Soluble and membrane-bound adenylate kinase and nucleotidases augment ATP-mediated inflammation in diabetic retinopathy eyes with vitreous hemorrhage.

ATP and adenosine are important signaling molecules involved in vascular remodeling, retinal function, and neurovascular coupling in the eye. Current knowledge on enzymatic pathways governing the duration and magnitude of ocular purinergic signaling is incompletely understood. By employing sensitive analytical assays, this study dissected ocular purine homeostasis as a complex and coordinated network. Along with previously characterized ecto-5'-nucleotidase/CD73 and adenylate kinase activities, other enzymes have been identified in vitreous fluids, including nucleoside triphosphate diphosphohydrolase (NTPDase), adenosine deaminase, and alkaline phosphatase. Strikingly, activities of soluble adenylate kinase, adenosine deaminase, ecto-5'-nucleotidase/CD73, and alkaline phosphatase, as well as intravitreal concentrations of ATP and ADP, were concurrently upregulated in patients suffering from diabetic retinopathy (DR) with non-clearing vitreous hemorrhage (VH), when compared to DR eyes without VH and control eyes operated due to macular hole or pucker. Additional histochemical analysis revealed selective distribution of key ecto-nucleotidases (NTPDase1/CD39, NTPDase2, ecto-5'-nucleotidase/CD73, and alkaline phosphatase) in the human sensory neuroretina and optic nerve head, and also in pathological neofibrovascular tissues surgically excised from patients with advanced proliferative DR. Collectively, these data provide evidence for specific hemorrhage-related shifts in purine homeostasis in DR eyes from the generation of anti-inflammatory adenosine towards a pro-inflammatory and pro-angiogenic ATP-regenerating phenotype. In the future, identifying the exact mechanisms by which a broad spectrum of soluble and membrane-bound enzymes coordinately regulates ocular purine levels and the further translation of purine-converting enzymes as potential therapeutic targets in the treatment of proliferative DR and other vitreoretinal diseases will be an area of intense interest. KEY MESSAGES: NTPDase, alkaline phosphatase, and adenosine deaminase circulate in human vitreous. Purinergic enzymes are up-regulated in diabetic eyes with vitreous hemorrhage. Soluble adenylate kinase maintains high ATP levels in diabetic retinopathy eyes. Ecto-nucleotidases are co-expressed in the human retina and optic nerve head. Alkaline phosphatase is expressed on neovascular tissues excised from diabetic eyes.

PERSISTENT OVERPRODUCTION OF INTRAOCULAR VASCULAR ENDOTHELIAL GROWTH FACTOR AS A CAUSE OF LATE VITREOUS HEMORRHAGE AFTER VITRECTOMY FOR PROLIFERATIVE DIABETIC RETINOPATHY.

PURPOSE: The purpose of this study was to investigate whether vitreous levels of vascular endothelial growth factor (VEGF) predict late vitreous hemorrhage (VH) after vitrectomy for proliferative diabetic retinopathy, and how VEGF level changes in patients with postoperative late VH. METHODS: Eighty-five eyes of 68 patients with proliferative diabetic retinopathy who underwent vitrectomy were analyzed retrospectively. Vitreous samples were collected from eyes undergoing primary vitrectomy and from eyes with late VH undergoing second vitrectomy. Vitreous VEGF levels were measured using enzyme-linked immunosorbent assay. The relationship between VEGF level and late VH (>4 weeks) occurring during follow-up as well as clinical findings, and changes in VEGF level in eyes with late VH undergoing second vitrectomy were analyzed. RESULTS: Late VH occurred in 20 (24%) of 85 eyes, and 9 eyes required second vitrectomy. Vitreous levels of VEGF were significantly higher (median: 1,945 pg/mL; P < 0.0001) in eyes with late VH than in those without. Preexisting iris neovascularization (P < 0.0001), hypertension (P = 0.002), and proteinuria (P = 0.040) were also significant risk factors of late VH. Multivariate logistic regression analysis showed that a higher vitreous VEGF level was independently associated with a risk of postoperative late VH in patients with proliferative diabetic retinopathy (odds ratio: 20.8, 95% confidence interval: 2.72-159.47; P = 0.003). Vitreous VEGF level at second vitrectomy in patients with late VH was significantly lower compared with that at primary vitrectomy, but remained elevated (median: 1,610 pg/mL; P = 0.023). CONCLUSION: In patients with proliferative diabetic retinopathy, high intraocular VEGF level at primary vitrectomy was identified as an independent risk factor of postoperative late VH. Persistent overproduction of intraocular VEGF may be associated with postoperative late VH.

The kinetics of VEGF and MCP-1 in the second vitrectomy cases with proliferative diabetic retinopathy.

PurposeTo determine whether the concentrations of vascular endothelial growth factor (VEGF) and monocyte chemoattractant protein (MCP)-1 in the vitreous changed after vitrectomy in patients with proliferative diabetic retinopathy (PDR).ParticipantsTwenty-one eyes of 21 patients who needed a second surgery for PDR were included. The reasons for the second surgery were tractional retinal detachment (TRD), neovascular glaucoma, persistent vitreous hemorrhage, macular pucker, and secondary intraocular lens (IOL) implant.MethodsWe measured the VEGF and MCP-1 levels using sandwich enzyme-linked immunosorbent assays in vitreous samples collected from patients with PDR before pars plana vitrectomy (without IOL implantation), and from the same patients during the second surgery.ResultsThere was not significant change in mean VEGF concentrations when comparing first (0.81±0.88 ng/ml) and second surgeries (1.09±1.51 ng/ml). The MCP-1 level was significantly elevated at the time of second surgery (2.20±2.21 ng/ml) compared with the first vitrectomy (0.72±0.57 ng/ml). The MCP-1 levels of the second surgery cases with TRD (3.18±2.27 ng/ml) increased significantly compared with those with other complications (1.72±2.10 ng/ml).ConclusionsAt the second vitrectomy, VEGF did not change significantly in the vitreous of the patients examined. The MCP-1 concentration was markedly elevated at the second vitrectomy, implying an association between the prolonged inflammation after vitrectomy and complications, especially TRD.

Anillo de Malyugin para miosis intraoperatoria en femtofacovitrectomía / Malyugin ring for intraoperative miosis in femtosecond laser phacovitrectomy

OBJETIVO: Evaluar la utilidad del anillo de Malyugin transoperatorio en escasa dilatación pupilar durante facoemulsificación asistida con láser de Fs combinado con vitrectomía pars plana 23 G (femtofacovitrectomía). MÉTODO: Se presenta una mujer de 57 años con catarata y hemorragia vítrea, dilatación pupilar de 5,5 mm. Se realiza facoemulsificación asistida con láser de femtosegundo, colocando anillo de Malyugin posterior a extracción de cápsula anterior, seguido de vitrectomía pars plana y retirándolo al final. RESULTADOS: Se logró una dilatación pupilar transoperatoria adecuada, sin complicaciones, con una agudeza visual posoperatoria de 20/40. CONCLUSIONES: El uso del anillo de Malyugin puede ser una alternativa útil en casos con escasa dilatación pupilar en femtofacovitrectomía, conservando la integridad anatómica-funcional pupilar

OBJECTIVE: To evaluate the usefulness of the Malyugin ring in poor pupil dilation during phacoemulsification assisted with femtosecond laser with 23 gauge pars plana vitrectomy. METHOD: A 57-year-old female with cataract and vitreous hemorrhage, and poor pupil dilation (5.5 mm). The phacoemulsification assisted with femtosecond laser, using Malyugin ring after capsulorrhexis, followed by pars plana vitrectomy, and removing at the end without complications. RESULTS: A successfull intraoperative pupil dilation was achieved without complications, with a final BCVA of 20/40. CONCLUSIONS: The Malyugin ring is an effective alternative in cases with poor pupil dilation in femtophacovitrectomy, preserving the anatomical and functional integrity

Intraocular VEGF level as a risk factor for postoperative complications after vitrectomy for proliferative diabetic retinopathy.

PURPOSE: To investigate whether vitreous and aqueous humor concentrations of vascular endothelial growth factor (VEGF) predict postoperative complications after vitrectomy for proliferative diabetic retinopathy (PDR). METHODS: Sixty eyes of 52 patients with PDR who underwent vitrectomy were enrolled. Vitreous and aqueous humor were obtained from eyes with PDR during primary vitrectomy and the levels of VEGF were measured using a commercial flow cytometer. Patients were followed for more than 6 months after surgery. Demographic data and both intraoperative and postoperative findings were recorded. The relationship between VEGF levels in ocular fluids and the main postoperative complications of early vitreous hemorrhage (VH) and neovascular glaucoma (NVG) occurring during follow-up was analyzed. Logistic regression analyses were performed to examine risk factors related to postoperative complications. RESULTS: Early VH occurred in 25%, and NVG occurred in 8% of 60 eyes. The vitreous levels of VEGF were significantly higher (P = 0.015) in eyes with early VH than in those without. The aqueous humor and vitreous levels of VEGF were significantly higher (P = 0.005 and P = 0.001, respectively) in eyes with NVG than in those without. Axial length was significantly shorter in eyes with early VH than in those without (P = 0.028). Multivariate logistic regression analysis showed that the higher vitreous VEGF level was associated with a risk of early VH after vitrectomy for PDR (odds ratio, 5.1; P = 0.020). CONCLUSIONS: High intraocular VEGF level at the time of primary vitrectomy in patients with PDR was identified as a significant risk factor for postoperative early VH.

Vitreous vascular endothelial growth factor concentrations in proliferative diabetic retinopathy versus proliferative vitreoretinopathy.

PURPOSE: To assess vitreous vascular endothelial growth factor (VEGF) concentrations in proliferative diabetic retinopathy (PDR) in comparison to proliferative vitreoretinopathy (PVR). PATIENTS AND METHODS: Vitreous samples were collected from 69 eyes of 69 patients with traumatic lens dislocation (n = 10), grade B PVR with rhegmatogenous retinal detachment (n = 13), grade C PVR with rhegmatogenous retinal detachment (n = 14), PDR with vitreous hemorrhage (n = 18), and PDR with vitreous hemorrhage and tractional retinal detachment (n = 14). Vitreous fluid samples were obtained at vitrectomy, and the levels of VEGF were measured by enzyme-linked immunosorbent assay. RESULTS: The mean vitreous level of VEGF was 15.14 ± 5.22 pg/ml in eyes with grade B PVR, 99.15 ± 38.58 pg/ml in eyes with grade C PVR, 4,534.01 ± 1,193.28 pg/ml in eyes with vitreous hemorrhage secondary to PDR, 5,157.29 ± 969.44 pg/ml in eyes with vitreous hemorrhage and tractional retinal detachment secondary to PDR, and 16.19 ± 5.76 pg/ml in eyes of the control group with traumatic lens dislocation. Vitreous VEGF concentrations were significantly higher in the patients with grade C PVR, PDR with vitreous hemorrhage and PDR with vitreous hemorrhage and tractional retinal detachment in comparison to the control patients (p < 0.05). A significant alteration was not observed in patients with grade B PVR (p = 0.55). CONCLUSIONS: Vitreous VEGF concentrations are increased in PDR and grade C PVR. The high VEGF concentrations could suggest a possible effect of VEGF on advanced PVR.

Intravitreous VEGF-A in eyes with massive vitreous hemorrhage.

PURPOSE/BACKGROUND: Although vascular endothelial growth factor (VEGF) is abundant in serum, the intraocular concentration of VEGF in eyes with massive vitreous hemorrhage (VH) is not well-known. The present study was conducted to elucidate the effects of a massive VH on intravitreous VEGF concentration. METHODS: Vitreous samples were obtained during vitrectomy: 12 samples from eyes with epiretinal membrane without diabetic retinopathy (DR), and nine samples from massive VH with no DR, such as age-related macular degeneration, rhegmatogenous VH, Terson's syndrome and macro-aneurysm rupture. Twelve samples were obtained from proliferative DR. VEGF was measured with an enzyme-linked immunosorbent assay (ELISA). Samples incubated with or without heparin were also examined for the release of VEGF binding to the vitreous body. The localization of VEGF and type II collagen in the vitreous was evaluated from immunohistochemistry. RESULTS: The concentration of VEGF was significantly higher in eyes with proliferative DR (821 ± 949 pg/ml) than in non-DR with massive VH (2.75 ± 7.5 pg/ml, P < 0.01, chi-square test) or non-DR with no VH (less than detectable level, P < 0.01, chi-square test) There was no statistically significant difference between eyes with massive VH and non-diabetic eyes without VH. Treatment with heparin did not significantly affect the concentration of vitreous VEGF. VEGF was localized mainly in the clot from the results of an immunohistochemical analysis. CONCLUSIONS: Even with a massive VH, diffusible VEGF does not increase significantly in the liquid phase and is principally present in a clot. VH alone should not be an indication for vitrectomy from the point of view of VEGF-related pathology.

Serum interferon-gamma/interleukin-4 imbalance in patients with Eales' disease.

BACKGROUND: Eales' disease (ED) is an idiopathic obliterative vasculopathy that usually affects the peripheral retina of young adults. The aim of this study is to investigate Th1/Th2 serum cytokine profiling in patients with ED. METHODS: This study included 30 male patients with ED and 10 healthy controls. The ED patients were divided into two subgroups: the vitreous haemorrhage (VH) group (n = 18) and non-vitreous haemorrhage (NVH) group (n = 12). Sixteen patients (six from the VH group and 10 from the NVH group) received glucocorticoid treatment for three months and were followed for six months. Levels of six cytokines including interferon-gamma (IFN-gamma), tumour necrosis factor-alpha (TNF-alpha) and four interleukins (IL-2, IL-4, IL-5 and IL-10) in the serum samples were determined by Luminex assays. RESULTS: Compared to controls, ED patients showed significantly higher levels of IL-10 and TNF-alpha, increased IFN-gamma/IL-4 (Th1/Th2) ratio, and lower levels of IL-4 (p < 0.05). Glucocorticoid treatment caused a restoration in the cytokine levels and the IFN-gamma/IL-4 ratio. Multivariate analysis revealed that reduced IL-4 (less than 4 pg/ml) and elevated IL-10 (greater than 4 pg/ml) levels were independent predictors of ED with odds ratios of 0.024 (95% CI, 0.002-0.255; p = 0.002) and 12.108 (95% CI, 1.045-140.233; p = 0.046), respectively. CONCLUSION: The findings demonstrate for the first time that there is an imbalance of Th1/Th2 cytokines in ED patients, which can be reversed by glucocorticoid treatment. Additionally, both IL-4 and IL-10 might represent potential diagnostic markers for the disease.

Intra-ocular expression of vascular endothelial growth factor (VEGF) and pigment epithelial-derived factor (PEDF) in a case of Eales' disease by immunohistochemical analysis: a case report.

We report a immunohistochemical study of expression of VEGF and PEDF in Eales' disease. An enucleated eye from a patient with Eales' disease and an age and sex-matched donor eyeball were subjected to immunohistochemical and histopathological analysis to study the expression of VEGF and PEDF in the retinal region. Strong positive anti-VEGF immunostaining was found around the vessel walls in the retina in the eyeball from the Eales' disease patient compared with the donor control, from which it was almost absent. PEDF staining was detected in the normal donor eyeball retinal layers surrounding the blood vessels, and the photoreceptor and ganglion cell layer, whereas in the eyeball from Eales' disease patient PEDF staining was restricted to the surrounding blood vessels. The strong expression of VEGF in eyes with Eales' disease as opposed to weak expression of PEDF indicates the propensity of the disease to show neovascularization and recurrent hemorrhages.

Detection of elevated signaling amino acids in human diabetic vitreous by rapid capillary electrophoresis.

Elevated glutamate is implicated in the pathology of PDR. The ability to rapidly assess the glutamate and amino acid content of vitreous provides a more complete picture of the chemical changes occurring at the diabetic retina and may lead to a better understanding of the pathology of PDR. Vitreous humor was collected following vitrectomies of patients with PDR and control conditions of macular hole or epiretinal membrane. A capillary electrophoresis method was developed to quantify glutamate and arginine. The analysis is relatively fast (<6 minutes) and utilizes a poly(ethylene)oxide and sodium dodecylsulfate run buffer. Both amino acid levels show significant increases in PDR patients versus controls and are comparable to other reports. The levels of vitreal glutamate vary inversely with the degree of observed hemorrhage. The results demonstrate a rapid method for assessment of a number of amino acids to characterize the chemical changes at the diabetic retina to better understand tissue changes and potentially identify new treatments.

Risk evaluation of outcome of vitreous surgery based on vitreous levels of cytokines.

AIM: To ascertain whether vitreous and plasma levels of vascular endothelial growth factor (VEGF), interleukin-6 (IL-6) and fundus findings could predict the outcome of vitreous surgery in patients with proliferative diabetic retinopathy (PDR). METHODS: Vitreous fluid samples were obtained during vitreoretinal surgery from 73 consecutive eyes with PDR. The levels of VEGF and IL-6 in vitreous fluid and plasma were determined by enzyme-linked immunosorbent assay. Patients were prospectively followed for 6 months and the postoperative outcome was analysed by logistic regression analysis. RESULTS: No improvement and/or progression of PDR occurred in 23 (32%) of the 73 eyes (progression group). The vitreous levels of VEGF and IL-6 were significantly higher in eyes from the progression group than in eyes with regression of PDR (regression group) (P=0.0032 and 0.0088, respectively). Multivariate logistic regression analysis showed that higher vitreous levels of VEGF were associated with the progression of PDR after vitreous surgery (odds ratio 2.72, P=0.0003). CONCLUSIONS: High vitreous levels of VEGF identified as a significant risk factor for the outcome of vitreous surgery in patients with PDR. A model was developed to predict the probability of PDR progression and measurement of the vitreous level of VEGF may be useful for predicting the outcome of surgery.

The activated form of gelatinase B/matrix metalloproteinase-9 is associated with diabetic vitreous hemorrhage.

We aimed to investigate the presence and activation status of matrix metalloproteinase (MMP)-2 and MMP-9 in vitreous samples from proliferative diabetic retinopathy (PDR) patients. Paired vitreous and serum samples were obtained from patients undergoing vitrectomy for the treatment of rhegmatogenous retinal detachment (RD) (65 patients) and PDR (67 patients). PDR patients were diagnosed for the presence of hemorrhage and/or patent new vessels. Quantitative assays were performed for vitreous protein content, MMP-2, MMP-9, tissue inhibitor of metalloproteinases-1 (TIMP-1) and hemoglobin. Qualitative evaluation of the MMP-2 and MMP-9 activation status was performed by zymography. Vitreous samples contained proMMP-2 but levels were unselectively related to total protein content. ProMMP-9 and activated MMP-9 levels were significantly increased in PDR patients (p<0.001 for both comparisons). In addition, TIMP-1 levels were significantly increased in PDR patients (p=0.004) and functionally inhibited activation of MMP-9 in vitreous samples. None of the parameters significantly differed between PDR patients with patent new vessels and those with inactive disease. However, activated MMP-9 levels in vitreous samples of PDR patients with hemorrhage (75.7+/-106.3 scanning units per 2 microl) were significantly higher than those in PDR patients without hemorrhage (7.1+/-16.2 scanning units per 2 microl) (p<0.001) and strongly correlated with hemoglobin levels (r=0.7525; p<0.001). Activated MMP-9 was not detected in paired serum samples. We conclude that activated MMP-9 might be involved in hemorrhagic transformation in patients with PDR.

Unbalanced vitreous levels of pigment epithelium-derived factor and vascular endothelial growth factor in diabetic retinopathy.

PURPOSE: To determine the levels of pigment epithelium-derived factor (PEDF) and vascular endothelial growth factor (VEGF) in the vitreous of patients with diabetic retinopathy (DR). DESIGN: Experimental study of PEDF and VEGF levels in vitreous samples collected during vitrectomy. METHODS: The levels of PEDF and VEGF were measured by enzyme-linked immunosorbent assay in the vitreous of 46 eyes of 43 patients who underwent vitrectomy with diabetic retinopathy (DR) (32 eyes of 29 patients) and an idiopathic macular hole (MH) (14 eyes of 14 patients). RESULTS: The vitreal concentration of PEDF was significantly lower at 1.11 +/- 0.14 microg/ml (mean +/- standard error) in eyes with DR than in eyes with MH at 1.71 +/- 0.22 microg/ml (P =.021). The VEGF level was 1799 +/- 478 pg/ml in eyes with DR and not detectable in MH. The PEDF level in proliferative DR (PDR) (0.94 +/- 0.12 microg/ml) was lower than that in nonproliferative DR (NPDR) (2.25 +/- 0.32 microg/ml), and that in active DR (0.85 +/- 0.14 microg/ml) was significantly lower than that in inactive DR (1.59 +/- 0.24 microg/ml; P =.01). The VEGF level was 2025 +/- 533 pg/ml in PDR and 215 +/- 201 pg/ml in NPDR and that in active DR (2543 +/- 673 pg/ml) was significantly higher than that in inactive DR (395 +/- 188 pg/ml; P =.0098). CONCLUSIONS: These results suggest that lower levels of PEDF and higher levels of VEGF may be related to the angiogenesis in DR that leads to active PDR.

Human vitreal prostaglandin levels and proliferative diabetic retinopathy.

PURPOSE: To determine the association of prostaglandins E1 (PGE1), E2 (PGE2), and F2-alpha (PGF2-alpha) with proliferative diabetic retinopathy (PDR) in human vitreous. METHODS: We collected human vitreous samples from eyes undergoing pars plana vitrectomy for proliferative diabetic retinopathy with vitreous hemorrhage (N=13) and for other reasons including macular gliosis and Stage IV idiopathic macular holes (N=7). Vitreal prostaglandins E1, E2, and F2-alpha were measured by radioimmunoassay. RESULTS: Eyes with PDR had significantly lower vitreal levels of PGE1 (74.77 pg/ml +/- 15.70) compared to those without PDR (91.86 pg/ml +/- 13.36) (p=0.025) using t-test analysis. Eyes with PDR also had significantly lower levels of PGE2 (127.52 pg/ml +/- 70.52) compared to those eyes without PDR (194.43 pg/ml +/- 57.10) (p=0.045). In addition, eyes with PDR had significantly lower levels of PGF2-alpha (34.62 pg/ml +/- 11.56) compared to those eyes without PDR (51.43 pg/ml +/- 18.44) (p=0.021). Panretinal photocoagulation in diabetic eyes did not have an effect on vitreal concentrations of PGE1 (p=0.588). PGE2 (p=0.460) and PGF2-alpha (p=0.351), but sample size was too small. CONCLUSIONS: Diabetic eyes with PDR had significantly lower vitreal levels of PGE1, PGE2 and PGF2-alpha compared to controls consistent with decreased production of these prostaglandins by the endothelial cells of diabetic eyes. Laser treatment did not appear to have a significant effect on vitreal concentrations of these prostaglandins, but sample size was small. The lower concentration of these vasodilatory prostaglandins may reflect the vasculature's inability to produce these substances and the vasoconstrictive state of the end-stage diabetic eye with PDR.

Purification and characterization of a novel 88 kDa protein from serum and vitreous of patients with Eales' disease.

Eales' disease is a perivasculitis that affects the peripheral retina of young adults and results in recurrent vitreous hemorrhage. Although increased oxidative stress and decreased antioxidant defense have been reported to be associated with Eales' disease, the exact cause for the disease and its pathogenesis are not known. Here is reported the identification, purification and characterization of a new protein from the serum and vitreous of patients with Eales' disease. This protein was purified using preparative electrophoresis and HPLC. The purified protein had a retention time of 9.2 min in RP HPLC. Its molecular weight as determined by gel permeation chromatography was 88 kDa hence, it was termed as 88 kDa protein. Alcian blue and Schiffs staining revealed 88 kDa protein to be a glycoprotein. Proteins purified from both serum and vitreous exhibited anti lipid peroxidation effect on erythrocyte when added during in vitro assay of thiobarbuteric acid reactive substances (TBARS). In addition to this property the protein also has Fe(2+)sequestering effect. The anti TBARS activity of 88 kDa protein was completely inhibited by 0.1 m M concentration of parachlromercuric benzoate (PCMB) and 5,5' dithiobis(2-nitrobenzoic acid) DTNB. The total thiol content (cysteine) of the purified 88 kDa protein was found to be 8% by mass. Eighty eight kDa protein from both the sources namely vitreous and serum are immunologically identical when studied using polyclonal antibodies raised in goat against purified serum protein. The N terminal sequence of 88 kDa protein by automated Edman's degradation chemistry is A D D P N S L S P S A F A E A L A L L R D S X L A R F V. The protein and DNA data base search revealed no match to 88 kDa protein and hence this was considered as unique protein. Further knowledge on the in vivo function of 88 kDa protein is very important to understand its role in the pathogenesis of Eales' disease.

Changes in vitreous concentrations of human hepatocyte growth factor (hHGF) in proliferative diabetic retinopathy: implications for intraocular hHGF production.

We measured human hepatocyte growth factor (hHGF) concentrations in the original vitreous and in the artificial vitreous after vitrectomy in 13 patients with proliferative diabetic retinopathy (PDR) undergoing repeated pars plana vitrectomy, in order to investigate whether the vitreous hHGF concentration is related to the recurrence of PDR after vitrectomy as well as to the original occurrence of PDR. We also examined the relationship between vitreous concentrations of hHGF and transforming growth factor-beta(2) (TGF-beta(2)), the predominant TGF-beta isoform in the vitreous, in 14 patients with PDR. For the original vitreous, mean hHGF concentrations were higher (P<0.05) in that from patients with severe PDR (vitreous haemorrhage, fibrovascular proliferation and tractional retinal detachment) than in that from patients with vitreous haemorrhage alone. In the artificial vitreous, mean vitreous hHGF concentrations were higher (P<0.05) in that from patients with severe PDR than in that from patients with vitreous haemorrhage alone or with vitreous haemorrhage plus fibrovascular proliferation. No correlation was found between the hHGF concentration in the artificial vitreous and time between vitrectomies. Vitreous hHGF concentrations were directly proportional to vitreous concentrations of latent TGF-beta(2) (r=0. 831; P=0.0002), but inversely proportional to vitreous concentrations of active TGF-beta(2) (r=0.495; P=0.072), which inhibits hHGF production. A decreased conversion of latent into active TGF-beta(2) in ocular disorders such as PDR is likely to result in an increased concentration of hHGF in the vitreous. Thus intraocular hHGF may be involved in pathological mechanisms causing not only the occurrence, but also the recurrence, of PDR.

Vascular adhesion molecules in vitreous from eyes with proliferative diabetic retinopathy.

PURPOSE: To investigate whether proliferative vitreoretinopathy (PDR) is associated with a selective increase in vitreous levels of soluble vascular cell adhesion molecules that mediate leukocyte extravasation and interaction with endothelium during processes of inflammation and neovascularization. METHODS: Vitreous from 55 patients undergoing vitrectomy for treatment of PDR complicated by vitreous hemorrhage and/or traction retinal detachment was assayed for the presence of the soluble vascular cell adhesion molecules sICAM-1, sVCAM-1, and sE-selectin using a standard enzyme-linked immunosorbent assays (ELISA). Vitreous from 12 cadaveric eyes matching age and sex of the patients were used as control samples. RESULTS: Vitreous levels of sICAM-1, sVCAM-1, and sE-selectin were significantly higher in eyes with PDR than in control cadaveric vitreous, and levels of all three molecules did not relate to the type or duration of diabetes mellitus. However, eyes with either traction retinal detachment alone or both traction retinal detachment and vitreous hemorrhage exhibited significantly higher levels of sICAM-1 and sE-selectin than eyes with vitreous hemorrhage alone. Vitreous levels of sVCAM-1 were similar in eyes with either vitreous hemorrhage or traction retinal detachment alone. CONCLUSIONS: The present observations suggest that molecular inflammatory mechanisms may contribute to processes of neovascularization and fibrosis observed in PDR, possibly not as the causative event, but as a result of endothelial, Müller, and retinal pigment epithelial cell activation. The results also indicate that retinal detachment amplifies the existing inflammation within the diabetic retina. Identification of any abnormalities in the production and control of specific adhesion molecules could have important implications in the design of new therapeutic regimens to treat and prevent this sight-threatening complication of diabetes mellitus.