Shida Chen

Choroidal thickness in fellow eyes of patients with acute primary angle-closure measured by enhanced depth imaging spectral-domain optical coherence tomography.

PURPOSE We evaluated choroidal thickness in the fellow eyes of patients with acute primary angle-closure (APAC) and compared findings to those of normal controls. METHODS The study group comprised 44 fellow eyes defined as primary angle-closure suspect (PACS) of 44 subjects who had experienced APAC and 43 eyes of 43 healthy volunteers. Using enhanced depth imaging optical coherence tomography (EDI-OCT), the peripapillary and macular choroidal thickness of the PACS eyes and the control eyes were measured and compared at each location or segment. Pearson correlation analysis and a multivariable regression model were used to evaluate the relationships between choroidal thickness and related factors. RESULTS At all the macular locations, the choroidal thickness was thickest at the subfovea. The PACS eyes had a thicker choroid than the control eyes at all macular locations (all P < 0.05), and it still was significantly thicker after controlling for age, axial length, and sex, except at 3 mm superior from the fovea (P = 0.124). Multivariable linear regression analysis showed that the subfoveal choroidal thickness was significantly thicker in association with the PACS diagnosis, and thinner in association with older subjects and longer axial length eyes. There were no statistically significant differences in the choroidal thickness between the groups at any peripapillary location or segment (P > 0.05). CONCLUSIONS PACS eyes that had a fellow eye experience of APAC had a thicker macular choroid than the control eyes. The potential role of a thicker choroid as a risk factor for APAC must be investigated further.

Peripapillary choroidal thickness in healthy Chinese subjects

BackgroundTo evaluate the peripapillary choroidal thickness of a healthy Chinese population, and to determine its influencing factors.MethodsA total of 76 healthy volunteers (76 eyes) without ophthalmic or systemic symptoms were enrolled. Choroidal scans (360-degree 3.4 mm diameter peripapillary circle scans) were obtained for all eyes using enhanced depth imaging spectral-domain optical coherence tomography. Choroid thickness was measured at the temporal, superotemporal, superior, superonasal, nasal, inferonasal, inferior, and inferotemporal segments.ResultsThe average peripapillary choroidal thicknesses were 165.03 ± 40.37 μm. Inferonasal, inferior, and inferotemporal thicknesses were significantly thinner than temporal, superotemporal, superior, superonasal, nasal thicknesses (p < 0.05). No statistically significant difference was found among inferonasal, inferior, and inferotemporal thicknesses. The average peripapillary choroidal thickness decreased linearly with age (β = −1.33, 95% CI −1.98, -0.68, P < 0.001). No correlation was noted between average choroidal thickness and other factors (gender, refractive error, axial length, average retinal nerve fiber layer thickness, intraocular pressure, diastolic blood pressure, systolic blood pressure, mean blood pressure, diastolic ocular perfusion pressure, systolic ocular perfusion pressure, and mean ocular perfusion pressure).ConclusionsThe inferonasal, inferior, inferotemporal peripapillary choroidal thicknesses were significantly thinner than temporal, superotemporal, superior, superonasal, and nasal thicknesses. A thinner peripapillary choroid is associated with increasing age.

Choroidal Thickness in the Subtypes of Angle Closure: An EDI-OCT Study

PURPOSE To evaluate choroidal thickness (CT) in the subtypes of angle-closure (AC) disease compared with CT in a healthy control. METHODS A total of 297 subjects (eyes) were enrolled in the study: 87 were nonglaucoma controls and 210 were AC subtype eyes (primary AC suspect [PACS], 73 eyes; acute primary AC [APAC], 46 eyes; primary AC [PAC], 35 eyes; and primary AC glaucoma [PACG], 56 eyes). Enhanced depth imaging spectral-domain optical coherence tomography (EDI-OCT) was used to measure the macular CT in the subtypes of AC disease and in healthy control subjects. The average CT was compared among the five groups. RESULTS Thinner CT was associated with older age and longer axial length (AL) (all P < 0.001). All AC groups had thicker subfoveal CT (SFCT) compared with the control eyes (all P < 0.05), even after controlling for age and the AL factor. Acute primary angle-closure eyes had the thickest SFCT and were 61.9-μm thicker than healthy eyes, while PACS, PAC, and PACG eyes were 32.9-, 30.9-, and 25.4-μm thicker than healthy eyes, respectively. No significant difference was observed among the PACS, PAC, and PACG groups. CONCLUSIONS Increased CT might be another anatomic characteristic of AC eyes. These findings may support the hypotheses that choroidal expansion is a contributing factor to the development of AC disease.

Retinal Microglia in Glaucoma.

Objective:To review the current research on microglia as it relates to glaucoma, and summarize the potential microglia-targeted therapies. Data Sources:The data were collected from PubMed and Google Scholar databases published in English up to July 2014. Keywords used, both alone and in combination, in the database search included retinal microglia, over-activation and inhibition of microglia, and glaucoma. Study Selection:Articles were selected and reviewed if they involved microglia in animal models or human patients with glaucoma. Moreover, we also cited some comprehensive amalgamation of published literature. Results:Together with the macroglia [astrocytes, ependymal cells, oligodendrocytes, radial (Müller) cells], the microglia form the supportive tissue of the central nervous system (CNS). Glial cells are generally smaller than the neural cells, but outnumber them by a factor of 5 to 10 with marked regional differences in the CNS. Approximately half of the volume of the CNS is composed of glial cells. Because of the blood-retina barrier, blood-born immunologic cells cannot penetrate into the retina under physiological conditions; the retinal microglial cells are the primary immunocompetent cells in the retina. The microglial cells are involved in any process of cell degeneration and loss, including retinal ganglion fiber and cell loss. Surveying the retinal tissue in normal situations as “spiders in a net,” the retinal microglial cells change their form from a resting dendritic-like shape to an activated ameboid form in the case of invading microorganisms or cell damage. They are involved in the process of cell apoptosis and removal of the dead cells. Studies suggested that inhibition of the microglial cell activation in the case of optic nerve damage can increase the number of surviving retinal ganglion cells and may thus be neuroprotective. Conclusions:Activated microglia appear early in the glaucomatous process and may contribute detrimentally to the neuronal apoptosis in the later stage. Neuroprotective strategies that inhibit activated microglia may provide novel treatment modalities for glaucomatous optic neuropathy and any other retinal and optic nerve disease.

Anterior and Posterior Ocular Biometry in Healthy Chinese Subjects: Data Based on AS-OCT and SS-OCT

Background To measure the anterior and posterior ocular biometric characteristics concurrently and to determine the relationship between the iris and choroid in healthy Chinese subjects. Methods A total of 148 subjects (270 eyes) were enrolled in this cross-section study. The anterior and posterior ocular biometric characteristics were measured simultaneously by anterior segment optical coherence tomography (AS-OCT) and swept-source optical coherence tomography (SS-OCT). Results Compared with male eyes, female eyes had narrower anterior biometric parameters that presented with smaller anterior segment parameters [including anterior chamber depth (ACD), width (ACW), area (ACA), and volume (ACV); (all p<0.001)], narrower anterior chamber angle parameters [including angle opening distance (AOD750), trabecular–iris space area (TISA750), and angle recess area (ARA); (all p<0.001)], higher iris curvature (ICURV) (p = 0.003), and larger lens vaults (LV) (p = 0.019). These anterior ocular biometric parameters were correlated with increasing age (p<0.01). Iris thickness (IT750) and iris area (IAREA) were associated with age, ACW, and pupil diameter (all p<0.05), while choroidal thickness (CT) was associated with age, gender, and axial length (all p<0.05). Univariate regression analysis showed that greater CT was significantly associated with smaller IAREA (p = 0.026). Conclusion Compared with male eyes, female eyes had narrower anterior biometric parameters that correlated with increasing age, which would be helpful in explaining the higher prevalence of angle closure rates in the female gender and in aging people. Increased CT might be associated with smaller iris area; however, this possibility needs to be investigated in future studies before this conclusion is made.

Dynamic mobilization of PGC-1α mediates mitochondrial biogenesis for the protection of RGC-5 cells by resveratrol during serum deprivation

Mitochondrial dysfunction contributing to the pathogenesis of glaucomatous neurodegeneration has stimulated considerable interest recently. In this study, we explored the role of peroxisome proliferator activated receptor-γ co-activator 1α (PGC-1α) in resveratrol-triggered mitochondrial biogenesis for preventing apoptosis in a retinal ganglion cell line RGC-5. Our results showed that serum deprivation induced cell apoptosis in a time-dependent manner. Applying resveratrol maintained the normal mitochondrial membrane potential, decreased the levels of both total and cleaved caspase-3, and inhibited the release of cytochrome c, which subsequently enhanced cell survival. Moreover, resveratrol stimulated mitochondrial biogenesis by increasing the absolute quantity of mitochondria as well as their DNA copies. Treatment with resveratrol promoted the protein expression of SIRT1, but not PGC-1α; instead, resveratrol facilitated PGC-1α translocation from the cytoplasm to the nucleus and up-regulated NRF1 and TFAM, which were blocked by nicotinamide. Collectively, we demonstrate that the SIRT1-dependent PGC-1α subcellular translocation following resveratrol application potentially attenuates serum deprivation-elicited RGC-5 cell death, thereby raising the possibility of mitigating glaucomatous retinopathy by enhancement of mitochondrial biogenesis.

Association of glutathione S-transferase polymorphisms (GSTM1 and GSTT1) with primary open-angle glaucoma: An evidence-based meta-analysis

Studies investigating the associations between glutathione S-transferase (GST) genetic polymorphisms and primary open-angle glaucoma (POAG) have reported controversial results. Therefore, a meta-analysis was performed to clarify the effects of GSTM1 and GSTT1 polymorphisms on POAG risk. Published literatures from PubMed, EMBASE, ISI Web of Science and CBM databases were retrieved. All studies evaluating the association between GSTM1/GSTT1 polymorphisms and POAG were included. Pooled odds ratio (OR) and 95% confidence interval (CI) were calculated using fixed- or random-effects model. Eleven studies on GSTM1 (1339 cases and 1412 controls) and seven studies on GSTT1 (958 cases, 1003 controls) were included. Overall analysis showed that the association between GSTM1 and GSTT1 null genotype and POAG risk is not statistically significant. Subgroup analyses showed that the null genotype of GSTM1 increased the risk of POAG in Asians. In GSTM1-GSTT1 interaction analysis, individuals with dual null genotype were associated with a significantly increased risk of POAG when compared with the dual present genotype. In conclusion, the present meta-analysis suggested that GSTM1 null genotypes are associated with increased POAG risk in Asian populations but not in Caucasian and mixed populations. Dual null genotype of GSTM1/GSTT1 is associated with increased risk of POAG. Given the limited sample size, the finding on GST polymorphisms needs further investigation.

Effects of Valsalva Maneuver on Anterior Chamber Parameters and Choroidal Thickness in Healthy Chinese: An AS-OCT and SS-OCT Study

PURPOSE This study concurrently evaluated the effects of the Valsalva maneuver (VM) on the anterior and posterior ocular biometric parameters in a healthy Chinese cohort. METHODS This prospective, cross-sectional study used anterior segment optical coherence tomography (AS-OCT) and swept-source optical coherence tomography (SS-OCT) to measure the anterior and posterior ocular biometric parameters before and during the VM. Sixty-three volunteers (126 eyes; 17 males and 46 females) were enrolled. The IOP, blood pressure (BP), and refractive error were recorded before and during a VM. RESULTS The mean IOP showed a statistically significant increase (from 13.86-14.25 mm Hg, P = 0.005), but the different layers of the retina and the choroidal thickness (CT) showed no significant changes. The anterior chamber parameters decreased sharply from the baseline, with a smaller angle opening distance (AOD500; from 0.35-0.31 mm, P < 0.001), AOD750 (from 0.44-0.39 mm, P = 0.007), trabecular-iris space area (TISA500; from 0.14-0.13 mm, P = 0.027), TISA750 (from 0.25-0.23 mm, P = 0.007), and anterior chamber volume (ACV; from 143.09-139.84 mm3P = 0.036). Regression analyses revealed an association between ΔIOP and the baseline IOP (β = 0.26 [0.15, 0.37], P < 0.001) and ΔACW (β = -3.24 [-5.65, -0.83], P = 0.008). CONCLUSIONS This study is the first to provide simultaneous evaluation of the effects of the VM on anterior and posterior ocular biometric parameters. The VM caused a significant IOP increase and narrowing of the angles in healthy subjects. However, it did not change the CT in the macular region. The relationship between IOP elevation and choroidal expansion during the VM needs further investigation.

Levels of angiogenesis-related vascular endothelial growth factor family in neovascular glaucoma eyes

This study aimed to evaluate the angiogenesis‐related factors of the vascular endothelial growth factor (VEGF) family in the aqueous humour of patients with neovascular glaucoma (NVG).

Enhanced depth imaging–optical coherence tomography of the choroid in moderate and severe primary angle-closure glaucoma

To compare the choroidal thickness (CT) in eyes with moderate and severe primary angle‐closure glaucoma (PACG) with the eyes of healthy controls.