Effects of Indocyanine green on cultured retinal ganglion cells in-vitro

<p>Abstract</p> <p>Background</p> <p>Indocyanine green (ICG) dye is commonly used to stain the inner limiting membrane during macular surgery. There are reports documenting the toxicity of ICG on retinal pigment epithelial cells, with conflicting results in retinal ganglion cells. In the present study, we evaluated the effect of ICG on retinal ganglion cells in vitro.</p> <p>Cultured rat retinal ganglion cells (RGC-5) were exposed to different concentrations of ICG (0.25, 0.5, 1.0, 1.25, & 5 mg/ml) and at various time intervals (1, 5, 15, 30, & 60 minutes). Changes in structural morphology were identified using phase contrast bright field microscopy. Cell viability was quantified using the neutral red assay and cell death was characterized using Annexin-V staining.</p> <p>Findings</p> <p>Significant morphologic changes were observed at the 15 and 60 min intervals for all concentrations, where a reduction in cell size and loss of normal spindle shape was noted. A dose dependent decrease in cell viability was observed with increasing concentration of ICG as well as increasing exposure intervals. Compared to control, 48-74% reduction in neutral red uptake at all concentrations for exposures 5 min or greater (p < 0.001). Even at 1 min exposure, a dose dependent decline was observed in cell viability, with a 28-48% decline for doses above 1.25 mg/ml (p = 0.007). Staining with Annexin-V, demonstrated a similar dose and time dependent increase in number of cells exhibiting early apoptosis. A greater than two-fold increase in Annexin-V expression for all doses at exposures greater than 1 min was noted.</p> <p>Conclusion</p> <p>ICG dye exhibits toxicity to retinal ganglion cells at clinically relevant doses following 1 min exposure.</p

Conversion of Central Subfield Thickness Measurements of Diabetic Macular Edema Across Cirrus and Spectralis Optical Coherence Tomography Instruments

Purpose: Develop equations to convert Cirrus central subfield thickness (CST) to Spectralis CST equivalents and vice versa in eyes with diabetic macular edema (DME). Methods: The DRCR Retina Network Protocol O data were split randomly to train (70% sample) and validate (30% sample) conversion equations. Data from an independent study (CADME) also validated the equations. Bland-Altman 95% limits of agreement between predicted and observed values evaluated the equations. Results: Protocol O included 374 CST scan pairs from 187 eyes (107 participants). The CADME study included 150 scan pairs of 37 eyes (37 participants). Proposed conversion equations are Spectralis = 40.78 + 0.95 × Cirrus and Cirrus = 1.82 + 0.94 × Spectralis regardless of age, sex, or CST. Predicted values were within 10% of observed values in 101 (90%) of Spectralis and 99 (88%) of Cirrus scans in the validation data; and in 136 (91%) of the Spectralis and 148 (99%) of the Cirrus scans in the CADME data. Adjusting for within-eye correlations, 95% of conversions are estimated to be within 17% (95% confidence interval, 14%-21%) of CST on Spectralis and within 22% (95% confidence interval, 18%-28%) of CST on Cirrus. Conclusions: Conversion equations developed in this study allow the harmonization of CST measurements for eyes with DME using a mix of current Cirrus and Spectralis device images. Translational Relevance: The CSTs measured on Cirrus and Spectralis devices are not directly comparable owing to outer boundary segmentation differences. Converting CST values across spectral domain optical coherence tomography instruments should benefit both clinical research and standard care efforts

Impact of The Protective Renin-Angiotensin System (RAS) on The Vasoreparative Function of CD34+ CACs in Diabetic Retinopathy

Purpose: In diabetes, the impaired vasoreparative function of Circulating Angiogenic Cells (CACs) is believed to contribute to the progression of diabetic retinopathy (DR). Accumulating evidence suggests that the protective arm of renin-angiotensin system (RAS) ACE2 Angiotensin-(1-7) Mas plays an important role in restoring the function of diabetic CACs. We examined the protective RAS in CACs in diabetic individuals with different stages of retinopathy. Methods: Study subjects (n43) were recruited as controls or diabetics with either no DR, mild non-proliferative DR (NPDR), moderate NPDR, severe NPDR or proliferative DR (PDR). Fundus photography and fluorescein angiograms were analyzed using Vessel Generation Analysis (VESGEN) software in a cohort of subjects. CD34+ CACs were isolated from peripheral blood of diabetics and control subjects. RAS gene expressions in CACs were measured by qPCR. The vasoreparative function of CACs was assessed by migration ability toward CXCL12 using the QCM 5M 96-well chemotaxis cell migration assay. Results: ACE2 gene is a key enzyme converting the deleterious Angiotensin II to the beneficial Angiotensin-(1-7). ACE2 expression in CACs from diabetic subjects without DR was increased compared to controls, suggestive of compensation (p0.0437). The expression of Mas (Angiotensin-(1-7) receptor) in CACs was also increased in diabetics without DR, while was reduced in NPDR compared to controls (p0.0002), indicating a possible loss of compensation of the protective RAS at this stage of DR. The presence of even mild NPDR was associated with CD34+ CAC migratory dysfunction. When pretreating CACs of DR subjects with Angiotensin-(1-7), migratory ability to a chemoattractant CXCL12 was restored (p0.0008). By VESGEN analysis, an increase in small vessel density was observed in NPDR subjects when compared with the controls. Conclusions: These data suggest the protective RAS axis within diabetic CACs may help maintain their vasoreparative potential. The VESGEN analysis supports the presence of retinal repair in small vessels. The loss of the protective arm of RAS may predict the progression of DR

Comparative efficacy of topical tetraVisc versus lidocaine gel in cataract surgery

<p>Abstract</p> <p>Background</p> <p>To compare the clinical efficacy of lidocaine 2% with tetracaine 0.5% for cataract surgery.</p> <p>Methods</p> <p>In a randomized, multi-surgeon, controlled clinical trial,122 consecutive cataract cases eligible for topical anesthesia, were randomly assigned to receive lidocaine 2% gel (1 ml) or tetracaine solution 0.5% (TetraVisc, 0.5 ml) before clear corneal phacoemulsification. Main outcome measure was visual analog scale (0 to 10), which was used to measure intra-operative pain. Secondary outcome measures included patients' discomfort due to tissue manipulation and surgeon graded patients' cooperation. Duration of surgery and intra-operative complications were also recorded.</p> <p>Results</p> <p>The mean age in TetraVisc (TV) group was 70.4 years and in the lidocaine gel group (LG) it was 70.6 years (p = 0.89). Patient reported mean intra-operative pain scores by visual analog scale were 0.70 ± 0.31 in TV group and 1.8 ± 0.4 in LG group (<it>P </it>< 0.001). Mean patient cooperation was also marginally better in the TV group (8.3 ± 0.3) compared to LG group (8.4 ± 0.6) (P = 0.25). 96% of patients in TV group showed intra-operative corneal clarity compared to 91% in LG group. TV group had less (1 out of 61 patients, 1.6%) intra-operative complications than LG group (3 out of 61 patients, 4.8%). No anesthesia related complications were noted in either group</p> <p>Conclusion</p> <p>Topical TetraVisc solution was superior to lidocaine 2% gel for pain control in patients undergoing clear corneal phacoemulsification. Lidocaine 2% gel is similar to TetraVisc in patient comfort and surgeon satisfaction.</p> <p>Trial Registration</p> <p><b>Clinical trials number</b>: ISRCTN78374774</p

Brief Report - Mini outbreak of Kaposi's varicelliform eruption in skin ward: A study of five cases

Background: Kaposi's varicelliform eruption (KVE) represents widespread cutaneous herpes simplex virus (HSV) infection in patients with preexisting dermatoses. Occasionally, this infection can present as a nosocomial infection in skin wards, if adequate bed-spacing and barrier nursing methods are not followed. We are reporting five cases of KVE; four cases acquired the infection in a makeshift ward after admission of the first case in May 2005, due to the renovation work of the regular skin ward. Aim: The purpose of this study is to create clinical awareness about this uncommon dermatologic entity and to stress upon the importance of bed-spacing and barrier nursing in skin wards. Methods: Five cases of KVE, three females and two males with different primary dermatoses (pemphigus foliaceus - one, pemphigus vulgaris - two, paraneoplastic pemphigus - one and toxic epidemal necrolysis - one) were included in this study. Diagnosis was made clinically and supported with Tzanck smear and HSV serology. All the cases were treated with oral acyclovir. Results: Four out of five cases of KVE recovered with treatment, one case of extensive pemphigus vulgaris with KVE succumbed to death. Conclusion: Mini outbreaks of KVE can occur in skin wards with inadequate bed-spacing and overcrowding of patients. Therefore adequate bed-spacing, barrier nursing and isolation of suspected cases are mandatory to prevent such life-threatening infections

Miniaturized high-resolution wide-field contact lens for panretinal photocoagulation

Keyvan Koushan, KV Chalam Department of Ophthalmology, University of Florida College of Medicine, Jacksonville, FL, USA Background and objective: We describe a miniaturized lightweight high-refractive-index panretinal contact lens for diagnostic and therapeutic visualization of the peripheral retina. Instrument design: The miniaturized high-resolution wide-field contact lens includes three optical elements in a light (15 g) and miniaturized (16 mm footplate, 24 mm external aperture, and 21 mm vertical height) casing contributing to a total dioptric power of +171 diopters. This lens provides up to 165&deg; visualization of the retina for diagnostic and therapeutic applications while allowing easier placement due to its miniaturization. Conclusion: This new lens (50% lighter and 89% smaller) improves upon earlier contact lenses for visualization of the peripheral retina. Keywords: contact lens, panretinal photocoagulation, retinal examination, peripheral retina, high resolution view, wide-angle lens, len

Bilateral isolated concurrent superior ophthalmic vein thrombosis in systemic lupus erythematosus

Kumar Sambhav, Omar Shakir, Kakarla V Chalam Department of Ophthalmology, College of Medicine &ndash; Jacksonville, University of Florida, Jacksonville, FL, USA Abstract: We describe a case of bilateral consecutive superior ophthalmic vein thrombosis as a presenting feature in a patient previously not known to have systemic lupus erythematosus (SLE). A 68-year-old African&ndash;American female presented with decreased vision in right eye, mild right orbital tenderness, and frontotemporal headache of 3 days duration. MRI of the orbits confirmed thrombosis of the right superior ophthalmic vein without extension into the cavernous sinus. Sequential MRI at 1 month showed interval improvement of the right superior ophthalmic vein thrombosis and a new thrombosis in the left superior ophthalmic vein. Renal biopsy revealed granular membranous and mesangial deposits of IgG, IgA, IgM, C3, and C1q and confirmed the diagnosis of SLE. Keywords: superior ophthalmic vein thrombosis, systemic lupus erythematosus, MRI in SOV