Potential effects of angiogenesis-related factors on the severity of APAC and surgical outcomes of trabeculectomy.

BACKGROUND: EPO (erythropoietin) and PDGF (platelet derived growth factor) families are thought to be associated with angiogenesis under hypoxic condition. The sharp rise of intraocular pressure in acute primary angle closure (APAC) results in an inefficient supply of oxygen and nutrients. We aimed to measure the expression of EPO and PDGF family members in APAC eyes and demonstrate their associations with APAC's surgical success rate. METHODS: Concentrations of EPO, PDGF-AA, -BB, -CC and -DD collected in aqueous humor samples of 55 patients recruited were measured. Before operations, correlations between target proteins and IOP (intraocular pressure) were detected between APAC (acute primary angle closure) and cataract patients. Based on the post-operative follow-up, the effects of EPO and PDGF family members on the successful rate of trabeculectomy were tested. RESULTS: The levels of EPO, PDGF-CC and -DD were significantly elevated in the APAC group compared to the cataract group. During the post-operative follow-up, EPO, PDGF-CC and -DD showed significant differences between the success and failure groups. In multivariable linear regression analyses, failed filtration surgery was more likely in APAC eyes with higher EPO level. The Kaplan-Meier survival plot suggested that the success rate in eyes with low EPO level was significantly higher than that in eyes with high EPO level. CONCLUSION: The levels of EPO, PDGF-CC and -DD were significantly elevated in failure group. EPO level correlated with preoperative IOP and numbers of eyedrops, and higher EPO level in aqueous humor is a risk factor for trabeculectomy failure. It can be a biomarker to estimate the severity of APAC and the success rate of surgery. The investigation of mechanism of EPO in APAC a may have potential clinical applications for the surgical treatment of APAC.

Ex-PRESS implantation versus trabeculectomy in Chinese patients with POAG: fellow eye pilot study.

AIM: To compare the outcomes of Ex-PRESS implantation in one eye versus trabeculectomy with mitomycin C in the fellow eye in Chinese patients with primary open-angle glaucoma (POAG). METHODS: This was a prospective, non-randomized comparative study. Forty-eight eyes of 24 patients with bilateral POAG necessitating surgery were included and underwent Ex-PRESS implantation under the scleral flap in one eye and trabeculectomy in the other eye according to patients' choice. Primary outcome measures included mean intraocular pressure (IOP) and success rate. Secondary outcome measures were aqueous flare, postoperative medication use, visual acuity, and incidence of complications. RESULTS: All 24 patients finished a 1-year follow-up. Both groups maintained significant reductions in IOP after surgery throughout the follow-up period. At any point in time, the IOP of the two groups did not differ significantly. The Kaplan-Meier survival curve analysis showed no significant differences in success between the two groups (P=0.289). The mean number of anti-glaucoma medicines and visual acuity in both groups were not significantly different. Eyes with Ex-PRESS implantation had lower aqueous flare values on days 1 and 3 (both P<0.05). Instances of early postoperative hypotony and choroidal effusion were significantly fewer in frequency after Ex-PRESS implantation under the scleral flap compared with those after trabeculectomy (P<0.001). CONCLUSION: Ex-PRESS is comparable to trabeculectomy in terms of IOP, success rate, number of glaucoma medications used, and visual acuity. However, Ex-PRESS resulted in fewer cases of inflammation and a lower rate of complications.

Short-term effect of intravitreal ranibizumab on intraocular concentrations of vascular endothelial growth factor-A and pigment epithelium-derived factor in neovascular glaucoma.

BACKGROUND: This study aims to evaluate concentrations of pigment epithelium-derived factor (PEDF) and vascular endothelial growth factor (VEGF)-A in aqueous of patients with neovascular glaucoma prior to, and shortly after, an intravitreal ranibizumab injection. DESIGN: Interventional comparative study. PARTICIPANTS: The study included patients undergoing an intravitreal ranibizumab injection about one week before anti-glaucomatous surgery (study group) or who underwent routine cataract surgery (control group). METHODS: Aqueous and blood samples were collected at the occasions of intravitreal injections, anti-glaucomatous surgery or cataract surgery. They were analysed by enzyme-linked immunosorbent assay. MAIN OUTCOME MEASURES: Concentrations of PEDF and VEGF-A in aqueous. RESULTS: At baseline, concentrations VEGF-A (3698 ± 2105 pg/mL vs. 233 ± 98 pg/mL) and PEDF (18.9 ± 11.9 ug/mL vs. 2.2 ± 0.6 ug/mL) were higher (P < 0.001) in the study group (n = 20 patients) than control group (n = 20 patients). The VEGF-A/PEDF concentration ratio was higher in the study group (396 ± 554 vs. 110 ± 49; P = 0.02). One week after the ranibizumab injection, iris neovascularization had completely regressed in 17 (85%) eyes, and VEGF-A concentration decreased significantly (P < 0.001) to 184 ± 130 pg/mL. The PEDF concentration remained unchanged (19 ± 12 ug/mL). The VEGF-A/PEDF concentration ratio decreased to 13.2 ± 13.6. Plasma concentrations of VEGF-A and PEDF did not differ significantly between both groups (P = 0.65 and P = 0.15, respectively) nor were they significantly correlated with the aqueous concentrations (all P > 0.15). CONCLUSIONS: Aqueous concentrations of VEGF-A and PEDF were significantly elevated in eyes with neovascular glaucoma. Within one week after intravitreal injection of ranibizumab, VEGF-A concentration decreased to subnormal levels, while the PEDF concentration remained unchanged and the VEGF-A/PEDF ratio decreased.

[A comparison study of glaucoma drainage implant with three different of tube coverages].

OBJECTIVE: To evaluate the efficacy and complication of glaucoma drainage implant surgery with scleral graft, scleral flap and artificial biological dural graft as the tube coverage. METHODS: Thirty-five cases (35 eyes) with refractory glaucoma who underwent FP-7 Ahmed glaucoma drainage implantation from January 2009 to June 2011 were retrospectively studied. Kaplan-Meier survival curve was applied to analyze the probability of success rate of three different tube coverage, the log-rank test used to compare the difference between tubes, and Cox proportional hazards regression analysis performed to predict the risk factors for failure. RESULTS: Conjunctival shrink back leading to exposure of tube coverage occurred in 6 eyes in artificial biological dural graft group. Intraocular pressure (IOP) elevation by encapsulated cystic blebs around the plate was seen in scleral flap group (2 eyes) and scleral graft group (1 eyes), respectively. The drainage tube exposure occurred in 1 eye in scleral graft group. Kaplan-Meier survival curve analysis showed that the success rate was 8/10, 3/9 and 14/16 in scleral graft group, artificial biological dural graft group and scleral flap group, respectively, at 12 month and 15 month. There was a significant difference among three groups (P = 0.009). The proportional hazards regression showed that artificial biological dural graft was statistically significant risk factors for failure (HR = 10.844, P = 0.015). Compared with pre-operation, the post-operative mean IOP was significantly decreased in all three groups. Postoperative IOP was not significantly different among three groups in different follow-up time point (F = 0.028 - 1.218, P > 0.05). CONCLUSIONS: Both of scleral flap group and scleral graft group are comparable in the efficacy and complication of glaucoma drainage implant surgery and have a high success rate. However, artificial biological dural graft has poor compatibility with conjunctiva resulting in severe complications, which is not recommended to be used in glaucoma drainage implant surgery.

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.

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.