A Case of Vogt-Koyanagi-Harada Disease in a Patient With Graves Disease

A case of Vogt-Koyanagi-Harada disease (VKH) that developed in a 36-year-old woman with Graves' disease was described. The patient was treated with Lugol's solution and presented with bilateral serous retinal detachment. She had also suffered from methimazole-induced hypersensitivity and steroid-induced myopathy. Fluorescein angiography showed multiple leakage points and a lumbar puncture revealed pleocytosis, which was compatible with VKH. High dose steroid pulse therapy was successful. Altered immune regulation associated with drug-induced hypersensitivity may contribute to the development of VKH in patients with Graves' disease

Early versus Late Intravitreal Triamcinolone Acetonide for Macular Edema associated with Branch Retinal Vein Occlusion

PURPOSE: To compare the effect of early versus late intravitreal injection of triamcinolone in patients with macular edema due to branch retinal vein occlusion (BRVO). METHODS: Twenty eyes of 20 patients with macular edema from BRVO, including 10 with duration after onset of or 3 months, improvements in visual acuity and foveal thickness, though apparent at 1 month, were not maintained at 3 and 6 months post-triamcinolone. CONCLUSIONS: Intravitreal triamcinolone is more effective in patients with BRVO who are treated earlier

The Safety and Efficacy of Transconjunctival Sutureless 23-gauge Vitrectomy

PURPOSE: To evaluate the efficacy and safety of vitreoretinal surgery using a 23-gauge transconjunctival sutureless vitrectomy (TSV) system for various vitreoretinal diseases. METHODS: A retrospective, consecutive, interventional case series was performed for 40 eyes of 40 patients. The patients underwent vitreoretinal procedures using the 23-gauge TSV system, including idiopathic epiretinal membrane (n=7), vitreous hemorrhage (n=11), diabetic macular edema (n=10), macular hole (n=5), vitreomacular traction syndrome (n=5), diabetic tractional retinal detachment (n=1), and rhegmatogenous retinal detachment (n=1). Best corrected visual acuity (BCVA), intraocular pressure (IOP), and intra- and post-operative complications were evaluated. RESULTS: Intraoperative suture placement was necessary in 3 eyes (7.5%). The median BCVA improved from 20/400 (LogMAR, 1.21+/-0.63) to 20/140 (LogMAR, 0.83+/-0.48) at 1 week (p=0.003), 20/100 (LogMAR, 0.85+/-0.65) at 1 month (p=0.002), 20/100 (LogMAR, 0.73+/-0.6) at 3 months (p=0.001). In 1 eye, IOP was 5 mmHg at 2 hours and 4 mmHg at 5 hours, but none of the eyes showed hypotony after 1 postoperative day. No serous postoperative complications were observed during a mean follow-up of 8.4+/-3.4 months (range 3-13 months) CONCLUSIONS: The 23-gauge TSV system shows promise as an effective and safe technique for a variety of vitreoretinal procedures. It appears to be a less traumatic, more convenient alternative to 20-gauge vitrectomy in some indications

A Neurostimulator Design for Long-term Animal Experiments

This article reports on a neural prosthesis stimulation system for long-term use in animal electrical stimulation experiments. The presented system consists of an implantable stimulator which provides continuous electrical stimulation, and an external component which provides preset stimulation parameters and power to the implanted stimulator via a paired RF (radio frequency) coil. A rechargeable internal battery and a parameter memory component were introduced to the implanted neural stimulator. As a result, the external component was not necessary during the stimulation cycles. The implantable stimulator was implemented with IC chips and the electronics, except for the stimulation electrodes, were hermetically packaged in a biocompatible metal case. A polyimide-based gold electrode array was used for realization of the animal implantation test using retinal prosthesis approach.This work was supported by the Korean Science and Engineering Foundation (KOSEF) through the Nano Bioelectronics and Systems Research Center (NBS-ERC) of Seoul National University under Grant R11-2000-075-01001-0 and by the Ministry of Health & Welfare, Republic of Korea through the Nano Artificial Vision Research Center under Grant of the Korea Health 21 R&D Project (A050251)

Development of Microelectrode Arrays for Artificial Retinal Implants using Liquid Crystal Polymers

Purpose: To develop a liquid crystal polymer (LCP) based, long-term implantable, retinal stimulation microelectrode array using a novel fabrication method. Methods: The fabrication process used laser micromachining and customized thermal press bonding to produce LCP based microelectrode arrays. To evaluate the fabrication process and the resulting electrode arrays, in vitro reliability tests and in vivo animal experiments were performed. The in vitro tests consisted of electrode site impedance recording and electrode inter-layer adhesion monitoring during accelerated soak tests. For in vivo testing, the fabricated electrode arrays were implanted in the suprachoroidal space of rabbit eyes. Optical coherence tomography (OCT) and electrically evoked cortical potentials (EECPs) were used to determine long-term biocompatibility and functionality of the implant.Results: The fabricated structure had a smooth, rounded edge profile and exhibited moderate flexibility, which are advantageous features for safe implantation without guide tools. Following accelerated soak tests at 75°C in phosphate buffered saline, the electrode sites showed no degradation and the inter-layer adhesion of the structure showed acceptable stability for more than 2 months. The electrode arrays were safely implanted in the suprachoroidal space of rabbit eyes, and 1 EECP waveforms were recorded. Over a 3-month postoperative period, no choroioretinal inflammation or structural deformities were observed by OCT and histological examination. Conclusions: LCP based flexible microelectrode arrays can be successfully applied as retinal prostheses. The results demonstrate that such electrode arrays are safe, biocompatible, mechanically stable, and can be effective as part of a chronic retinal implant system.This paper was supported by the Korea Science and Engineering Foundation (KOSEF) through the Nano Bioelectronics and Systems Research Center (NBS-ERC) at Seoul National University, and by a grant from the Korea Health 21 R&D Project(A050251), Ministry of Health & Welfare, Republic of Korea

Feasibility of Micro Electrode Array (MEA) Based on Silicone-Polyimide Hybrid for Retina Prosthesis

Purpose: To adopt micropatterning technology in manufacturing silicone elastomer based microelectrode arrays for retinal stimulation, a silicone-polyimide hybrid microelectrode array was proposed and tested in vivo. Methods: Gold microelectrodes were created by semiconductor manufacturing technology based on polyimide, and were hybridized with silicone elastomer by spin coating. The stability of the hybrid between the two materials was flex and blister tested. The feasibility of the hybrid electrode was evaluated in rabbit eye by reviewing optical coherence tomography (OCT) findings after suprachoroidal implantation. Results: The flex test showed no dehiscence between the two materials for 24 h of alternative flexion and extension from -45.0° to +45.0°. During the blister test, delamination was observed at 8.33±1.36 psi of pressure stress; however, this property was improved to 11.50±1.04 psi by oxygen plasma treatment before hybridization. OCT examination revealed that, the implanted electrodes were safely located in the suprachoroidal space during the 4-week follow-up period. Conclusion: The silicone-polyimide hybrid microelectrode array showed moderate physical properties, which are suitable for in vivo application. Appropriate pretreatment before hybridization improved electrode stability. In vivo testing indicated that thiselectrode is suitable as a stimulation electrode in artificial retina.This paper was supported by the Korea Science and Engineering Foundation (KOSEF) through the Nano Bioelectronics and Systems Research Center (NBS-ERC) at Seoul National University, and by a grant from the Korea Health 21 R&D Project(A050251), Ministry of Health & Welfare, Republic of Korea

Down-regulation of IFN-gamma-producing CD56+ T cells after combined low-dose cyclosporine/prednisone treatment in patients with Behcet's uveitis

PURPOSE: To investigate the effects of combined low-dose cyclosporine and prednisone (Cs/Pd) treatment on circulating CD56+ T cells in patients with Behcet's uveitis. METHODS: Ten patients with Behcet's uveitis and 10 healthy control subjects were prospectively recruited. The patients were treated with Cs/Pd for 2 months. Phenotypic and functional changes in circulating CD56+ T cells were assayed before and after treatment. CD56+ T-cell subsets were determined by flow cytometric analysis with monoclonal antibodies for CD3, CD4, CD8, CD56, pan gammadelta TCR, and Valpha24. The absolute numbers of cells in the lymphocyte subsets were calculated. Cytokine (IFN-gamma, IL-4, and IL-10) expressions were measured by ELISA and by intracellular cytokine staining. RESULTS: The proportions of CD56+ T cells, specifically CD8highCD56+ and CD56+gammadelta T-cell subsets, were significantly higher in active Behcet's uveitis but normalized after treatment, whereas the total T-lymphocyte count and the absolute numbers of CD56- T cells were unaffected by treatment. The levels of IFN-gamma and IL-4 were elevated in aqueous humor and serum in Behcet's uveitis (P < 0.001), whereas IL-10 was not detected. After treatment, serum IL-4 levels markedly increased (P < 0.001), and IFN-gamma production by circulating CD56+ T cells was then suppressed. IL-4 and -10 production by CD56+ T cells was increased by treatment, but in contrast, minimal changes were found in CD56- T cells. CONCLUSIONS: The results imply that Cs/Pd treatment for Behcet's uveitis selectively affects the population of and the cytokine expression in CD56+ T cells, but without significant changes in CD56- T cells, and that IFN-gamma-producing CD56+ T cells are the central pathogenic immune cells in Behcet's uveitis