Motokazu Tsujikawa

Intraflagellar Transport Genes Are Essential for Differentiation and Survival of Vertebrate Sensory Neurons

Cilia play diverse roles in vertebrate and invertebrate sensory neurons. We show that a mutation of the zebrafish oval (ovl) locus affects a component of the ciliary transport (IFT) mechanism, the IFT88 polypeptide. In mutant retina, cilia are generated but not maintained, producing the absence of photoreceptor outer segments. A loss of cilia also occurs in auditory hair cells and olfactory sensory neurons. In all three sense organs, cilia defects are followed by degeneration of sensory cells. Similar phenotypes are induced by the absence of the IFT complex B polypeptides, ift52 and ift57, but not by the loss of complex A protein, ift140. The degeneration of mutant photoreceptor cells is caused, at least partially, by the ectopic accumulation of opsins. These studies reveal an essential role for IFT genes in vertebrate sensory neurons and implicate the molecular components of intraflagellar transport in degenerative disorders of these cells.

Efficacy of intravitreal bevacizumab for polypoidal choroidal vasculopathy

Aims: The aim of the study was to assess the short-term efficacy of intravitreal injections of bevacizumab for polypoidal choroidal vasculopathy (PCV). Methods: Intravitreal bevacizumab (1 mg) was injected into 11 eyes of 11 patients with PCV in this retrospective, interventional case series. The main outcome measure was the change in the polypoidal vessels on indocyanine green angiography (IA) 3 months after injection. The foveal height determined by optical coherence tomography and the best-corrected visual acuity (BCVA) also were evaluated before and after treatment. Results: At baseline, subretinal fluid was observed in five eyes and a pigment epithelial detachment in eight eyes. The foveal height 1 month after injection decreased significantly (p = 0.023), but at 3 months, no significant decrease was observed, although an additional injection was administrated in five of 11 eyes. The IA at 3 months showed resolution of polyps in one eye but residual or enlarged lesions in the other ten eyes. The BCVA did not improve significantly, although the subjects had relatively good BCVA at baseline (mean 0.45). Conclusion: Intravitreal injection of bevacizumab may reduce the fluid from PCV but seems to be ineffective for diminishing its choroidal vascular changes.

Complications in patients after intravitreal injection of bevacizumab

Purpose:  To report complications in patients after intravitreal injection of bevacizumab to treat ocular diseases associated with vascular endothelial growth factor.

Intravitreal injection of bevacizumab for choroidal neovascularisation associated with pathological myopia

Aim: To assess the efficacy and safety of an intravitreal injection of bevacizumab (Avastin®) for myopic choroidal neovascularisation (mCNV). Methods: Intravitreal bevacizumab (1 mg) was injected into eight eyes of eight patients with mCNV in this non-randomised, interventional case series. The best-corrected visual acuity (BCVA) was measured and the optical coherence tomography (OCT) and fluorescein angiography findings were examined before and after treatment. The minimum follow-up time was 3 months. Results: The mean BCVA was 0.26 before treatment and 0.51 at the last visit (p = 0.009). The BCVA improved to two or more lines in six eyes (75%) and remained the same in two eyes (25%). Leakage from the mCNV on fluorescein angiography decreased in seven eyes (87.5%). The choroidal neovascularisation area on fluorescein angiography (p = 0.049) and the foveal thickness on OCT images decreased significantly (p = 0.027) after the treatment. No major complications developed. Conclusion: Intravitreal injection of bevacizumab seems to be an effective and safe treatment for mCNV.

Intravitreal Bevacizumab for Choroidal Neovascularization Attributable to Pathological Myopia: One-Year Results

PURPOSE To assess the potential effect of intravitreal bevacizumab (IVB) (Avastin) on retinal function and anatomic recovery in eyes with choroidal neovascularization attributable to pathological myopia (mCNV). DESIGN Retrospective case series. METHODS setting: Institutional. patient population: Sixty-three eyes of 63 patients were treated with IVB for mCNV. intervention procedure: 1 mg of bevacizumab was injected into the vitreous via the pars plana. IVB was repeated after two to three months if there was fluorescein leakage in fluorescein angiogram (FA), apparent subretinal fluid in optical coherence tomography (OCT) persisted, or both. main outcome measurement: Best-corrected visual acuity (BCVA) and CNV size measured on FA. RESULTS IVB was performed one to six times during the first 12 months (mean, 2.4 +/- 1.4 times). The size of the mCNV decreased and the BCVA improved significantly (P < .01 for both comparisons). The BCVA improved more than three lines in 25 eyes (40%), worsened more than three lines in three eyes (5%), and was unchanged in 35 (56%) eyes 12 months after. Fluorescein leakage from the mCNV ceased in 30 eyes (48%), diminished in 28 (44%), and was unchanged in five (8%) eyes. Stepwise analysis showed that the number of IVB (P < .01), macular atrophy associated with mCNV (P < .05), and myopic atrophy (P < .05) were significant predictive factors for BCVA at 12 months. CONCLUSIONS Although the current study lacked a control group, IVB seems to be an effective treatment for mCNV after a long-term. The absence of chorioretinal atrophy and that of recurrence and persistency of mCNV are positive predictive factors.

Identification of the gene responsible for gelatinous drop-like corneal dystrophy

Gelatinous drop-like corneal dystrophy (GDLD; OMIM 204870) is an autosomal recessive disorder characterized by severe corneal amyloidosis leading to blindness, with an incidence of 1 in 300,000 in Japan. Our previous genetic linkage study localized the gene responsible to a 2.6-cM interval on chromosome 1p (ref. 6). Clinical manifestations, which appear in the first decade of life, include blurred vision, photophobia and foreign-body sensation. By the third decade, raised, yellowish-grey, gelatinous masses severely impair visual acuity, and lamellar keratoplasty is required for most patients. Here we report DNA sequencing, cDNA cloning and mutational analyses of four deleterious mutations (Q118X, 632delA, Q207X and S170X) in M1S1 (formerly TROP2 and GA733-1), encoding a gastrointestinal tumour-associated antigen. The Q118X mutation was the most common alteration in the GDLD patients examined, accounting for 33 of 40 (82.5%) disease alleles in our panel of families. Protein expression anaysis revealed aggregation of the mutated, truncated protein in the perinuclear region, whereas the normal protein was distributed diffusely in the cytoplasm with a homogenous or fine granular pattern. Our successful identification of the gene that is defective in GDLD should facilitate genetic diagnosis and potentially treatment of the disease, and enhance general understanding of the mechanisms of amyloidosis.

Morphologic Changes in Acute Central Serous Chorioretinopathy Evaluated by Fourier-Domain Optical Coherence Tomography

OBJECTIVE To investigate morphologic alterations around fluorescein leakage sites using Fourier-domain optical coherence tomography (FD OCT) in acute central serous chorioretinopathy (CSC). DESIGN Observational case series. PARTICIPANTS Twenty-one eyes with acute CSC with subjective symptoms for under 3 months. METHODS Patients underwent measurement of visual acuity, fundus observations, and FD OCT examinations at every visit with the intervals of 2 to 4 weeks until subretinal fluid (SRF) resolved. Fluorescein angiography was performed at baseline to confirm dye leakage sites. Horizontal and vertical OCT scans (B-scans and consecutive raster scans) of the fovea and fluorescein leakage sites were obtained. MAIN OUTCOME MEASURES Morphologic changes in the retinal pigment epithelium (RPE), detached retina, and subretinal space around the leakage sites were evaluated repeatedly during follow-up. RESULTS The mean period between baseline and the final examination was 108 days (mean no. of examinations, 3.9). Among 23 leakage sites in 21 eyes, FD OCT showed RPE abnormalities in 22 (96%) sites (14 sites [61%] with a pigment epithelial detachment [PED] and 8 [35%] with a protruding or irregular RPE layer). Fibrinous exudates in the subretinal space and sagging/dipping of the posterior layer of the neurosensory retina above the leakage sites were seen at 12 (52%) and 10 (43%) leakage points, respectively. An RPE defect at the edge of or within the PED was observed in 5 leakage sites (22%); in 2 of these, a defect was detectable after the SRF decreased. The posterior surface of the detached retina was smooth in 17 eyes (81%) and granulated in 4 eyes (19%) (mean duration of subjective symptoms, 10 days and 42 days, respectively). The smooth posterior detached retina became granulated in the presence of residual SRF. A PED remained at the 5 leakage sites in 5 eyes (22%) despite SRF resolution. CONCLUSIONS Fourier-domain OCT examinations showed detailed morphologic changes in eyes with acute CSC including an RPE defect within the PED at a leakage site through which fluid might pass from the sub-RPE to the subretinal area. Fourier-domain OCT findings may offer new information to facilitate understanding of the mechanisms of acute CSC.

Generation of Corneal Epithelial Cells from Induced Pluripotent Stem Cells Derived from Human Dermal Fibroblast and Corneal Limbal Epithelium

Induced pluripotent stem (iPS) cells can be established from somatic cells. However, there is currently no established strategy to generate corneal epithelial cells from iPS cells. In this study, we investigated whether corneal epithelial cells could be differentiated from iPS cells. We tested 2 distinct sources: human adult dermal fibroblast (HDF)-derived iPS cells (253G1) and human adult corneal limbal epithelial cells (HLEC)-derived iPS cells (L1B41). We first established iPS cells from HLEC by introducing the Yamanaka 4 factors. Corneal epithelial cells were successfully induced from the iPS cells by the stromal cell-derived inducing activity (SDIA) differentiation method, as Pax6+/K12+ corneal epithelial colonies were observed after prolonged differentiation culture (12 weeks or later) in both the L1B41 and 253G1 iPS cells following retinal pigment epithelial and lens cell induction. Interestingly, the corneal epithelial differentiation efficiency was higher in L1B41 than in 253G1. DNA methylation analysis revealed that a small proportion of differentially methylated regions still existed between L1B41 and 253G1 iPS cells even though no significant difference in methylation status was detected in the specific corneal epithelium-related genes such as K12, K3, and Pax6. The present study is the first to demonstrate a strategy for corneal epithelial cell differentiation from human iPS cells, and further suggests that the epigenomic status is associated with the propensity of iPS cells to differentiate into corneal epithelial cells.

Association Between the Efficacy of Photodynamic Therapy and Indocyanine Green Angiography Findings for Central Serous Chorioretinopathy

PURPOSE To determine the efficacy of photodynamic therapy (PDT) and indocyanine green angiography (ICGA) findings for treating chronic central serous chorioretinopathy (CSC). DESIGN Observational case series. METHODS Thirty-two eyes of 27 patients with chronic CSC and symptoms for at least 6 months were recruited. The minimum follow-up was 1 year. The total PDT energy was reduced to about 36 to 42 mJ/cm(2). The baseline middle-phase ICGA findings were classified as intense, intermediate, or no hyperfluorescence depending on the degree of hyperfluorescence. The resolution of the subretinal fluid and recurrence rates were assessed in relation to each ICGA finding at baseline. RESULTS ICGA before PDT showed intense hyperfluorescence in 23 eyes (72%), intermediate hyperfluorescence in 6 eyes (19%), and no hyperfluorescence in 3 eyes (9%). The subretinal fluid resolved completely 3 months after 1 application of PDT in 23 eyes (100%) with intense hyperfluorescence, 6 eyes (100%) with intermediate hyperfluorescence, and no eyes (0%) with no hyperfluorescence. In the last group, the subretinal fluid did not resolve throughout the follow-up period despite additional applications of PDT. The subretinal fluid recurred in 7 of 29 eyes (24%) in which the subretinal fluid resolved at 3 months; recurrence was frequent in eyes with intermediate hyperfluorescence (5 eyes; 83%). CONCLUSION The PDT success rate in eyes with chronic CSC depends on the degree of hyperpermeability on ICGA. PDT is not effective or the recurrence rate is predicted to be high in eyes without intense hyperfluorescence.

Chronic Photo-oxidative Stress And Subsequent Mcp-1 Activation As Causative Factors For Age-related Macular Degeneration

Age-related macular degeneration (AMD) is the leading cause of blindness among the elderly in developed countries. Although pathogenic factors, such as oxidative stress, inflammation and genetics are thought to contribute to the development of AMD, little is known about the relationships and priorities between these factors. Here, we show that chronic photo-oxidative stress is an environmental factor involved in AMD pathogenesis. We first demonstrated that exposure to light induced phospholipid oxidation in the mouse retina, which was more prominent in aged animals. The induced oxidized phospholipids led to an increase in the expression of monocyte chemoattractant protein-1, which then resulted in macrophage accumulation, an inflammatory process. Antioxidant treatment prevented light-induced phospholipid oxidation and the subsequent increase of monocyte chemoattractant protein-1 (also known as C-C motif chemokine 2; CCL2), which are the beginnings of the light-induced changes. Subretinal application of oxidized phospholipids induced choroidal neovascularization, a characteristic feature of wet-type AMD, which was inhibited by blocking monocyte chemoattractant protein-1. These findings strongly suggest that a sequential cascade from photic stress to inflammatory processes through phospholipid oxidation has an important role in AMD pathogenesis. Finally, we succeeded in mimicking human AMD in mice with low-level, long-term photic stress, in which characteristic pathological changes, including choroidal neovascularization formation, were observed. Therefore, we propose a consecutive pathogenic pathway involving photic stress, oxidation of phospholipids and chronic inflammation, leading to angiogenesis. These findings add to the current understanding of AMD pathology and suggest protection from oxidative stress or suppression of the subsequent inflammation as new potential therapeutic targets for AMD.