Genome-Wide Association Study of Age-Related Macular Degeneration Reveals 2 New Loci Implying Shared Genetic Components with Central Serous Chorioretinopathy.

PURPOSE: To investigate the genetic architecture of age-related macular degeneration (AMD) in a Japanese population. DESIGN: Genome-wide association study (GWAS). PARTICIPANTS: Three thousand seven hundred seventy-two patients with AMD and 16 770 control participants from the Japanese population were enrolled in the association analyses. METHODS: We conducted a meta-analysis of 2 independent GWASs that included a total of 2663 patients with AMD and 9471 control participants using the imputation reference panel for genotype imputation specified for the Japanese population (n = 3541). A replication study was performed using an independent set of 1109 patients with AMD and 7299 control participants. MAIN OUTCOME MEASURES: Associations of genetic variants with AMD. RESULTS: A meta-analysis of the 2 GWASs identified 6 loci significantly associated with AMD (P < 5.0 × 10-8). Of these loci, 4 were known to be associated with AMD (CFH, C2/FB, TNFRSF10A, and ARMS2), and 2 were novel (rs4147157 near WBP1L and rs76228488 near GATA5). The newly identified associations were confirmed in a replication study (P < 0.01). After the meta-analysis of all datasets, we observed strong associations in these loci (P = 1.88 × 10-12 and P = 1.35 × 10-9 for meta-analysis for rs4147157 and rs76228488, respectively). When we looked up the associations in the reported central serous chorioretinopathy (CSC) GWAS conducted in the Japanese population, both loci were associated significantly with CSC (P = 4.86 × 10-3 and P = 4.28 × 10-3 for rs4147157 and rs76228488, respectively). We performed a genetic colocalization analysis for these loci and estimated that the posterior probabilities of shared causal variants between AMD and CSC were 0.39 and 0.60 for WBP1L and GATA5, respectively. Genetic correlation analysis focusing on the epidemiologically suggested clinical risk factors implicated shared polygenic architecture between AMD and smoking cessation (rg [the measure of genetic correlation] = -0.33; P = 0.01; false discovery rate, 0.099). CONCLUSIONS: Our findings imply shared genetic components conferring the risk of both AMD and CSC. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found after the references.

Serous Retinal Detachment without Leakage on Fluorescein/Indocyanine Angiography in MEK Inhibitor-Associated Retinopathy.

The aim of this paper was to report the cases of 3 consecutive patients with mitogen-activated protein kinase kinase inhibitor (MEKi)-associated retinopathy with characteristic multiple serous retinal detachments (SRDs). A functional analysis of the retinal pigment epithelium was performed in 2 patients by electro-oculography (EOG). In all 3 patients, SRD lesions were observed in the posterior pole including the fovea of both eyes. Interestingly, neither obvious leakage in fluorescein/indocyanine angiography nor abnormal fundus autofluorescence was associated. SRDs and associated cystoid macular edema in one case rapidly resolved with the cessation of MEKi but recurred quickly after treatment resumption. In EOG tests, three of four eyes with multiple SRDs showed a marked decrease in the light-peak-to-dark-trough ratio (LP:DT ratio). The LP:DT ratio in EOG reflects the transepithelial potential of the retinal pigment epithelium, suggesting the involvement of disrupted tight junctions and impaired active transport of fluid/ions in MEKi-associated retinopathy. The latter may be the major cause of SRDs as we observed that fluid leakage in angiography was absent in the areas of the patients' SRDs.

One-Year Outcomes following Intravitreal Aflibercept for Polypoidal Choroidal Vasculopathy in Japanese Patients: The APOLLO Study.

PURPOSE: To evaluate 1-year outcomes of intravitreal injections of aflibercept (IVA) in Japanese polypoidal choroidal vasculopathy (PCV) patients. METHODS: In this prospective, open-label, single-arm multicenter clinical trial, treatment-naïve PCV patients received IVA (2.0 mg) every 2 months, after 3 initial monthly doses. The primary endpoint assessed was the proportion of patients maintaining baseline best-corrected visual acuity (BCVA) at 1 year. RESULTS: Fifty eyes with PCV were included in the study. BCVA was maintained or improved in 97.6% of the patients. Mean logMAR BCVA at baseline was 0.33, and had improved to 0.12 logMAR 1 year after the initiation of aflibercept treatment (p < 0.001). Mean central foveal thickness decreased from 356 to 239 µm (p < 0.001). Complete regression of polypoidal lesions was seen in 72.5% after 1 year of treatment. CONCLUSIONS: One year of IVA resulted in stabilization of BCVA and anatomical improvement in Japanese PCV patients.

Low-frequency coding variants in CETP and CFB are associated with susceptibility of exudative age-related macular degeneration in the Japanese population.

Age-related macular degeneration (AMD) is a major cause of blindness in the elderly. Previous sequencing studies of AMD susceptibility genes have revealed the association of rare coding variants in CFH, CFI, C3 and C9 in European population; however, the impact of rare or low-frequency coding variants on AMD susceptibility in other populations is largely unknown. To identify the role of low-frequency coding variants on exudative AMD susceptibility in a Japanese population, we analysed the association of coding variants of 34 AMD candidate genes in the two-stage design by a multiplex PCR-based target sequencing method. We used a total of 2,886 (1st: 827, 2nd: 2,059) exudative AMD cases including typical AMD, polypoidal choroidal vasculopathy, and retinal angiomatous proliferation and 9,337 (1st: 3,247 2nd: 6,090) controls. Gene-based analysis found a significant association of low-frequency variants (minor allele frequency (MAF) < 0.05) in CETP, C2 and CFB. The association of CETP remained after conditioned with all known genome-wide association study (GWAS) associated variants. In addition, when we included only disruptive variants, enrichment of rare variants (MAF < 0.01) was also observed after conditioned with all GWAS associated variants (P = 1.03 × 10−6, odds ratio (OR) = 2.48). Haplotype and conditional analysis of the C2-CFB-SKIV2L locus showed a low-frequency variant (R74H) in CFB would be individually associated with AMD susceptibility independent of the GWAS associated SNP. These findings highlight the importance of target sequencing to reveal the impact of rare or low-frequency coding variants on disease susceptibility in different ethnic populations.

Plasma Kallikrein-Kinin System as a VEGF-Independent Mediator of Diabetic Macular Edema.

This study characterizes the kallikrein-kinin system in vitreous from individuals with diabetic macular edema (DME) and examines mechanisms contributing to retinal thickening and retinal vascular permeability (RVP). Plasma prekallikrein (PPK) and plasma kallikrein (PKal) were increased twofold and 11.0-fold (both P < 0.0001), respectively, in vitreous from subjects with DME compared with those with a macular hole (MH). While the vascular endothelial growth factor (VEGF) level was also increased in DME vitreous, PKal and VEGF concentrations do not correlate (r = 0.266, P = 0.112). Using mass spectrometry-based proteomics, we identified 167 vitreous proteins, including 30 that were increased in DME (fourfold or more, P < 0.001 vs. MH). The majority of proteins associated with DME displayed a higher correlation with PPK than with VEGF concentrations. DME vitreous containing relatively high levels of PKal and low VEGF induced RVP when injected into the vitreous of diabetic rats, a response blocked by bradykinin receptor antagonism but not by bevacizumab. Bradykinin-induced retinal thickening in mice was not affected by blockade of VEGF receptor 2. Diabetes-induced RVP was decreased by up to 78% (P < 0.001) in Klkb1 (PPK)-deficient mice compared with wild-type controls. B2- and B1 receptor-induced RVP in diabetic mice was blocked by endothelial nitric oxide synthase (NOS) and inducible NOS deficiency, respectively. These findings implicate the PKal pathway as a VEGF-independent mediator of DME.

Intravitreal bevacizumab treatment for neovascular glaucoma: histopathological analysis of trabeculectomy specimens.

BACKGROUND: Neovascular glaucoma (NVG) is a serious complication for patients with proliferative diabetic retinopathy (PDR). Bevacizumab is a full-length humanized monoclonal antibody that binds all isoforms of vascular endothelial growth factor (VEGF). Recently, encouraging results regarding the off-label use of intravitreal bevacizumab (IVB) for the treatment of NVG have been reported. We evaluated the histology of bevacizumab-treated trabeculectomy specimens to clarify IVB's biological effects on angle neovascularization. METHODS: We retrospectively reviewed the charts of a consecutive series of 15 eyes of 13 patients who underwent trabeculectomy to treat NVG caused by PDR. In ten eyes of eight patients, 1.25 mg bevacizumab was injected intravitreally via the pars plana. Using light or electron microscopy, the surgically excised trabecular tissue was compared to that without IVB. RESULTS: Light microscopy revealed decreased edema, fibrin deposition, inflammation and vascular congestion in the trabecular meshwork in specimens with IVB compared to those without IVB. Electron microscopy revealed endothelial cell degeneration in the bevacizumab-treated specimens. CONCLUSIONS: The biological effects on angle neovascularization after IVB may involve reduced vascular permeability, decreased inflammatory reaction, loss of vascular function, and endothelial cell degeneration.

TEM7 (PLXDC1) in neovascular endothelial cells of fibrovascular membranes from patients with proliferative diabetic retinopathy.

PURPOSE: Proliferative diabetic retinopathy (PDR) results from the formation of fibrovascular membranes (FVMs) in the posterior fundus that can lead to a severe decrease of vision. Tumor endothelial marker 7 (TEM7) is a protein that is highly expressed in the endothelial cells of tumors, but whether it plays a role in FVMs is unknown. The purpose of this study was to determine whether TEM7 is associated with the formation of FVMs. METHODS: FVMs were obtained during vitrectomy from patients with PDR. RT-PCR was performed to determine the level of expression of the mRNA of TEM7. The splice variants of TEM7 were identified by direct sequencing. Immunohistochemical analyses and in situ hybridization was performed to determine the sites of TEM7 in the FVMs. RESULTS: The level of the mRNA of TEM7 was high in 10 of 10 FVMs but was barely detectable in the five idiopathic epiretinal membranes. Direct sequencing of subcloned TEM7 PCR products revealed several splice variants (intracellular, secreted, and membrane-bound forms of TEM7) in the FVMs. Immunohistochemical analysis showed a colocalization of TEM7 and CD34, an endothelial cell marker, in most of the neovascular endothelial cells in the FVMs. Immunoelectron microscopy revealed that membrane-bound TEM7 was expressed on the luminal surfaces of the vascular endothelial cells of FVMs. CONCLUSIONS: This study indicates that TEM7 may play a significant role in the proliferation and maintenance of neovascular endothelial cells in the FVMs. If correct, TEM7 may be a molecular target for new diagnostic and therapeutic strategies for PDR.

Critical role of the Rho-kinase pathway in TGF-beta2-dependent collagen gel contraction by retinal pigment epithelial cells.

Retinal pigment epithelial cells (RPEs) are thought to be one of the main components of fibrous membrane observed in eyes with proliferative vitreo-retinopathy. We investigated the signalling mechanisms of TGF-beta2-dependent collagen gel contraction by RPEs. An in vitro type I collagen gel contraction assay was performed to evaluate the effect of TGF-beta2 on gel contraction. The expression of alpha-smooth muscle actin (alpha-SMA) and the phosphorylation state of myosin light chain (MLC) were analyzed by Western blotting. The involvement of protein kinases such as p44/42 mitogen-activated protein kinase (MAPK), protein kinase C (PKC), p38 MAPK and phosphatidylinositol-3 kinase was investigated. The contribution of Rho-kinase and/or MLC-kinase was also evaluated using respective kinase inhibitors (Y27632, hydroxyfasudil and ML7). Additionally, RPEs were immunostained to examine whether the expression of alpha-SMA detected in our western blotting correlated to the stress fiber formation within the cells. TGF-beta2 caused time (0-5 days)-and dose (0 10 ng ml(-1))-dependent gel contraction associated with overexpression of alpha-SMA and phosphorylation of MLC (p < 0.01, respectively). PKC inhibitor (GF109203X, 5 microM) and p38 MAPK inhibitor (SB203580, 10 microM) significantly attenuated TGF-beta2-elicited gel contraction via partial downregulation of both alpha-SMA expression and MLC phosphorylation (p < 0.01, respectively). The gel contraction was prominently inhibited in the presence of Y27632 (10 microM) or hydroxyfasudil (10 microM) with strong suppression of MLC phosphorylation but had no significant effect on alpha-SMA expression. Treatment with ML7, in contrast, resulted in a marginal inhibition of MLC phosphorylation and gel contraction. Finally, pretreatment of the cells with Y27632 or hydroxyfasudil prevented the formation of stress fiber within the cells. These results indicate that TGF-beta2-dependent myofibroblastic transdifferentiation and MLC phosphorylation by RPEs involve both PKC and p38 MAPK pathways at least in part. Myofibroblastic transdifferentiation of RPEs appears to be independent of the Rho-kinase pathway, and the presence of alpha-SMA does not necessarily reflect the contractile potential of a cell. While Rho-kinase inhibitors are incapable of preventing myofibroblastic transdifferentiation itself, this pathway could be one of the critical targets of cell-mediated contraction of the tissue containing fibrillar collagens by transdifferentiated RPEs.

Functional properties of hyalocytes under PDGF-rich conditions.

PURPOSE: To investigate the functional properties and intracellular signaling of hyalocytes under platelet-derived growth factor (PDGF)-rich conditions. METHODS: The hyalocytes were isolated from bovine eyes and identified by immunocytochemistry and electron microscope. The expression of PDGF receptor alpha/beta and its phosphorylation in response to PDGF-BB was analyzed by Western blot analysis. PDGF-BB-induced proliferation and migration were evaluated by thymidine uptake and Boyden's chemotaxis assay. The expression of the urokinase-type plasminogen activator (uPA) gene and the fibrinolytic activity were assessed by Northern blotting and fibrin zymography. An in vitro type I collagen gel contraction assay was performed to determine the effect of PDGF-BB on cellular contraction. RESULTS: The hyalocytes were immunocytochemically positive for S-100 and negative for glial fibrillary acidic protein (GFAP) and cytokeratin, as previously described. The electron microscope demonstrated that hyalocytes possess lysosome-like granules, mitochondria, and micropinocytotic vesicles in their cytoplasm. The hyalocytes expressed PDGF receptor alpha and beta, both of which were immediately phosphorylated in response to PDGF-BB. PDGF-BB also activated p85 PI3-kinase, p44/p42 mitogen-activated protein (MAP) kinase and p38 MAP kinase. PDGF-BB induced thymidine uptake and migration in a concentration-dependent (0-10 ng/mL) manner. Inhibitors of the respective kinases prohibited PDGF-BB-dependent thymidine uptake and migration with the exception of the p44/p42 MAP kinase inhibitor, which displayed no inhibitory effects on migration. PDGF-BB increased uPA gene expression and fibrinolytic activity. Collagen gel contraction observed under PDGF-BB-rich conditions was not prohibited by the respective inhibitors investigated. CONCLUSIONS: The hyalocytes demonstrated macrophage-like characteristics and may have both physiologic and pathologic roles, such as the maintenance of vitreous transparency through fibrinolytic activity and the pathogenesis of proliferative-vitreoretinal diseases through cellular proliferation and vitreous hyper-contraction.

Fibrinogen stimulates in vitro angiogenesis by choroidal endothelial cells via autocrine VEGF.

BACKGROUND: The purpose of this study is to investigate the effect of fibrinogen on angiogenesis in vitro formed by cultured bovine choroidal endothelial cells (BCECs) and the involvement of vascular endothelial growth factor (VEGF) in this mechanism. METHODS: For in vitro tube formation assay, BCECs were seeded on collagen gel containing fibrinogen (0-1.5 mg/ml). After 3 days of cultivation, the total length of the tubular structure was measured using Macscope Analyzer. Total RNA and conditioned media were collected after fibrinogen treatment and subjected to Northern and Western blot analyses, respectively. Transcription factor HIF-1alpha was also analyzed by Western blot analysis using cytosolic and nuclear fraction of BCECs. Involvement of VEGF in fibrinogen-dependent in vitro tube formation was evaluated using anti-VEGF neutralizing antibody or VEGF receptor 2-selective inhibitor (SU5416). RESULTS: Formation of the tubular structure was enhanced 20 to approximately 50 times in fibrinogen-containing gel in a concentration-dependent manner. The treatment of BCECs with fibrinogen resulted in a significant increase in VEGF gene and protein expression. Accumulation of HIF-1alpha protein in the nuclear fraction was also detected after the treatment with fibrinogen. Finally, fibrinogen-induced tube formation was significantly inhibited in the presence of anti-VEGF-neutralizing antibody (52.0% inhibition at the concentration of 1 microg/ml, P<0.05) or SU5416 (54.8% inhibition at the concentration of 3 microM, P<0.05). CONCLUSIONS: Extravasated fibrinogen might play an important role in the development of choroidal neovascularization associated with age-related macular degeneration, at least in part, through the function of VEGF in an autocrine manner. Transcription factor HIF-1 appears to be involved in fibrinogen-induced VEGF expression.

Lattice corneal dystrophy type I without typical lattice lines: role of mutational analysis.

PURPOSE: To describe a Japanese patient with lattice corneal dystrophy type I (LCD I) who lacked the typical lattice lines. DESIGN: Interventional case report. METHODS: A complete ophthalmologic examination was performed on a 54-year-old woman, and the TGFBI gene was analyzed by direct genomic sequencing. RESULTS: The patient had diffuse opacification of the central corneal stroma but without lattice lines and corneal epithelial erosions bilaterally. Molecular genetic analysis identified a lattice corneal dystrophy I-associated heterozygous missense alteration (C417T) that changed arginine in codon 124 to cysteine (R124C) in the TGFBI gene. CONCLUSIONS: The cornea of the patient appeared to represent late-stage lattice corneal dystrophy I, which suggests the existence of interactions of modifier genes, environmental factors during corneal aging, or both. The molecular genetic analysis of TGFBI can offer rapid, accurate diagnosis of patients with atypical corneal appearance.

Suppression of experimental choroidal neovascularization utilizing KDR selective receptor tyrosine kinase inhibitor.

BACKGROUND: We investigated the role of the VEGF-VEGF receptor 2 (KDR) system in the development of choroidal neovascularization (CNV) and its possibility as a therapeutic target utilizing KDR selective receptor tyrosine kinase (RTK) inhibitor (SU5416) both in vitro and in an experimental CNV model. METHODS: VEGF-induced phosphorylation of KDR and p44/p42 MAPK in cultured bovine choroidal endothelial cells (BCECs) was determined by Western blot analysis. The proliferation and in vitro tube formation were analyzed by [3H]thymidine uptake and three-dimensional collagen gel model. For experimental CNV model, intense fundus laser photocoagulation was performed on pigmented rats. The anti-angiogenic efficacy of intraperitoneally injected SU5416 on experimental CNV was evaluated by fluorescein angiography and histology. The extent of fluorescein leakage on late-phase angiograms was scored, and the thickness of CNV membrane was histologically measured under a light microscope. RESULTS: VEGF-induced KDR phosphorylation in cultured BCECs was inhibited by SU5416 in a dose-dependent manner (0-3 microM) with IC50 of 0.29 +/- 0.071 microM. SU5416 treatment also resulted in a dose-dependent prohibition of VEGF-induced p44/p42 MAPK phosphorylation, [3H]thymidine uptake and in vitro tube formation with corresponding concentrations that inhibited KDR phosphorylation. The leakage score on fluorescein angiography for experimental CNV was significantly lower in the SU5416-treated group than in the control group (P<0.01). Histologically, the CNV membranes in the SU5416-treated group were 31.6% thinner than those in the control group (P<0.01). CONCLUSION: These results strengthen the evidence for a critical role of the VEGF-KDR system in the development of CNV, indicating that KDR selective inhibitor might be beneficial for the treatment of intraocular angiogenic diseases, including age-related macular degeneration.

Elevated adrenomedullin in the vitreous of patients with diabetic retinopathy.

Adrenomedullin (AM) is a multifunctional peptide with various physiological actions, including vasodilatation, a defense mechanism against microorganisms, the regulation of growth and the regulation of insulin and glucose. In this study, we measured the vitreous AM levels in patients with diabetes mellitus to determine its potential involvement in the pathogenesis of diabetic retinopathy (DR). We used an immunoradiometric assay to measure the vitreous AM concentrations in a total of 28 eyes: 13 with DR and 15 with macular holes (15 men and 13 women, 62.9 +/- 10.4 years old). The AM levels in the vitreous fluid of patients with DR (22.9 +/- 7.9 fmol/ml) were found to be significantly higher than the corresponding AM levels in patients with macular holes (4.7 +/- 1.1 fmol/ml) (p < 0.05). These results indicate that the increase in the vitreous AM is related to DR.

Possible benefits of triamcinolone-assisted pars plana vitrectomy for retinal diseases.

PURPOSE: To study the advantages and complications of triamcinolone acetonide (TA)-assisted pars plana vitrectomy (PPV) for various retinal diseases. METHODS: This report is an interventional case series and nonrandomized study. One hundred seventy-seven eyes from 158 patients underwent PPV with or without TA. Group TA(+) consisted of 94 eyes and group TA(-) consisted of 83 eyes. The improvement in vision and postoperative complications were prospectively studied. RESULTS: Sixty-two percent of the eyes in group TA(+) and 49% of the eyes in group TA(-) had improved vision after surgery (P = 0.34). Twelve eyes in group TA(+) and 12 eyes in group TA(-) had an intraocular pressure higher than 21 mmHg after the operation, with no statistically significant difference (P = 0.63). Four eyes with proliferative diabetic retinopathy in group TA(+) and five eyes with proliferative diabetic retinopathy in group TA(-) needed an additional filtering surgery. Group TA(+) (five eyes) had a lower incidence (P = 0.041) of reoperation caused by preretinal fibrous membrane formation than group TA(-) (13 eyes). No apparent corneal disorder or infectious signs were found in any eyes. CONCLUSIONS: Triamcinolone acetonide-assisted PPV appears to be potentially useful to reduce the incidence of reoperation owing to preretinal fibrosis with no serious complications.

Functional role of Egr-1 mediating VEGF-induced tissue factor expression in the retinal capillary endothelium.

PURPOSE: To investigate the causal relationship between VEGF and tissue factor (TF) expression, and its intracellular signaling in the retinal capillary endothelium both in vitro and in vivo. METHODS: TF mRNA and protein expression in cultured bovine retinal capillary endothelial cells (BRECs) were detected by RT-PCR and western blotting. The expression and subcellular localization of Egr-1 were analyzed by immunocytochemistry and western blotting. Involvement of p44/p42 MAPK pathway in this signaling was assessed using PD98059. Electrophoretic mobility shift assay (EMSA) was performed using human TF Egr-1/Sp-1 overlapping promoter region (-85 to -70). Decoy oligonucleotide was transfected into BRECs to clarify the critical transcription factor mediating VEGF-induced TF gene expression. To evaluate the importance of GC rich region in VEGF-induced TF protein expression in rat retinas, Mithramycin was intraperitoneally administered. RESULTS: VEGF stimulated TF mRNA and protein expression in cultured BRECs, reaching maximal effect after 4 h and 10 h, respectively. VEGF activated transcription factor Egr-1 within 60 min. Inactivation of Egr-1 by PD98059 resulted in the prohibition of VEGF-induced TF gene expression. EMSA revealed the increment of Egr-1 binding with TF promoter region by displacing Sp1 after treatment with VEGF. Transfection of the Egr-1/Sp-1 overlapping decoy into BRECs inhibited VEGF-dependent TF gene expression. Mithramycin almost completely suppressed VEGF-induced TF protein expression in retinal capillary system in vivo (80%, p<0.01). CONCLUSION: Transcription factor Egr-1, which lies downstream of p44/p42 MAPK, critically mediates VEGF-dependent TF expression in the retinal capillary endothelium.

Re-worsening factor after successful vitrectomy for diabetic retinopathy: optic disc fibrovascular proliferation and macular disease.

PURPOSE: To investigate the factors that influence the visual-changing pattern in proliferative diabetic retinopathy even after successful vitrectomy. METHODS: One hundred and forty-seven consecutive eyes were retrospectively reviewed for 6-48 (average 20) months, and were divided into the following 4 groups based on their changing pattern of vision: group A, the visual acuity improved postoperatively and maintained the maximal corrected vision throughout the observation period (n = 49); group B, the visual acuity improved postoperatively but deteriorated thereafter (n = 68); group C, the visual acuity remained the same as before operation (n = 17), and group D, the visual acuity deteriorated immediately after vitrectomy (n = 13). Various issues including systemic conditions, blood tests, preoperative ocular findings, the operative procedures and postoperative complications were reviewed based on the patient records. These issues were analyzed by Spearman's rank correlation, chi(2) test, an analysis of variance (ANOVA) and the Kruskal-Wallis test. Finally, the discriminate factors between groups A and B were examined by a stepwise logistic regression analysis. RESULTS: The following tendencies were observed in all 4 groups: younger patients tended to show a better visual-changing pattern (p = 0.02); patients with younger age at diabetes onset had a better visual-changing pattern after vitrectomy (p = 0.001), and a lower hemoglobin (Hb) A1c level is associated with a better visual changing pattern (p = 0.017). Preoperative rubeosis and macular detachment were frequently found in groups C and D, as well as postoperative rubeosis, vitreous bleeding and retinal detachment. Finally, a stepwise logistic regression analysis showed both fibrovascular proliferation (p = 0.016) from the optic disc and postoperative macular disease (p = 0.0009) to be significant factors for differentiating group A from group B. CONCLUSIONS: In addition to the factors which have already been indicated to affect the visual outcome of a vitrectomy, preoperative findings such as optic disc fibrovascular proliferation and postoperative macular disease were found to affect the visual-changing pattern after a successful vitrectomy. The optimal timing of surgery is very important not only in order to obtain good visual acuity but also to maintain good vision even after a successful vitrectomy.