Post-treatment change in the localization of recurrent or persistent macular edema secondary to branch retinal vein occlusion.

PURPOSE: To investigate the change in localization of recurrent or persistent macular edema (ME) secondary to branch retinal vein occlusion (BRVO) after a therapeutic intervention. METHODS: Twenty-six eyes of 23 patients with recurrent or persistent ME secondary to BRVO were included in this retrospective case series. We analyzed the distance between the fovea and the top of the ME (fovea-ME top distance) and the ME area using optical coherence tomography before treatment and when ME recurred or persisted. RESULTS: The fovea-ME top distance decreased from 1.8 ± 1.6 to 1.2 ± 1.3 mm (p = 0.008). The ME area also decreased from 11.9 ± 4.9 to 7.6 ± 5.0 mm(2) (p = 0.0003). The retinal vascular leakage area correlated with the ME area in all eyes. CONCLUSION: The site of recurrent or persistent ME tends to shift toward the fovea. These results suggest that residual perifoveal vascular leakage might be the predominant cause of recurrent or persistent ME.

Vitreous levels of soluble vascular endothelial growth factor receptor (VEGFR)-1 in eyes with vitreoretinal diseases.

BACKGROUND/AIMS: To determine the vitreous levels of soluble vascular endothelial growth factor receptor (sVEGFR)-1 in patients with various vitreoretinal diseases, and to investigate its correlation with patients' age and the activity of proliferative diabetic retinopathy (PDR). METHODS: Vitreous fluid samples were obtained from 187 eyes of 170 patients who underwent vitrectomy for the treatment of idiopathic macular hole (MH, n=30), branch retinal vein occlusion (BRVO, n=37), central retinal vein occlusion (CRVO, n=27), diabetic macular oedema (DME, n=42) and PDR (n=51). The levels of sVEGFR-1 in the vitreous were measured by ELISA. RESULTS: The levels of sVEGFR-1 (pg/ml) were not significantly different among each disease examined (MH 3900.1 ± 1188.9, BRVO 3969.7 ± 1741.6, CRVO 4897.7 ± 1717.7, DME 3856.21 ± 1374.7, PDR 4212.3 ± 1474.9). There was a significant positive correlation between vitreous concentrations of sVEGFR-1 and patients' age (r=0.430, p<0.01). The sVEGFR-1 concentration in subjects with active PDR was significantly lower than in those with quiescent PDR (p<0.0001), even after being adjusted for age (p<0.0001). CONCLUSIONS: Vitreous concentrations of sVEGFR-1 increase with advancing age and are associated with quiescent rather than active PDR even after adjustment for age.

Histopathology of neovascular tissue from eyes with proliferative diabetic retinopathy after intravitreal bevacizumab injection.

PURPOSE: To examine the histopathologic effect of a single intravitreal injection of bevacizumab on newly formed vessels in eyes with proliferative diabetic retinopathy (PDR). DESIGN: Interventional case series and laboratory investigation. METHODS: Two days after intravitreal injection of bevacizumab (1.25 mg/eye), pars plana vitrectomy or trabeculectomy was performed for the treatment of PDR or neovascular glaucoma (NVG) associated with PDR. Ten surgically removed preretinal proliferative tissues and 6 deep scleral flaps containing trabecular meshwork were fixed in 2% glutaraldehyde or 4% paraformaldehyde and were subjected to transmission electron microscopic analysis, immunohistochemical analysis, and terminal deoxyuridiine triphosphate (dUTP) nick-end labeling staining. Two surgically removed preretinal proliferative tissues and 2 deep scleral flaps from patients with PDR and NVG, but without preoperative intravitreal injection of bevacizumab (IVB), served as controls. RESULTS: In control tissues, vascular endothelial cells possessed many fenestrations and were accompanied by pericytes. Apoptotic vascular endothelial cells frequently were observed in tissue after intravitreal injection of bevacizumab, whereas they were not observed in control tissues. Additionally, no apparent fenestration was observed in newly formed vessels from either proliferative tissue or trabecular meshwork after intravitreal injection of bevacizumab. In both PDR and NVG tissues after intravitreal injection of bevacizumab, overexpression of smooth muscle actin was observed in newly formed vessels, suggesting that the treatment may have increased pericytes on the vasculature as compared with control tissue. CONCLUSIONS: Intravitreal injection of bevacizumab may induce changes in immature, newly formed vessels of PDR or NVG tissue, leading to endothelial apoptosis with vascular regression, while inducing normalization of premature vessels by increasing pericyte coverage and reducing vessel fenestration.

Comprehensive analysis of inflammatory immune mediators in vitreoretinal diseases.

Inflammation affects the formation and the progression of various vitreoretinal diseases. We performed a comprehensive analysis of inflammatory immune mediators in the vitreous fluids from total of 345 patients with diabetic macular edema (DME, n = 92), proliferative diabetic retinopathy (PDR, n = 147), branch retinal vein occlusion (BRVO, n = 30), central retinal vein occlusion (CRVO, n = 13) and rhegmatogenous retinal detachment (RRD, n = 63). As a control, we selected a total of 83 patients with either idiopathic macular hole (MH) or idiopathic epiretinal membrane (ERM) that were free of major pathogenic intraocular changes, such as ischemic retina and proliferative membranes. The concentrations of 20 soluble factors (nine cytokines, six chemokines, and five growth factors) were measured simultaneously by multiplex bead analysis system. Out of 20 soluble factors, three factors: interleukin-6 (IL-6), interleukin-8 (IL-8), and monocyte chemoattractant protein-1 (MCP-1) were significantly elevated in all groups of vitreoretinal diseases (DME, PDR, BRVO, CRVO, and RRD) compared with control group. According to the correlation analysis in the individual patient's level, these three factors that were simultaneously increased, did not show any independent upregulation in all the examined diseases. Vascular endothelial growth factor (VEGF) was significantly elevated in patients with PDR and CRVO. In PDR patients, the elevation of VEGF was significantly correlated with the three factors: IL-6, IL-8, and MCP-1, while no significant correlation was observed in CRVO patients. In conclusion, multiplex bead system enabled a comprehensive soluble factor analysis in vitreous fluid derived from variety of patients. Major three factors: IL-6, IL-8, and MCP-1 were strongly correlated with each other indicating a common pathway involved in inflammation process in vitreoretinal diseases.

Equivalent tamponade by room air as compared with SF(6) after macular hole surgery.

BACKGROUND: To evaluate the effect of tamponade by room air after vitrectomy for the treatment of idiopathic macular hole (MH). METHODS: There were 156 eyes of 151 patients studied. The patients' ages ranged from 35 to 88 years old (mean: 65.1 years). After conventional pars plana vitrectomy with internal limiting membrane peeling, fluid air exchange was performed using 20% SF(6) (Gas group: 91 eyes) or room air (Air group: 65 eyes). Surgical outcomes were retrospectively analyzed. RESULTS: Mean preoperative hole diameter was 352 microm in the Gas group and 370 microm in the Air group (P = 0.558). The closure rate of all cases was 91.0% after first surgery and 98.7% at last follow-up. The primary closure rate was 90.1% in the Gas group after 7.44 +/- 1.66 (mean +/- SD) days prone positioning period, and 92.3% in the Air group after 3.83 +/- 0.97 days of prone positioning. There was significant difference in prone positioning period (P < 0.0001), but not in the first closure rate (P = 0.132). CONCLUSION: This study suggests that room air may have an equivalent tamponade effect, in spite of the shorter prone positioning period, than SF(6) after MH surgery.

Anatomical findings of vitreoretinal interface in eyes with asteroid hyalosis.

PURPOSE: To investigate the anatomical features of vitreoretinal interface in eyes with asteroid hyalosis (AH) with optical coherence tomography (OCT) and intravitreal triamcinolone acetonide (TA) during vitreous surgery. METHODS: This study was an interventional clinical case series. Records relating to ten eyes from ten patients who underwent a TA-assisted vitrectomy for the treatment of diverse vitreoretinal diseases complicated with AH. The posterior vitreoretinal interface was examined by preoperative OCT and by intraoperative visualization of posterior vitreous cortex utilizing TA. RESULTS: In eight of ten AH eyes, preoperative OCT revealed abnormal vitreoretinal adhesions. In four of these eight eyes, posterior vitreoschisis could be seen on OCT. In the other four of these eight eyes, a clear no posterior vitreous detachment (PVD) pattern could be seen on OCT. Although posterior vitreous cortex could not be clearly identified with preoperative OCT in two of ten AH eyes, a complete PVD was refuted by intraoperative visualization of the posterior vitreous cortex with TA identical to the other eight eyes. CONCLUSION: These results indicate that complete PVD appears to be unlikely to occur in eyes with AH. In addition, spontaneous PVD in eyes with AH might lead to vitreoschisis or residual whole layer or posterior vitreous cortex, possibly due to anomalous vitreoretinal adhesion.

Role of TGF-beta in proliferative vitreoretinal diseases and ROCK as a therapeutic target.

Cicatricial contraction of preretinal fibrous membrane is a cause of severe vision loss in proliferative vitreoretinal diseases such as proliferative diabetic retinopathy (PDR) and proliferative vitreoretinopathy (PVR). TGF-beta is overexpressed in the vitreous of patients with proliferative vitreoretinal diseases and is also detectable in the contractile membranes. Therefore, TGF-beta is presumed to contribute to the cicatricial contraction of the membranes, however, the underlying mechanisms and TGF-beta's importance among various other factors remain to be elucidated. Vitreous samples from PDR or PVR patients caused significantly larger contraction of hyalocyte-containing collagen gels, compared with nonproliferative controls. The contractile effect was strongly correlated with the vitreal concentration of activated TGF-beta2 (r = 0.82, P < 0.0001). PDR or PVR vitreous promoted expression of alpha-smooth muscle actin (alpha-SMA) and phosphorylation of myosin light chain (MLC), a downstream mediator of Rho-kinase (ROCK), both of which were dramatically but incompletely suppressed by TGF-beta blockade. In contrast, fasudil, a potent and selective ROCK inhibitor, almost completely blocked the vitreous-induced MLC phosphorylation and collagen gel contraction. Fasudil disrupted alpha-SMA organization, but it did not affect its vitreal expression. In vivo, fasudil significantly inhibited the progression of experimental PVR in rabbit eyes without affecting the viability of retinal cells by electroretinographic and histological analyses. These results elucidate the critical role of TGF-beta in mediating cicatricial contraction in proliferative vitreoretinal diseases. ROCK, a key downstream mediator of TGF-beta and other factors might become a unique therapeutic target in the treatment of proliferative vitreoretinal diseases.

Potent inhibition of cicatricial contraction in proliferative vitreoretinal diseases by statins.

OBJECTIVE: Despite tremendous progress in vitreoretinal surgery, certain postsurgical complications limit the success in the treatment of proliferative vitreoretinal diseases (PVDs), such as proliferative diabetic retinopathy (PDR) and proliferative vitreoretinopathy (PVR). One of the most significant complications is the cicatricial contraction of proliferative membranes, resulting in tractional retinal detachment and severe vision loss. Novel pharmaceutical approaches are thus urgently needed for the management of these vision-threatening diseases. In the current study, we investigated the inhibitory effects of statins on the progression of PVDs. RESEARCH DESIGN AND METHODS: Human vitreous concentrations of transforming growth factor-beta2 (TGF-beta2) were measured by enzyme-linked immunosorbent assay. TGF-beta2-and vitreous-dependent phosphorylation of myosin light chain (MLC), a downstream mediator of Rho-kinase pathway, and collagen gel contraction simulating cicatrical contraction were analyzed using cultured hyalocytes. Inhibitory effects of simvastatin on cicatrical contraction were assessed both in vitro and in vivo. RESULTS: Human vitreous concentrations of TGF-beta2 were significantly higher in the samples from patients with PVD compared with those without PVD. Simvastatin inhibited TGF-beta2-dependent MLC phosphorylation and gel contraction in a dose- and time-dependent manner and was capable of inhibiting translocation of Rho protein to the plasma membrane in the presence of TGF-beta2. Vitreous samples from patients with PVD enhanced MLC phosphorylation and gel contraction, whereas simvastatin almost completely inhibited these phenomena. Finally, intravitreal injection of simvastatin dose-dependently prevented the progression of diseased states in an in vivo model of PVR. CONCLUSIONS: Statins might have therapeutic potential in the prevention of PVDs.

Posterior vitreous cortex characteristics of an eye with asteroid hyalosis.

PURPOSE: To describe both the clinical and the histological characteristics of the vitreoretinal interface of an eye with asteroid hyalosis (AH). METHODS: A 76-year-old woman presented with a left eye with AH and an epiretinal membrane (ERM). Preoperative slit-lamp biomicroscopy revealed anatomical posterior vitreous detachment with a Weiss ring. Preoperative best-corrected visual acuity (BCVA) was 20/50. The patient underwent triamcinolone acetonide-assisted vitrectomy, along with peeling of the internal limiting membrane (ILM). The ERM and ILM were removed together with surgical ILM forceps. The excised ILM was analyzed with transmission electron microscopy (TEM). We also compared the histological characteristics of this tissue with those of tissue from a non-AH eye with idiopathic ERM. RESULTS: A massive collagenous matrix with few cellular components, suggesting residual posterior vitreous but not ERM, was observed on the excised ILM of the AH eye. BCVA improved to 20/25 6 months after surgery. TEM of a non-AH eye with idiopathic ERM revealed a cellular rich component and extracellular matrix on the ILM. CONCLUSION: We found evidence demonstrating a split in the posterior vitreous cortex, representing, to our knowledge, the first case report of this phenomenon in an eye with AH.

Intracellular events in retinal glial cells exposed to ICG and BBG.

PURPOSE: To investigate the intracellular events in retinal glial cells exposed to indocyanine green (ICG) and brilliant blue G (BBG). METHODS: The human Müller cell line MIO-M1 was exposed to a low dose (0.25 mg/mL) and a clinical dose (2.5 mg/mL) of ICG and a clinical dose (0.25 mg/mL) of BBG for 15 minutes, respectively. To quantify the proliferation and viability of the cells, [(3)H]-thymidine incorporation was measured and cell numbers were counted 24 hours after treatment. Cell morphology was evaluated using phase-contrast microscopy and transmission electron microscopy. The effects of ICG and BBG on phosphorylation of p38 MAPK and cleavage of caspase-9 and caspase-3 were examined by Western blot. RESULTS: ICG and BBG significantly reduced [(3)H]-thymidine incorporation in MIO-M1 cells compared with the vehicle-treated controls (P < 0.01). Cell number significantly decreased after exposure to ICG at 2.5 or 0.25 mg/mL (P < 0.01) but did not decrease after exposure to BBG at 0.25 mg/mL. Transmission electron microscopy revealed apoptotic changes only in the ICG-treated cells. Prominent p38 MAPK phosphorylation was observed in the presence of ICG, even at the low concentration and within a short time exposure; however, no apparent enhancement was observed in the presence of 0.25 mg/mL BBG. Furthermore, ICG, but not BBG, induced the cleavage of caspase-9 and caspase-3, which was inhibited by an inhibitor of p38 MAPK. CONCLUSIONS: ICG is toxic to retinal glial cells because it induces apoptosis, involving induction of the caspase cascade through p38 MAPK phosphorylation. In contrast, BBG does not cause apoptosis and thus could be a safer adjuvant during vitreoretinal surgery.

Biocompatibility of brilliant blue G in a rat model of subretinal injection.

PURPOSE: To evaluate the toxicity of brilliant blue G (BBG) compared with those of indocyanine green (ICG) and trypan blue (TB) in a rat model of subretinal injection. METHODS: Retinal detachment was produced by subretinal injection of the dyes. The biocompatibility of BBG (0.25 mg/mL) was evaluated over 2 months and 2 weeks by ophthalmic examinations. The eyes were enucleated and analyzed by light, fluorescence, as well as transmission electron microscopy. Apoptotic cell death was detected by TdT-dUTP terminal nick-end labeling. The results were compared with those for ICG (5 mg/mL) and TB (1 mg/mL). RESULTS: ICG caused retinal degeneration and retinal pigment epithelial (RPE) cell atrophy 2 weeks after subretinal injection. Apoptotic cell death was detected in the inner and outer nuclear layers and the RPE layer, especially the photoreceptors. TB caused less retinal degeneration, mainly in the area detached by the subretinal injection. BBG had no detectable toxic effects after 2 months and 2 weeks. Apoptotic cell death was detected in the ICG and TB groups, mainly in the photoreceptors. CONCLUSIONS: Subretinal injection of the dyes caused retinal cell degeneration at lower concentrations than those reported for intravitreous injection. However, subretinal injection of BBG at 0.25 mg/mL appeared to provide satisfactory biocompatibility.

Evaluating adjunctive surgical procedures during vitrectomy for diabetic macular edema.

PURPOSE: To evaluate the long-term outcomes of adjunctive surgical procedures during pars plana vitrectomy (PPV) for the treatment of diabetic macular edema (DME). METHODS: In this nonrandomized study, we retrospectively analyzed 57 eyes of 54 patients who had DME and had undergone PPV. We performed PPV using three different surgical procedures: conventional PPV (group PVD; 13 eyes), triamcinolone acetonide (TA)-assisted PPV (group TA; 22 eyes), and TA-assisted PPV combined with internal limiting membrane (ILM) peeling (group ILM; 22 eyes). We also evaluated the preoperative and postoperative best-corrected visual acuity (BCVA) results. RESULTS: The overall mean preoperative BCVA was 0.86 logarithm of the minimal angle of resolution unit. In groups PVD, TA, and ILM, BCVAs were 0.99, 0.90, and 0.74 (P = 0.310), respectively. The mean postoperative BCVA for all patients improved to 0.68 (P = 0.005). The postoperative BCVA improved in 47% of the treated eyes, it remained unchanged in 37% of the treated eyes, and it deteriorated in 16% of the treated eyes. However, we observed no significant difference in the mean postoperative BCVAs between the three groups. Furthermore, we found that there was no significant difference in postoperative BCVA improvements between any of the groups (P = 0.450). CONCLUSION: The present study suggests that these 3 PPV approaches do not significantly affect postoperative BCVAs after 18 months of DME treatment.

[Effects of implementing clinical pathways for the care of patients undergoing ophthalmic surgery for cataract, glaucoma, and vitreoretinal disorder].

PURPOSE: To evaluate the actual use of clinical pathways and variances, and compare the length of hospital stay for surgery of cataract, glaucoma, and vitreoretinal disorder. METHODS: We designed eight types of clinical pathways for the treatment of cataract, glaucoma, and retinal-vitreous disease. We performed 102 phacoemulsifications and intraocular lens (IOL) implantations, 19 glaucoma or combined trabeculotomy and phacoemulsification/IOL, and 69 retinal-vitreous surgeries during a 1-year period from February 2002. We compared the length of the hospital stay before and after clinical pathway implementation. RESULTS: We applied the clinical pathways to 102 eyes (100%) of 67 patients undergoing phacoemulsification/IOL, to 17 eyes (89.5%) of those undergoing glaucoma surgery, and to 69 eyes (100%) of those undergoing retinal-vitreous surgery. The vaiances occurred in 20 eyes (29.9%) of 67 phacoemulsification/IOLs, 6 eyes (31.6%) of glaucoma, and 24 eyes (34.2%) of retinal-vitreous surgery. The length of hospital stay was shortened in phacomulsification/IOL after clinical pathway implemenation: 7.8 +/- 3.3 to 6.7 +/- 2.5 (mean +/- standard deviation) days. Glaucoma patients had a significantly shorter stay, from 16.4 +/- 5.0 to 12.6 +/- 3.3 days Mann-Whitney U test ; p = 0.032), and the hospital tay for retinal-vitreous surgery was shortened rom 22.8 +/- 11.1 to 17.9 +/- 6.2 days (p = 0.001). CONCLUSIONS: The application of clinical pathways resulted in substantially reduced hospital stay.

Construction of an in vitro allergy reaction evaluation system using human leukemia cell lines.

Human leukemia cell lines, KU812 and KU812F, are immature prebasophillic cell lines and have a potential to differentiate into basophils. Hydrocortisone (HC) and sodium nitroprusside (SNP) can enhance the cell surface FcepsilonRI expression of KU812 cells. However, the differentiated phenotypes of KU812 cells were unstable, hindering the application of KU812 cells to construct a practical invitro allergy reaction evaluation system. Here, we attempted to enhance the cell surface expression of FcepsilonRI on hydrocortisone (HC)- or sodium nitroprusside (SNP)-treated KU812 cells by IgE. The cell surface FcepsilonRI expression was observed in about 20, 20 and 26% of 1 muM HC-, 1 nM SNP- and 450 ng ml(-1) IgE-treated KU812 cells, respectively. Whereas, the cell surface FcepsilonRI expression was observed in about 54% of KU812 cells treated with both 450 ng ml(-1) IgE and 1 muM HC for 8 days, and in about 33% of KU812 cells treated with both 450 ng ml(-1) IgE and 1 nM SNP for 4 days. Ninety five% of the IgE/HC- or IgE/SNP-treated KU812 cells expressed CD 13 antigen, a cell surface marker of basophils. An electrophoretic mobility shift assay revealed that AP-1, NF-AT and NF-kappaB transcription factors were all activated in IgE/HC- and IgE/SNP-treated KU812 cells. Since the differentiated KU812F cells were more sensitive than KU812 cells for histamine release by sensitization with human IgE and anti-IgE antibody, a practical in vitro allergy reaction evaluation system for general use was constructed using IgE/HC-treated KU812F cells. The differentiated KU812F cells sensitized with an allergicpatient's IgE and mite allergen exhibited histamine release. The constructed in vitro allergy reaction evaluation system using differentiated human leukemia KU812F cells will be useful to study allergic reaction and to analyze physiologically functional substances in allergic disease.