Validation of a new technique using 4-0 nylon thread as a guide for tube insertion of the Ahmed glaucoma valve into the ciliary sulcus.

ABSTRACT: In this study, we validated the new technique for inserting the tube of the Ahmed glaucoma valve (AGV) into the ciliary sulcus. AGV tube insertion was performed by introducing a 4-0 nylon thread into the anterior chamber from the corneal incision on the opposite side of the AGV. The thread was placed in the lumen of a 23-G needle that was inserted into the sclera and ciliary sulcus from the AGV side. Withdrawing the 23-G needle, the thread was led out of the eye from the scleral wound, passing through the ciliary sulcus. The thread was then placed in the AGV tube lumen, and the tube was inserted through the scleral wound into the ciliary sulcus by using the thread as a guide, as per the Seldinger technique. In all seven eyes, the tube was precisely inserted into the ciliary sulcus without serious intraoperative complications such as vitreous straying of the tube.

Development of microglia-targeting adeno-associated viral vectors as tools to study microglial behavior in vivo.

Here we describe the microglia-targeting adeno-associated viral (AAV) vectors containing a 1.7-kb putative promoter region of microglia/macrophage-specific ionized calcium-binding adaptor molecule 1 (Iba1), along with repeated miRNA target sites for microRNA (miR)-9 and miR-129-2-3p. The 1.7-kb genomic sequence upstream of the start codon in exon 1 of the Iba1 (Aif1) gene, functions as microglia preferential promoter in the striatum and cerebellum. Furthermore, ectopic transgene expression in non-microglial cells is markedly suppressed upon adding two sets of 4-repeated miRNA target sites for miR-9 and miR-129-2-3p, which are expressed exclusively in non-microglial cells and sponged AAV-derived mRNAs. Our vectors transduced ramified microglia in healthy tissues and reactive microglia in lipopolysaccharide-treated mice and a mouse model of neurodegenerative disease. Moreover, live fluorescent imaging allowed the monitoring of microglial motility and intracellular Ca2+ mobilization. Thus, microglia-targeting AAV vectors are valuable for studying microglial pathophysiology and therapies, particularly in the striatum and cerebellum.

Occlusion of a Vortex Vein After Treatment With Half-Fluence Photodynamic Therapy Combined With Intravitreal Aflibercept Injection for Pachychoroid Neovasculopathy.

Photodynamic therapy (PDT) is a treatment option for pachychoroid diseases such as central serous chorioretinopathy (CSC), pachychoroid neovasculopathy (PNV), polypoidal choroidal vasculopathy (PCV), and peripapillary pachychoroid syndrome (PPS). On the other hand, morphological changes of choroidal vessels in the irradiated field after PDT have also been discussed, with occlusion of choriocapillaris and stenosis of choroidal middle and large vessels being reported. Here, we report a case of vortex vein occlusion after half-fluence PDT (HF-PDT) combined with an anti-vascular endothelial growth factor (VEGF) agent for PNV. In this case, HF-PDT achieved complete occlusion of PNV; in addition, a vortex vein that flowed in PNV but was located outside the PDT irradiation field was fully occluded three months post-treatment. At the occluded site of the vortex vein, indocyanine green video angiography revealed pulsation downstream of the vortex vein. Such occlusion of a large vessel by HF-PDT has not been reported previously. Occlusion could be induced by two factors: the potentiality of PDT and risk factors for thromboembolism, such as older age, smoking, and arrhythmia. Further studies are required to determine the mechanisms of these large vessel occlusions.

Retinal ganglion cell analysis in patients with sellar and suprasellar tumors with sagittal bending of the optic nerve.

The study investigated clinical features of sellar and suprasellar tumors with optic nerve bending. Twenty-five patients (13 men/12 women; age, 59.0 ± 12.9 years) with optic nerve bending in one eye who underwent tumor resection for sellar and suprasellar tumors were included. The other eye, without optic nerve bending, was the control. The pre- and postoperative best-corrected visual acuity (BCVA) and ganglion cell layer (GCL) + inner plexiform layer (IPL) thickness were studied retrospectively using optical coherence tomography. Preoperative BCVA in the eye with optic nerve bending was significantly poor and improved significantly after tumor resection. Eyes with optic nerve bending had significantly less GCL + IPL thickness on the temporal side than eyes without optic nerve bending. Preoperative GCL + IPL thickness of the entire macula was reduced in eyes with optic nerve bending and poor postoperative BCVA compared to those with good postoperative BCVA. There was no significant difference in GCL + IPL thickness of eyes with optic nerve bending before and after tumor resection. Optic nerve bending caused by sellar and suprasellar tumors resulted in visual impairment and decreased retinal ganglion cells. Eyes with optic nerve bending and severely reduced GCL + IPL thickness may have less BCVA improvement after tumor resection.

Analysis of visual field disturbance in patients with sellar and suprasellar lesions: relationship with magnetic resonance imaging findings and sagittal bending of the optic nerve.

PURPOSE: Visual dysfunction due to sellar and suprasellar lesions is thought to be caused by chiasmatic compression and bending of the optic nerve at the entrance of the optic canal. We examined the relationship between visual field impairment and magnetic resonance (MR) imaging. METHODS: This study reviewed 122 consecutive patients with sellar and suprasellar tumors. We have newly devised a simple visual field impairment score (SVFIS) that was divided into 12 areas. SVFIS is classified into four grades as mild (0-3 points), moderate (4-6 points), severe (7-9 points), and most severe (10-12 points) for each eye. We investigated the relationship between SVFIS grades and MR imaging, including the recently reported optic nerve-canal bending angle (ONCBA) and visual acuity. RESULTS: Ipsilateral visual acuity tended to deteriorate with increased SVFIS grade. Larger ONCBA was associated with increased SVFIS grades. Bitemporal hemianopia occurred in the early stage (mild case), but the central visual field within 30° was particularly likely to be impaired. The visual field disturbance progressed clockwise (counterclockwise on the left side) from the upper temporal side. Disorders of the central visual field within 5° were associated with ipsilateral large ONCBA. CONCLUSIONS: The newly developed SVFIS grades are closely associated with indicators of visual pathway impairment on MR imaging, and are useful as indicators of the severity and progression of visual field impairment due to sellar and suprasellar lesions. Disorders of the central visual field within 5° were found to be associated with ipsilateral large ONCBA.

Clinical Findings of Melanoma-Associated Retinopathy with anti-TRPM1 Antibody.

INTRODUCTION: We report the clinical features and clinical course of melanoma-associated retinopathy (MAR), in which autoantibodies against the transient receptor potential cation channel subfamily M member 1 (TRPM1) were detected. Case Presentation. A 74-year-old man was referred to our hospital for treatment of bilateral vision loss. The best-corrected visual acuity was 20/100 in the right eye and 20/200 in the left eye. His electroretinogram (ERG) showed a reduced b-wave and a normal dark-adapted a-wave in both eyes. Optical coherence tomography (OCT) revealed loss of the interdigitation zone in both eyes. We strongly suspected MAR based on the markedly reduced b-wave in the ERG and a history of intranasal melanoma. The diagnosis was confirmed after autoantibodies against TRPM1 were detected in his blood serum. Fifteen months later, his ERG remained unchanged, and OCT showed bilateral cystic changes in the internal nuclear layer. The visual acuity in both eyes also remained unchanged. CONCLUSIONS: Anti-TRPM1 autoantibodies were detected in a patient diagnosed with MAR who had negative flash ERG and retinal microstructural abnormalities, and the impairment did not recover during the follow-up period. Identification of anti-TRPM1 antibodies was helpful in confirming the diagnosis of MAR.

Effects of Neutralizing Antibody Production on AAV-PHP.B-Mediated Transduction of the Mouse Central Nervous System.

Adeno-associated virus (AAV)-PHP.B, a capsid variant of AAV serotype 9, is highly permeable to the blood-brain barrier. A major obstacle to the systemic use of AAV-PHP.B is the generation of neutralizing antibodies (NAbs); however, temporal profiles of NAb production after exposure to AAV-PHP.B, and the influence on later AAV-PHP.B administration, remains unknown. To address these, AAV-PHP.Bs expressing either GFP or mCherry by neuron-specific or astrocyte-specific promoters were intravenously administered to mice at various intervals, and brain expression was examined. Injection of two AAV-PHP.Bs, separated temporally, showed that as little as a 1-day interval between injections resulted in a significant decrease in expression of the second transgene, with a complete loss of expression after 7 days, paralleling an increase in serum NAb titers. Brain parenchymal injection was explored to circumvent the presence of NAbs. Mice systemically pre-treated with an AAV-PHP.B were injected intra-cerebrally with an AAV-PHP.B expressing GFP. After 2 weeks, marked GFP expression in the cerebellum was evident, showing that pre-existing NAbs did not affect the AAV-PHP.B directly injected into the brain. In contrast, reversing the injection order, i.e., cerebellar injection followed by systemic injection, completely eliminated expression of the second transgene. We confirmed that intra-cerebellar injection produced NAbs in the serum, but not in the cerebrospinal fluid (CSF). Our results indicate that the preclusion of brain transduction by a second AAV-PHP.B administration begins from the first day following systemic injection and is established within 1 week. Serum NAbs can be avoided by directly injecting AAV-PHP.Bs into brain tissue.

Intravenous administration of the adeno-associated virus-PHP.B capsid fails to upregulate transduction efficiency in the marmoset brain.

Intravenous administration of adeno-associated virus (AAV)-PHP.B, a capsid variant of AAV9 containing seven amino acid insertions, results in a greater permeability of the blood brain barrier (BBB) than standard AAV9 in mice, leading to highly efficient and global transduction of the central nervous system (CNS). The present study aimed to examine whether the enhanced BBB penetrance of AAV-PHP.B observed in mice also occurs in non-human primates. Thus, a young adult (age, 1.6 years) and an old adult (age, 7.2 years) marmoset received an intravenous injection of AAV-PHP.B expressing enhanced green fluorescent protein (EGFP) under the control of the constitutive CBh promoter (a hybrid of cytomegalovirus early enhancer and chicken ß-actin promoter). Age-matched control marmosets were treated with standard AAV9-capsid vectors. The animals were sacrificed 6 weeks after the viral injection. Based on the results, only limited transduction of neurons (0-2%) and astrocytes (0.1-2.5%) was observed in both AAV-PHP.B- and AAV9-treated marmosets. One noticeable difference between AAV-PHP.B and AAV9 was the marked transduction of the peripheral dorsal root ganglia neurons. Indeed, the soma and axons in the projection from the spinal cord to the nucleus cuneatus in the medulla oblongata were strongly labeled with EGFP by AAV-PHP.B. Thus, except for the peripheral dorsal root ganglia neurons, the AAV-PHP.B transduction efficiency in the CNS of marmosets was comparable to that of AAV9 vectors.

Short-term outcomes after EX-PRESS implantation versus trabeculectomy alone in patients with neovascular glaucoma.

BACKGROUND: The purpose of this study was to investigate postoperative clinical outcomes in patients with neovascular glaucoma (NVG) who underwent trabeculectomy or EX-PRESS implantation and to identify predictors of successful EX-PRESS implantation. METHODS: The study designed as a retrospective observational analysis and was set in a single tertiary center. Eighty-nine patients (89 eyes) with NVG, were treated using trabeculectomy alone (Trab group; n=39) or EX-PRESS implantation (EX group; n=50). All patients with a history of glaucoma surgery were excluded. The main outcome measures were postoperative intraocular pressure (IOP), visual acuity (VA), number of medications, complications, additional therapy, and success rate. RESULTS: The mean follow-up duration was 4.6 months in the Trab group and 4.2 months in the EX group. There was no significant difference in IOP between the groups except at 1-month follow-up (P=0.045). The number of patients with early postoperative hypotony, a shallow anterior chamber, hyphema, or anterior chamber irrigation was significantly lower in the EX group than in the Trab group (P=0.016, 0.008, 0.019, and 0.014, respectively). The other outcomes, ie, VA, number of medications, and success rate, were similar between the two groups. In the EX group, the success rate was significantly lower in 15 patients with a history of vitrectomy compared to that in 35 patients without a history of vitrectomy (P=0.047). CONCLUSION: Implantation of an EX-PRESS device may be more effective and safer than trabeculectomy alone in patients with NVG. However, a history of vitrectomy may affect the surgical success rate when using EX-PRESS.

Different Filling Patterns of the Choriocapillaris in Fluorescein and Indocyanine Green Angiography in Primate Eyes Under Elevated Intraocular Pressure.

Purpose: To investigate the hemodynamics of the choriocapillaris in primate eyes under elevated intraocular pressure. Methods: Indocyanine green angiography (ICGA) and fluorescein angiography (FA) were performed in two monkeys after elevation of the intraocular pressure (IOP) to 35 and 60 mm Hg. Results: ICGA and FA showed no perfusion delays in the choriocapillaris at 35 mm Hg. The slow dye filling at 60 mm Hg made it possible to observe the early phase angiography sequence. During ICGA, C-shaped precapillary arterioles multiplied in numbers and emerged in the posterior pole, forming the outer rim of the numerous mosaics or lobules. Dye subsequently infiltrated into the lobules. During FA, after numerous hyperfluorescent spots emerged in the posterior pole, each of the spots enlarged and became numerous mosaics with a dark outer rim. When the FA and ICGA images were superimposed, the C-shaped arterioles observed during the ICGA were shown to correspond to the outer dark rim of the mosaics seen during the FA. The earliest dye emergence was delayed during FA compared to ICGA, with 13 seconds elapsing in monkey 1 and 4 seconds in monkey 2. The horizontal diameter of the optic disc contained three to four mosaics in both monkeys. Conclusions: The choriocapillaris lobules appear to be supplied from peripheral arterioles, not central. After blood perfuses the lobules, it drains into the venules at the center. Mosaic or lobular patterns during FA may reflect extravasated fluorescein from the fenestrated choriocapillaris.

Viral Vector-Based Evaluation of Regulatory Regions in the Neuron-Specific Enolase (NSE) Promoter in Mouse Cerebellum In Vivo.

We investigated the neuron-specific enolase (NSE) promoter in terms of its promoter strength and neuronal specificity in the cerebellum in vivo. The 1.8 kb rat NSE promoter was divided into three regions, A (0.8 kb), B (0.7 kb), and C (0.3 kb), starting from the 5' side. Then, we made various deletion constructs and assessed them by virally expressing GFP under the control of one of the deleted promoters. Removing region A reduced GFP expression to ~6% of that of the original 1.8 kb promoter. Further deletion of region B (presence of region C alone) did not influence the promoter strength, but removing region B from the original 1.8 kb promoter reduced the GFP expression to ~6% of the original level, similar to the level observed after deletion of region A. Immunohistochemistry showed robust GFP expression in Purkinje cells and modest expression in interneurons by the original promoter. Removing region A and/or region B abolished the GFP expression in Purkinje cells in most cerebellar lobules, with the expression in interneurons almost unchanged. These results suggest that region C, which is a proximal 0.3 kb sequence, contains cis-acting elements that drive transcription predominantly in interneurons. The addition of either region A or B onto region C does not alter the promoter properties; however, the addition of both regions A and B to region C drastically enhanced the promoter activity in Purkinje cells, suggesting the synergistic action of cis-acting regulatory elements in regions A and B for strong activation in Purkinje cells.

Evaluation of Fundus Blood Flow in Normal Individuals and Patients with Internal Carotid Artery Obstruction Using Laser Speckle Flowgraphy.

PURPOSE: We investigated whether laser speckle flowgraphy (LSFG) results are comparable in both eyes and whether it is useful in the diagnosis of disparity in ocular ischemic syndrome (OIS) patients. METHODS: We compared the mean blur rate (MBR) value for various fundus regions in both eyes of 41 healthy subjects and 15 internal carotid artery occlusion (ICAO) cases. We calculated the standard value of the Laterality Index (LI), which was the MBR comparison of both eyes in each of the regions, in the control subjects. We then investigated the correlation between both eyes for the LIs in the entire fundus, the degree of ICAO and visual function. RESULTS: The disparity of the LIs in both eyes was least in the entire area of the fundus in control subjects and there was a significant correlation between both eyes of the 41 healthy individuals (P = 0.019). Significant correlations were found for the LI, visual acuity and degree of ICAO. The specificity and sensitivity of LI in the entire area was 93.8% and 100%, respectively. CONCLUSIONS: LSFG revealed normal individuals have symmetrical fundus blood flow. LSFG could detect OIS and might be a useful tool for detecting disparities in fundus blood flow.

Viral Vector-Based Dissection of Marmoset GFAP Promoter in Mouse and Marmoset Brains.

Adeno-associated virus (AAV) vectors are small in diameter, diffuse easily in the brain, and represent a highly efficient means by which to transfer a transgene to the brain of a large animal. A major demerit of AAV vectors is their limited accommodation capacity for transgenes. Thus, a compact promoter is useful when delivering large transgenes via AAV vectors. In the present study, we aimed to identify the shortest astrocyte-specific GFAP promoter region that could be used for AAV-vector-mediated transgene expression in the marmoset brain. The 2.0-kb promoter region upstream of the GFAP gene was cloned from the marmoset genome, and short promoters (1.6 kb, 1.4 kb, 0.6 kb, 0.3 kb and 0.2 kb) were obtained by progressively deleting the original 2.0-kb promoter from the 5' end. The short promoters were screened in the mouse cerebellum in terms of their strength and astrocyte specificity. We found that the 0.3-kb promoter maintained 40% of the strength of the original 2.0-kb promoter, and approximately 90% of its astrocyte specificity. These properties were superior to those of the 1.4-kb, 0.6-kb (20% promoter strength) and 0.2-kb (70% astrocyte specificity) promoters. Then, we verified whether the 0.3-kb GFAP promoter retained astrocyte specificity in the marmoset cerebral cortex. Injection of viral vectors carrying the 0.3-kb marmoset GFAP promoter specifically transduced astrocytes in both the cerebral cortex and cerebellar cortex of the marmoset. These results suggest that the compact 0.3-kb promoter region serves as an astrocyte-specific promoter in the marmoset brain, which permits us to express a large gene by AAV vectors that have a limited accommodation capacity.

Intravitreal gas injection without vitrectomy for macular detachment associated with an optic disk pit.

PURPOSE: To evaluate the clinical outcomes after gas tamponade without vitrectomy for retinal detachment associated with an optic disk pit using optical coherence tomography. METHODS: Intravitreal gas injection was performed on 8 consecutive patients (mean age, 35.0 years; range, 15-74 years) with unilateral macular detachment associated with an optic disk pit. A 0.3-mL injection of 100% sulfur hexafluoride 6 gas was carried out without an anterior chamber tap. Patients treated with gas injection were instructed to remain facedown for 5 days. RESULTS: Complete retinal reattachment after only gas tamponade was achieved in four out of eight eyes. The mean number of gas injections was 1.8. The mean best-corrected visual acuity before and after the treatment with gas tamponade was approximately 30/100 and 20/20, respectively. The period required for reattachment after final gas treatment was 12 months. There were no incidences of recurrence after complete reattachment by gas tamponade in any of the cases during the 94-month average follow-up period (range, 64-132 months). CONCLUSION: Gas tamponade appears to be an effective alternative method for macular detachment associated with an optic disk pit, even though the mechanisms of optic disk pit maculopathy are still unknown.

Alteration of choroidal thickness in a case of carotid cavernous fistula: a case report and a review of the literature.

BACKGROUND: To measure the alterations of the choroidal thickness in Carotid cavernous fistula (CCF) using enhanced depth imaging optical coherence tomography (EDI-OCT). CASE PRESENTATION: A 64-year-old woman was referred to us for redness, exophthalmos and visual disturbance in her right eye. She was diagnosed with CCF by magnetic resonance imaging (MRI) and magnetic resonance angiography.Observations; Embolization resulted in improvement of ocular symptoms, and there was a reduction of the subfoveal choroidal thickness in the right eye from 351 µm preoperatively to 142 µm postoperatively in EDI-OCT. CONCLUSION: EDI-OCT demonstrated that the choroidal thickness increases occurred due to congestion in a CCF case.