Publications by authors named "Toru Nakazawa"

Latanoprost was first developed for use in glaucoma therapy as an ocular hypotensive agent targeting the prostaglandin F2α (FP) receptor. Subsequently, latanoprost showed a neuroprotective effect, an additional pharmacological action. However, although it is well-known that latanoprost exerts an ocular hypotensive effect via the FP receptor, it is not known whether this is also true of its neuroprotective effect.

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Age-dependent formation of macular drusen caused by the focal accumulation of extracellular deposits beneath the retinal pigment epithelium precede the development of age-related macular degeneration (AMD), one of the leading causes of blindness worldwide. It is established that inflammation contributes to the pathogenesis of drusen and AMD. However, development of a preemptive therapeutic strategy targeting macular drusen and AMD has been impeded by the lack of relevant animal models because most laboratory animals lack macula, an anatomic feature present only in humans and a subset of monkeys.

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It has been suggested that unoprostone isopropyl (UNO) has potent neuroprotective activity in the retina. The effect of sustained transscleral UNO delivery to the posterior segment of the eye on photoreceptor degeneration was evaluated. UNO was loaded into a device made of poly(ethyleneglycol) dimethacrylate by polydimethylsiloxane mold-based UV-curing.

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Purpose: To evaluate the optic nerve head (ONH) microcirculation in autosomal dominant optic atrophy (ADOA) patients.

Methods: This study comprised 22 eyes of 12 ADOA patients, diagnosed according to clinical findings including family history and the presence of mutations in the OPA1 gene. Twenty-four normal eyes of 24 age-matched subjects, with either the right or left eye randomly selected for use, served as controls.

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We compared the clinical features of optic neuritis (ON) that are frequently observed in various central nervous system demyelinating diseases, including multiple sclerosis (MS), anti-aquaporin 4 (AQP4) antibody- and anti-myelin oligodendrocyte glycoprotein (MOG) autoantibody-related diseases. Almost all the AQP4-ON patients were female, whereas half of the MOG-ON patients were male. The ON-onset age was younger in MS-ON and was older in AQP4-ON.

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Estimation of polarimetric parameters has been a fundamental issue to assess biological tissues that have form birefringence or polarization scrambling in polarization-sensitive optical coherence tomography (PS-OCT). We present a mathematical framework to provide a maximum likelihood estimation of the target covariance matrix and its incoherent target decomposition to estimate a Jones matrix of a dominant scattering mechanism, called Cloude-Pottier decomposition, thereby deriving the phase retardation and the optic axis of the sample. In addition, we introduce entropy that shows the randomness of the polarization property.

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Objective: To compare surgical outcomes between the first and second operated eyes in patients who underwent trabeculectomy in both eyes.

Methods: This retrospective clinical cohort study at five clinical centers in Japan included 84 patients with open-angle glaucoma who underwent primary trabeculectomy in both eyes. The primary outcome was surgical success or failure, with failure being defined according to three criteria: <20% reduction of the preoperative intraocular pressure (IOP), or Criterion A, IOP >21 mmHg; Criterion B, IOP >18 mmHg; or Criterion C, IOP >15 mmHg.

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Purpose: To objectively classify the optic discs of open-angle glaucoma (OAG) patients into Nicolela's four disc types, i.e., focal ischemic (FI), myopic (MY), senile sclerotic (SS), and generalized enlargement (GE), with swept-source optical coherence tomography (SS-OCT).

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Purpose: We conducted a survey to evaluate the current status of glaucoma-related medical data management and standardization, aiming to improve the development of glaucoma care and research in Japan. Materials and methods: The survey was performed as a paper-based questionnaire of 14 universities that both participate in the glaucoma-related data standardization committee, established by the Japan Glaucoma Society in 2014, and actively perform glaucoma care. Results: All enrolled university hospitals installed an electronic hospital information system and used any of three ophthalmology-limited electronic chart systems.

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Background: The aim of the study is to determine the relationship between post-trabeculectomy bleb structure evaluated using anterior segment optical coherence tomography (AS-OCT) and postoperative intraocular pressure (IOP).

Design: Rretrospective is showed for the design of this study.

Participants: There are twenty-seven eyes of 27 trabeculectomy patients.

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Glaucoma is a group of eye diseases characterized by alterations in the contour of the optic nerve head (ONH), with corresponding visual field defects and progressive loss of retinal ganglion cells (RGCs). This progressive RGC death is considered to originate in axonal injury caused by compression of the axon bundles in the ONH. However, the molecular pathomechanisms of axonal injury-induced RGC death are not yet well understood.

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Purpose: To investigate changes in retinal ganglion cell (RGC) activity by measuring the positive scotopic threshold response (pSTR) of the electroretinogram (ERG) in axotomized eyes after brimonidine injection.

Methods: In 50 adult Sprague-Dawley rats, the left eye was axotomized and injected with phosphate buffered saline (PBS) or brimonidine and the contralateral right eye was left untreated. Scotopic ERGs were recorded simultaneously from both eyes on days 1, 2, 3, 7, and 10 after the intravitreal injection, and the amplitude of the a- and b-waves and the pSTR were measured.

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Article Synopsis
  • A new technique was developed to toughen and clarify human amniotic membrane (AM) tissue for potential use in corneal transplants, improving its physical properties through a laminating process and chemical cross-linking.
  • The enhanced AM laminates, which required at least 4 layers, exhibited increased light transmittance, mechanical strength, and resistance to degradation from enzymes known to affect corneal tissues.
  • The study confirmed the biocompatibility of the modified AM by successfully implanting it in rabbits, demonstrating it only required one set of sutures, which is more efficient compared to previous multi-layer techniques.
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The development of new treatments for intractable retinal diseases requires reliable functional assessment tools for animal models. In vivo measurements of neural activity within visual pathways, including electroretinogram (ERG) and visually evoked potential (VEP) recordings, are commonly used for such purposes. In mice, the ERG and VEPs are usually recorded under general anesthesia, a state that may alter sensory transduction and neurotransmission, but seldom in awake freely moving mice.

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Aims: To determine whether skin autofluorescence (SAF) and serum pentosidine, biomarkers of advanced glycation end products (AGEs), were associated with ocular microcirculation in type 2 diabetes patients with early diabetic retinopathy (DR).

Methods: This study included 46 eyes of 46 type 2 diabetes patients with no DR or non-proliferative DR. SAF was measured with an autofluorescence reader.

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Purpose: To compare optic nerve head (ONH) blood flow in healthy eyes, eyes with preperimetric glaucoma (PPG), and eyes with mild normal-tension glaucoma (NTG) using laser speckle flowgraphy (LSFG).

Methods: In 172 eyes (normal: 44 eyes; PPG: 62 eyes; mild NTG: 66 eyes), LSFG was used to measure mean blur rate in the ONH tissue area (MBR), an index of capillary blood flow. Multiple regression analysis was performed to determine factors affecting circumpapillary retinal nerve fiber layer thickness (cpRNFLT), mean deviation (MD) and pattern standard deviation (PSD) of the visual field.

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Purpose: To investigate the influence of various risk factors on thinning of the lamina cribrosa (LC), as measured with swept-source optical coherence tomography (SS-OCT; Topcon).

Methods: This retrospective study comprised 150 eyes of 150 patients: 22 normal subjects, 28 preperimetric glaucoma (PPG) patients, and 100 open-angle glaucoma patients. Average LC thickness was determined in a 3 x 3 mm cube scan of the optic disc, over which a 4 x 4 grid of 16 points was superimposed (interpoint distance: 175 μm), centered on the circular Bruch's membrane opening.

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Objectives: The visual acuity prognoses of patients with neuromyelitis optica (NMO) are worse than those with optic neuritis (ON) caused by other diseases. Predicting the prognoses of ON at the time of onset is important for selecting treatments for NMO patients.

Methods: Twenty-three consecutive anti-aquaporin-4 autoantibody-positive NMO patients who presented with ON and had contrast-enhanced optic MRIs in the acute phase of their first ON episode were examined.

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The retinal ganglion cells (RGCs) are the main source of therapeutic targets for neuroprotective glaucoma treatment, and evaluating RGCs is key for effective glaucoma care. Thus, we developed a minimally invasive, quick, real-time method to evaluate RGC death in mice. In this article we describe the details of our method, report new results obtained from C57BL/6J mice, and report that our method was usable in wild type (WT) and knockout (KO) mice lacking an RGC-death-suppressing gene.

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An 81-year-old woman presented with a retinal tumor after unsuccessful surgery was performed for a macular hole (MH) in the 1990s. A histopathological analysis revealed retinal pigment epithelium hyperplasia with no evidence of neoplastic cells. This case highlights two points: first, MHs that remain open after unsuccessful MH surgery can cause retinal tumors, leading to further visual loss; and second, in this case, the MH-associated tumor showed no evidence of neoplastic cells.

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Axial spondylometaphyseal dysplasia (axial SMD) is an autosomal recessive disease characterized by dysplasia of axial skeleton and retinal dystrophy. We conducted whole exome sequencing and identified C21orf2 (chromosome 21 open reading frame 2) as a disease gene for axial SMD. C21orf2 mutations have been recently found to cause isolated retinal degeneration and Jeune syndrome.

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Background: Recently, topical dexamethasone-induced ocular hypertension and a consequent loss of retinal ganglion cells (RGCs) have been described in mice. This has been proposed as a model of steroid-induced glaucoma. In this study, we set up and evaluated a similar model in rats.

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Ocular Blood Flow and Influencing Factors for Glaucoma.

Asia Pac J Ophthalmol (Phila)

September 2016

Open-angle glaucoma (OAG) is characterized by optic nerve fiber atrophy and deterioration of the visual field, corresponding to damage to the optic nerve head. Intraocular pressure (IOP) is currently the only evidence-based, treatable risk factor for OAG. However, normal-tension glaucoma, the most common type of OAG in Asia, is a type of glaucoma with an unclear pathogenesis.

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Purpose: To investigate the relationship between various characteristics of a normal population and laser speckle flowgraphy (LSFG) measurements of mean blur rate (MBR) in the optic nerve head (ONH).

Methods: A total of 189 eyes of 189 normal subjects (93 male, 96 female, mean age 45 ± 14 years old, age range: 20-72) without any history of hypertension, hyperlipidemia or diabetes were enrolled. ONH microcirculation was measured with LSFG and overall MBR (MA), vessel-area MBR (MV), and tissue-area MBR (MT) were derived from these measurements.

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