Publications by authors named "Yasuyuki Yamauchi"
Background: It is generally stated that opacities of the ocular media, including senile cataract, have little effect on the electrical responses of the retina. However, lower amplitudes and longer implicit times are sometimes observed in electroretinograms (ERGs) of patients with mature cataract.
Methods: Single flash ERGs of mature cataractous eyes with decimal visual acuity less than 0.
Purpose: To measure intraocular cytokine levels in patients with exudative age-related macular degeneration and analyze changes in the cytokine profile 2 days after intravitreal bevacizumab injection.
Methods: This prospective case-control study enrolled 37 patients (37 eyes) with age-related macular degeneration including polypoidal choroidal vasculopathy. Twenty-eight age-matched patients (28 eyes) who underwent cataract surgery were used as controls.
Purpose: To determine the objective and quantitative hyperspectral parameters for distinguishing between age-related macular degeneration (AMD) and a normal macula.
Methods: Near-infrared hyperspectral images were taken of 71 eyes of 62 AMD patients with exudative AMD and 21 eyes of 12 control subjects without AMD. The spatial information included a 480 × 321-pixel image in a 50° field located at the ocular fundus and a 720-950-nm-per-pixel reflectance spectrum.
Background: Recent research on macular diseases has prompted investigations into the condition of the intersection between the photoreceptor inner and outer segments (IS/OS) and the relationship with retinal photoreceptor abnormalities. Although the origin of the IS/OS in optical coherence tomography (OCT) images is unclear, it may be related to either the cellular activity of the photoreceptors or the structure of the OS disks. To address this question, we compared the IS/OS status in OCT images of rat retinas before and after euthanasia.
View Article and Find Full Text PDFBackground: Recent research on macular diseases has prompted investigations into the condition of the intersection between the inner and outer segments (IS/OS), and its relationship with retinal photoreceptor abnormalities. Because the correlation between optical coherence tomography (OCT) images and histopathology is unclear, the authors compared them in an N-methyl-N-nitrosourea (MNU)-induced photoreceptor degeneration rat model.
Methods: MNU (60 mg/kg), which is toxic to photoreceptors, was injected in 12 Brown Norway rats.
Background: Recent research on macular disease has prompted investigation into the condition of the intersection of the inner and outer segments (IS/OS) and its relationship with retinal photoreceptor abnormalities. Because the relationship between optical coherence tomography (OCT) images and histopathology is unclear, we compared these in an iodoacetic acid (IAA)-induced model of photoreceptor degeneration in rabbits.
Methods: IAA (20 mg/kg), which is toxic to photoreceptors, was injected into six coloured rabbits.
Purpose: To analyze results of pars plana vitrectomy for acute retinal necrosis (ARN) syndrome.
Methods: We reviewed the records of 52 eyes with ARN syndrome who underwent pars plana vitrectomy at the Tokyo Medical University Hospital from 1989 to 2007. The mean age was 50.
This study investigated the anatomical consequences of a photoreceptor toxin, iodoacetic acid (IAA), in the rabbit retina. Retinae were examined 2 weeks, 1, 3, and 6 months after systemic IAA injection. The retinae were processed using standard histological methods to assess the gross morphology and topographical distribution of damage, and by immunohistochemistry to examine specific cell populations in the retina.
View Article and Find Full Text PDFPurpose: To investigate the relationship between retinal vein occlusion (RVO) and carotid artery lesions.
Methods: For patients with RVO who presented to the Ophthalmology Department of Tokyo Medical University Hospital between 2000 and 2003, carotid artery evaluation was possible on 58 eyes of 57 patients aged 51 years to 88 years (mean, 70.1 years).
Aim: While cytomegalovirus is well known as a pathogenic organism of retinitis, especially associated with human immunodeficiency virus infection, there are few reports of anterior uveitis associated with cytomegalovirus.
Methods: The authors present a case of keratouveitis associated with cytomegalovirus.
Results: A 70-year-old Japanese man was referred to the authors because of poorly controlled hypertensive keratouveitis in the left eye.
Stem cell regeneration of damaged tissue has recently been reported in many different organs. Since the loss of retinal pigment epithelium (RPE) in the eye is associated with a major cause of visual loss - specifically, age-related macular degeneration - we investigated whether hematopoietic stem cells (HSC) given systemically can home to the damaged subretinal space and express markers of RPE lineage. Green fluorescent protein (GFP) cells of bone marrow origin were used in a sodium iodate (NaIO(3)) model of RPE damage in the mouse.
View Article and Find Full Text PDFWe characterized changes in the visual behavior of mice in which a loss of the retinal pigment epithelium (RPE) was experimentally induced with intravenous (i.v.) administration of sodium iodate (NaIO3).
View Article and Find Full Text PDFAim: To report a 47-year-old Japanese woman with a one-year history of Behçet's disease who complained of sudden bilateral visual loss with concurrent anterior ischemic optic neuropathy (AION).
Case Report: The patient's Snellen visual acuity was 0.1 (OD) and 0.
Purpose: To compare the conjunctival flora of human immunodeficiency virus (HIV)-positive and HIV-negative patients. Also, to assess the prophylactic effect of oral clarithromycin against Mycobacterium avium complex on the conjunctival flora of HIV-positive patients.
Methods: Ninety-four eyes of 47 HIV-positive patients and 122 eyes of 61 control patients were examined.
The aim of the study was to directly compare the threshold electrical charge density of the retina (retinal threshold) in rabbits for the generation of electrical evoked potentials (EEP) by delivering electrical stimulation with a custom-made microelectrode array (MEA) implanted into either the subretinal or suprachoroidal space. Nine eyes of seven Dutch-belted rabbits were studied. The electroretinogram (ERG), visual evoked potentials (VEP) and EEP were recorded.
View Article and Find Full Text PDFPurpose: We examined eyeballs collected from autopsied acquired immunodeficiency syndrome patients with cytomegalovirus (CMV) retinitis, and analyzed the precise pathogenesis of CMV retinitis.
Material And Methods: Eyeballs were fixed with 10% buffered formalin embedded in paraffin. CMV antigens were investigated by histopathological and immunohistochemical analyses.
Purpose: To investigate the differentiation of rat neural stem cells (rNSCs) into cells of retinal pigment epithelial (RPE) lineage both in vitro and in vivo, after subretinal transplantation into normal rats and in a sodium iodate (NaIO(3)) model of RPE loss.
Methods: rNSCs prepared from the cortex of embryonic day (E)14 Fisher F344 rats were cocultured with different concentrations of vasoactive intestinal peptide (VIP), adult rat RPE cells, or neurosensory retina (NSR) for 5 days. Cell morphology and expression of RPE-specific markers (cytokeratin, CD68, microphthalmia-inducing transcription factor [MITF]) were studied.