Published papers

In the wake of the devastating earthquake and tsunami of March 11, our group at Keio University worked diligently to bring the Vision Van, a mobile eye clinic, from Miami, Florida, to disaster areas where medicines, eyeglasses, and indeed all other ophthalmological supplies and services, were nonexistent, thereby assisting many tsunami survivors suffering from eye problems. This act was encouraging not only to the patients and those working in the disaster-hit areas but also to ophthalmologists who wanted to use their medical specialty to assist those in need. © 2012 by The Keio Journal of Medicine.

Background: Decrease in lacrimal gland secretory function is related to age-induced dry eye disease. Lactoferrin, the main glycoprotein component of tears, has multiple functions, including anti-inflammatory effects and the promotion of cell growth. We investigated how oral administration of lactoferrin affects age-related lacrimal dysfunction. Methods and Findings: Twelve-month-old male C57BL/6Cr Slc mice were randomly divided into a control fed group and an oral lactoferrin treatment group. Tear function was measured at a 6-month time-point. After euthanasia, the lacrimal glands were subjected to histological examination with 8-hydroxy-2′-deoxyguanosine (8-OHdG) antibodies, and serum concentrations of 8-OHdG and hexanoyl-lysine adduct (HEL) were evaluated. Additionally, monocyte chemotactic protein-1(MCP-1) and tumor necrosis factor-α (TNF-α) gene expression levels were determined by real-time PCR. The volume of tear secretion was significantly larger in the treated group than in the control. Lactoferrin administration reduced inflammatory cell infiltration and the MCP-1 and TNF-α expression levels. Serum concentrations of 8-OHdG and HEL in the lactoferrin group were lower than those in the control group and were associated with attenuated 8-OHdG immunostaining of the lacrimal glands. Conclusion: Oral lactoferrin administration preserves lacrimal gland function in aged mice by attenuating oxidative damage and suppressing subsequent gland inflammation. © 2012 Kawashima et al.

Purpose: Vascular adhesion protein (VAP)-1 is an adhesion molecule elucidated as a mediator of the leukocyte recruitment cascade. The purpose of this study was to investigate the role of VAP-1 in ocular inflammatory neovascularization using a mouse laser-induced choroidal neovascularization (CNV) model. Methods: CNV was induced with 532 nm laser irradiation in C57BL/6 mice, and production of VAP-1 protein in the retinal pigment epithelium (RPE) choroid during CNV formation was examined. CNV animals were treated with the specific VAP-1 inhibitor U-V002 or vehicle solution, and the volume of CNV tissue was evaluated with volumetric measurements. Macrophage infiltration into the CNV lesions was evaluated using two different techniques, flatmount staining and real-time polymerase chain reaction (PCR) for F4/80. The protein levels of intercellular adhesion molecule (ICAM)-1, monocyte chemoattractant protein (MCP)-1, P-selectin, and vascular endothelial growth factor (VEGF) in the RPE-choroid were measured with enzyme-linked immunosorbent assay (ELISA). Results: VAP-1 inhibition significantly suppressed CNV formation in a dose-dependent manner and reduced macrophage infiltration into CNV lesions. Furthermore, VAP-1 blockade decreased the expression of ICAM-1 and MCP-1, both of which play a pivotal role in macrophage recruitment. Conclusions: Our data suggest VAP-1 has an important role during ocular inflammatory neovascularization through leukocyte recruitment. VAP-1 inhibition may be a novel and potent therapeutic strategy in treating CNV formation. © 2012 Molecular Vision.

Purpose: Falls are among the most serious public health concerns for the elderly. Information conveyed via the visual sense is relevant to postural balance and movement, and proper visual function is essential to avoid falls. Here we investigated the prevalence of injurious falls among patients with primary open-angle glaucoma (POAG) who were more than 45 years old, compared with comparably aged healthy subjects. Methods: This is a cross-sectional study. Consecutive patients who visited the Tanabe Eye Clinic, Yamanashi, Japan between January 1 and March 30, 2009 were screened for eligibility by ophthalmic examination. A total of 117 control subjects (77 men, 40 women; aged 60.2 ± 7.5 years) who were free of ocular disease and 101 POAG patients (58 men, 43 women; aged 62.3 ± 8.7 years) were consecutively enrolled. Participants answered a questionnaire on injurious fall experience during the previous 10 years. The prevalence of injurious fall in subjects with POAG versus healthy controls was examined with Fisher's exact test. Adjusted odds ratios and 95% confidence intervals were estimated with logistic regression models for the subjects with POAG (factors: age, gender, mean deviation in the better eye or worse eye). Results: The self-reported prevalence of injurious fall was 0.9% (1/117) in the control group and 6.9% (7/101) in the POAG group. The association between injurious fall and POAG was statistically significant (P = 0.026, Fisher's exact test). Within the POAG patients, the group reporting falls was significantly older and had a lower BMI, worse BCVA, and worse mean deviation in both the better and worse eye than the group reporting no falls. Worse mean deviation in the eye with the better visual field (odds ratios 0.75; 95% confidence intervals: 0.57 to 0.99; P = 0.036) was a significant risk factor for injurious falls in subjects with POAG. Conclusions: POAG was significantly associated with injurious falls. © 2012 Tanabe et al, publisher and licensee Dove Medical Press Ltd.

The vascular and nervous systems display a high degree of cross-talk and depend on each other functionally. In the vascularization of the central nervous system, astrocytes have been thought to sense tissue oxygen levels in hypoxia-inducible factors (HIFs)-dependent manner and control the vascular growth into the hypoxic area by secreting VEGF. However, recent genetic evidences demonstrate that not only astrocyte HIFs but also astrocyte VEGF expression is dispensable for developmental angiogenesis of the retina. This study demonstrates that hypoxia-inducible factor 1 alpha subunit (HIF-1α), a key transcription factor involved in cellular responses to hypoxia, is most abundantly expressed in the neuroretina, especially retinal progenitor cells (RPCs). A neuroretina-specific knockout of HIF-1α (αCre +Hif1α flox/flox) showed impaired vascular development characterized by decreased tip cell filopodia and reduced vessel branching. The astrocyte network was hypoplastic in αCre +Hif1α flox/flox mice. Mechanistically, platelet-derived growth factor A (PDGF-A), a mitogen for astrocytes, was downregulated in the neuroretina of αCre +Hif1α flox/flox mice. Supplementing PDGF-A restored reduced astrocytic and vascular density in αCre +Hif1α flox/flox mice. Our data demonstrates that the neuroretina but not astrocytes acts as a primary oxygen sensor which ultimately controls the retinal vascular development by regulating an angiogenic astrocyte template. © 2011 Elsevier Inc.

IgG4-related disease (IgG4RD) is a novel clinical disease entity characterized by elevated serum IgG4 concentration and tumefaction or tissue infiltration by IgG4-positive plasma cells. IgG4RD may be present in a certain proportion of patients with a wide variety of diseases, including Mikulicz's disease, autoimmune pancreatitis, hypophysitis, Riedel thyroiditis, interstitial pneumonitis, interstitial nephritis, prostatitis, lymphadenopathy, retroperitoneal fibrosis, inflammatory aortic aneurysm, and inflammatory pseudotumor. Although IgG4RD forms a distinct, clinically independent disease category and is attracting strong attention as a new clinical entity, many questions and problems still remain to be elucidated, including its pathogenesis, the establishment of diagnostic criteria, and the role of IgG4. Here we describe the concept of IgG4RD and up-to-date information on this emerging disease entity. © Japan College of Rheumatology 2011.

Purpose: To describe a new method of alignment of toric intraocular lenses (IOLs) and evaluation of their rotation errors using anterior segment optical coherence tomography (AS-OCT). Methods: Twenty-nine eyes of 22 patients who had cataract extraction and implantation of an acrylic toric IOL were included. The new AS-OCT method was used for the alignment of toric IOLs and evaluation of their rotation errors. These rotation errors were evaluated and compared with those measured using the internal map of a wavefront aberrometer. Results: The mean rotation error ± standard deviation (SD) of the toric IOLs evaluated by AS-OCT was 3.2 ± 2.2° and 3.2 ± 2.4° at 1 week and 1 month after surgery, respectively. The mean difference in the reference axis between the visits was 1.8 ± 2.1°. The mean difference between the rotation errors of the alignment axes measured by AS-OCT and the internal map was 2.5 ± 1.9° (P = 0.037). Conclusion: The current method is clinically useful not only for the accurate alignment of toric IOLs but also for evaluating their rotation errors. © Japanese Ophthalmological Society 2011.

Although a large variety of pharmaceutical therapies for treating disease have been developed in recent years, there has been little progress in disease prevention. In particular, the protection of neural tissue is essential, because it is hardly regenerated. The use of nutraceuticals for maintaining the health has been supported by several clinical studies, including cross-sectional and interventional studies for age-related macular disease. However, mechanistic evidence for their effects at the molecular level has been very limited. In this review, we focus on lutein, which is a xanthophyll type of carotenoid. Lutein is not synthesized in mammals, and must be obtained from the diet. It is delivered to the retina, and in humans, it is concentrated in the macula. Here, we describe the neuroprotective effects of lutein and their underlying molecular mechanisms in animal models of vision-threatening diseases, such as innate retinal inflammation, diabetic retinopathy, and light-induced retinal degeneration. In lutein-treated mouse ocular disease models, oxidative stress in the retina is reduced, and its downstream pathological signals are inhibited. Furthermore, degradation of the functional proteins, rhodopsin (a visual substance) and synaptophysin (a synaptic vesicle protein also influenced in other neurodegenerative diseases such as Alzheimer's disease and Parkinson's disease), the depletion of brain-derived neurotrophic factor (BDNF), and DNA damage are prevented by lutein, which preserves visual function. We discuss the possibility of using lutein, an antioxidant, as a neuroprotective treatment for humans. © 2012 Bentham Science Publishers.

Anthocyanin-rich bilberry extract, a plant-derived antioxidant, has been utilized as a popular supplement for ocular health worldwide. However, it is unclear whether this extract has any biological effect on visual function, and the mechanism for such an effect is completely unknown. In this study, we generated a mouse model of endotoxin-induced uveitis (EIU) that shows retinal inflammation, as well as uveitis, by injecting lipopolysaccharide. We pretreated the mice with anthocyanin-rich bilberry extract and analyzed the effect on the retina. Anthocyanin-rich bilberry extract prevented the impairment of photoreceptor cell function, as measured by electroretinogram. At the cellular level, we found that the EIU-associated rhodopsin decreased and the shortening of outer segments in photoreceptor cells were suppressed in the bilberry-extract-treated animals. Moreover, the extract prevented both STAT3 activation, which induces inflammation-related rhodopsin decrease, and the increase in interleukin-6 expression, which activates STAT3. In addition to its anti-inflammatory effect, the anthocyanin-rich bilberry extract ameliorated the intracellular elevation of reactive oxygen species and activated NF-B, a redox-sensitive transcription factor, in the inflamed retina. Our findings indicate that anthocyanin-rich bilberry extract has a protective effect on visual function during retinal inflammation. © 2012 USCAP, Inc All rights reserved.

Purpose: Our aim was to evaluate changes in dry eye diagnostic status following implementation of the new dry eye diagnostic criteria in Japan. Design: This was a multicenter cross-sectional study. Methods: We recruited 295 individuals (81 men, 214 women, average age 43.6 ± 14.3 years) seen for general ophthalmic checkup and dry eye examinations. Using results of the Schirmer I test, tear breakup time, and fluorescein and Rose Bengal staining, patients were diagnosed as having definite dry eye (DDE), probable dry eye (PDE), or as being normal according to both the old and new Japanese dry eye diagnostic criteria. Results: Mean ages of normal participants and patients with PDE and DDE were 37.0 ± 10.4, 41.7 ± 14.4, and 47.7 ± 15.3 years, respectively (p < 0.001). All 37 individuals diagnosed as normal following the old criteria were also diagnosed as normal with the new diagnostic criteria. Among the 60 patients diagnosed as PDE with the old criteria, 19 (31.7%) were diagnosed as normal and 41(68.3%) as PDE with the new diagnostic criteria. Of the 198 patients diagnosed with DDE following the old criteria, 59 (29.7%) were diagnosed as PDE and 139 (70.2%) as DDE with the new diagnostic criteria. There was no significant difference in dry eye severity index scores between the old and new diagnostic criteria. Conclusion: A shift in the final dry eye diagnostic status from DDE to PDE and from PDE to normal was observed with the implementation of the new dry eye diagnostic criteria, suggesting that patients at the severe end of the dry eye disease spectrum are now diagnosed as DDE disease under the new criteria. © Japanese Ophthalmological Society 2011.

Aims: To compare the incidence and severity of dry eye (DE) after allogeneic haematopoietic stem cell transplantation (HSCT) according to the stem cell source. The authors specifically focused on patients who received bone marrow transplantation (BMT), peripheral blood stem cell transplantation (PBSCT) and cord blood transplantation (CBT). Methods: Ninety-nine HSCT recipients who were prospectively followed-up for at least 100 days at Keio University Hospital were recruited. Ophthalmological examinations included evaluation of ocular surface findings and tear dynamics. The data on systemic graft-versus-host disease were collected by chart review. Results: Of the 99 patients (BMT, 67; PBSCT, 18; CBT, 14), 42 developed DE or showed worsened pre-existing DE after HSCT; 31 (46.3%) BMT group; 8 (44.0%) PBSCT group; and 3 (21.4%) CBT group (p=0.78). The median onset time of DE tended to be later in the PBSCT group (474 days, range 95-1559) than in the BMT (287 days, range 67-1216) or CBT (168 days, range 33-481) group, but the difference was not significant (p=0.23). However, the proportion of patients with severe DE was significantly higher in the PBSCT group (N=7, 87.5%) than in the BMT (N=12, 38.7%) or CBT (N=1, 33.3%) group (p=0.04) and CBT showed the lowest among all three stem cell sources. Conclusion: The data in this study suggested that the severity and onset time of DE were affected by the stem cell source. Close attention must be paid to the development of late-onset severe DE in PBSCT recipients.

Biological carriers, such as the amniotic membrane and serum-derived fibrin, are currently used to deliver cultivated corneal epithelial sheets to the ocular surface. Such carriers require being transparent and allowing the diffusion of metabolites in order to maintain a healthy ocular surface. However, safety issues concerning biological agents encouraged the development of safer, biocompatible materials as cell carriers. We examined the application of porous silk fibroin films with high molecular permeability prepared by mixing silk fibroin and poly(ethylene glycol) (PEG), and then removal of PEG from the silk-PEG films. Molecular permeability of porous silk fibroin film is higher than untreated silk fibroin film. Epithelial cells were isolated from rabbit limbal epithelium, and seeded onto silk fibroin coated wells and co-cultured with mitomycin C-treated 3T3 fibroblasts. Stratified epithelial sheets successfully engineered on porous silk fibroin film expressed the cornea-specific cytokeratins K3 and K12, as well as the corneal epithelial marker pax6. Basement membrane components such as type-IV collagen and integrin β1 were expressed in the stratified epithelial sheets. Further more, colony-forming efficiency of dissociated cells was similar to primary corneal epithelial cells showing that progenitor cells were preserved. The biocompatibility of fibroin films was confirmed in rabbit corneas for up to 6 months. Porous silk fibroin film is a highly transparent, biocompatible material that may be useful as a carrier of cultivated epithelial sheets in the regeneration of corneal epithelium. © Koninklijke Brill NV, Leiden, 2011.

Purpose: Indicators of aging such as disruption of telomeric function due to shortening may be more frequent in dysfunctional lacrimal gland. The aims of this study were to 1) determine the viability of quantitative fluorescence in situ hybridization of telomeres (telo-FISH) for the assessment of telomere length in lacrimal gland in Sjögren and non- Sjögren syndrome patients; and 2) investigate the relationship between progenitor cell markers and telomere length in both groups. Methods: Quantitative fluorescence in situ hybridization with a peptide nucleic acid probe complementary to the telomere repeat sequence was performed on frozen sections from human lacrimal gland tissues. The mean fluorescence intensity of telomere spots was automatically quantified by image analysis as relative telomere length in lacrimal gland epithelial cells. Immunostaining for p63, nucleostemin, ATP-binding cassette, sub-family G, member 2 (ABCG2), and nestin was also performed. Results: Telomere intensity in the Sjögren syndrome group (6,785.0±455) was significantly lower than that in the non- Sjögren syndrome group (7,494.7±477; p=0.02). Among the samples from the non-Sjögren syndrome group, immunostaining revealed that p63 was expressed in 1-3 acinar cells in each acinar unit and continuously in the basal layer of duct cells. In contrast, in the Sjögren syndrome group, p63 and nucleostemin showed a lower level of expression. ABCG2 was expressed in acinar cells in both sjogren and non-Sjogren syndrome. Conclusions: The results of this study indicate that 1) telo-FISH is a viable method of assessing telomere length in lacrimal gland, and 2) telomere length in Sjögren syndrome is shorter and associated with lower levels of expression of p63 and nucleostemin than in non-Sjögren syndrome. © 2011 Molecular Vision.

Purpose: To report the clinical features and investigate the underlying pathological processes of spontaneous corneal perforation in patients with ocular chronic graft-versus-host disease (cGVHD). Methods: A full ophthalmological evaluation of corneal perforation in four patients with cGVHD was performed. Three of them underwent deep anterior lamellar keratoplasty and samples from two of three patients were used for histopathological analyses. Results: Three patients were successfully treated by corneal transplantation. One patient was treated with a therapeutic soft contact lens, and the wound healed within 2 days. The common clinical features of these patients were (1) the presence of definite dry eye related to cGVHD in 3 of 4 patients and probable dry eye in one patient, (2) a central or paracentral site of corneal ulceration and perforation, with no sign of infection, and (3) prior use of a topical or systemic corticosteroid, and/or topical non-steroidal anti-inflammatory drugs. Immunohistochemical findings revealed an increased number of cluster of differentiation 68+ (CD68+) macrophages and matrix metalloproteinase 9 (MMP-9) expression in the tissue surrounding the perforation. Conclusions: Our report extends current information on the clinical features and pathological processes of corneal perforation in cGVHD by showing increased MMP-9 expression and the accumulation of CD68+ positive macrophages in the affected areas. © 2011 Molecular Vision.

Purpose: To investigate the transcriptional factors associated with epithelial-mesenchymal transition (EMT) in choroidal neovascularization (CNV) secondary to age-related macular degeneration (AMD) Methods: Paraffin sections of CNV obtained from patients with AMD (n=12) were stained for transcriptional factors related to EMT, i.e., Snail, Slug, SIP1, and Twist. As a control, postmortem sections of ocular normal tissue were used. Furthermore, using a human retinal pigment epithelial (RPE) cell line (ARPE-19), reverse transcription-polymerase chain reaction (RT-PCR) and immunofluorescence microscopy were performed to explore the cellular localization and expression levels of EMT-associated transcriptional factors upon cytokine stimulation. Results: Of 12 specimens, 11 CNV tissues (91.6%) showed staining for Snail localized in cellular nuclei, particularly in those of RPE cells. Snail was strongly co-localized with α-smooth muscle antigen (SMA) in RPE cells. In contrast, postmortem human retina showed no Snail staining in RPE cells. Other transcriptional factors, Slug, Twist and SIP1 were not detected in CNV or normal human retina. In ARPE-19 cells, RT-PCR and immunofluorescence microscopy showed that Snail mRNA was upregulated by transforming growth factor (TGF)-β and VEGF stimulation. Furthermore, TGF-β induced relocalization of Snail to the nucleus in RPE cells. Conclusions: The current data indicate that Snail is a major transcriptional factor for EMT changes of RPE cells in human CNV. © 2011 Molecular Vision.

Diabetic retinopathy, a vision-threatening disease, has been regarded as a vascular disorder. However, impaired oscillatory potentials (OPs) in the electroretinogram (ERG) and visual dysfunction are recorded before severe vascular lesions appear. Here, we review the molecular mechanisms underlying the retinal neural degeneration observed in the streptozotocin-(STZ-) induced type 1 diabetes model. The renin-angiotensin system (RAS) and reactive oxygen species (ROS) both cause OP impairment and reduced levels of synaptophysin, a synaptic vesicle protein for neurotransmitter release, most likely through excessive protein degradation by the ubiquitin-proteasome system. ROS also decrease brain-derived neurotrophic factor (BDNF) and inner retinal neuronal cells. The influence of both RAS and ROS on synaptophysin suggests that RAS-ROS crosstalk occurs in the diabetic retina. Therefore, suppressors of RAS or ROS, such as angiotensin II type 1 receptor blockers or the antioxidant lutein, respectively, are potential candidates for neuroprotective and preventive therapies to improve the visual prognosis. © 2011 Yoko Ozawa et al.

Objective: To estimate the prevalence and risk factors of dry eye disease (DED) in a rural setting in Japan. Design: Cross-sectional study. Participants: We included 3294 subjects, aged <40 years who were in the residential registry for Koumi town. Intervention: Subjects in a rural mountain area, Koumi town, completed questionnaires designed to detect dry eye diagnosis and risk factors. Main Outcome Measures: Clinically diagnosed DED was defined as the presence of a previous clinical diagnosis of DED by ophthalmologists or severe symptoms of DED (both dryness and irritation constantly or often). Current symptoms of DED and possible risk factors such as age, gender, educational history, smoking history, alcohol drinking history, height and weight, visual display terminal (VDT) use, and contact lens (CL) wear, and past/current history of certain common systemic diseases were the main outcome measures. We used logistic regression analysis to examine associations between DED and other demographic factors. Results: Of the 3294 eligible residents, 2791 residents (85%) completed the questionnaire. The percentage of women with a composite outcome of clinically diagnosed DED or severe symptoms (21.6%; 95% confidence interval [CI], 19.523.9) was higher than that of men (12.5%; 95% CI, 10.714.5; P<0.001). A low body mass index (BMI; odds ratio [OR], 2.07; 95% CI, 0.984.39), CL use (OR, 3.84; 95% CI, 1.4610.10), and hypertension (HT) (OR, 1.39; 95% CI, 0.942.06) were risk factors for DED in men. Use of a VDT (OR, 2.33; 95% CI, 1.124.85), CL use (OR, 3.61; 95% CI, 2.136.10), and myocardial infarction or angina were the risk factors (OR, 2.64; 95% CI, 1.514.62), whereas high BMI was a preventive factor (OR, 0.69; 95% CI, 0.481.01) for DED in women. Conclusions: Among a Japanese cohort, DED leading to a clinical diagnosis or severe symptoms is prevalent. Use of CLs was a common dry eye risk factor in both genders. The condition is more prevalent in men with low BMI, HT, and in women with myocardial infarction or angina and VDT use. Relevant measures directed against the modifiable risks may provide a positive impact on public health and quality of life of Japanese. © 2011 by the American Academy of Ophthalmology.

Purpose: To evaluate the effect of contact lens (CL) wear and visual display terminal (VDT) work on the ocular surface and tear functions. Design: Prospective case-control study. Methods: Sixty-nine CL wearers (45 women and 24 men; mean age, 35.2 ± 7.3 years), and 102 age- and sex-matched non-CL wearers were enrolled in the study (66 women and 36 men; mean age, 36.7 ± 7.3 years). Ocular surface and tear function tests, including vital stainings (fluorescein and rose bengal), Schirmer test, tear meniscus height measurement, and tear film break-up time were performed. The subjective symptoms of dry eyes were evaluated using a dry eye symptom questionnaire. The participants were divided into 4 subgroups according to the total time of VDT work in 1 day (VDT work time in 1 day < 4 hours or < 4 hours) and presence of CL wear. Main outcome measures included ocular surface vital staining scores, Schirmer test results, tear film break-up time, tear meniscus height measurement, and symptom questionnaire score. Results: CL users and long-term VDT workers showed significantly worse tear meniscus height values than non-CL users and short-term VDT workers (P <.001). The mean visual symptom scores in CL wearers and long-term VDT workers were significantly higher than the other groups (P <.001). Conclusions: Office workers who wore CLs and spent more than 4 hours engaged in VDT work had a lower tear meniscus volume with significant dry eye and visual symptoms triggered by environmental factors. © 2011 Elsevier Inc.