Oral Intake of Hydrogen Water Improves Retinal Blood Flow Dysregulation in Response to Flicker Stimulation and Systemic Hyperoxia in Diabetic Mice.

Purpose: To examine the effects of hydrogen water on retinal blood flow (RBF) dysregulation in diabetes, we evaluated changes in RBF in response to flicker stimulation and systemic hyperoxia in diabetic mice. Methods: Twelve type 2 diabetic mice were divided into a group that received non-hydrogen water (n = 6, control group) and the other that received hydrogen-rich water (0.6-0.8 mM) (n = 6, HRW group) from six weeks of age. Body weight, blood glucose, intraocular pressure, and blood pressure were evaluated from eight to 14 weeks of age. RBF was measured in the vascular area of the optic disc as mean blur rate using laser speckle flowgraphy in the resting state and response to flicker stimulation and hyperoxia. We evaluated glial activation and oxidative stress based on immunofluorescence expression. Results: At 14 weeks, blood glucose level was significantly lower in the HRW group, though still elevated. RBF changes improved significantly in the HRW group compared with the control group from eight weeks of age and persisted throughout the study. Immunofluorescent expression of glial fibrillary acidic protein, particularly in the outer plexiform layer, was significantly decreased in the HRW group. Among oxidative stress markers, 3-nitrotyrosine was significantly suppressed in the HRW group. Conclusions: Hydrogen-rich water intake significantly improved RBF dysregulation in diabetic mice. Hydrogen may improve impaired neurovascular coupling function in diabetic mice by suppressing gliosis and oxidative stress in the retina. Translational Relevance: This study highlights the potential of oral intake of hydrogen-rich water to mitigate retinal dysfunction in diabetic mice.

A Case of Binocular Metastatic Choroidal Tumor Originating from Pulmonary Adenocarcinoma Successfully Treated with Molecular Target Therapy.

The occurrence of ocular metastasis from lung cancer is uncommon. In our current case, we report on a 64-year-old male patient found to have metastatic lesions in both choroids after being diagnosed with lung adenocarcinoma. As the patient was found to have a mutation in the epidermal growth factor receptor (EGFR), he was treated with the EGFR tyrosine kinase inhibitor (EGFR TKI), afatinib. However, the treatment response suggested the presence of a progressive disease. Thus, due to cancerous meningitis, the patient's treatment was changed from afatinib to erlotinib, in addition to adding bevacizumab. Although the general condition of the patient did not change, improvement was noted for the choroidal metastasis. Moreover, the drug change also resulted in an improvement of the visual power of both eyes. Therefore, the results for this patient suggest that systemic administration of erlotinib and bevacizumab may be an effective treatment that leads to morphological and functional improvement in choroidal metastasis cases.

Effect of a new phacoemulsification and aspiration handpiece on anterior chamber stability.

PURPOSE: To evaluate the responsiveness of 3 phacoemulsification and aspiration (PEA) systems and a new handpiece to occlusion break by measuring anterior chamber depth (ACD) and intraocular pressure (IOP). SETTING: Zengyo Suzuki Eye Clinic, Kanagawa, Japan. DESIGN: Experimental study. METHODS: ACD change during intentional occlusion breaks was observed and evaluated using the slit side view (SSV) method and IOP measurement with the Centurion Vision System (Group 1), Centurion Vision System with Active Sentry (Group 2), Infiniti Vision System (Group 3), and Constellation Vision System (Group 4). 5 eyes were included per group. Occlusion breaks were triggered at IOP of 30 mm Hg, vacuum limits of 550 mm Hg, and aspiration rate of 40 mL/min. ACD change ratio, surge duration, and surge volume were analyzed from videos of SSV and IOP measurement. RESULTS: The smallest ACD change was observed in Group 2 with SSV. ACD change ratios in Groups 1 to 4 were 17.5% ± 3.9%, 7.3% ± 1.2%, 35.7% ± 9.5%, and 74.1 ± 7.7%, respectively. Surge duration and surge volume were calculated only for Groups 1 and 2 and were significantly lower in Group 2 than in Group 1 (0.32 ± 0.03 vs 1.17 ± 0.07 seconds; 18.91 ± 4.70 vs 45.70 ± 0.83 µL). In these 2 groups, ACD change ratio correlated with surge volume. CONCLUSIONS: This study evaluated the responsiveness of 3 PEA systems and a new handpiece to occlusion breaks by measuring IOP and ACD. The Active Sentry system was useful for maintaining the ACD even during occlusion breaks.

Statistical Analysis of Factors Affecting Surgically Induced Astigmatism Following Trabeculectomy.

Purpose: To objectively evaluate surgically induced astigmatism (SIA) after trabeculectomy with mitomycin C and investigate the relationships between SIA and various factors. Patients and Methods: This retrospective study included the right eyes of 66 consecutive patients who underwent standard trabeculectomy performed in the superior temporal quadrant for the first time by a single surgeon. Keratometry recordings made before surgery and 3 months after surgery were collected to calculate the SIA in each patient. The arithmetic mean of SIA (M-SIA) and the centroid of SIA (C-SIA) were determined using vector analysis. The relationships between the magnitude of SIA and the following possible related factors were assessed: age, sex, pre-operative corneal astigmatism, pre-operative intraocular pressure (IOP), 3-month postoperative IOP, pre-operative best-corrected visual acuity (BCVA), 3-month postoperative BCVA, the number of total scleral flap sutures (T-SFS), the number of leftover scleral flap sutures without laser suture lysis at 3 months postoperatively (L-SFS), shape of the scleral flap (triangle or trapezoid), and incision type of the conjunctival flap (fornix- or limbal-based). Results: The mean (± standard deviation) M-SIA was 1.00 ± 0.85 D, and the mean C-SIA was 0.34 ± 1.28 D at 104°. The direction of C-SIA showed a trend of corneal steepening to the superior temporal location, in the direction of the scleral flap location. There were significant correlations of the magnitudes of SIA with the number of T-SFS (P = 0.001) and the number of L-SFS (P < 0.001). Conclusion: Trabeculectomy induced SIA in the direction of the scleral flap location, and scleral sutures are significantly associated with the SIA. The scleral suture may play a key role in steepening the cornea toward the scleral flap direction in post-trabeculectomy patients.

Drinking hydrogen water improves photoreceptor structure and function in retinal degeneration 6 mice.

Retinitis pigmentosa (RP) is a genetically heterogeneous group of inherited retinal disorders involving the progressive dysfunction of photoreceptors and the retinal pigment epithelium, for which there is currently no treatment. The rd6 mouse is a natural model of autosomal recessive retinal degeneration. Given the known contributions of oxidative stress caused by reactive oxygen species (ROS) and selective inhibition of potent ROS peroxynitrite and OH·by H2 gas we have previously demonstrated, we hypothesized that ingestion of H2 water may delay the progression of photoreceptor death in rd6 mice. H2 mice showed significantly higher retinal thickness as compared to controls on optical coherence tomography. Histopathological and morphometric analyses revealed higher thickness of the outer nuclear layer for H2 mice than controls, as well as higher counts of opsin red/green-positive cells. RNA sequencing (RNA-seq) analysis of differentially expressed genes in the H2 group versus control group revealed 1996 genes with significantly different expressions. Gene and pathway ontology analysis showed substantial upregulation of genes responsible for phototransduction in H2 mice. Our results show that drinking water high in H2 (1.2-1.6 ppm) had neuroprotective effects and inhibited photoreceptor death in mice, and suggest the potential of H2 for the treatment of RP.

A Patient with Primary Open-Angle Glaucoma with Re-Elevated Nocturnal Sitting Intraocular Pressure after Restarting Medical Therapy due to a Bleb Failure.

We describe the case of a primary open-angle glaucoma patient with re-elevated nocturnal sitting intraocular pressure (IOP) after restarting medical therapy due to a failing bleb. IOP was markedly higher than diurnal IOP during multiple-drug therapy in both eyes, but it did not increase in the left eye with a functional bleb without medical therapy after trabeculectomy with adjuvant mitomycin. However, nocturnal sitting IOP was re-elevated after restarting multiple-drug therapy due to a failing bleb, while diurnal IOP was maintained at a low level.

Changes in Tear Osmolarity after Cataract Surgery.

BACKGROUND: The purpose of this study was to examine changes in the ocular surface before and after phacoemulsification with small incisions and to examine the changes in tear osmolarity. METHODS: This was a prospective, observational study involving 55 eyes of 39 patients (19 male, 20 female patients; average age 72.0±7.3 years) who had cataract surgery at a Nippon Medical School Hospital between December 2013 and June 2018. Compromised tear dynamics were determined by the Schirmer test or the tear break-up time (BUT). An abnormal ocular surface was identified by positive vital staining with fluorescein or lissamine green. Moreover, tear osmolarity (Tosm) and corneal sensitivity were measured. All assessments were done preoperatively and 1 and 4 weeks (P1W and P4W) after the surgery. RESULTS: None of the operations had any complications. Operating time was 17.8±9.3 minutes. BUT was significantly decreased at P1W, and it recovered at P4W. The Schirmer test did not change significantly. The fluorescein staining score (FSS) increased significantly at P1W and recovered at P4W. The Lissamine green score (LSS) did not change significantly. Tear osmolarity increased significantly at P1W and did not recover at P4W. Corneal sensitivity decreased significantly at P1W and recovered at P4W. CONCLUSION: In the present study, there were temporary changes in dry eye-related examinations including tear osmolarity after cataract surgery. In particular, tear osmolarity increased significantly 4 weeks after surgery compared to before surgery, and it showed long-term changes, unlike other factors. After cataract surgery, tear osmolarity, BUT, and FSS increase, resulting in dry eye symptoms. Therefore, it is necessary to pay attention to discomfortable eye symptoms of patients after cataract surgery.

Brain-derived Neurotrophic Factor in the Aqueous Humor of Glaucoma Patients.

BACKGROUND: Brain-derived neurotrophic factor (BDNF) may be involved in the pathogenesis of glaucoma. BDNF concentrations reported in previous studies have varied widely, and the concentration of BDNF in aqueous humor is unknown. In this study, BDNF concentrations in the aqueous humor of glaucoma patients and control patients were measured with ELISA kits. METHODS: This prospective, observational study examined BDNF levels in aqueous humor in 62 eyes of 43 patients who underwent cataract surgery or trabeculectomy (11 glaucoma patients and 32 non-glaucoma cataract patients as controls). BDNF concentrations were examined by 4 different enzyme-linked immunosorbent assay (ELISA) techniques. RESULTS: The mean ± SD patient age was 72.0 ± 10.1 (range 35 to 87) years. Two of the techniques detected no BDNF in aqueous humor in any samples (n=3 and n=9, respectively); the average value was less than zero. An ultrasensitive ELISA kit did not yield reliable measurements. Finally, in an even more sensitive ELISA (Simoa-HD1), performed by an outside contractor, 25 (54.3%) eyes were below the detection limit, including 20 (55.6%) control and 5 (50%) glaucoma cases. For eyes with detectable BDNF, the overall BDNF concentration was 0.158 pg/mL (n=21): 0.196 pg/mL (n=16) in controls and 0.034 pg/mL (n=5) in glaucoma cases. CONCLUSIONS: BDNF level in aqueous humor varies widely.

Changes in the Ganglion Cell Complex after Inner Limiting Membrane Peeling for Epiretinal Membrane in Glaucoma Patients.

BACKGROUND: Epiretinal membrane (ERM) is a disease that affects the vitreoretinal interface and causes metamorphopsia, anorthopia, and decreased visual acuity. In this study, ERM patients who underwent internal limiting membrane (ILM) peeling were classified as those with glaucoma (Group G) and a control group (Group C). Changes in ganglion cell complex (GCC) thickness were compared between these groups to investigate whether such changes had an effect on progression of glaucoma from structural change. METHODS: This was a retrospective, observational study that included 27 eyes of 27 patients. Group C included 22 eyes, and Group G included 5 eyes. Patients underwent ILM peeling, and cataract surgery was combined with vitrectomy for 16 phakic eyes; 2 phakic eyes and 9 aphakic eyes were treated only with vitrectomy. GCC thickness was measured preoperatively and at 2 weeks and 1, 3, and 6 months postoperatively, and these values and the rates of thinning were compared between the two groups. RESULTS: The mean age of patients was 66.7±12.8 years (range 30-84 years). There was no significant difference between groups in the thickness of the GCC or its rate of thinning after ILM peeling. CONCLUSIONS: The present results suggest that this procedure does not cause structural exacerbation of glaucoma in glaucoma patients. Although further studies of the functional effects of ILM peeling are required, the present results suggest that there is no significant difference between the two groups.

Amount of Green Fluorescent Protein in the Anterior Chamber after Intravitreal Injection of Triple-Mutated Self-Complementary AAV2 Vectors is Not Affected by Previous Vitrectomy Surgery.

BACKGROUND: The adeno-associated virus (AAV) vector is a promising vector for ocular gene therapy. Surgical internal limiting membrane peeling before AAV vector administration is useful for efficient retinal transduction. However, no report has investigated localization of AAV vectors after administration into a post-vitrectomy eye. This study investigated the effects of vitrectomy surgery on intravitreal-injected AAV vector-mediated gene expression in the anterior segment and examined the presence of neutralizing antibodies (NAbs) in serum before and after AAV vector administration. METHODS: Of six eyes from three female cynomolgus monkeys, four were vitrectomized (Group VIT) and two were non-vitrectomized (Group IV). All eyes were injected with 50 µL of triple-mutated self-complementary AAV2 vector (1.9 × 1013 v.g./mL) encoding green fluorescent protein (GFP). NAbs in the serum were examined before administration and at 2 and 6 weeks after administration. GFP expression was analyzed at 19 weeks after administration. RESULTS: Immunohistological analysis showed no GFP expression in the trabecular meshwork in any eye. The GFP genome copy in two slices of the anterior segment was 2.417 (vector genome copies/diploid genome) in Group VIT and 4.316 (vector genome copies/diploid genome) in group IV. The NAb titer was 1:15.9 (geometric mean) before administration, 1:310.7 at 2 weeks after administration, and 1:669.4 at 6 weeks after administration. CONCLUSION: Previous vitrectomy surgery did not affect gene expression in the anterior segment after intravitreal injection of AAV vectors.

Cystoid Macular Edema Associated with Omidenepag Isopropyl in Phakic Eyes after Laser Iridotomy: A Case Report.

Decreased vision and cystoid macular edema (CME) developed in phakic eyes of a patient who underwent laser iridotomy after changing the glaucoma eye drops from carteolol 2% long-acting ophthalmic solution to omidenepag isopropyl 0.002%. CME completely disappeared at approximately 2 months after discontinuation of omidenepag isopropyl in conjunction with the use of bromfenac sodium 0.1%.

Optical Coherence Tomography Angiography of Nonarteritic Cilioretinal Artery Occlusion Alone.

Cilioretinal artery occlusion (CLRAO) is a rare disease. Here, we report the case of a 70-year-old man with nonarteritic cilioretinal artery occlusion alone. The patient was allergic to fluorescein. Therefore, we followed the retinal circulation with optical coherence tomography angiography (OCTA). OCTA at 40 days postonset showed partial improvement in the retinal circulation.

Multimodal imaging analysis of macular dystrophy in patient with maternally inherited diabetes and deafness (MIDD) with m.3243A>G mutation.

Purpose: Maternally inherited diabetes and deafness (MIDD) is caused by a heteroplasmic m.3243A>G mutation in the mitochondrial DNA. The main ocular feature in MIDD is macular dystrophy. The purpose of this study was to identify the phenotypical characteristics of a patient with MIDD by multimodal high-resolution imaging analyses.Methods: A detailed history and ophthalmic examination were performed on a 39-year-old patient with MIDD. Multi-modal imaging included fundus photography, fundus autofluorescence imaging, fluorescein angiography, spectral-domain optical coherence tomography, OCT-angiography, and adaptive optics imaging. The PCR-invader and whole exome sequencing (WES) methods were performed on the DNA of the patient.Results: A 39-year-old woman with sensorineural hearing loss, diabetes mellitus presented with atrophic perifoveal changes and MIDD was suspected. The PCR-invader and WES methods showed that the patient had a m.3243A>G mutation in the mitochondrial DNA with 29% and 16.7% of the heteroplasmy in the peripheral blood, respectively. Morphological analyses revealed that the areas of photoreceptor degeneration and chorioretinal atrophy were present mainly in the perifoveal region. Multifocal ERGs showed that the perifoveal responses were reduced. Goldmann visual field was significant for a cecocentral scotoma in the right eye and an enlarged blind spot in the left eye. The central isopter was constricted bilaterally. The results of high-resolution retinal imaging by AO revealed that the densities of the cone photoreceptor were significantly reduced in the fovea where no obvious atrophy of the RPE and choroid was observed.Conclusions: Our findings indicate that WES analysis can be used to detect the m.3243A>G mutation in the mtDNA. The results of multimodal imaging analyses indicated that the primary dysfunction of the photoreceptors in the fovea might precede the dysfunction of the RPE in patient with MIDD.

Serum Brain-Derived Neurotrophic Factor in Glaucoma Patients in Japan: An Observational Study.

PURPOSE: The aim of this study was to measure serum levels of brain-derived neurotrophic factor (BDNF) in Japanese patients with primary open angle glaucoma (POAG) and normal tension glaucoma (NTG). METHODS: This was a prospective observational study of serum BDNF levels in 78 patients who underwent cataract surgery or trabeculectomy (27 glaucoma patients and 51 non-glaucoma cataract patients as controls). Patient age was 68.8 ± 11.1 years (mean ± standard deviation; range 35-86 years). The numbers of patients with POAG and NTG were 16 and 11, respectively. POAG was diagnosed by intraocular pressure measurement, gonioscopy, optic nerve head change, and presence of a visual field defect. RESULTS: Serum BDNF concentration was significantly lower in the glaucoma group (including both POAG and NTG) than in the control group (7.2 ± 3.6 ng/mL vs. 12.2 ± 9.3 ng/mL, p=0.004). Serum BDNF concentration was lower in early glaucoma than in moderate glaucoma. There was no correlation between serum BDNF concentration and age. When patients with NTG and POAG were compared, serum BDNF concentration was lower in the former. Serum BDNF concentration was not significantly correlated with glaucoma parameters, including optical coherence tomography and visual field defects. CONCLUSION: This is the first study to investigate serum BDNF concentration in glaucoma patients in Japan. Future studies should evaluate the role of BDNF as a potential biomarker of glaucoma.

Role of Pediatric Departments in Community Hospitals in Countermeasures against Measles Epidemics at Olympic Games Sites.

BACKGROUND: In preparation for the 2021 Tokyo Olympic/Paralympic Games, the Japanese government assessed the risks of infectious disease outbreaks and identified necessary preparations. This present study reviewed efforts made during a previous measles epidemic and describes the roles of hospitals. METHODS: This descriptive study investigated the records of 198 children with measles. All children were treated at a general hospital during the period from January 1997 through February 1998. We also examined the actions of pediatricians during and after a measles outbreak in the community. RESULTS: Of the 198 children, 145 (73%) were hospitalized. The measles vaccination rate in the previous year was approximately 75%. Of the patients examined, 53% were younger than 2 years of age; mean age was 2.75 years. Pneumonia and gastroenteritis accounted for 46% and 30% of the complications, respectively. Issues requiring attention included the number of hospital beds located in a negative pressure room or private room with a window, the need for gamma globulin preparations with high measles antibody titers, the necessity of increasing vaccination opportunities, and extension of physician working hours. CONCLUSIONS: Visitors from other countries could cause measles outbreaks in Japan. Measures that might mitigate an outbreak were maintenance of high vaccination rates, ready availability of information on the location of negative pressure hospital rooms, knowledge of the status of the measle outbreak, and flexible medical staffing. There is a risk of measles outbreaks among infants and among those who do not have a measles antibody titer.

Evaluation of the Utility of Capsular Stabilization Devices in a Zonular Fiber Defect Model with the Slit Side View System.

Capsular stabilization devices were evaluated in a zonular fiber defect model using the slit side view (SSV) system to confirm their utility for capsular stabilization during phacoemulsification. A zonular fiber defect model was made by cutting Zinn's zonule under observation with a slit lamp microscope in a porcine eye. Phacoemulsification was performed, and the movement of the lens capsule and the depth of the anterior chamber were observed using the SSV in three groups: control group: no surgical instruments used, CE group: a capsule expander was inserted, and CTR group: a capsular tension ring was inserted. In the control group, the equator of the lens was unstable and was easily suctioned to the port of the ultrasound handpiece. The lens capsule was stable in both in the CE and CTR groups. In the CTR group, the equator responsible for the zonular rupture also returned and closed true to its original position. The utility of the capsular stabilization devices in this zonular fiber defect model was confirmed with the SSV system.

Hydrogen promotes the activation of Cu, Zn superoxide dismutase in a rat corneal alkali-burn model.

AIM: To investigate the effects of hydrogen (H2) on Cu, Zn superoxide dismutase (SOD1) activation in a rat model of corneal alkali burn. METHODS: In each rat, one cornea was subjected to alkali exposure. Physiological saline (saline group) or H2-dissolved saline (H2 group) was instilled continuously on the cornea for 5min before and after alkali exposure. Inflammatory cells, neovascularization, and cytoplasmic SOD1 levels were evaluated immunohistochemically in enucleated eyes from both groups. Three-dimensional ultrastructural tissue changes in the eyes were analyzed using low-vacuum scanning electron microscopy. RESULTS: The numbers of both inflammatory and vascular endothelial cells were significantly reduced in the corneas of the H2 group (P<0.01). Furthermore, H2 treatment increased both cytoplasmic SOD1 levels (P<0.01) and activity in corneal epithelial cells (P<0.01). Notably, the SOD1 activity level in the H2 group was approximately 2.5-fold greater than that in the saline group. CONCLUSION: H2 treatment suppresses inflammation and neovascularization in the injured cornea and indirectly suppresses oxidative insult to the cornea by upregulating the SOD1 enzyme protein level and activity.

High-resolution photoreceptor imaging analysis of patients with autosomal dominant retinitis pigmentosa (adRP) caused by HK1 mutation.

PURPOSE: The hexokinase 1 (HK1) gene encodes one of the four human hexokinases that play essential roles in glucose metabolism. Recently, several cases of E847K mutation in the HK1 gene were reported to cause inherited retinal dystrophy. The purpose of this study was to identify the phenotypical characteristics of patients with a recurrent E847K mutation in the HK1 gene. METHODS: Three generations of one family with autosomal dominant retinitis pigmentosa were examined. Whole exome sequencing was performed on the DNA. Fundus imaging by an adaptive optics fundus camera was used to obtain high-resolution photoreceptor images. RESULTS: Fundus examination of the proband showed degeneration of the mid-peripheral retina, and SD-OCT images showed an absence of the ellipsoid zone (EZ) and interdigitation zone (IZ) in the parafovea and more peripherally. SD-OCT images of the mother of the proband showed an absence of the EZ and IZ, and fundus autofluorescence images showed hypo-autofluorescence surrounding the macular region. One daughter of the proband had only mild night blindness, however, the density of the cone photoreceptors was reduced in the parafoveal region. Whole exome sequencing identified a heterozygous variant, E847K, in the HK1 gene. This variant was found to co-segregate with the disease in three family members. CONCLUSIONS: Although the systemic phenotypes were found to be associated with the HK1 mutations, only the E847K mutation can cause a non-syndromic photoreceptor degeneration. Our study strengthened the hypothesis that the amino acid E847 might play a critical role in the maintenance of the morphology and function of the photoreceptors.

Tyrosine triple mutated AAV2-BDNF gene therapy in an inner retinal injury model induced by intravitreal injection of N-methyl-D-aspartate (NMDA).

Purpose: Glaucoma is a group of chronic optic neuropathies characterized by the degeneration of retinal ganglion cells (RGCs) and their axons, and they ultimately cause blindness. Because neuroprotection using neurotrophic factors against RGC loss has been proven a beneficial strategy, extensive attempts have been made to perform gene transfer of neurotrophic proteins. This study used the inner retinal injury mouse model to evaluate the neuroprotective effect of tyrosine triple mutated and self-complementary adeno-associated virus (AAV) encoding brain-derived neurotrophic factor (BDNF; tm-scAAV2-BDNF). Methods: C57BL/6J mice were intravitreally injected with 1 µl of tm-scAAV2-BDNF and its control AAV at a titer of 6.6 E+13 genome copies/ml. Three weeks later, 1 µl of 2 mM N-methyl-D-aspartate (NMDA) was administered in the same way as the viral injection. Six days after the NMDA injection, we assessed the dark-adapted electroretinography (ERG). Mice were sacrificed at one week after the NMDA injection, followed by RNA quantification, protein detection, and histopathological analysis. Results: The RNA expression of BDNF in retinas treated with tm-scAAV2-BDNF was about 300-fold higher than that of its control AAV. Meanwhile, the expression of recombinant BDNF protein increased in retinas treated with tm-scAAV2-BDNF. In addition, histological analysis revealed that tm-scAAV2-BDNF prevented thinning of the inner retina. Furthermore, b-wave amplitudes of the tm-scAAV2-BDNF group were significantly higher than those of the control vector group. Histopathological and electrophysiological evaluations showed that tm-scAAV2-BDNF treatment offered significant protection against NMDA toxicity. Conclusions: Results showed that tm-scAAV2-BDNF-treated retinas were resistant to NMDA injury, while retinas treated with the control AAV exhibited histopathological and functional changes after the administration of NMDA. These results suggest that tm-scAAV2-BDNF is potentially effective against inner retinal injury, including normal tension glaucoma.

Novel GUCY2D Variant (E843Q) at Mutation Hotspot Associated with Macular Dystrophy in a Japanese Patient.

BACKGROUND: The GUCY2D (guanylate cyclase 2D) gene encodes a photoreceptor guanylate cyclase (GC-E), that is predominantly expressed in the cone outer segments. Mutations in the GUCY2D lead to severe retinal disorders such as autosomal dominant cone-rod dystrophy (adCRD) and autosomal recessive Leber congenital amaurosis type 1. The purpose of this study was to identify the phenotype of a Japanese patient with a probably pathogenic GUCY2D variant. METHODS: Detailed ophthalmic examinations were performed, and whole exome sequencing was performed on DNA obtained from the patient. The variants identified by exome sequencing and targeted analysis were further confirmed by direct sequencing. RESULTS: A 47-year-old man had atrophic and pigmentary changes in the macula of both eyes. Amplitudes and implicit times on full-field electroretinograms (ERGs) were within normal limits; however, the densities of multifocal ERGs in the central area were reduced in both eyes. Whole exome sequencing identified heterozygous variant c.2527G>C, p.Glu843Gln in the GUCY2D gene within the mutation hot spot for adCRD. The allelic frequencies of this variant are extremely low and, according to American College of Medical Genetics and Genomics standards and guidelines, the variants are classified as likely pathogenic. CONCLUSIONS: This is the first report of a heterozygous variant, c.2527G>C, p.Glu843Gln, in the GUCY2D, in a patient presenting with mild macular dystrophy without a general reduction in cone function. Our findings expand the spectrum of the clinical phenotypes of GUCY2D-adCRD and help clarify the morphological and functional changes caused by defects of dimerization of GC-E in the phototransduction cascade.