Preoperative laser reduces silicone oil use in primary diabetic vitrectomy.

AIM: To identify the predictive factors and laser photocoagulation associated with the use of silicone oil as endotamponade during primary diabetic vitrectomy. METHODS: The medical and surgical records of 690 patients (798 eyes) who underwent primary diabetic vitrectomy at a tertiary eye hospital in China from January 2018 to December 2018 were reviewed in this retrospective cohort study. The patients' baseline characteristics and preoperative treatments were recorded. The binary Logistic regression model was used to evaluate the risk factors for the use of silicone oil as endotamponade agent during primary vitrectomy for proliferative diabetic retinopathy (PDR)-related complications. RESULTS: Among 690 patients with mean age of 52.1±10.5y (range: 18-85y), 299/690 (43.3%) were female. The 31.6% of the eyes received preoperative laser treatment, and 72.4% of the eyes received preoperative anti-VEGF adjuvant therapy. Non-clearing vitreous haemorrhage (VH) alone or combined with retinal detachment was the main surgical indication (89.5%) for primary vitrectomy. Silicone oil was used as endotamponade in 313 (39.2%) eyes. Lack of preoperative laser treatment [odds ratio (OR) 0.66, 95% confidence interval (CI): 0.48-0.92; P=0.015] and older age (OR 0.96, 95%CI: 0.95-0.98; P<0.001) were predictors of silicone oil tamponade during primary vitrectomy for PDR. CONCLUSION: The lack of preoperative laser treatment is a significant predictor of silicone oil tamponade during primary vitrectomy for PDR. However, the severity of PDR relevant to silicone oil use should be further evaluated.

Aqueous proinflammatory cytokines in acute primary angle-closure eyes.

AIM: To evaluate changes of proinflammatory cytokines in aqueous humor of patients with acute primary angle-closure (APAC) and age-related cataracts. METHODS: Twenty eyes of 20 APAC patients and 15 eyes of 15 age-related cataract patients were included in this cross-sectional study. Aqueous humor samples were collected prospectively. The levels of 20 proinflammatory cytokines were evaluated in the aqueous humor of the APAC and cataract patients using the multiplex bead immunoassay technique. Clinical data were collected for correlation analysis. RESULTS: Seven of the 20 proinflammatory cytokines included in the magnetic bead panel were detectable in both APAC eyes and cataract eyes: interleukin (IL)-10, IL-12, IL-15, IL-21, IL-6, chemokine (C-C motif) ligand 20, and tumor necrosis factor alpha (TNF-α). IL-27 was only detectable in APAC eyes. Compared with the cataract eyes, the APAC eyes had significantly elevated concentrations of IL-12 (P=0.036), IL-15 (P=0.001), IL-6 (P=0.012), and IL-27 (only detectable in APAC eyes). Age was positively correlated with IL-12 (P=0.022) and IL-6 (P=0.037), and time elapsed between APAC onset and aqueous humor samples collection was positively correlated with IL-15 (P=0.037), IL-27 (P=0.040), and TNF-α (P=0.042). CONCLUSION: Several proinflammatory cytokines including IL-12, IL-15, IL-6 and IL-27, were elevated in the APAC eyes and may be implicated in its pathologic mechanism.

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.

Adjunctive with versus without intravitreal bevacizumab injection before Ahmed glaucoma valve implantation in the treatment of neovascular glaucoma.

BACKGROUND: Neovascular glaucoma (NVG) is a refractory disease which is difficult to manage. This study aimed at evaluating the efficacy and safety of adjunctive intravitreal bevacizumab (IVB) injection in conjunction with Ahmed glaucoma valve implantation (AGVI) in the management of NVG. METHODS: This was a retrospective study of patients with NVG in whom AGVI was performed between October 2008 and May 2012. The sample was divided into two groups according to the pretreatment: with adjunctive IVB injection (the IVB group, n = 25 eyes) and without adjunctive IVB injection (the control group, n = 28 eyes). The surgical success rate, number of antiglaucoma medications used, best-corrected visual acuity (BCVA), postoperative complications, regression, and recurrence of iris neovascularization (NVI) were analyzed between the groups. RESULTS: The surgical outcomes of the two groups were compared. The complete success rates in the IVB and control groups were 84.0% and 64.3% at 12 months and 80.0% and 53.6% at 18 months, respectively. There was a significant difference between the two groups (P = 0.041). Mean postoperative intraocular pressures, mean number of postoperative antiglaucoma medications, and BCVA were not significant between the two groups. The NVI in 22 (88.0%) eyes had completely regressed within 2 - 8 days after IVB. However, NVI recurred in 10 eyes (40.0%) 2 - 9 months later after IVB. The IVB group had only 1 case (4.0%) of hyphema out of 25 eyes, while there were 8 (28.6%) cases of hyphema out of 28 eyes in the control group (P = 0.026). CONCLUSIONS: This study showed that preoperative IVB injection reduced NVI remarkably, decreased hyphema, and led to higher surgical success rates. Pre-operative IVB injection may be an effective adjunct to AGVI in the management of NVG.

Neuroprotection in glaucoma: present and future.

OBJECTIVE: To review the updated research on neuroprotection in glaucoma, and summarize the potential agents investigated so far. DATA SOURCES: The data in this review were collected from PubMed and Google Scholar databases published in English up to September 2012, with keywords including glaucoma, neuroprotection, and retinal ganglion cells, both alone and in combination. Publications from the past ten years were selected, but important older articles were not excluded. STUDY SELECTION: Articles about neuroprotection in glaucoma were selected and reviewed, and those that are cited in articles identified by this search strategy and judged relevant to this review were also included. RESULTS: Although lowering the intraocular pressure is the only therapy approved as being effective in the treatment of glaucoma, increasing numbers of studies have discovered various mechanisms of retinal ganglion cells death in the glaucoma and relevant neuroprotective strategies. These strategies target neurotrophic factor deprivation, excitotoxic damage, oxidative stress, mitochondrial dysfunction, inflammation, activation of intrinsic and extrinsic apoptotic signals, ischemia, and protein misfolding. Exploring the mechanism of axonal transport failure, synaptic dysfunction, the glial system in glaucoma, and stem cell used in glaucoma constitute promising research areas of the future. CONCLUSIONS: Neuroprotective strategies continue to be refined, and future deep investment in researching the pathogenesis of glaucoma may provide novel and practical neuroprotection tactics. Establishing a system to assess the effects of neuroprotection treatments may further facilitate this research.

Disorder of blood-aqueous barrier following Ahmed Glaucoma Valve implantation.

BACKGROUND: Ahmed Glaucoma Valve implantation (AGVI) is used to treat refractory glaucoma. Breakdown of the blood-aqueous barrier (BAB) has been noted after some surgical techniques. The current study was designed to assess BAB disruption after AGVI. METHODS: Anterior chamber protein content was measured by the laser flare cell photometry in 22 eyes of 22 patients with refractory glaucoma before AGVI and at each postoperative visit up to 1 month. RESULTS: Before AGVI the mean aqueous flare values in all eyes were (15.17 ± 9.84) photon counts/ms. After AGVI, the values significantly increased at day 1, day 3, and week 1 compared to those before AGVI (all P < 0.05) with a peak at day 3. They returned to pre-operative levels at week 2, and were lower than preoperative level at month 1. Eyes with previous intraocular surgery history had greater aqueous flare values than those without previous intraocular surgery history, but there were no significant differences at all time points postoperatively (all P > 0.05). Furthermore, eyes with shallow anterior chambers had greater aqueous flare values at day 3 and week 1 (all P < 0.05). When comparing eyes with other refractory glaucoma conditions, neovascular glaucoma combined with intravitreal bevacizumab injection resulted in lower aqueous flare values after AGVI, but no significant differences were observed at all time points, postoperatively (all P > 0.05). CONCLUSIONS: The BAB was impaired and inflammation was present in the anterior chamber in refractory glaucomatous eyes following AGVI. However, such conditions were resolved within 1 month postoperatively. Intravitreal bevacizumab treatment in neovascular glaucoma eyes before AGVI may prevent BAB breakdown.

[Bibliometric analysis of current glaucoma research based on Pubmed database].

OBJECTIVE: To survey the distribution pattern and subject domain knowledge of worldwide glaucoma research based on literatures in Pubmed database. METHODS: Literatures on glaucoma published in 2007 to 2011 were identified in Pubmed database. The analytic items of an article include published year, country, language author, and journal. After core mesh terms had been characterized by BICOMS, the co-occurrence matrix was built. Cluster analysis was finished by SPSS 20.0. Then visualized network was drawn using ucinet 6.0. RESULTS: Totally 6427 literatures were included, the number of annual articles changed slightly between 2007 and 2011. The United States, England, Germany, Australia, and France together accounted for 77.63% of articles. There were 52 high-frequency subjects and hot topics were clustered into the following 10 categories: (1) Pathology of optic disc and nerve fibers and OCT application, (2) METHODS: of visual field (VF) and visual function examination, (3) Glaucoma drug medications, (4) Pathology and physiology of primary open angle glaucoma (POAG) including VF and intraocular pressure (IOP), (5) Glaucoma surgery, (6) Gene research related to POAG, (7) Glaucoma disease pathology and animal models, (8) Ocular hypertension (OHT) induced complications and corneal changes, (9) Etiology of congenital glaucoma and complications, (10) Etiology and epidemiology of glaucoma. The visualized domain knowledge mapping was successfully built. The pathology of optic disc and nerve fibers, medications, and surgery were well developed. Study on IOP and visual field was in the core domain, which have an important link to etiology, diagnosis, and therapy. The researches on glaucomatous gene, disease pathology model, congenital glaucoma, etiology and epidemiology were not developed well, which are of great promotion space. CONCLUSIONS: The distribution pattern and subject domain knowledge of worldwide glaucoma research in the recent five years were shown by using bibliometric analysis.Western developed countries play a leading role in the field of glaucoma research, the international influence of related research in China needs to be strengthened.

[Clinical analysis of radiation optic neuropathy].

OBJECTIVE: To investigate the clinical features, risk factors, diagnostic methods, treatment regimens and outcomes of Chinese adult patients with radiation optic neuropathy (RON). METHODS: Retrospective case series. Clinical data with RON admitted to Zhongshan Ophthalmic Center from June 1999 to October 2010 were investigated retrospectively. RESULTS: Thirty-five cases (61 eyes) with RON were analyzed. All cases manifested as sudden binocular or monocular painless vision decrease. In 18 cases (51.4%), symptoms occurred within 36 months after the completion of radiation. In 43 eyes (70.5%), the visual acuity was less than 0.05 and/or with a visual field less than 10 degrees. In 52 eyes which the fundus could be examined, 41 eyes (78.8%) showed a clear boundary of optic papilla, including 6 eyes (14.6%) with normal appearance of optic papilla, 30 eyes (73.2%) with lighter color, 5 eyes (12.2%) with pale optic papilla, and 11 eyes (21.2%) with edematous or hemorrhagic and/or exudative optic papilla. Only 14 eyes showed abnormal visual field examination, mainly manifested as nerve bundle defect scotoma. Seven eyes (50%) manifested as arcuate scotoma, 3 eyes (21.4%) manifested as central scotoma and/or paracentral scotoma, 2 eyes accompanied by blind spot enlargement, 1 eye showed paracentral scotoma and 1 eye with quadrantanopia. Twenty-three eyes received fluorescein angiography (FFA), the major manifestations were low fluorescence at the optic nerve and areas of capillary nonperfusion. Pattern visual evoked potential revealed reduced amplitude and/or extended incubation period in 83.3% eyes. Treatment regimens including systemic corticosteroids, hyperbaric oxygen therapy, hyperbaric oxygen in combination with corticosteroid and laser photocoagulation, the visual acuity of 10 eyes (16.4%) had merely been improved. CONCLUSIONS: The prognosis of visual function in RON is poor resulting from devastating visual loss and/or visual field defect. The main damage of the fundus is retinal vascular occlusion and optic atrophy at different degrees. No adequately effective therapies are proved currently. The treatment aimed on the complication could only provide a short-term improvement of the vision.

Role of PI3K/Akt signaling in the protective effect of magnesium sulfate against ischemia-perfusion injury of small intestine in rats.

BACKGROUND: The protective effects of magnesium sulfate against ischemia-reperfusion injury of the small intestine in Sprague-Dawley (SD) rats have been confirmed in our previous research. However, its exact mechanism is unclear. This study was to evaluate the role of PI3K/Akt signal pathway in the protective effect of magnesium sulfate against ischemia-reperfusion injury of the small intestine in SD rats. METHODS: Rat model of intestinal ischemia-reperfusion injury was used. The SD rats were divided into four groups randomly: sham operation group, ischemia-reperfusion group, magnesium sulfate group and magnesium sulfate plus LY294002 (an inhibitor of PI3K) group. The pathological changes of intestinal mucosa were examined; the activity of diamine oxidase (DAO) in plasma, the plasma contents of malondialdehyde (MDA), and apoptosis rate of the intestinal mucosal cells were determined and compared. The expression of p-Akt was detected by Western blotting. RESULTS: There were more evident pathological changes of the intestinal mucosa (higher Chiu's score, P < 0.05), enhanced DAO activity (P < 0.05), elevated contents of MDA (P < 0.05), higher apoptosis rate (P < 0.05), and lower level of p-Akt (P < 0.05) in the ischemia-reperfusion group compared with the sham operation group. There were less evident pathological changes of the intestinal mucosa (lower Chiu's score, P < 0.05), lower DAO activity (P < 0.05), lower contents of MDA (P < 0.05), and lower apoptosis rate (P < 0.05), but higher level of p-Akt (P < 0.05) in the magnesium sulfate group compared with the ischemia-reperfusion group. There were more evident pathological changes of the intestinal mucosa (higher Chiu's score, P < 0.05), higher contents of MDA (P < 0.05), higher DAO activity (P < 0.05) and higher apoptosis rate (P < 0.05), and lower level of p-Akt (P < 0.05) in the magnesium sulfate plus LY294002 group compared with the magnesium sulfate group. CONCLUSIONS: Activation of PI3K/Akt signal pathway results in the reduction of cell apoptosis, which likely accounts for the protective effect of magnesium sulfate against intestinal ischemia-reperfusion injury.