Showing papers in "Current Eye Research in 2014"

In vivo confocal microscopy of the ocular surface: from bench to bedside.

Abstract: In vivo confocal microscopy (IVCM) is an emerging technology that provides minimally invasive, high resolution, steady-state assessment of the ocular surface at the cellular level. Several challenges still remain but, at present, IVCM may be considered a promising technique for clinical diagnosis and management. This minireview summarizes some key findings in IVCM of the ocular surface, focusing on recent and promising attempts to move ‘‘from bench to bedside’’. IVCM allows prompt diagnosis, disease course follow-up, and management of potentially blinding atypical forms of infectious processes, such as acanthamoeba and fungal keratitis. This technology has improved our knowledge of corneal alterations and some of the processes that affect the visual outcome after lamellar keratoplasty and excimer keratorefractive surgery. In dry eye disease, IVCM has provided new information on the whole-ocular surface morphofunctional unit. It has also improved understanding of pathophysiologic mechanisms and helped in the assessment of prognosis and treatment. IVCM is particularly useful in the study of corneal nerves, enabling description of the morphology, density, and disease- or surgically induced alterations of nerves, particularly the subbasal nerve plexus. In glaucoma, IVCM constitutes an important aid to evaluate filtering blebs, to better understand the conjunctival wound healing process, and to assess corneal changes induced by topical antiglaucoma medications and their preservatives. IVCM has significantly enhanced our understanding of the ocular response to contact lens wear. It has provided new perspectives at a cellular level on a wide range of contact lens complications, revealing findings that were not previously possible to image in the living human eye. The final section of this mini-review provides a focus on advances in confocal microscopy imaging. These include 2D wide-field mapping, 3D reconstruction of the cornea and automated image analysis.

From mechanosensitivity to inflammatory responses: new players in the pathology of glaucoma.

Abstract: Purpose of the study: Many blinding diseases of the inner retina are associated with degeneration and loss of retinal ganglion cells (RGCs). Recent evidence implicates several new signaling mechanisms as causal agents associated with RGC injury and remodeling of the optic nerve head. Ion channels such as Transient receptor potential vanilloid isoform 4 (TRPV4), pannexin-1 (Panx1) and P2X7 receptor are localized to RGCs and act as potential sensors and effectors of mechanical strain, ischemia and inflammatory responses. Under normal conditions, TRPV4 may function as an osmosensor and a polymodal molecular integrator of diverse mechanical and chemical stimuli, whereas P2X7R and Panx1 respond to stretch- and/or swelling-induced adenosine triphosphate release from neurons and glia. Ca 2þ influx, induced by stimulation of mechanosensitive ion channels in glaucoma, is proposed to influence dendritic and axonal remodeling that may lead to RGC death while (at least initially) sparing other classes of retinal neuron. The secondary phase of the retinal glaucoma response is associated with microglial activation and an inflammatory response involving Toll-like receptors (TLRs), cluster of differentiation 3 (CD3) immune recognition molecules associated with the T-cell antigen receptor, complement molecules and cell type-specific release of neuroactive cytokines such as tumor necrosis factor-a (TNF-a) and interleukin-1b (IL-1b). The retinal response to mechanical stress thus involves a diversity of signaling pathways that sense and transduce mechanical strain and orchestrate both protective and destructive secondary responses. Conclusions: Mechanistic understanding of the interaction between pressure-dependent and independent pathways is only beginning to emerge. This review focuses on the molecular basis of mechanical strain transduction as a primary mechanism that can damage RGCs. The damage occurs through Ca 2þ -dependent

Evaluation of Oxidative Stress Markers in Aqueous Humor of Primary Open Angle Glaucoma and Primary Angle Closure Glaucoma Patients

Abstract: Purpose: The present study was designed to determine the levels of antioxidant enzymes (superoxide dismutase, catalase, and glutathione peroxidase) and non-enzymatic antioxidants (vitamins C and E) in aqueous humor of primary open angle glaucoma (POAG) and primary angle closure glaucoma (PACG) patients.Materials and Methods: In this study, aqueous humor of POAG (n = 30) and PACG (n = 30) patients was obtained. For control, aqueous humor of 30 age-matched cataract patients (n = 30) was collected. Activities of antioxidant enzymes and non-enzymatic antioxidants levels were measured spectrophotometrically.Results: A significant increase in superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities was found in aqueous humor of POAG and PACG patients as compared to cataract patients (p < 0.001). No significant changes were observed in catalase activity. The levels of vitamins C and E were significantly lower in the aqueous humor of POAG and PACG as compared to cataract patients (p < 0.001)...

Effects of K-115, a Rho-Kinase Inhibitor, on Aqueous Humor Dynamics in Rabbits

Abstract: Purpose: To evaluate the topical instillation of K-115, a selective Rho-associated coiled coil-containing protein kinase (ROCK) inhibitor, on intraocular pressure (IOP), ocular distribution, and aqueous humor dynamics in experimental animals.Methods: Kinase inhibition by K-115 was measured by biochemical assay. IOP was monitored using a pneumatonometer in albino rabbits and monkeys after topical instillation of K-115. The ocular distribution of [14C]K-115 was determined by whole-head autoradiography. The aqueous flow rate was determined by fluorophotometry. The total outflow facility and uveoscleral outflow were measured by two-level constant pressure perfusion and perfusion technique using fluorescein isothiocyanate-dextran, respectively.Results: Biochemical assay showed that K-115 had selective and potent inhibitory effects on ROCKs. In rabbits, topical instillation of K-115 significantly reduced IOP in a dose-dependent manner. Maximum IOP reduction was observed 1 h after topical instillation, w...

Review of Alternative Carrier Materials for Ocular Surface Reconstruction

Abstract: Severe ocular surface disorders can result in deficiency of limbal stem cells that is potentially associated with chronic inflammation, impaired vision and even blindness. Advanced stem cells deficiency requires reconstruction of the OS with autologous or allogeneic limbal stem cells. To address such deficiency, a limbal tissue biopsy is taken and limbal cells are expanded on a carrier, which then can be used for OS reconstruction. Human amniotic membrane - currently the most common carrier for transplantation of limbal epithelial stem cells - has the downsides of carrying the risk of disease transmission, limited transparency, variable and unstable quality and low mechanical strength. This article reviews the advantages and disadvantages of the established carrier materials for limbal stem cell transplantation, as well as discussing emerging alternatives, including carriers based on collagen, fibrin, siloxane hydrogel contact lenses, poly(e-caprolactone), gelatin-chitosan, silk fibroin, human anterior lens capsule, keratin, poly(lactide-co-glycolide), polymethacrylate, hydroxyethylmethacrylate and poly(ethylene glycol) for their potential use in the treatment of limbal stem cell deficiency.

Effect of Smoking on Choroidal Thickness in Healthy Smokers

Abstract: Purpose: To evaluate the acute and chronic effects of cigarette smoking on the choroidal thickness of young male smokers with smoking histories exceeding 10 years using spectral domain optical coherence tomography (SD OCT).Materials and methods: The right eyes of 40 never-smoking and 30 smoking healthy subjects were included in this study. We measured the choroidal thicknesses of the never-smoking subjects as a control group. The choroidal thicknesses of the smoking subjects were measured before, 5, 30 and 60 min after smoking. Choroidal thickness measurements were taken at the fovea and at two points that were 1500 µm nasal and temporal to the fovea.Results: No significant difference was found for the retinal thickness, choroidal thicknesses, spherical equivalent, intraocular pressure and central corneal thickness of the smokers and non-smokers (p > 0.05 for all). In the measurements that were taken after smoking, a statistically significant increase was found in choroidal thickness that was obse...

Pulse-Waveform Analysis of Normal Population using Laser Speckle Flowgraphy

Abstract: Purpose: Laser speckle flowgraphy (LSFG), a new, non-invasive method of measuring the mean blur rate (MBR) of ocular blood flow, allows for the analysis of the pulse waveform of a heartbeat as it changes dynamically. Here, we investigated the relationship between the pulse waveform and clinical parameters, particularly age.Materials and methods: Sixty eyes of 60 healthy subjects without diabetes were enrolled from among patients undergoing annual health examinations. LSFG, and its analysis software, were used to determine pulse waveform parameters including MBR, skew, blowout score (BOS), blowout time (BOT), rising rate and falling rate in the optic nerve head (ONH), both specifically in the tissue area and in the ONH overall. Fifteen clinical parameters were also recorded, including age and blood pressure, as well as triglyceride and creatinine levels.Results: Skew, BOT and falling rate had a strong correlation (|r| > 0.60) with age, but not with the other clinical parameters. This correlation wi...

Imaging and quantification of endothelial cell loss in eye bank prepared DMEK grafts using trainable segmentation software.

Abstract: Purpose: To improve accuracy and efficiency in quantifying the endothelial cell loss (ECL) in eye bank preparation of corneal endothelial grafts.Methods: Eight cadaveric corneas were subjected to Descemet Membrane Endothelial Keratoplasty (DMEK) preparation. The endothelial surfaces were stained with a viability stain, calcein AM dye (CAM) and then captured by a digital camera. The ECL rates were quantified in these images by three separate readers using trainable segmentation, a plug-in feature from the imaging software, Fiji. Images were also analyzed by Adobe Photoshop for comparison. Mean times required to process the images were measured between the two modalities.Results: The mean ECL (with standard deviation) as analyzed by Fiji was 22.5% (6.5%) and Adobe was 18.7% (7.0%; p = 0.04). The mean time required to process the images through the two different imaging methods was 19.9 min (7.5) for Fiji and 23.4 min (12.9) for Adobe (p = 0.17).Conclusions: Establishing an accurate, efficient and re...

Effects of Eye Drops Containing a Mixture of Omega-3 Essential Fatty Acids and Hyaluronic Acid on the Ocular Surface in Desiccating Stress-induced Murine Dry Eye

Abstract: Purpose: To investigate the efficacy of the topical application of omega-3 essential fatty acids (EFAs) and hyaluronic acid (HA) mixtures in a mouse model of experimental dry eye (EDE).Methods: Eye drops consisting of 0.1% HA, 0.02%, or 0.2% omega-3 EFAs alone and mixture of 0.02%, or 0.2% omega-3 EFAs and 0.1% HA were applied in desiccating stress-induced murine dry eye. Corneal irregularity scores and fluorescein staining scores were measured 5 and 10 days after treatment. Levels of interleukin (IL)-1β, -17, and interferon gamma-induced protein (IP)-10 were measured in the conjunctiva at 10 days using a multiplex immunobead assay. The concentrations of hexanoyl-lys (HEL) and 4-hydroxynonenal (4-HNE) in conjunctiva tissue were measured with enzyme-linked immunosorbent assays.Results: Mice treated with the mixture containing 0.2% omega-3 EFAs showed a significant improvement in corneal irregularity scores and corneal fluorescein staining scores compared with EDE, HA, 0.02% or 0.2% omega-3 EFAs alo...

Prediction of residual astigmatism after cataract surgery using swept source fourier domain optical coherence tomography.

Abstract: Purpose: To compare corneal measurements obtained by a swept source fourier domain OCT (CASIA SS-1000), an autokeratometer (Haag-Streit Lenstar), a hybrid topographer (Tomey TMS-5), a Placido topographer (Tomey TMS-5 in Placido mode) and a Scheimpflug tomographer (Oculus Pentacam) to manifest subjective refraction.Methods: One hundred and four pseudophacic patients with non-toric IOLs were measured at least 6 months after surgery. Corneal astigmatism as measured on the anterior corneal surface as well as total corneal astigmatism including posterior surface data was compared to manifest refractive cylinder (cross-cylinder strategy) by computing difference vectors and correlation analysis of power vectors.Results: The OCT (0.43 ± 0.25 D) and the hybrid topographer (0.44 ± 0.25 D) yielded the smallest difference vector to subjective cylinder and by far the lowest percentage of outliers >0.75 D (≈10%). The rotating Scheimpflug camera showed the largest (0.70 ± 0.41 D) difference vector. The best pred...

Correlation of foveal photoreceptor integrity with visual outcome in idiopathic epiretinal membrane

Abstract: Purpose: To evaluate the correlation of foveal photoreceptor integrity with visual outcome in patients undergoing idiopathic epiretinal membrane (ERM) surgery using spectral domain optical coherence tomography (SD-OCT).Materials and methods: Forty-three eyes of 43 patients were examined by SD-OCT before and at 1 and 6 months after vitrectomy for idiopathic ERM. Patients were divided into two groups based on the preoperative integrity of photoreceptor inner and outer segment junction (IS/OS) – Group I, intact IS/OS and Group D, disrupted IS/OS. Where present, disrupted length of IS/OS was measured, and the association between disrupted length of IS/OS and foveal thickness with best corrected visual acuity (BCVA) was evaluated.Results: There were 27 eyes with an intact IS/OS (Group I) and 16 eyes with a disrupted IS/OS (Group D). Patients in Group I had significantly better postoperative BCVA and greater improvement than those in Group D at 6 months after surgery (p = 0.001 and p = 0.030, respective...

Changes of choroidal thickness after treatment for diabetic retinopathy.

Abstract: Purpose: To investigate the choroidal thickness changes after intravitreal bevacizumab injection (IVB), panretinal photocoagulation (PRP) or both for diabetic retinopathy treatment.Materials and Methods: The study included 31 eyes (31 patients) in the IVB group, 35 eyes (35 patients) in the PRP group and 35 eyes (35 patients) in the IVB–PRP group. Enhanced depth imaging optical coherence tomography (EDI-OCT) was performed before and 1 month after each treatment to measure subfoveal and extrafoveal (500 and 1000 μm) choroidal thicknesses. The best-corrected visual acuity (BCVA) and central macular thickness (CMT) were also measured.Results: The choroidal thickness at all locations significantly decreased after treatment in all groups, but there was no significant difference in the amount of change among the three groups. The subfoveal choroidal thickness and CMT significantly decreased after treatment in the IVB and IVB–PRP groups. In the PRP group, the CMT significantly increased, while the choroi...

Tear dynamics in healthy and dry eyes.

Abstract: Purpose: Dry-eye disease, an increasingly prevalent ocular-surface disorder, significantly alters tear physiology. Understanding the basic physics of tear dynamics in healthy and dry eyes benefits both diagnosis and treatment of dry eye. We present a physiological-based model to describe tear dynamics during blinking.Materials and methods: Tears are compartmentalized over the ocular surface; the blink cycle is divided into three repeating phases. Conservation laws quantify the tear volume and tear osmolarity of each compartment during each blink phase. Lacrimal-supply and tear-evaporation rates are varied to reveal the dependence of tear dynamics on dry-eye conditions, specifically tear osmolarity, tear volume, tear-turnover rate (TTR), and osmotic water flow.Results: Predicted periodic-steady tear-meniscus osmolarity is 309 and 321 mOsM in normal and dry eyes, respectively. Tear osmolarity, volume, and TTR all match available clinical measurements. Osmotic water flow through the cornea and conjun...

Evaluation of Subfoveal Choroidal Thickness in Pregnant Women Using Enhanced Depth Imaging Optical Coherence Tomography

Abstract: Purpose: To evaluate the subfoveal choroidal thickness (SFCT) measured by enhanced depth imaging optical coherence tomography (EDI-OCT) in pregnant women.Methods: In this prospective and cross-sectional study, 100 pregnant women and 100 age-matched nonpregnant women were enrolled. The SFCT was measured by EDI-OCT. The refractive error, intraocular pressure (IOP), axial length (AL), central corneal thickness (CCT), systolic and diastolic blood pressure, and ocular perfusion pressure (OPP) were also measured. Pregnancy-related factors including gestational age, maternal weight gain, and fetal weight were noted.Results: Mean SFCT was 371.1 ± 61.8 µm in the study group and 337.2 ± 62.4 µm in the control group (p < 0.001). No significant correlation was found between SFCT and spherical refraction, IOP, AL, CCT, OPP, gestational age, maternal weight gain, or fetal weight.Conclusion: Our results suggest that subfoveal choroidal thickness increases in pregnant women compared with age-matched nonpregnant w...

Subfoveal choroidal thickness in patients with chronic heart failure analyzed by spectral-domain optical coherence tomography.

Abstract: Purpose: To evaluate the subfoveal choroidal thickness (SFCT) measured by enhanced depth imaging optical coherence tomography (EDI-OCT) in eyes of chronic heart failure (CHF) patients.Methods: Fifty-six patients with CHF and 56 age- and gender-matched healthy individuals were enrolled. The SFCT was measured by EDI-OCT. The ejection fraction of left ventricle (EFLV), age, intraocular pressure (IOP), axial length (AL), systolic and diastolic blood pressure, and ocular perfusion pressure (OPP) were also measured.Results: Mean SFCT was 181.2 ± 80.23 μm in the study group and 283.6 ± 52.4 μm in the control group (p = 0.000). There was a statistically significant correlation between the SFCT and each of EFLV and age. SFCT value was not statistically significantly associated with AL, IOP and OPP.Conclusion: Our results suggest that SFCT is lower in eyes of CHF patients compared to age- and gender-matched healthy individuals.

The Beneficial Effects of Doxycycline, An Inhibitor of Matrix Metalloproteinases, on Sulfur Mustard-Induced Ocular Pathologies Depend on the Injury Stage

Abstract: Purpose: Sulfur mustard (SM) induces acute ocular lesions, including erosions and inflammation that may be followed by delayed injuries expressed by epithelial defects and neovascularization (NV). Based on the matrix metalloproteinases (MMPs) activity, we evaluated the clinical and biochemical effects of topical treatment with doxycycline, an MMP inhibitor, targeted to the various injury stages.Methods: Rabbit eyes were exposed to SM vapor. A clinical follow-up was carried out up to 2 months. Tear fluid and cornea samples were collected at different time points for measurements of MMPs activity by zymography. Efficacy of a post-exposure topical doxycycline (2 mg/ml in phosphate buffer saline, ×4/d), targeted to the different phases of the clinical injury, was evaluated.Results: Elevated MMP-9 and MMP-2 activities were found in all corneas during the acute injury and in vascularized corneas during the delayed pathology. In the tear fluid, high MMP-9 activity and negligible MMP-2 activity were found...

Scleral Buckling and Pars Plana Vitrectomy for Rhegmatogenous Retinal Detachment: An Analysis of 542 Eyes

Abstract: Purpose: To investigate the anatomical success rates of scleral buckling (SB) and pars plana vitrectomy (PPV) performed for rhegmatogenous retinal detachment (RRD) in a large case series and to identify prognostic factors for the primary anatomical success rates of surgical techniques.Methods: We reviewed 542 consecutive eyes for primary RRD in this retrospective study. Follow-ups were performed for at least six months. In each of the two groups, 271 eyes were examined. The main outcome measure was the primary anatomical success rate. Multivariate analysis was also performed to determine whether independent risk factors of the preoperative parameters for redetachment exist.Results: The primary anatomical success rates were 93.7% and 96.3% in the SB and PPV groups; and the final anatomical success rates were 100% in both groups (each with 271 eyes). In the SB group, eyes with macula-off had significantly lower primary anatomical success rates than those with macula-on (p = 0.002). Preoperative brea...

Matricellular protein thrombospondins: influence on ocular angiogenesis, wound healing and immuneregulation.

Abstract: Thrombospondins are a family of large multi-domain glycoproteins described as matricelluar proteins based on their ability to interact with a broad range of receptors, matrix molecules, growth factors or proteases, and to modulate array of cellular functions including intracellular signaling, proliferation and migration. Two members of the thrombospondin family, thrombospondin 1 (TSP-1) and thrombospondin 2 (TSP-2) are studied extensively to determine their structure and function. While expressed at low levels in normal adult tissues, their increased expression is seen predominantly in response to cellular perturbations. Despite structural similarities, a notable functional difference between TSP-1 and TSP-2 includes the ability of former to activate of latent TGF-β and its competitive inhibition by the latter. Both these thrombospondins are reported to play important roles in TGF-β rich ocular environment with most reports related to TSP-1. They are expressed by many ocular cell types and detectable in the aqueous and vitreous humor. TSP-1 and TSP-2 influence many cellular interactions in the eye such as angiogenesis, cell migration, wound healing, TGF-β activation and regulation of inflammatory immune responses. Together, these processes are known to contribute to the immune privilege status of the eye. Emerging roles of TSP-1 and TSP-2 in ocular functions and pathology are reviewed here.

Regulation of Human Corneal Epithelial Mucins by Rebamipide

Abstract: Purpose Membrane-associated mucins (MAMs) play important roles in barrier function and tear stability, and their expression on the ocular surface is altered in dry eye disease. Rebamipide is a mucin secretagogue that promotes the production of mucin-like glycoproteins in human corneal epithelial (HCE) cells. However, the expression of MAMs on the corneal epithelia (MUC1, MUC4, MUC16), which is induced by rebamipide, is poorly understood. In this study, we investigated the effect of rebamipide on the regulation of MAM expression in HCE cells. Materials and methods MUC16, Ki67 and PCNA expression levels in HCE cells isolated at confluence and at 24 hours after confluence were examined by Western blotting to assess cell proliferation. HCE cells isolated at 24 hours after confluence were cultured in medium supplemented with 1-10 µM rebamipide or 0.3-30 nM of epidermal growth factor (EGF). Real-time PCR (RT-PCR) and Western blot analysis of MAMs were performed to evaluate the effect of rebamipide. Western blot analysis of cells treated with an EGF receptor inhibitor (AG1478) or MEK1/2 inhibitor (U0126) was performed to reveal the relationship between EGF receptor activation and rebamipide-induced MAM expression. Results HCE cells isolated at 24 hours after confluence had lower cell proliferation activity and increased MUC16 expression compared with cells isolated at confluence. RT-PCR and Western blot analysis revealed that rebamipide increased MAM gene expression for 2 hours and protein expression for 24 hours in HCE cells. EGF inhibitor treatment led to reduced levels of all three MAMs that are normally induced by rebamipide, whereas EGF induced the expression of all three MAMs. Conclusions We suggested that rebamipide increased MUC1, MUC4 and MUC16 expression levels through signals involved in EGF receptor activation in the human corneal epithelia. These data suggest that rebamipide may improve subjective symptoms of dry eye disease by upregulating MAM expression.

Anti-VEGF Therapy (Bevacizumab) for Sulfur Mustard-Induced Corneal Neovascularization Associated with Delayed Limbal Stem Cell Deficiency in Rabbits

Abstract: Purpose: To investigate the involvement of VEGF in corneal neovascularization (CNV) following sulfur mustard (SM) exposure and to test the therapeutic effects of bevacizumab (Avastin) in respect to dose, route of administration and timing.Materials and methods: Topical bevacizumab (6 or 25 mg/ml, ×2/day) was applied to rabbit eyes, before or after appearance of NV, following SM vapor exposure, and was compared with subconjunctival injection (25 mg/ml, ×2/week) and topical dexamethasone (1%, ×4/day). Treatments were given for 3 weeks. VEGF levels were monitored by immunohistochemistry and ELISA assay. Clinical evaluations included slit-lamp examination, impression cytology for diagnosis of Limbal Stem Cell Deficiency (LSCD), pachymetry, measurement of NV length and histology.Results: Corneal NV was developed, as early as 2 weeks after exposure, in 50–70% of the eyes, associated with increased levels of VEGF. Topical bevacizumab treatment with both doses, starting at 4 weeks, reduced vascularization...

Retinal Blood Flow Velocity in Patients with Age-Related Macular Degeneration

Abstract: Purpose/Aim of the study: To study changes in retinal blood flow velocity in patients with early and neovascular age-related macular degeneration (AMD). We used the Retinal Function Imager (RFI, Optical Imaging Ltd., Rehovot, Israel), a noninvasive diagnostic approach for measuring blood flow velocity.Materials and Methods: Sixty eyes of 43 AMD patients and 53 eyes of 35 healthy individuals over the age of 50 were recruited for this study. All patients were scanned by the RFI with analysis of blood flow velocity of secondary and tertiary branches of arteries and veins. Differences among groups were assessed by mixed linear models.Results: The average velocity in AMD patients was significantly lower compared to controls in arteries (3.6 ± 1.4 versus 4.3 ± 1.0 mm/sec, p = 0.009) but not in veins (2.6 ± 0.9 versus 3.1 ± 0.6 mm/sec, p = 0.08). When comparing the velocity between low- and high-grade AMD eyes, venous velocity was slower in the high grade AMD eyes only in the “narrow” group of vessels.Co...

The Application of Autologous Serum Eye Drops in Severe Dry Eye Patients; Subjective and Objective Parameters Before and After Treatment

Abstract: Aim: To assess the impact of autologous serum (AS) eye drops on the ocular surface of patients with bilateral severe dry eye and to draw a comparison between the clinical and laboratory examinations and the degree of subjective symptoms before and after serum treatment.Materials and methods: A three-month prospective study was conducted on 17 patients with severe dry eye. AS eye drops were applied a maximum of 12 times a day together with regular therapy. Dry eye status was evaluated by clinical examination (visual acuity, Schirmer test, tear film breakup time, vital staining, tear film debris and meniscus), conjunctival impression cytology (epithelial and goblet cell density, snake-like chromatin, HLA-DR-positive and apoptotic cells) and subjectively by the patients.Results: The application of AS eye drops led to a significant improvement in the Schirmer test (p < 0.01) and tear film debris (p < 0.05). The densities of goblet (p < 0.0001) and epithelial cells (p < 0.05) were significantly increas...

A replication competent HSV-1(McKrae) with a mutation in the amino-terminus of glycoprotein K (gK) is unable to infect mouse trigeminal ganglia after cornea infection.

Abstract: Purpose: To determine the role of the amino terminus of herpes simplex virus-1 (HSV-1) glycoprotein K (gK) in corneal infection, neuroinvasion, and establishment of virus latency in trigeminal ganglia of mice.Methods: The recombinant virus HSV-1 (McKΔgK31-68) was constructed by engineering gK genes encoding gK lacking 38 amino acids immediately after the gK signal sequence. A rescued virus was also produced. Mouse eyes were scarified and infected with 105 plaque forming units (PFU) in each eye. Clinical signs of ocular disease were monitored daily. Thirty days postinfection trigeminal ganglia were collected and processed for quantitative PCR (qPCR) analysis of viral DNA and recovery of infectious virions by cell culture of ganglionic tissues.Results: Deletion of the amino terminus of gK encoded by the McKΔgK31-68 mutant virus did not substantially affect its replication kinetics on African green monkey kidney cells (Vero), while it reduced cell-to-cell spread. McK viral infection of scarified mous...

Obstructive sleep apnea in patients with central serous chorioretinopathy.

Abstract: Purpose: In this study, we aimed to evaluate the relation between obstructive sleep apnea (OSA) and central serous retinopathy (CSR).Methods: Twenty-three consecutive subjects aged >18 years with the diagnosis of CSR were included in this prospective study. Overnight polysomnography was performed to all subjects. Desaturation index and apnea-hypopnea index (AHI) were recorded. Obstructive sleep apnea was classified according to AHI as mild, moderate, or severe. Statistical analysis was performed using chi-square test, Fisher’s exact test, and Mann–Whitney U test.Results: Fourteen of 23 CSR patients (60.9%) had OSA. Prevalence of OSA was significantly higher in male subjects with CSR compared to female subjects with CSR (p = 0.018). One (16.7%) female subject with CSR had OSA whereas thirteen (76.5%) male subjects were found to have OSA. Desaturation index was found to be 5.1 ± 4.2 in females and 12.9 ± 11.1 in males (p = 0.036).Conclusion: Obstructive sleep apnea is seen nearly in 2/3 of patients ...

Intraocular Pressure Lowering Effect of Orbital Decompression is Related to Increased Venous Outflow in Graves Orbitopathy

Abstract: Purpose: To investigate the effects of combined orbital bone and fat decompression on intraocular pressure (IOP) and superior ophthalmic vein blood flow velocity (SOV-BFV), and their association with the clinical features of Graves orbitopathy (GO).Methods: During the 2002–2008 period, 72 eyes of 36 GO cases demonstrating moderate to severe orbitopathy were evaluated according to their clinical features as: cases with or without dysthyroid optic neuropathy (DON), and underwent orbital decompression. A control group comprised 40 eyes of 20 healthy subjects. In both groups, a full ophthalmic examination including IOP and Hertel measurements was performed, and SOV-BFV was analyzed with color Doppler imaging. Examinations were repeated after orbital decompression in GO patients.Results: All the cases demonstrated clinical features of inactive disease. Among the patients 24 of 72 eyes (33.3%) showed clinical features of DON. After surgery, the mean decrease in Hertel values was 6.2 ± 1.8 mm (p = 0.001)...

Impact of Visual Impairment on Vision-Specific Quality of Life among Older Adults Living in Nursing Home

Abstract: Background: Visual impairment (VI) has a significant negative impact on quality of life (QoL) amongst older people living in nursing homes. The purpose of this study was to determine the prevalence of VI and blindness and to explore the association between severity of VI and vision-specific QoL among older people living in nursing homes of Kathmandu, Nepal.Methods: This cross-sectional study involved 158 residents aged 60 years or older residing in seven nursing homes of Kathmandu Valley, Nepal. Near acuity, presenting and the best corrected distance visual acuity (VA) were assessed in each eye and considered in the better eye after adequate refraction. A complete anterior and posterior segment examination was carried out. Face-to-face interviews were conducted using a 57-item Nursing Home Vision-Targeted Health-Related Quality of Life (NHVQoL) questionnaire.Results: The mean age of residents was 75.60 ± 7.12 years and the majority were female (66.46%). The prevalence of VI and blindness was 45.57...

Systematic Analysis of Wide-Field Fundus Autofluorescence (FAF) Imaging in Posterior Uveitis

Abstract: Purpose: To evaluate wide-field fundus autofluorescence (FAF) in patients with uveitis with retinal or chorioretinal involvement. Materials and methods: We included 78 study eyes in this prospective study. Best-corrected visual acuity, a full clinical examination, wide-field green-light FAF and composite color, green and red laser separation fundus imaging with Optomap SLO were performed. In a systematic analysis, the number, extension and margins of central and peripheral retinal or chorioretinal alterations, scars and infiltrates in infectious and non-infectious uveitic study eyes were evaluated. Wide-field FAF and color fundus imaging results were compared regarding their diagnostic properties. Results: Nine out of 78 study eyes were diagnosed with infectious, 69 cases with non-infectious uveitis. Six infectious uveitic study eyes had changes of the peripheral fundus compared with 48 of 69 non-infectious uveitic eyes. In 33 (infectious versus non-infectious: 4 versus 29) cases, wide-field FAF images revealed more retinal or chorioretinal alterations or pathologies with a farther extended demarcation than wide-field composite color fundus imaging. Eleven out of 69 non-infectious study eyes were diagnosed with vasculitis which could be more precisely evaluated with wide-field FAF than wide-field composite color, green or red light filtered fundus imaging. Conclusions: Non-invasive wide-field FAF detects more retinal or chorioretinal involvement in patients with posterior uveitis than seen in color imaging and thus is useful in diagnosis and follow-up of uveitic patients.

Choroidal Blood Flow Decreases with Age: An MRI Study

Abstract: Purpose: To verify that a visual fixation protocol with cued eye blinks achieves sufficient stability for magnetic resonance imaging (MRI) blood-flow measurements and to determine if choroidal blood flow (ChBF) changes with age in humans. Methods: The visual fixation stability achievable during an MRI scan was measured in five normal subjects using an eye-tracking camera outside the MRI scanner. Subjects were instructed to blink immediately after recorded MRI sound cues but to otherwise maintain stable visual fixation on a small target. Using this fixation protocol, ChBF was measured with MRI using a 3 Tesla clinical scanner in 17 normal subjects (24–68 years old). Arterial and intraocular pressures (IOP) were measured to calculate perfusion pressure in the same subjects. Results: The mean temporal fluctuations (standard deviation) of the horizontal and vertical displacements were 29 ± 9mm and 38 ± 11mm within individual fixation periods, and 50 ± 34mm and 48 ± 19mm across different fixation periods. The absolute displacements were 67 ± 31mm and 81 ± 26mm. ChBF was negatively correlated with age (R = � 0.7, p = 0.003), declining 2.7 ml/100 ml/min per year. There were no significant correlations between ChBF versus perfusion pressure, arterial pressure, or IOP. There were also no significant correlations between age versus perfusion pressure, arterial pressure, or IOP. Multiple regression analysis indicated that age was the only measured independent variable that was significantly correlated with ChBF (p = 0.03). Conclusions: The visual fixation protocol with cued eye blinks was effective in achieving sufficient stability for MRI measurements. ChBF had a significant negative correlation with age.

Epigallocatechin Gallate (EGCG) Prevents H2O2-Induced Oxidative Stress in Primary Rat Retinal Pigment Epithelial Cells

Abstract: Purpose: To determine whether the green tea polyphenol epigallocatechin gallate (EGCG) could prevent H2O2-induced oxidative stress in primary rat retinal pigment epithelial cells.Methods: Primary cultures of retinal pigment epithelium (RPE) cells were established from Long–Evans newborn rats. RPE cells were pretreated with various concentrations of EGCG for 24 h before being exposed to hydrogen peroxide (H2O2) for 2 h to induce oxidative stress. Cell metabolic activity was measured using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Cell death was quantified by flow cytometry using propidium iodide (PI).Results: Treatment of RPE cells with EGCG alone does not affect the cell viability up to 50 µM. Exposure of RPE cells to 600 µM H2O2 caused a significant decrease in cell viability; whereas pretreatment with 10, 25, and 50 µM EGCG significantly reduced this decrease in a dose-dependent manner. The proportion of PI-positive cells increased significantly in cultures treate...

Altered Retinal MicroRNA Expression Profiles in Early Diabetic Retinopathy: An In Silico Analysis

Abstract: Purpose: MicroRNAs (miRNAs) – as negative regulators of target genes – are associated with various human diseases, but their precise role(s) in diabetic retinopathy (DR) remains to be elucidated. T...