Ocular Biometric Characteristics in Preoperative Diagnosis of Acute Angle Closure With and Without Zonular Laxity.

PRCIS: Biometric parameters, including binocular difference of anterior chamber depth (ACD), lens vault (LV) in affected eyes, and binocular difference of the LV, had high efficiency in diagnosing acute angle closure (AAC) with zonular laxity. PURPOSE: To investigate the ocular biometric characteristics of eyes with AAC with zonular laxity to further explore the sensitive parameters for preoperative diagnosis. METHODS: This study included 50 patients with AAC with zonular laxity and 54 patients with AAC without zonular laxity. Demographic data, ocular examination results, and biometric parameters on ultrasound biomicroscopy images were compared between the affected and fellow eyes in 2 groups. Parameters significant in the multiple linear regression model were included in a regression equation and the diagnostic efficiency was evaluated by area under the curve. RESULTS: In patients with AAC with zonular laxity, the binocular difference of central ACD, LV in affected eyes, and binocular difference of the LV were significantly larger than those in patients without zonular laxity respectively and these three parameters were all significant in multiple linear regression analysis (all P <0.001). The area under the curve of binocular difference of ACD, LV in affected eyes, and binocular difference of LV were 0.972, 0.796, and 0.855, respectively, with the cutoff values of 0.23, 1.28, and 0.19 mm. The regression equation containing these three parameters was: ln ( P /(1- P ))=-4.322 + 1.222 [LV in affected eyes (mm)] + 3.657 [binocular difference of LV (mm)] + 6.542 [binocular difference of ACD (mm)], with the accuracy of prediction reaching 94.05%. CONCLUSION: Binocular difference of ACD, LV in affected eyes, and binocular difference of LV had high efficiency in diagnosing AAC with zonular laxity.

Occurrence of Oxidative Stress and Premature Senescence in the Anterior Segment of Acute Primary Angle-Closure Eyes.

Purpose: To explore whether oxidative stress and premature senescence occur in the anterior segment of acute primary angle-closure (APAC) eyes after increased intraocular pressure. Methods: The eye samples of 21 APAC patients, 22 age-related cataract patients, and 10 healthy donors were included. Aqueous humor (AqH), iris, and anterior lens capsule samples were collected. The levels of oxidative stress markers and senescence-associated secretory phenotype (SASP)-related cytokines in AqH were estimated using relevant reagent kits and multiplex bead immunoassay technique. The intensity of relevant markers in anterior segment tissues was examined by immunofluorescence- and senescence-associated ß-galactosidase (SA-ß-gal) staining. Results: Oxidative stress marker levels elevated significantly in the AqH of APAC eyes. Reactive oxygen species (ROS) and 8-hydroxydeoxyguanosine levels were positively correlated with preoperative peak intraocular pressure and age, whereas reduced glutathione/oxidized glutathione (GSH/GSSH) ratio was negatively correlated with both parameters. The levels of several SASP-related cytokines were markedly increased. ROS and malondialdehyde levels were positively correlated with the levels of some SASP-related cytokines, whereas superoxide dismutase level and GSH/GSSH ratio showed an opposite trend. The number of cells positive for oxidative mitochondrial DNA damage and apoptosis-related markers increased in the iris and anterior lens capsule of the APAC group. Senescence-associated markers (p16, p21, and p53) and SA-ß-gal activity were increased in the iris of the APAC group. Conclusions: Oxidative stress and premature senescence occurred in the anterior segment of APAC patients, suggesting that they may be involved in the development of pathological changes in the anterior segment of APAC eyes.

Segmentation Errors in the Measurement of Volumetric Parameters by Swept-Source Anterior Segment Optical Coherence Tomography.

Purpose: To investigate the error rate of segmentation in the automatic measurement of anterior chamber volume (ACV) and iris volume (IV) by swept-source anterior segment optical coherence tomography (SS-ASOCT) in narrow-angle and wide-angle eyes. Methods: In this study, fifty eyes from 25 narrow-angle subjects and fifty eyes from 25 wide-angle subjects were enrolled. SS-ASOCT examinations were performed and each SS-ASOCT scan was reviewed, and segmentation errors in the automatic measurement of ACV and IV were classified and manually corrected. Error rates were compared between the narrow-angle and the wide-angle groups, and ACV and IV before and after manual correction were compared. Results: A total of 12,800 SS-ASOCT scans were reviewed. Segmentation error rates of angle recess, iris root, posterior surface of the iris, pupil margin, and anterior surface of the lens were 84.06, 93.30, 13.15, 59.21, and 25.27%, respectively. Segmentation errors of angle recess, iris root, posterior surface of the iris, and pupil margin occurred more frequently in narrow-angle eyes, while more segmentation errors of the anterior surface of the lens were found in wide-angle eyes (all P < 0.001). ACV decreased and IV increased significantly after manual correction of segmentation errors in both groups (all P < 0.01). Conclusion: Segmentation errors were prevalent in the volumetric measurement by SS-ASOCT, particularly in narrow-angle eyes, leading to mismeasurement of ACV and IV.

Awareness, knowledge and attitudes towards cardiopulmonary resuscitation among people with and without heart disease relatives in South China: a cross-sectional survey.

OBJECTIVES: To assess the awareness, knowledge and attitudes towards cardiopulmonary resuscitation (CPR) among relatives of people with and without heart disease and their influence in South China. DESIGN: This is a cross-sectional survey. Logistic regression was used to evaluate the demographic factors associated with CPR training, learning and knowledge. SETTING: The study was conducted in two hospitals, the largest cardiovascular institute and the largest eye care centre in South China. PARTICIPANTS: Healthy individuals who accompanied their relatives with heart disease to the outpatient department of cardiovascular disease and systemically healthy patients who came for regular ophthalmic examination and had no relatives with heart disease were consecutively recruited for the study. A total of 1644 respondents with heart disease relatives and 813 respondents without heart disease relatives completed the survey. RESULTS: Thirty three per cent of respondents never heard of CPR and only 11% had received CPR training. Factors associated with a higher rate of CPR training were higher level of education and income (p<0.001). Most respondents stated that CPR training was necessary and would like to learn CPR. However, only one-third considered it beneficial to perform CPR as a layperson. In addition, healthcare respondents (p<0.001), younger (p<0.05) and more educated respondents (p<0.001) earned higher scores on the knowledge of CPR skills. Only 5.3% had perfect scores on a CPR skills test. Notably, respondents with relatives suffering from heart disease had significantly less training experience and CPR knowledge than those without (p<0.001). CONCLUSIONS: Although the attitudes towards learning CPR are very positive, there was a lack of knowledge on this topic among the general public. This study demonstrates an urgent need to boost awareness and training in CPR in South China, especially among people whose relatives have heart disease.

Down Syndrome Critical Region 1 Reduces Oxidative Stress-Induced Retinal Ganglion Cells Apoptosis via CREB-Bcl-2 Pathway.

Purpose: Irreversible retina ganglion cell (RGC) loss is a key process during glaucoma progression. Down syndrome critical region 1 (DSCR1) has been shown to have protective effects against neuronal death. In this study, we aimed to investigate the neuroprotective mechanisms of DSCR1 on RGCs. Methods: DBA/2J mice and optic nerve crush (ONC) rat model were used for vivo assays. Oxidative stress model of primary RGCs was carried out with in vitro transduction. DSCR1 protein localization was assessed by immunofluorescence. Differential protein expression was validated by Western blot, and gene expression was detected by real-time PCR. TUNEL was used to identify cell apoptosis, and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide was used to analyze cell viability. Results: Significant upregulation of DSCR1 was observed in DBA/2J mice, ONC rat model, and RGCs treated with H2O2, reaching peaks at the age of 6 months in DBA/2J mice, 5 days after ONC in rats, and 24 hours after H2O2 treatment in RGCs, respectively. DSCR1 was shown to be expressed in the ganglion cell layer. In vitro, overexpressed DSCR1 significantly promoted phosphorylation of cyclic AMP response element binding protein (CREB), B-cell lymphoma 2 (Bcl-2) expression, and RGC survival rate while reducing cleaved caspase 3 expression in H2O2-treated RGCs. On the other hand, the opposite effects were shown after knockdown of DSCR1. In addition, silencing of CREB inhibited expression of DSCR1. Conclusions: Our results suggested that DSCR1 might protect the RGCs against oxidative stress via the CREB-Bcl-2 pathway, which may provide a theoretical basis for future treatments of glaucoma.

Asymmetry of Macular Vessel Density in Bilateral Early Open-angle Glaucoma With Unilateral Central 10-2 Visual Field Loss.

PRéCIS:: Glaucomatous eyes without detectable 10-2 visual field loss showed significant macular vessel density loss, especially in inferior quadrant of perifoveal area. Macular vessel density loss spatially corresponded with structural and functional damage. PURPOSE: The purpose of this study was to investigate the characteristics, intereye and intraeye asymmetry of macular vessel density assessed by optical coherence tomography (OCT) angiography in bilateral early open-angle glaucoma with unilateral 10-2 visual field loss. MATERIALS AND METHODS: Thirty-two eyes of 16 patients with bilateral early open-angle glaucoma and unilateral 10-2 visual field loss, and 13 eyes of 13 healthy participants were consecutively enrolled. All subjects underwent 30-2, 10-2 visual fields, OCT, and OCT angiography examinations. Intereye differences were compared between the perimetrically affected eye and the unaffected eye in the same patient. Intraeye differences were compared between the affected hemifields and the unaffected hemifields in the same eye with single-hemifield 10-2 visual field loss. RESULTS: Macular whole image vessel density of the perimetrically unaffected eyes was lower than the healthy eyes (46.6% vs. 51.1%; P<0.001). Parafoveal vessel density parameters of the perimetrically affected eyes were comparable to the unaffected eyes (all P>0.05). Although inferior perifoveal vessel density of the perimetrically affected eyes was significantly lower than the unaffected eyes (42.2% vs. 46.2%; P=0.007), similar results were found in macular ganglion cell complex. In glaucomatous eyes with single-hemifield loss, perifoveal vessel density and macular ganglion cell complex of the affected hemifields were significantly worse than the unaffected hemifields (43.6% vs. 47.0%, 78.4 µm vs. 89.0 µm; P=0.023 and 0.005; respectively). CONCLUSIONS: Significant macular microvascular damage was present in glaucomatous eyes without detectable 10-2 visual field damage. The damage of inferior perifoveal vessel density was more significant in early glaucoma. Macular microvascular damage spatially corresponded with functional and structural damage.

Correlation of iris collagen and in-vivo anterior segment structures in patients in different stages of chronic primary angle-closure in both eyes.

Purpose: To compare the density of iris collagen and anterior segment parameters in eyes with chronic primary angle closure glaucoma (CPACG) and their fellow eyes with confirmed or suspected primary angle closure (PAC/PACS). Methods: Nineteen patients with CPACG in one eye and PAC/PACS in the fellow eye requiring trabeculectomy in the CPACG eye and iridectomy in the fellow eye were recruited. Anterior segment optical coherence tomography (AS-OCT) measurements were conducted under light and dark conditions. Iris specimens, obtained by iridectomy/trabeculectomy, were analyzed by sirius red polarization for quantifying type I/III collagen density. AS-OCT parameters and type I/III collagen densities were compared between the two eyes. Results: The iris curvatures were flatter in CPACG eyes in light and dark conditions (P < 0.05). The iris areas in light condition and iris thicknesses in dark condition were smaller in CPACG eyes (P < 0.05). The density of collagen type I in CPACG eyes was lower (P = 0.048). The light-to-dark changes in CPACG eyes and PAC/PACS eyes, respectively, were -0.679 ± 0.701 and -1.627 ± 0.802 mm for pupil diameters, and 0.069 ± 0.113 and 0.258 ± 0.157 mm2 for iris areas, which differed significantly (P < 0.001). With the decrease of type I collagen, anterior chamber width increased and iris areas decreased in dark condition. Conclusion: Dynamic changes in pupil diameter and iris areas differed significantly between CPACG eyes and their fellow PAC/PACS eyes. Decreased type I collagen density in iris tissue was associated with decreased iris area and increased anterior chamber width, which may contribute to disease progression.

Spatiotemporal Expression Changes of PACAP and Its Receptors in Retinal Ganglion Cells After Optic Nerve Crush.

Pituitary adenylate cyclase-activating polypeptide (PACAP) has been demonstrated to play a crucial part in protecting retinal ganglion cells (RGCs) from apoptosis in various retinal injury animal models. PACAP has two basic groups of receptors: PACAP receptor type 1 (PAC1R) and vasoactive intestinal polypeptide/PACAP receptors (VPAC1R and VPAC2R). However, few studies illustrated the spatial and temporal expression changes of endogenous PACAP and its receptors in a rodent optic nerve crush (ONC) model. In this study, a significant upregulation of PACAP and PAC1R in the retina after ONC was observed in both protein and RNA levels. The peak level of PACAP and PAC1R expression could be found on the fifth day following ONC. In addition, immunofluorescent labeling indicated that PACAP and PAC1R were localized mainly in RGCs. On the contrary, VPAC1R and VPAC2R were hardly detected in the retina. Collectively, the spatiotemporal expression of PACAP and its high-affinity receptor PAC1R were remarkably changed after ONC, and mainly expressed in the ganglion cell layer of the retina. This suggested that the upregulation of PACAP and PAC1R may play a vital role in RGC death after ONC.

Effect of sorbed and desorbed Zn(II) on the growth of a green alga (Chlorella pyrenoidosa).

Toxic effect of Zn(II) on a green alga (Chlorella pyrenoidosa) in the presence of sepiolite and kaolinite was investigated. The Zn-free clays were found to have a negative impact on the growth of C. pyrenoidosa in comparison with control samples (without adding any clay or Zn(II)). When Zn(II) was added, the algae in the presence of clays could be better survived than the control samples, which was actually caused by a decrease in Zn(II) concentration in the solution owing to the adsorption of Zn(II) on the clays. When the solution system was diluted, the growth of algae could be further inhibited as compared to that in a system which had the same initial Zn(II) concentration as in the diluted system. This in fact resulted from desorption of Zn(II) from the zinc-contaminated clays, although the effect varied according to the different desorption capabilities of sepiolite and kaolinite. Therefore the adsorption and desorption processes of Zn(II) played an important part in its toxicity, and adsorption and desorption of pollutants on soils/sediments should be well considered in natural eco-environmental systems before their risk of toxicity to aquatic organisms was assessed objectively.

[Toxic effects of hexavalent chromium on the growth of blue-green microalgae].

A standard method of algal bioassay for determining the toxicity of toxic chemicals was applied to the interaction between Cr(VI) and six blue-green microalgae. The 96h-EC50 of hexavalent chromium on the growth of Chlorella pyrenoidosa, Synechococcus, Spirulina maxima, Spirulina platensis, Selenastrum capriornutum and Scenedesmus quadricauda were 4.96, 6.50, 11.16, 11.74, 12.43 and 20.89 mg/L, respectively. The tolerance of the six blue-green microalgae to Cr(VI) was in the order of Scenedesmus quadricauda > Selenastrum capriornutum > Spirulina platensis > Spirulina maxima > Synechococcus > Chlorella pyrenoidosa. The sensitivity of these species to Cr(VI) might relate to the cell size, the structure of cell wall, as well as the redox reaction caused by the exudate or enzyme. X-ray absorption near edge structure(XANES) was used to study the accumulation and transformation of Cr(VI) in Chlorella pyrenoidosa.