Differences in collateral vessel formation after experimental retinal vein occlusion in spontaneously hypertensive rats and wild-type rats.

Objective: Retinal vein occlusion (RVO) can lead to visual impairment, but the development of collateral vessels can sometimes mitigate significant damage. This study aimed to investigate the relationship between collateral vessels and hypertension, the most common underlying condition associated with RVO, by comparing spontaneously hypertensive rats (SHRs) and wild-type Wister rats (WWRs). We also examined the differences between WWRs and SHRs in terms of sphingosine 1-phosphate receptor 1 (S1PR1) expression and its product nitric oxide synthase 3 (NOS3) expression, which are involved in the formation of collateral vessels after vascular occlusion. Methods: Laser photocoagulation (PC) was used to occlude one randomly selected retinal vein in WWRs and SHRs, and the area surrounding the occluded vessel was examined using optical coherence tomography angiography. If reperfusion of the occluded vessel occurred within 2 weeks, the vessel was re-occluded repeatedly by PC. The number of eyes with successfully occluded vessels accompanied by collateral vessels was recorded. Then, WWRs and SHRs were divided into the following four groups: 1) control (no treatment), 2) vehicle (20% DMSO), 3) S1PR1 agonist (2 mg/mL SEW2871), and 4) S1PR1 antagonist (0.25 mg/mL VPC 23019) groups. The drugs were administered intravitreally in all groups except the control. The number of laser shots required for successful RVO was recorded. Histological evaluation and quantitative real-time PCR of S1PR1 and NOS3 were performed to elucidate the mechanisms underlying collateral vessel formation. Results: The proportion of eyes achieving successful vein occlusion was lower in SHRs (4/12 eyes, 33.3%) than in WWRs (8/10 eyes, 80%, p = 0.043). NOS3 expression at 6 h after PC was significantly higher in WWRs than in SHRs (p = 0.021). In WWRs treated with SEW2871, vein occlusion failed in 7 of 10 eyes (70%). The expression of NOS3 was significantly higher in the SEW2871 treatment group than in the untreated group (p < 0.001). Furthermore, NOS3 expression was significantly higher after SEW2871 treatment in WWRs than in SHRs (p = 0.011). Conclusion: In hypertensive environments, collateral vessels are less likely to develop, and S1PR1 may be involved in this phenomenon.

Treatment strategy for BVO-ME based on long-term outcomes correlating retinal structure by OCT image and visual acuity.

BACKGROUND: Intravitreal anti-vascular endothelial growth factor (VEGF) is a mainstream treatment for reducing ME secondary to BRVO (BVO-ME). Regrettably, most reports of intravitreal anti-VEGF for BVO-ME have disclosed only short-term outcomes. Here, we characterized long-term indicators for the visual prognosis of patients with BVO-ME, including the correlation between retinal structure by OCT and visual acuity. METHODS: Patients with BVO-ME were retrospectively recruited based on clinical records in Kansai Medical University Hospital from June 2012 to March 2022. This study enrolled patients with vision loss who received intravitreal injection of anti-VEGF for BVO-ME. Inclusion criteria were that patients received intravitreal injection of anti-VEGF as their first treatment and were followed for at least 36 months. Exclusion criteria were those patients with ocular disease other than BRVO or who had been previously treated for BVO-ME. Patients were divided into two groups according to BCVA at the final visit: Group A (≥ 0.7) and Group B (< 0.7). RESULTS: Forty-seven eyes from 45 patients were assessed. The mean follow-up period from initial to final visit was 64.38 ± 15.07 (range, 38-100) months. BCVA in Group A (n = 32) was significantly greater than in Group B (n = 15) at all timepoints. The ratio that the number of eyes which the EZ band and the foveal bulge were intact in Group A was higher than in Group B (p = 0.0004 and p = 0.0002, respectively). The ratio that the number of eyes which recurrence SRD was observed by the final visit in Group A was lower than in Group B (p = 0.0485). CONCLUSIONS: The integrity of the EZ band and an intact foveal bulge were significant predictors for visual acuity. In contrast, recurrent SRD led to poor visual acuity in the long term, even if BCVA was good in the short term.

16S rRNA nanopore sequencing for the diagnosis of ocular infection: a feasibility study.

OBJECTIVE: We conducted a feasibility study to verify the effectiveness of 16S ribosomal RNA (rRNA) gene analysis using the nanopore sequencer MinION for identifying causative bacteria in several types of ocular infections. METHODS AND ANALYSIS: Four cases of corneal ulcers, one case of endophthalmitis and one case of a conjunctival abscess were included in this study. DNA was extracted from corneal scraping, vitreous samples and secretions from the conjunctival abscess. We conducted 16S rRNA gene amplicon sequencing using MinION and metagenomic DNA analysis. The efficacy of bacterial identification was verified by comparing the conventional culture method with smear observations. RESULTS: 16S rRNA gene sequencing analysis with MinION identified the causative organisms promptly with high accuracy in approximately 4 hours, from ophthalmic specimens. The results of the conventional culture method and 16S rRNA gene sequencing were consistent in all cases. In four of the six cases, a greater variety of organisms was found in the 16S rRNA gene analysis than in bacterial culture. CONCLUSION: Using our workflow, 16S rRNA gene analysis using MinION enabled rapid and accurate identification possible in various kinds of bacterial ocular infections.

Successful identification of Granulicatella adiacens in postoperative acute infectious endophthalmitis using a bacterial 16S ribosomal RNA gene-sequencing platform with MinION™: A case report.

Purpose: To evaluate the efficacy of identifying the bacteria by aqueous sampling and vitreous sampling in postoperative infectious endophthalmitis using 16S ribosomal RNA (rRNA) gene analysis with a nanopore sequencer (MinION™). Observation: A 55-year-old woman who underwent cataract surgery at an ophthalmology clinic 18 days ago was referred to our hospital for suspected endophthalmitis. She had light perception visual acuity in her right eye; however, the eye was severely inflamed, with a hypopyon and a fibrinous membrane in the anterior chamber. The fundus was not visible because of vitreous opacity on a B-scan image. Based on the diagnosis of postoperative acute infectious endophthalmitis, we performed a vitrectomy, intraocular lens extraction, and silicone oil tamponade. On postoperative day 14, the inflammation resolved. An aqueous sample was collected before surgical treatment, and the vitreous sample was collected during the operation. Both samples underwent 16S rRNA gene analysis with a nanopore sequencer MinION™ to identify the causative organism. Conclusions and Importance: In the aqueous humor, Granulicatella adiacens and Cutibacterium acnes were identified before the operation, while only Granulicatella adiacens was detected in the vitreous sample after the operation. Although the aqueous humor sample might contain commensal bacteria, it could provide a predictable result before the operation. It can also provide a substitute for a vitreous sample to allow earlier identification of the causative organism.

Time course of collateral vessel formation after retinal vein occlusion visualized by OCTA and elucidation of factors in their formation.

BACKGROUND: It is clinically recognized that collateral vessels can form after retinal vein occlusion (RVO) in some cases and these vessels can lead to spontaneous recovery of the pathological condition. In recent years, optical coherence tomography angiography (OCTA) has become a decisive clinical instrument. Unlike previous angiography tests, OCTA enables the non-invasive visualization of fundus vasculature without the need for administration of a contrast agent. However, it remains to be determined if OCTA depicts the 'true' histological status as several studies have reported artifacts in OCTA imaging. METHODS: We generated a laser-induced mouse RVO model, and evaluated the subsequent formation of collateral vessels in order to understand the mechanisms by which collateral vessels form using OCTA imaging, as well as molecular and histological assessments. RESULTS: We succeeded in visualizing the time course of collateral vessel formation in a mouse RVO model and confirmed the similarity in formation of collateral vessels only within the deep layer of the retina in both human and mouse. We hypothesized that sphingosine 1-phosphate receptor-1 (S1PR1) may play important roles via vascular shear stress linking vein occlusion and collateral vessel formation. Results from OCTA revealed that collateral vessels are increased in response to administration of a S1PR1 agonist in a mouse RVO model. Based on quantitative reverse transcription polymerase chain reaction (qRT-PCR), S1PR1 messenger ribonucleic acid (mRNA) levels in the whole retina peaked 6 h after photocoagulation in this model. Immunohistochemical staining of retinal flat mounts revealed that S1PR1 staining occurred along the laser-occluded blood vessels. CONCLUSION: We observed the temporal process of collateral vessel formation in a mouse RVO model and identified the relationship between S1PR1 and shear stress as one of the factors in collateral vessel formation in RVO.

Long-term results of choroidal neovascularization secondary to angioid streaks.

PURPOSE: To investigate factors contributing to the visual prognosis of choroidal neovascularization (CNV) secondary to angioid streaks (AS) in a long-term follow-up (> 5 years) study. METHODS: Twenty-one patients (32 eyes) affected by CNV secondary to AS were enrolled retrospectively and divided into three groups according to the period of CNV recurrence from the final treatment: group A, no recurrence for more than 12 months; group B, no recurrence for 6-12 months; and group C, no recurrence for < 6 months or ongoing. According to the above classification, we assessed best-corrected visual acuity (BCVA), peau d'orange area, the number of photodynamic treatments and/or intravitreal antiangiogenic drug injections, central choroidal thickness (CCT) and central retinal thickness (CRT) using optical coherence tomography, and enlargement of retinal pigment epithelium (RPE) atrophy. RESULTS: The median follow-up time was 91 months. The median logarithm of the minimum angle of resolution BCVA significantly deteriorated from 0 at baseline to 1 at final follow-up (p < 0.05). Especially, final BCVA in group A showed worst visual outcome despite lowest number of treatments. Peau d'orange areas at baseline were found in 32 eyes (100%). There were no significant differences between initial CRT and final CRT. Median CCT was significantly reduced from 188 µm at baseline to 96 µm at final follow-up (p < 0.05). The median number of treatments was 3.5. Enlargement of RPE atrophy at baseline was found in 31 eyes (96.8%). CONCLUSIONS: Despite the regression of CNV secondary to AS following treatment, the visual prognosis was poor due to the presence of peau d'orange areas, choroidal thinning, and increased RPE atrophy.

Optical coherence tomographic angiography and ultra-widefield indocyanine green angiography of a choroidal macrovessel.

PURPOSE: We evaluated a choroidal macrovessel using optical coherence tomography angiography (OCTA) and indocyanine green angiography (ICGA). OBSERVATIONS: A 79-year-old female presented with blurred vision in both eyes and metamorphopsia of the left eye. Mild cataract was noted in both eyes. Color fundus photography of the left eye revealed a red-orange tortuous vessel originating from the fovea and running in an inferior-temporal direction. Enhanced-depth imaging OCT revealed a large caliber choroidal vascular shadow and ambiguous line of the photoreceptor and retinal pigment epithelium layers. OCTA demonstrated a serpentine-shaped choroidal vessel. This anomalous vessel was seen by early phase ICGA as a rapidly perfused vessel connected to a vortex vein. We diagnosed this anomalous vessel as a choroidal macrovessel. We identified that cataract induced blurred vision in both eyes and choroidal macrovessel induced metamorphopsia in left eye. She was received cataract surgery for both eyes. The degree of metamorphopsia and the choroidal macrovessel of the left eye remains unchanged after a year of follow-up. CONCLUSIONS AND IMPORTANCE: OCTA and ICGA are useful techniques to diagnose choroidal macrovessels.

Developmental and age-related changes to the elastic lamina of Bruch's membrane in mice.

BACKGROUND: Fibrillin-1, tropoelastin, fibulin-5, and latent transforming growth factor beta-binding protein-2 and protein-4 (LTBP-2 and LTBP-4) are essential proteins for the elastic lamina (EL). In this study, we analyzed each of these molecules in the EL of Bruch's membrane (BM) through development and aging. METHODS: C57BL/6 mice (embryonic (E) days E12.5, E15.5, and E18.5; postnatal (P) days P1, P4, and P7 and P3, P6, and P75 weeks of age) were used. To investigate localization, immunohistochemical staining (IH) was performed. Transmission electron microscopy (TEM) was used to evaluate the formation of microfibrils and tropoelastin. mRNA expression was determined by quantitative real-time PCR (qRT-PCR). RESULTS: All five proteins were expressed in the EL of BM by IH except in embryonic mice. TEM results showed that tropoelastin co-stained with microfibrils. Between 3 and 6 weeks of age, microfibrils became longer and thicker. It was difficult to evaluate the EL of BM in senile mice at 75 weeks of age because of abundant deposits which correspond to drusen. mRNA levels of each protein increased dramatically from E15.5 to P1 days and plateaued by P3 weeks as shown by qRT-PCR. CONCLUSIONS: In conclusion, these five proteins are possibly involved in elastic fiber assembly in BM. We define the date of full assembly of the EL of BM as 3 weeks of age in mice.

A new histological evaluation method to detect residual ophthalmic viscosurgical devices for cataract surgery.

PURPOSE: To establish a new evaluation method to quantify residual ophthalmic viscosurgical device (OVD) volume and corneal endothelium adhesion properties for phacoemulsification surgery. METHODS: We compared the performance of four OVDs (Viscoat®, Healon5®, Healon® and DisCoVisc®) using porcine eyes. First, OVDs were mixed with fluorescent-conjugated dextrans to render them visible under the microscope. A corneal side port was opened, followed by a continuous curvilinear capsulorhexis, and a corneal tunnel incision was made. OVDs were injected, then the lens was removed using one-handed phacoemulsification. After this procedure, the anterior segment of the eye was isolated via an equatorial incision and the tissue was immediately frozen in shimmering liquid nitrogen. Sagittal slices (20 µm) were cut with a Cryostat from limbus to limbus. Every tenth slide was imaged using a fluorescent microscope with a CCD camera. We evaluated the percentage of the corneal endothelium covered by each OVD as the OVD adhesion to corneal endothelium ratio (OAE ratio) and the volume of residual OVD in the anterior chamber. RESULTS: Viscoat® showed significantly higher endothelium coverage compared with both Healon® and DisCoVisc®. A statistically larger volume of Healon5® remained in the anterior chamber compared with Healon® and DisCoVisc®. CONCLUSION: The new evaluation methods used here provide precise quantitative analysis of OAE ratio and residual OVD volume. These results show that Viscoat® and Healon5® have a high potential for coating the corneal endothelium during phacoemulsification and aspiration surgery.

Comparison between optical coherence tomography angiography and immunolabeling for evaluation of laser-induced choroidal neovascularization.

This study aimed to investigate the differences between images obtained by optical coherence tomography angiography (OCTA) with those from immunohistochemical labeling of laser-induced choroidal neovascularization (CNV) in a mouse model. CNV was induced by laser photocoagulation (GYC-2000, NIDEK; wavelength 532 nm) in the left eyes of 10 female C57BL/6J mice aged 6 weeks. The laser parameters included a 100-µm spot, 100-ms pulse duration and 200-mW incident power to rupture Bruch's membrane. OCT and OCTA CNV images were obtained using the RS-3000 Advance (NIDEK) 5 days post-laser photocoagulation. After OCTA imaging, the isolated choroid/retinal pigment epithelium complexes were fluorescently labeled with CD31 (an endothelial cell marker), platelet-derived growth factor receptor ß (PDGFRß, a pericyte-like scaffold marker), α-smooth muscle actin (α-SMA) and collagen I. Area measurements of the lesions obtained by enface OCTA were compared with immunolabeled CD31+ CNV lesions in choroid flat-mounts. We also examined structural correlations between the PDGFRß+ pericyte-like scaffold and OCTA images. Laser-induced CNV was clearly detected by enface OCTA, appearing as a hyperflow lesion surrounded by a dark halo. Area measurements of the CNV lesion by immunolabeling were significantly larger than those obtained by enface OCTA (p = 0.006). The CNV lesion beneath the periphery of the pericyte-like scaffold was not clearly visible by enface OCTA due to the dark halo; however, the lesion was detectable as blood flow by cross-sectional OCTA and was also highly labeled by CD31. The periphery of the pericyte-like scaffold appeared to develop into subretinal fibrosis and this region was rich in myofibroblasts. Enface OCTA was unable to detect the entire area of laser-induced CNV in mice, with an undetectable portion located beneath the fibrotic periphery of the pericyte-like scaffold. Due to this OCTA fibrosis artifact, OCTA imaging has limited potential for accurately estimating CNV lesions.

Transmembrane topology and oligomeric structure of the high-affinity choline transporter.

The high-affinity choline transporter CHT1 mediates choline uptake essential for acetylcholine synthesis in cholinergic nerve terminals. CHT1 belongs to the Na(+)/glucose cotransporter family (SLC5), which is postulated to have a common 13-transmembrane domain core; however, no direct experimental evidence for CHT1 transmembrane topology has yet been reported. We examined the transmembrane topology of human CHT1 using cysteine-scanning analysis. Single cysteine residues were introduced into the putative extra- and intracellular loops and probed for external accessibility for labeling with a membrane-impermeable, sulfhydryl-specific biotinylating reagent in intact cells expressing these mutants. The results provide experimental evidence for a topological model of a 13-transmembrane domain protein with an extracellular amino terminus and an intracellular carboxyl terminus. We also constructed a three-dimensional homology model of CHT1 based on the crystal structure of the bacterial Na(+)/galactose cotransporter, which supports our conclusion of CHT1 transmembrane topology. Furthermore, we examined whether CHT1 exists as a monomer or oligomer. Chemical cross-linking induces the formation of a higher molecular weight form of CHT1 on the cell surface in HEK293 cells. Two different epitope-tagged CHT1 proteins expressed in the same cells can be co-immunoprecipitated. Moreover, co-expression of an inactive mutant I89A with the wild type induces a dominant-negative effect on the overall choline uptake activity. These results indicate that CHT1 forms a homo-oligomer on the cell surface in cultured cells.

The high-affinity choline transporter CHT1 is regulated by the ubiquitin ligase Nedd4-2.

The high-affinity choline transporter (CHT1), which is specifically expressed in cholinergic neurons, constitutes a rate-limiting step for acetylcholine synthesis. We have found that the exogenous ubiquitin ligase Nedd4-2 interacts with CHT1 expressed in HEK293 cells decreasing the amount of cell surface CHT1 by approximately 40%, and that small interfering RNA for endogenous Nedd4-2 enhances the choline uptake activity by CHT1 in HEK293 cells. These results indicate that Nedd4-2-mediated ubiquitination regulates the cell surface expression of CHT1 in cultured cells and suggest a possibility that treatments or drugs which inhibit the interaction between CHT1 and Nedd4-2 might be useful for diseases involving decrease in acetylcholine level such as Alzheimer's disease.

Identification of ARIA regulating endothelial apoptosis and angiogenesis by modulating proteasomal degradation of cIAP-1 and cIAP-2.

Endothelial apoptosis is a pivotal process for angiogenesis during embryogenesis as well as postnatal life. By using a retrovirus-mediated signal sequence trap method, we identified a previously undescribed gene, termed ARIA (apoptosis regulator through modulating IAP expression), which regulates endothelial apoptosis and angiogenesis. ARIA was expressed in blood vessels during mouse embryogenesis, as well as in endothelial cells both in vitro and in vivo. ARIA is a unique protein with no homology to previously reported conserved domain structures. Knockdown of ARIA in HUVECs by using small interfering RNA significantly reduced endothelial apoptosis without affecting either cell migration or proliferation. ARIA knockdown significantly increased inhibitor of apoptosis (cIAP)-1 and cIAP-2 protein expression, although their mRNA expression was not changed. Simultaneous knockdown of cIAP-1 and cIAP-2 abolished the antiapoptotic effect of ARIA knockdown. Using yeast 2-hybrid screening, we identified the interaction of ARIA with 20S proteasome subunit alpha-7. Thereafter, we found that cIAP-1 and cIAP-2 were degraded by proteasomes in endothelial cells under normal condition. Overexpression of ARIA significantly reduced cIAP-1 expression, and this reduction was abolished by proteasomal inhibition in BAECs. Also, knockdown of ARIA demonstrated an effect similar to proteasomal inhibition with respect to not only expression but also subcellular localization of cIAP-1 and cIAP-2. In vivo angiogenesis studied by Matrigel-plug assay, mouse ischemic retinopathy model, and tumor xenograft model was significantly enhanced by ARIA knockdown. Together, our data indicate that ARIA is a unique factor regulating endothelial apoptosis, as well as angiogenesis, presumably through modulating proteasomal degradation of cIAP-1 and cIAP-2 in endothelial cells.

Hypericin inhibits pathological retinal neovascularization in a mouse model of oxygen-induced retinopathy.

PURPOSE: Ocular neovascularization is a leading cause of blindness in ischemic retinopathies. Hypericin is an active ingredient in the medical herb St. John's Wort (SJW). Because hypericin inhibits intracellular signaling pathways that are believed to participate in the regulation of angiogenesis, we investigated the actions of hypericin and SJW in retinal neovascularization, using a mouse model of oxygen-induced retinopathy (OIR). METHODS: C57BL/6 neonatal mice were exposed to a 75% concentration of oxygen from postnatal day 7 (P7) to P12 and returned to room air from P12 to P17 to induce retinal neovascularization. SJW (15 mg/kg/day), hypericin (15, 45, or 135 mug/kg/day), or vehicle was given by gavage once a day for five days from P12 to P17. To quantify the area of retinal neovascularization and vasoobliteration, we stained retinas with isolectin B4 at P17. Phosphorylation of extracellular signal-regulated kinase (ERK) in ischemic retinas was determined by western blot analysis. To estimate retinal vascularization, we stained retinas with isolectin B4 at P7 after treatment with SJW, hypericin, or vehicle from P3 to P7. RESULTS: Gavage administration of hypericin or SJW significantly inhibited the degree of retinal neovascularization, but did not affect the area of retinal vasoobliteration in a mouse model of OIR. Both SJW and hypericin had no effect on normal vascularization over the treatment time course. Treatment with SJW or hypericin reduced phosphorylation of ERK in the retina. CONCLUSIONS: These data suggest that hypericin and SJW reduce pathological retinal neovascularization and that administration of these agents could have clinical utility for treatment of ischemic retinopathies.

Systematic screening of lysyl oxidase-like (LOXL) family genes demonstrates that LOXL2 is a susceptibility gene to intracranial aneurysms.

Four lysyl oxidase family genes (LOXL1, LOXL2, LOXL3, and LOXL4), which catalyze cross-linking of collagen and elastin, were considered to be functional candidates for intracranial aneurysms (IA) and were extensively screened for genetic susceptibility in Japanese IA patients. Total RNA was isolated from four paired ruptured IA and superficial temporal artery (STA) tissue and examined by real-time RT-PCR. The expression of LOXL2 in the paired IA and STA tissues was elevated in the IA tissue. A total of 55 single nucleotide polymorphisms (SNPs) of LOXL1-4 were genotyped for an allelic association study in 402 Japanese IA patients and 462 Japanese non-IA controls. Allelic associations were evaluated with the chi-square test and the permutation test especially designed for adjustment of multiple testing. SNPs of LOXL1 and LOXL4 were not significantly associated with IA, while several SNPs of LOXL2 and LOXL3 showed nominally significant associations in IA patients. We detected an empirically significant association with one SNP of LOXL2 in familial IA patients after adjustment for multiple testing [chi(2) = 10.23, empirical P = 0.023, OR (95% CI) = 1.49 (1.17, 1.90)]. Furthermore, multilocus interaction was evaluated by multifactor dimensionality reduction analysis. We found that the SNPs of LOXL2 have an interactive effect with elastin (ELN) and LIM kinase 1 (LIMK1) that have been previously found to be associated with IA. In conclusion, one SNP of LOXL2 showed a significant association with IA individually, and we also detected a gene-gene interaction of LOXL2 with ELN/LIMK1, which may play an important role in susceptibility to IA.

Human cord blood cells can differentiate into retinal nerve cells.

Retinal degeneration and dystrophy are the major causes of blindness in the developed world. It has been reported that human cord blood cells (HCBCs) can differentiate into neuron-like cells in vitro. We have recently demonstrated that bone marrow cells (BMCs) of both mice and rats can differentiate into retinal nerve cells (RNCs). In the present study, we show the differentiation capacity of HCBCs into RNCs in vivo. We transplanted lineage-negative HCBCs into the subretinal space of severe combined immunodeficiency (SCID) mice. Two weeks after the transplantation, some of the transplanted cells expressed human nestin, human MAP2, human neuron specific enolase (NSE), beta-III tubulin and also rhodopsin. These results indicate that HCBCs can differentiate into RNCs and suggest that our new strategy could be used for the regeneration of retinal nerve cells in degenerative or dystrophic diseases.

Long-term survival of bone marrow-derived retinal nerve cells in the retina.

Recently, we have demonstrated that bone marrow stem cells can differentiate into retinal nerve cells. In the present study, we show a new and efficient strategy for transplanting bone marrow stem cells into the retina. When bone marrow stem cells were injected into the vitreous cavity of untreated eyes, only very few cells were found in the retina 2 weeks after injection. In contrast, when laser photocoagulation was performed just before the injection of bone marrow stem cells, a large number of the injected cells survived 2 weeks after injection and the cells expressed neural cell-specific or retinal nerve cell-specific antigens. Moreover, we still detected bone marrow stem cell-derived retinal nerve cells in the retina 1 year after injection in the retina.

[Vitrectomy for proliferative diabetic retinopathy].

PURPOSE: We reviewed the outcome of vitrectomy for proliferative diabetic retinopathy (DR) and evaluated factors affecting the final visual outcome. METHODS: We performed primary vitreous surgery for proliferative DR in 148 eyes of 118 cases in three years from July 1999 to August 2002. All cases were followed for at least 3 months. We excluded vitreous surgery for diabetic maculopathy. Ages ranged from 24 to 80 (mean 57) years. Average postoperative follow-up period was 15 months. We evaluated the stage of DR by the new Fukuda classification. RESULT: Preoperative classification consisted of BIV (54 eyes, 36%), BV (94 eyes, 64%), and BV + VI (36 eyes). Final visual acuity was improved by 2 lines or more in 102 eyes (69%), remained unchanged in 28 eyes (19%), and decreased by two lines or more in 18 eyes (12%). There was a statistical correlation between preoperative visual acuity and final visual acuity. Earlier stages of DR had better visual outcome. Compared to the surgical outcome in the 1990s, the percentage of worsened eyes decreased. CONCLUSION: Vitrectomy for proliferative DR may be beneficial if performed in the earlier stages of DR or if the patient has better visual acuity before vitrectomy.

Choroidal neovascularization is provided by bone marrow cells.

Choroidal neovascularization (CNV) is a known cause of age-related macular degeneration (ARMD). Moreover, the most common cause of blindness in the elderly in advanced countries is ARMD with CNV. It has recently been shown that bone marrow cells (BMCs) can differentiate into various cell lineages in vitro and in vivo. Adults maintain a reservoir of hematopoietic stem cells included in BMCs that can enter the circulation to reach various organs in need of regeneration. It has recently been reported that endothelial progenitor cells (EPCs) included in BMCs are associated with neovascularization. We examine the role of BMCs in CNV using a model of CNV in adult mice. Using methods consisting of fractionated irradiation (6.0 Gy x 2) followed by bone marrow transplantation (BMT), adult mice were engrafted with whole BMCs isolated from transgenic mice expressing enhanced green fluorescent protein (EGFP). Three months after BMT, we confirmed that the hematopoietic cells in the recipients had been completely replaced with donor cells. We then carried out laser photocoagulation to induce CNV in chimeric mice (donor cells >95%). Two weeks after the laser photocoagulation, by which time CNV had occurred, immunohistochemical examination was carried out. The vascular wall cells of the CNV expressed both EGFP and CD31. These findings indicate that newly developed blood vessels in the CNV are derived from the BMCs and suggest that the inhibition of EPC mobilization from the bone marrow to the eyes could be a new approach to the fundamental treatment of CNV in ARMD.

Polypoidal choroidal vasculopathy: incidence, demographic features, and clinical characteristics.

OBJECTIVE: To clarify the incidence, demographic features, and clinical characteristics of polypoidal choroidal vasculopathy (PCV) in Japanese patients. METHODS: Consecutive patients with presumed neovascular age-related macular degeneration (AMD) who met the eligibility criteria were examined between January 1, 1999, and October 31, 2001. All patients underwent complete ophthalmologic examination and fluorescein and indocyanine green angiography. RESULTS: Among 471 eyes of 418 patients who met the criteria, 110 eyes (23%) of 100 patients were diagnosed as having PCV and 361 eyes (77%) of 318 patients as having neovascular AMD. Mean age of patients with PCV was 68.4 years, with a male preponderance (63% of patients); involvement was mostly unilateral (90% of patients), and polypoidal vascular lesions were located mainly in the macula (85% of eyes). Retinal manifestations of PCV were characterized by serous macular detachment (52% of eyes), submacular hemorrhage (30% of eyes), and retinal pigment epithelium degeneration (10% of eyes). There were few subretinal fibrovascular proliferations (7% of eyes). Mean visual acuity was 0.31 in eyes with PCV and 0.18 in eyes with AMD. The incidence of severe visual loss (0.2 or worse) was 35% in PCV and 53% in AMD. CONCLUSIONS: The incidence of PCV in Japanese patients is high, and the incidence and demographic features vary in different ethnic groups. The clinical manifestations of PCV and AMD resemble each other; however, PCV is characterized by low incidence of subretinal fibrovascular proliferation, slow progression of vascular abnormality, and minimal association with conventional choroidal neovascularization. These factors seem to lead to a more favorable visual outcome in PCV compared with neovascular AMD.