and ARPE-19 cell count decreased to 95% and 62.7% at 8 cobalt gray equivalent, respectively. Sub-analysis between 4 and 8 cobalt gray equivalent radiation revealed significant decrease in choroidal endothelial cell viability (43.1% at 7 cobalt gray equivalent and 32.3% at 8 cobalt gray equivalent of radiation). Correspondingly, RGC-5 and ARPE-19 cells did not show decrease in cell count or viability. Reactive oxygen species levels significantly increased in radiation-treated choroidal endothelial cells (8.3%-11.9%). CONCLUSIONS: At 6-8 cobalt gray equivalent proton beam radiation, retinal ganglion and retinal pigment epithelial cells are preserved while choroidal endothelial cells are completely inhibited. This dosage offers optimum therapeutic safety window for treatment using proton beam radiation for exudative AMD.
American Journal of Ophthalmology 06/2013; · 4.02 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The lens and retina of the human eye are exposed constantly to light and oxygen. In situ phototransduction and oxidative phosphorylation within photoreceptors produces a high level of phototoxic and oxidative related stress. Within the eye, the carotenoids lutein and zeaxanthin are present in high concentrations in contrast to other human tissues. We discuss the role of lutein and zeaxanthin in ameliorating light and oxygen damage, and preventing age-related cellular and tissue deterioration in the eye. Epidemiologic research shows an inverse association between levels of lutein and zeaxanthin in eye tissues and age related degenerative diseases such as macular degeneration (AMD) and cataracts. We examine the role of these carotenoids as blockers of blue-light damage and quenchers of oxygen free radicals. This article provides a review of possible mechanisms of lutein action at a cellular and molecular level. Our review offers insight into current clinical trials and experimental animal studies involving lutein, and possible role of nutritional intervention in common ocular diseases that cause blindness.
[Show abstract][Hide abstract] ABSTRACT: The purpose of this study was to evaluate cell cycle changes in choroidal endothelial cells treated with varying doses of bevacizumab in the presence of a range of concentrations of vascular endothelial growth factor (VEGF). Bevacizumab, a drug widely used in the treatment of neovascular age-related macular degeneration, choroidal neovascularization, and proliferative diabetic retinopathy, neutralizes all isoforms of VEGF. However, the effect of intravitreal administration of bevacizumab on the choroidal endothelial cell cycle has not been established.
Monkey choroidal endothelial (RF/6A) cells were treated with VEGF 50 ng/mL and escalating doses of bevacizumab 0.1-2 mg/mL for 72 hours. Cell cycle changes in response to bevacizumab were analyzed by flow cytometry and propidium iodide staining. Cell proliferation was measured using the WST-1 assay. Morphological changes were recorded by bright field cell microscopy.
Bevacizumab inhibited proliferation of choroidal endothelial cells by stabilization of the cell cycle in G0/G1 phase. Cell cycle analysis of VEGF-enriched choroidal endothelial cells revealed a predominant increase in the G2/M population (21.84%, P, 0.01) and a decrease in the G0/G1 phase population (55.08%, P, 0.01). Addition of escalating doses of bevacizumab stabilized VEGF-enriched cells in the G0/G1 phase (55.08%, 54.49%, 56.3%, and 64% [P, 0.01]) and arrested proliferation by inhibiting the G2/M phase (21.84%, 21.46%, 20.59%, 20.94%, and 16.1% [P, 0.01]). The increase in G0/G1 subpopulation in VEGF-enriched and bevacizumab-treated cells compared with VEGF-enriched cells alone was dose-dependent.
Bevacizumab arrests proliferation of VEGF-enriched choroidal endothelial cells by stabilizing the cell cycle in the G0/G1 phase and inhibiting the G2/M phase in a dose-dependent fashion.
[Show abstract][Hide abstract] ABSTRACT: Optimal phototransduction requires separation of the avascular photoreceptor layer from the adjacent vascularized inner retina and choroid. Breakdown of peri-photoreceptor vascular demarcation leads to retinal angiomatous proliferation or choroidal neovascularization, two variants of vascular invasion of the photoreceptor layer in age-related macular degeneration (AMD), the leading cause of irreversible blindness in industrialized nations. Here we show that sFLT-1, an endogenous inhibitor of vascular endothelial growth factor A (VEGF-A), is synthesized by photoreceptors and retinal pigment epithelium (RPE), and is decreased in human AMD. Suppression of sFLT-1 by antibodies, adeno-associated virus-mediated RNA interference, or Cre/lox-mediated gene ablation either in the photoreceptor layer or RPE frees VEGF-A and abolishes photoreceptor avascularity. These findings help explain the vascular zoning of the retina, which is critical for vision, and advance two transgenic murine models of AMD with spontaneous vascular invasion early in life. DOI:http://dx.doi.org/10.7554/eLife.00324.001.
[Show abstract][Hide abstract] ABSTRACT: Resveratrol, a polyphenolic phytoalexin present in red wine, has a protective role against tumor-induced angiogenesis. Exudative age-related macular degeneration is characterized by hypoxia-induced choroidal vascular endothelial cell (CVEC) proliferation. In this study, we evaluated the effect of resveratrol on hypoxic CVECs and the underlying signaling pathways involved.
CVECs (RF/6A) after induction of hypoxia with cobalt chloride (CoCl2, 200 μM) were exposed to increasing doses of resveratrol (2, 4, 6, 8, 10, and 12 μg/ml). Cell viability was measured with 4-[3-(4Iodophenyl)-2-(4-nitrophenyl)-2H-5-tetrazolio]-1, 3-benzene disulfonate (WST-1) colorimetric assay. The effect of resveratrol on hypoxia-induced vascular endothelial growth factor (VEGF) release was analyzed with enzyme-linked immunosorbent assay. The mechanistic pathway was further evaluated by analyzing phosphorylated stress-activated protein kinase/c-Jun N-terminal kinase (SAPK/JNK) using immunoblot and cleaved caspase-3 with In-Cell enzyme-linked immunosorbent assay.
Resveratrol inhibited hypoxic CVEC proliferation. Hypoxia-induced VEGF release (30.9±2.6 pg/ml) was inhibited in a dose-dependent fashion by 2, 4, 6, 8, 10, and 12 μg/ml resveratrol to 12.4±2.1, 11.0±1.9, 10.3±3.0, 7.5±1.9, 5.5±2.0, and 5.5±2.3 pg/ml, respectively. SAPK/JNK increased by 1.8-fold and 3.9-fold after treatment with 4 and 12 μg/ml resveratrol, respectively. Significant increase in caspase-3 levels was observed with 12 μg/ml resveratrol.
Our study demonstrates that resveratrol suppresses hypoxic CVEC proliferation through activation of the SAPK/JNK pathway. Resveratrol, a nutritional supplement and inhibitor of CVECs, may be a useful adjunct to current anti-VEGF therapy in wet age-related macular degeneration.
[Show abstract][Hide abstract] ABSTRACT: PURPOSE: To evaluate macular thickness in people with diabetes but minimal or no retinopathy using Heidelberg Spectralis optical coherence tomography (OCT). METHODS: In a multi-center, cross-sectional study of mean retinal thickness, on Spectralis OCT in the 9 standard OCT subfields, spanning a zone with 6 mm diameter, center point, and total retinal volume were evaluated. Central subfield (CSF) thickness was evaluated for association with demographic and clinical factors. Stratus OCT scans also were performed on each participant. Results: The analysis included 122 eyes (122 participants) with diabetes and no (N = 103) or minimal diabetic retinopathy (N = 19) and no macular retinal thickening on clinical exam. Average CSF thickness was 270 ± 24 µm. Central subfield thickness was significantly greater in men relative to women (mean 278 ± 23 µm versus 262 ± 22 µm, P<0.001). After adjusting for gender, no additional factors were found to be significantly associated with CSF thickness (P>0.10). Mean Stratus OCT CSF thickness was 199±24 µm. Conclusions: Mean CSF thickness is ~70 µm thicker when measured with Heidelberg Spectralis OCT as compared with Stratus OCT among individuals with diabetes in the absence of retinopathy or with minimal non-proliferative retinopathy and a normal macular architecture. CSF thickness values ≥320 µm for men and 305 µm for women (~2 standard deviations above the average for this normative cohort) are proposed as gender-specific thickness levels to have reasonable certainty that diabetic macular edema involving the CSF is present using Spectralis measurements.
[Show abstract][Hide abstract] ABSTRACT: This protocol outlines and evaluates a modified scanning procedure for a customized spectral domain optical coherence tomography (SD-OCT) imaging apparatus within the wild-type C57Bl/6 mouse posterior segment. This modified protocol allows for the capture of a 50 degree field of view spanning 3 mm by 3 mm perimeter with the optic disc as the central point. By utilizing this scanning protocol a more reliable measurement of retinal thickness can be achieved outside the fluctuating region of the optic disc. This protocol, when applied to this high resolution device, enables non-invasive in vivo histological imaging and biometric assessment of the various layers of the rodent posterior segment within a 20 -- 30 min procedural time-frame. This protocol could establish a standardized method for evaluating morphological changes, with this commercial SDOCT device, when assessing longitudinal disease pathophysiology and treatment response in mouse models for future vision science research.
[Show abstract][Hide abstract] ABSTRACT: OBJECTIVE To identify factors that predict the success or failure of treatment with intravitreal ranibizumab for patients with diabetic macular edema. METHODS A total of 37 baseline demographic, systemic, ocular, optical coherence tomographic, and fundus photographic variables were assessed for association with change in visual acuity or central subfield thickness between baseline and 1 year in 361 eyes that were randomly assigned to intravitreal ranibizumab with prompt or deferred laser treatment within a trial of ranibizumab, triamcinolone acetonide, and laser treatment for center-involved diabetic macular edema. A categorical variable describing follow-up anatomic responses to therapy was added to the visual acuity outcome model. RESULTS After adjusting for baseline visual acuity, a larger visual acuity treatment benefit was associated with younger age (P < .001), less severe diabetic retinopathy on clinical examination (P = .003), and absence of surface wrinkling retinopathy (P < .001). The reduction in central subfield thickness during the first treatment year also predicted better visual acuity outcomes (P < .001). After adjusting for baseline central subfield thickness, the presence of hard exudates was associated with more favorable improvement on optical coherence tomographic scan (P = .004). Because only 11 eyes experienced vision loss and 6 eyes experienced an increase in central subfield thickness, factors for poor outcomes could not be evaluated. CONCLUSIONS A review of baseline factors and anatomic responses during the first year of ranibizumab therapy for association with visual acuity outcome did not identify any features that would preclude ranibizumab treatment. However, baseline central subfield thickness is the strongest predictor of anatomic outcome, and reduction in central subfield thickness during the first treatment year is associated with better visual acuity outcomes.
Archives of ophthalmology 09/2012; 130(9):1153-1161. · 3.86 Impact Factor