Influence of argon laser trabeculoplasty on transforming growth factor-beta 2 concentration and bleb scarring following trabeculectomy

BACKGROUND: The purpose of this study was to evaluate the influence of previous argon laser trabeculoplasty (ALT) on transforming growth factor-beta 2 (TGF-beta 2) concentration of the aqueous humor and its influence on bleb scarring after trabeculectomy. METHODS: Fifty-one patients with primary open-angle glaucoma (POAG) and 29 patients with exfoliation (XFS) glaucoma were recruited for this prospective study before undergoing trabeculectomy. Sixty to 200 micro l of aqueous humor were analyzed for total and biologically active TGF-beta 2 concentrations (R and D Systems). TGF-beta 2 levels and a standardized bleb assessment were compared between the ALT- and non-ALT-treated groups. RESULTS: POAG eyes without ALT showed significantly higher total TGF-beta 2 levels (2,317.7+/-1,041.1 pg/ml) than eyes with previous ALT (1,621.6+/-899.6 pg/ml; P=0.026). No significant difference was found for active TGF-beta 2 levels (ALT: 238.1+/-119.0 pg/ml; no ALT: 220.1+/-96.9 pg/ml; P=0.585). In XFS patients ALT did not alter total TGF-beta 2 levels (ALT: 1,524.9+/-624.9 pg/ml, no ALT: 1,220+/-499.1 pg/ml; P=0.20), but active TGF-beta 2 was significantly higher in the ALT-treated (237.0+/-99.7 pg/ml) than in the non-ALT-treated (140.0+/-95.3 pg/ml, P=0.028) group. Bleb grading revealed no statistical difference between the ALT- and non-ALT-treated groups in POAG (P=0.545, Fisher's exact test), whereas XFS patients with ALT were at increased risk for scarring compared to non-ALT-treated patients (P=0.053). CONCLUSIONS: ALT appears to increase the risk of scarring in XFS patients because of increased levels of activated TGF-beta 2.     

Transforming growth factor-β2 levels in aqueous humor of glaucomatous eyes

PURPOSE: To determine whether clinical characteristics are correlated with increased levels of transforming growth factor-beta 2 (TGF-beta 2) in aqueous humor in glaucomatous eyes. METHODS: Aqueous humor samples were collected from 91 glaucomatous eyes. Included were samples from primary open-angle glaucoma (POAG) in 40 eyes, (pseudo)exfoliation syndrome (EXS) in 18 eyes, primary angle-closure glaucoma (PACG) in 26 eyes and uveitis-related secondary glaucoma (SG) in 7 eyes. TGF-beta 2 in aqueous humor was assessed with a specific-capture ELISA. RESULTS: The mean concentration (+/- standard error) of mature (biologically active) TGF-beta 2 in the aqueous humor of eyes with POAG was 293.6 +/- 33.6 pg/ml, significantly higher than that in eyes with PACG, EXS and SG: 147.5 +/- 28.1, 135.8 +/- 30.2 and 41.0 +/- 10.7 pg/ml, respectively (P = 0.0006, P = 0.0010 and P = 0.0003; analysis of variance). The mean concentration (+/- standard error) of total TGF-beta 2 in the aqueous humor of eyes with POAG was 1647.6 +/- 124.5 pg/ml, not significantly different from that in eyes with PACG, EXS and SG: 1482.9 +/- 148.2, 1442.7 +/- 187.8 and 1929.0 +/- 367.6 pg/ml, respectively. A multivariate analysis using logistic regression showed significant correlations between mature TGF-beta 2 concentration and history of cataract surgery (P = 0.0225) and the use of carbonic anhydrase inhibitors (P = 0.0143). CONCLUSIONS: Our results indicate that increased levels of TGF-beta 2 may play an important role in the pathogenesis of POAG.     

Transforming and insulin-like growth factors in the aqueous humour of patients with exfoliation syndrome

BACKGROUND: Growth factors circulating with the aqueous may play an important role in the pathogenesis of exfoliation syndrome (XFS), which is characterized by excessive synthesis and accumulation of abnormal extracellular material. METHODS: We investigated the concentration of three ubiquitous growth factors (TGF-beta1, TGF-beta2 and IGF-1) in the aqueous humour of 50 patients with XFS (27 from Erlangen, 23 from Thessaloniki) and 54 age-matched controls (27 from Erlangen, 27 from Thessaloniki). This study was performed in two centres, independently of each other, using different assay systems. RESULTS: In the aqueous humour samples collected in Erlangen, both the levels of total TGF-beta1 (P<0.001) and mature TGF-beta1 (P<0.05) were significantly increased in XFS patients compared with controls. Specifically, for total TGF-beta1 patients with XFS exhibited higher a mean value (90.5 +/- 37.4 pg/ml) than controls (30.2 +/- 8.3 pg/ml). The mean level of mature TGF-beta1 was also higher in XFS (14.2 +/- 2.8 pg/ml) than in controls (4.9 +/- 5.5 pg/ml). No difference was found between XFS and controls in the levels of total or mature TGF beta2 in the aqueous or in the level of these two growth factors in the serum. In aqueous humour samples collected in Thessaloniki a significant difference between XFS and controls was also observed for mature TGF-beta1 (XFS 17.06 +/- 11.02 pg/ml vs controls 9.01 +/- 5.69 pg/ml; P=0.006). No difference was observed in TGF-beta2 concentration or IGF-1 concentration in the aqueous. No correlation could be established between protein concentration and the levels of the three growth factors measured. A significant correlation was found between age and protein concentration in XFS, but not in the controls. CONCLUSION: Since TGF-beta1 induces the synthesis and accumulation of extracellular matrix, it is hypothesized that TGF-beta1 plays an important role in the pathogenesis of XFS. Our data suggest that the increased levels of TGF-beta1 are most likely due to enhanced local synthesis.     

Latanoprost therapy reduces the levels of TGF beta 1 and gelatinases in the aqueous humour of patients with exfoliative glaucoma

The aim of the present study was to evaluate the effect of latanoprost monotherapy on the aqueous humour concentrations of TGF-beta1, MMP-2, TIMP-2, MMP-9 and gelatinolytic activity in patients treated for exfoliative glaucoma (XFG). Aqueous samples from 50 XFG patients treated with latanoprost and 50 age-matched XFG patients treated with timolol were collected during phacoemulsification cataract surgery. The concentrations of TGF-beta1, MMP-2, TIMP-2, MMP-9 and gelatinase activity were determined by commercial immunoassays. The mean active TGF-beta1 concentration in the aqueous was significantly lower in XFG patients treated with latanoprost compared with those treated with timolol (3.1 +/- 0.65 vs 13.4 +/- 1.5 pg ml(-1)); (P = 0.0014). The mean total MMP-2 concentration was lower in latanoprost treated patients (31.75 +/- 3.8 vs 81.5 +/- 7.2 ng ml(-1)); (P < 0.0001). The TIMP-2 concentration was also lower in XFG-latanoprost treated patients (73.8 +/- 6.81 vs 101.28 +/- 7.29 ng ml(-1)); (P = 0.0096). Latanoprost monotherapy has a marked effect on the aqueous concentration of TGF-beta1, MMP-2 and TIMP-2 in XFG patients. A better understanding of its effect on the pathobiology of the disease may lead to its earlier use in the disease process to prevent progression from XFS to XFG.     

Serum methanol levels in subjects with or without optic nerve head disease

We evaluated serum methanol levels in subjects with or without optic nerve head disease. Serum methanol levels were determined using gas chromatography in 71 patients with optic nerve head disease and in 127 subjects without optic nerve head disease. Their ages ranged from 17 to 89 years. Serum methanol levels in 127 subjects without optic nerve head disease ranged from 0.12 to 3.86 microg/ml (mean +/- standard deviation, 1.72 +/- 0.86 microg/ml). In the subjects without optic nerve head disease, the differences in the levels between those with cataract versus retinal detachment, men versus women, and between each age-group (50-80 years) were not significant. The methanol levels in patients with optic neuritis (n = 2), Wolfram syndrome (n = 1), Leber hereditary optic neuropathy at the late stage (n = 2), retinitis pigmentosa (n = 23), and primary open-angle glaucoma (n = 16) were less than 3.86 microg/ml. Methanol levels in 1 patient with Leber hereditary optic neuropathy at the acute stage was 5.28 microg/ml. Of 10 patients with primary angle-closure glaucoma, 1 had a slightly elevated level and 9 had levels less than 3.86 microg/ml. Of 17 patients with normal tension glaucoma, 5 had methanol levels higher than 3.86 microg/ml, and 12 patients had levels less than 3.86 microg/ml. The present study shows that serum methanol levels in subjects without optic nerve head disease ranged from 0.12 to 3.86 microg/ml and were much lower than the levels that produce acute ocular symptoms of methanol intoxication. It is possible that high serum methanol levels may play a part in the acute stage of Leber hereditary optic neuropathy and normal tension glaucoma in certain patients. It is unlikely that increased serum methanol levels participate in primary angle-closure glaucoma.     

一氧化氮与青光眼患者眼压升高关系的研究

目的探讨一氧化氮(nitricoxide,NO)在青光眼患者眼压升高中的作用.方法对急性闭角型青光眼患者16例,老年性白内障患者29例,正常志愿者30例,应用高效液相色谱分析仪检测其血浆和房水中NO的含量,并以NO2和NO3之和表示.结果正常对照组血浆中NO的平均含量为(2969.37±862.85)ng/L;青光眼组血浆中NO的平均含量为(1390.78±302.95)ng/L,较对照组明显降低(t=2.853,P<0.01);白内障组血浆中NO的平均含量为(4234.89±1495.23)ng/L,较对照组明显升高.对照组房水中NO平均含量为(1405.83±602.70)ng/L;青光眼组房水中NO的平均含量为(2052.03±694.74)ng/L,与对照组比较差异无显著性(t=1.862,P＞0.05);白内障组房水中NO的平均含量为(2454.67±655.13)ng/L,较对照组明显升高.房水/血浆NO含量比值对照组为47.3%,白内障组为58.0%,二者的比值差异无显著性;而青光眼组为144.0%.结论血浆、房水中NO含量与急性闭角型青光眼眼压升高有关.     

Prooxidant–antioxidant balance, peroxide and catalase activity in the aqueous humour and serum of patients with exfoliation syndrome or exfoliative glaucoma

BACKGROUND: Oxidative stress plays an important role in the pathobiology of exfoliation syndrome (XFS) and exfoliative glaucoma (XFG). METHODS: We investigated the prooxidant-antioxidant balance (PAB) in aqueous humour and serum samples of 20 consecutive cases of XFS, 20 of XFG, and 20 age-matched controls, employing a recently described novel assay. The activity of catalase and the levels of (hydrogen) peroxide were also measured in these samples. RESULTS: There was no significant difference between the PAB in the aqueous humour of the XFS group (82.5 +/- 10 AU) and age-matched control patients (78.9 +/- 13.4 AU; p > 0.05). A significant shift of the PAB balance in favour of oxidants was detected in the XFG group (90.2 +/- 7.6 AU) compared with controls (p < 0.001). In the serum of patients with XFS (138.8 +/- 13.2 AU) and XFG (124.08 +/- 13.50 AU), PAB was significantly altered in favour of oxidants as compared to age-matched controls (114.9 +/- 9.91 AU); p < 0.001). Catalase activity in the aqueous from XFS (10.1 +/- 4.5 U/ml) and XFG (12.2 +/- 6 U/ml) patients was significantly lower than that measured in the normal aqueous (14.6 +/- 1.9 U/ml). Similarly, a significantly lower catalase activity was found in XFS (103 +/- 21.4 U/ml) and XFG (116 +/- 38 U/ml) serum samples compared with controls (189.6 +/- 84.3 U/ml). Finally, (hydrogen) peroxide concentration in aqueous and serum samples from patients with XFS (aqueous: 26.9 +/- 6.6 muM; serum: 41 +/- 10 muM) and XFG (aqueous: 21.7 +/- 7 muM; serum: 32 +/- 4 muM) were significantly higher than that of the controls (aqueous: 9.6 +/- 5.8 muM; serum: 24 +/- 9 muM; p < 0.001). CONCLUSIONS: These findings suggest that in XFS oxidative stress is counterbalanced in the aqueous, whereas the development of XFG is accompanied by a disruption of this balance in favour of oxidants.     

Effect of cytokines on regulation of the production of transforming growth factor beta-1 in cultured human Tenon's capsule fibroblasts

PURPOSE: Transforming growth factor-beta1 (TGF-beta1) is thought to play a pivotal role in the regulation of the wound healing process after glaucoma filtering surgery. The aim of the present study was to investigate whether platelet-derived growth factor isoforms (PDGF-AA, PDGF-BB), basic fibroblast growth factor (bFGF), epidermal growth factor (EGF), interleukin-1beta (IL-1beta) and transforming growth factor-beta1 (TGF-beta1) modulate the production of latent and/or active TGF-beta1 by cultured human Tenon's capsule fibroblasts (HTF). METHODS: Human Tenon's capsule fibroblasts were seeded at two different densities (30 cells/mm2 and 150 cells/mm2) and stimulated for five days with PDGF-AA, PDGF-BB, bFGF, EGF, IL-1beta and TGF-beta1. Control cells were treated with serum-free medium (WM/F12). The concentrations of latent and active TGF-beta1 in the medium were determined using an immunoassay before and after activation of TGF-beta1 by transient acidification. RESULTS: The concentration of latent TGF-beta1 in conditioned media from HTF seeded at high density (150 cells/mm2) significantly increased after stimulation with 5 ng/ml TGF-beta1 (151.5 +/-41.7 pg/ml) or 10 ng/ml IL-1beta (45.7+/-8.1 pg/ml). The concentration of active TGF-beta1 in conditioned media also significantly increased after stimulation of HTF with 5 ng/ml TGF-beta1 (48.4+/-27.5 pg/ml). CONCLUSIONS: The present results indicate that TGF-beta1 is the most potent inducer of its own synthesis in HTF. Activation of an autocrine TGF-beta1 loop may play a role in the wound healing response after glaucoma filtering surgery.     

Higher concentration of transforming growth factor-beta in aqueous humor of glaucomatous eyes and diabetic eyes

PURPOSE: Diabetic retinopathy and glaucoma are the primary causes of acquired blindness. Cytokines including transforming growth factor (TGF)-beta may be involved in these diseases. We therefore collected aqueous humor samples from patients with glaucoma and/or diabetes who were undergoing surgery, and determined the concentration of TGF-beta. METHODS: Aqueous humor samples were collected from 80 patients (84 eyes), including 19 eyes with primary open-angle glaucoma (POAG), 22 eyes with diabetes, and 18 eyes with diabetes complicated with POAG. Twenty-five eyes with cataract served as controls. The concentration of TGF-beta1 or TGF-beta2 was measured by enzyme-linked immunosorbent assay. RESULTS: The concentration of TGF-beta1 was less than 0.1 pg/mL in all of the groups. In contrast to controls who had 1001.4 +/- 444.1 pg/mL, the concentration of total TGF-beta2 in the diabetes group was 1715.6 +/- 882.1 pg/mL, and that in the diabetes complicated with POAG group was 1692.9 +/- 361.9 pg/mL. These were significantly higher than that in controls. In contrast to the controls who had 321.2 +/- 197.9 pg/mL, the concentration of mature TGF-beta2 with POAG was 822.5 +/- 484.4 pg/mL, and that of diabetes complicated with POAG was 1058.9 +/- 648.4 pg/mL. These were significantly higher than that in the controls. The eyes with diabetes complicated with POAG also had a significantly higher concentration than the eyes with diabetes alone. CONCLUSION: Total TGF-beta2 and mature TGF-beta2 in high concentration may correlate with progression of POAG, diabetes, and diabetes complicated with POAG.     

Transforming growth factor-beta levels in human aqueous humor of glaucomatous, diabetic and uveitic eyes

PURPOSE: Transforming growth factor-beta2 is known to be present at elevated levels in the aqueous humor of patients with primary open angle glaucoma (POAG) and diabetes but not in uveitis-related secondary glaucoma. We investigated total TGF-beta2 levels and levels of the active form of TGF-beta2 in the aqueous humor of eyes with different types of glaucoma. METHODS: The concentration of the total and active form of TGF-beta2 was measured in 63 patients with primary open angle glaucoma, neovascular glaucoma complicated with diabetes (NVG), and secondary open angle glaucoma complicated with uveitis (SOAG) using a double antibody 'sandwich-indirect' ELISA method. RESULTS: The levels of total TGF-beta2 in the aqueous samples of POAG, NVG, and SOAG were elevated. The levels of active TGF-beta2 in the aqueous samples of POAG, and NVG were also elevated, whereas the level of active TGF-beta2 was within the normal range in the aqueous samples of SOAG. CONCLUSIONS: These results suggest that the level of TGF-beta2 may play a role in the pathology of various types of glaucoma.