Perifoveal Microvascular Changes following Internal Limiting Membrane Peeling Surgery for Epiretinal Membrane and Macular Hole.

INTRODUCTION: The aim of the study was to evaluate perifoveal microvasculature changes following pars plana vitrectomy with internal limiting membrane peeling for the epiretinal membrane (ERM) and macular hole (MH). METHODS: This retrospective study included 59 eyes from 59 patients. Subjects were divided into two groups: an ERM group (n = 43) and an MH group (n = 16) based on the initial diagnosis. Swept-source optical coherence tomography angiography (SS-OCTA) was performed in the macular area, pre- and postoperatively. Perifoveal microvascular changes were calculated using MATLAB from the 6 × 6 mm SS-OCTA images, excluding the foveal avascular zone. Pre- and postoperative perifoveal vessel densities (pfVDs) were separately analyzed in six sectors (superior, superotemporal, inferotemporal, inferior, inferonasal, and superonasal) in the superficial capillary plexus (SCP) and deep capillary plexus (DCP). The baseline characteristics and other clinical factors were compared between the ERM and MH groups. RESULTS: The postoperative best-corrected visual acuity significantly improved in both groups (p < 0.05). One year after surgery, the pfVD in the SCP of the ERM group significantly decreased in the inferotemporal sector (p = 0.049). The postoperative pfVD in the DCP of the MH group significantly decreased in temporal sectors (p < 0.05). The postoperative mean pfVD in the SCP in the MH group was significantly lower than that in the ERM group (p = 0.003). The presence of a dissociated optic nerve fiber layer (DONFL) was 75% in the MH group and 22% in the ERM group (p = 0.018). The correlation between the pfVD and DONFL was not statistically significant. CONCLUSION: Postoperative pfVD reduction in the temporal sector, a corresponding area in which DONFL is present after MH surgery, was significantly observed. After vitreoretinal surgery in MH patients, OCTA may serve as a useful tool for monitoring perifoveal microvascular changes, especially in temporal sectors.

Peripapillary microvasculature changes after vitrectomy in epiretinal membrane via swept-source OCT angiography.

PURPOSE: To evaluate the peripapillary microvasculature changes in patients with epiretinal membrane (ERM) following pars plana vitrectomy (PPV) with internal limiting membrane (ILM) peeling using swept-source optical coherence tomography angiography (SS-OCTA). METHOD: Medical records and multimodal imaging data of 33 eyes after PPV for ERM were retrospectively reviewed. Peripapillary SS-OCTA images of 6×6 mm2 were recorded at at pre- and post-operatively every 6 months for 1 year. A semi-automated method was used to analyzed SS-OCTA images, excluding the optic disc area, using the MATLAB software. The peripapillary vessel density (pVD) of superficial capillary plexus (SCP) and deep capillary plexus (DCP) was quantified in four quadrants (superior, inferior, nasal and temporal). RESULT: The mean pVD in SCP and DCP decreased at 6- and 12-months follow-up. In sectoral analysis, superior, inferior, and temporal quadrants pVD in SCP and DCP were significantly reduced at 1 year after vitrectomy (all p < 0.05). Meanwhile, inferior quadrants pVD in SCP and DCP showed the earliest significant reduction at 6-months (p = 0.022 and 0.048, respectively). A reduction of post-operative mean pVD in DCP was significantly greater in patients with diabetic retinopathy (p = 0.043). CONCLUSION: Peripapillary capillary density significantly decreased after surgical removal of ERM. Vitrectomy with ILM peeling can cause peripapillary microvascular damage starting in inferior sector.

Clinical Characteristics and Long-term Outcomes in Diabetic Macular Edema Patients: With or without Additional Injection Following Ranibizumab Loading.

PURPOSE: To investigate the baseline characteristics in patients with diabetic macular edema (DME) during 7 years according to the need for additional treatments after intravitreal ranibizumab (RBZ) loading injections. METHODS: The medical records of 32 patients treated with intravitreal RBZ loading for DME during 7 years were reviewed. After three-consecutive monthly RBZ injections, additional treatment was decided according to the patient's response to RBZ loading. Based on whether the patients received treatment with or without additional injections, including intravitreal antivascular endothelial factor or steroid injection, they were divided into the "no add (NA)" or "add" groups, respectively. The baseline best-corrected visual acuity (BCVA), macular volume (MV), central subfoveal thickness, and other clinical factors were analyzed, and their 7-year changes were compared between the two groups. RESULTS: The BCVA of the NA group was better than that of the add group at 2, 3, 5, and 7 years (year 2, 3, and 5; p < 0.01, respectively). Baseline MV was significantly smaller in the NA group than in the add group (10.72 ± 0.88 µm vs. 11.98 ± 1.64 µm, p = 0.008). The DME duration before treatment in the NA group was significantly shorter than in the add group (1.03 ± 0.98 years vs. 1.91 ± 1.33 years, p = 0.042). The proportion of patients with serous retinal detachment or cystic macular edema was significantly lower in the NA group than in the add group (35.3% vs. 73.3%, p = 0.042). The NA group had smaller MV until 2 years than the add group (year 1, p = 0.002; year 2, p = 0.006). CONCLUSIONS: The DME patients without additional treatments during 7 years after the initial loading treatment had shorter duration of DME and diffuse retinal thickening morphologic type with lower MV at baseline, and better long-term visual prognosis.

Altitudinal Visual Field Defects Following Diagnostic Transfemoral Cerebral Angiography.

Transfemoral cerebral angiography (TFCA) has been increasingly used as diagnostic method for the evaluation of cerebral vessels. Ophthalmologic complication after TFCA has rarely been reported, and most complications are associated with an intraoperative thrombo-embolic event. We reported a patient who developed a superior altitudinal visual field defect one day after diagnostic TFCA. The ophthalmic exam revealed a prominent inferior optic disc edema, and the fluorescein angiographic showed the non-perfusion of the corresponding inferior sectoral optic disc. Diffusion-weighted MRI on the day following cerebral angiography revealed multiple focal scattered acute infarctions. Even one month after steroid pulse therapy, the superior nasal field defect remained with minimal improvement. We believe this case was consistent with an acute anterior ischemic optic neuropathy (AION) due to thrombo-embolism after TFCA. Ophthalmic examinations and a visual field test should be performed before and immediately after the TFCA, particularly in the case with a high risk of thromboembolic events.

Immunoglobulin E-mediated hypersensitivity reaction after intraperitoneal administration of vancomycin.

Intraperitoneal (IP) vancomycin is widely used to treat Gram-positive peritonitis associated with peritoneal dialysis. There have been two cases of red man syndrome (RMS), a vancomycin-specific nonimmunologic reaction, associated with IP vancomycin. However, immune-mediated hypersensitivity reaction to IP vancomycin has not yet been reported. A 49 year old woman on continuous ambulatory peritoneal dialysis developed her first peritonitis episode. The patient was treated with IP vancomycin once/wk for 4 weeks. She experienced mild itching and flushing throughout her body for 1 day after the second treatment. Whenever vancomycin was administered, generalized urticaria and a prickling sensation developed, and the intensity increased gradually; however, these symptoms improved after vancomycin was discontinued. An allergic skin test was performed 6 weeks after the previous urticarial episode, and an intradermal skin test revealed a positive response to vancomycin. To our knowledge, this is the first case report of immunoglobulin E-mediated hypersensitivity reaction to IP vancomycin administration.

The effect of low-GDP solution on ultrafiltration and solute transport in continuous ambulatory peritoneal dialysis patients.

BACKGROUND: Several studies have reported benefits for human peritoneal mesothelial cell function of a neutral-pH dialysate low in glucose degradation products (GDPs). However, the effects of low-GDP solution on ultrafiltration (UF), transport of solutes, and control of body water remain elusive. We therefore investigated the effect of low-GDP solution on UF, solute transport, and control of body water. METHODS: Among 79 new continuous ambulatory peritoneal dialysis (CAPD) patients, 60 completed a 12-month protocol (28 in a lactate-based high-GDP solution group, 32 in a lactate-based low-GDP solution group). Clinical indices--including 24-hour UF volume (UFV), 24-hour urine volume (UV), residual renal function, and dialysis adequacy--were measured at months 1, 6, and 12. At months 1, 6, and 12, UFV, glucose absorption, 4-hour dialysate-to-plasma (D/P) creatinine, and 1-hour D/P Na(+) were assessed during a modified 4.25% peritoneal equilibration test (PET). Body composition by bioelectric impedance analysis was measured at months 1 and 12 in 26 CAPD patients. RESULTS: Daily UFV was lower in the low-GDP group. Despite similar solute transport and aquaporin function, the low-GDP group also showed lower UFV and higher glucose absorption during the PET. Factors associated with UFV during the PET were lactate-based high-GDP solution and 1-hour D/P Na(+). No differences in volume status and obesity at month 12 were observed, and improvements in hypervolemia were equal in both groups. CONCLUSIONS: Compared with the high-GDP group, the low-GDP group had a lower UFV during a PET and a lower daily UFV during the first year after peritoneal dialysis initiation. Although the low-GDP group had a lower daily UFV, no difficulties in controlling edema were encountered.

Obstructive uropathy after inguinal herniorrhaphy with a mesh in a renal transplant patient.

A 67-year-old male renal transplant patient presented with a right inguinal bulging mass, and was diagnosed with a right indirect inguinal hernia. The day following inguinal herniorrhaphy, serum creatinine became elevated. The patient was oliguric and had abdominal pain on the first day after inguinal herniorrhaphy with a mesh. We diagnosed him with acute renal failure and subsequently performed acute hemodialysis. The kidney computed tomography showed hydronephroureter, with distal ureter obstruction. With urgent percutaneous nephrostomy, we were able to relieve the obstructive uropathy with distal ureteral stenosis. Subsequently, hernia repair was performed with removal of the mesh, followed by the antegrade ureteral stent insertion. Renal function was recovered after ureteral stent insertion. This case shows that acute renal failure can occur due to ureteral obstruction, complicated by an inguinal hernia repair, and this can be successfully treated with percutaneous nephrostomy and inguinal hernia repair with mesh removal.

Catheter revision for the treatment of intractable exit site infection/tunnel infection in peritoneal dialysis patients: a single centre experience.

AIM: Catheter-related infection is a major cause of catheter loss in peritoneal dialysis (PD). We evaluated the effect of catheter revision on the treatment of intractable exit site infection (ESI)/tunnel infection (TI) in PD patients who required catheter removal. METHODS: We reviewed the medical records of 764 continuous ambulatory peritoneal dialysis (CAPD) patients from May 1995 to April 2011 at our hospital. One hundred and twenty six patients had more than one occurrence of ESI. Catheter revision was performed to treat intractable ESI/TI. Incidence of ESI, causative organisms and the outcomes of catheter revision were analyzed. RESULTS: The total PD duration of all patients was 32,581 months. Three hundred and twelve ESI episodes occurred in 126 patients and the incidence of ESI was 1/104 patient-months (0.12/patient-year). The most common causative organism was methicillin-sensitive Staphylococcus aureus (MSSA) (98 episodes), followed by Pseudomonas aeruginosa (63 episodes) and methicillin-resistant S. aureus (MRSA) (28 episodes). Among these, catheter revision was required due to intractable ESI/TI in 36 patients. The most common causative organism was MSSA (14 episodes) followed by P. aeruginosa (10 episodes) and MRSA (six episodes) in catheter revision cases. The outcomes of catheter revision were as follows: ESI relapsed in 11 patients (30.6%) after catheter revision. Among them, five patients were treated with antibiotic treatment, two patients required secondary catheter revision, four patients required catheter removal due to ESI/TI accompanying peritonitis. The catheter survival rate after catheter revision was 89.7% in one year. There were no statistical differences in the rates of ESI relapse after catheter revision between ESI caused by P. aeruginosa (5/10, 50%) and ESI caused by S.aureus (6/21, 28.6%). CONCLUSION: Catheter revision may be an alternative treatment option to treat intractable ESI/TI before catheter removal is considered in PD patients.

Effect of icodextrin dialysis solution on body weight and fat accumulation over time in CAPD patients.

BACKGROUND: The purpose of this study was to analyse the changes of body composition and the effects of icodextrin dialysis solution over time on peritoneal dialysis (PD) in continuous ambulatory peritoneal dialysis (CAPD) patients. METHODS: Among 183 incident patients, 75 patients finished a complete 36-month protocol. Clinical indices including daily glucose absorption and body composition, by bioelectrical impedance analysis (BIA), were measured in both groups (icodextrin group: 36 patients, non-icodextrin group: 39 patients) at the 1st (baseline), 12th, 24th and 36th months. RESULTS: There were significant increases in body weight and fat mass during the 36 months after initiation of CAPD. It was found that 78% of 3 years of weight gain occurred during the first year and 88% of weight gain at the end of the first year was fat mass gain. The icodextrin group showed a significantly lower percent of fat mass during the first 36 months (P < 0.05) and also less changes in body weight, fat mass, percent (%) fat mass, visceral fat area and waist/hip ratio at 1, 2 and 3 years than the non-icodextrin group. There were no significant changes in total body water (TBW), extra cellular fluid (ECF), oedema index and lean body mass (LBM) through comparable daily and ultrafiltration volume (UFV) between the two groups during the initial 3 years. Factors associated with the higher percent of fat mass gain over time on peritoneal dialysis were age, diabetes, gender (female) and non-icodextrin group (all, P < 0.01, generalized estimating equation). CONCLUSION: The application of icodextrin solution may be a better option to alleviate excessive fat gain over time for patients on PD.

The heme oxygenase-1 genotype is a risk factor to renal impairment of IgA nephropathy at diagnosis, which is a strong predictor of mortality.

The induction of heme oxygenase-1 (HO-1) ameliorates oxidative stress and inflammatory process, which play important roles in IgA nephropathy. We hypothesized length polymorphism in the promoter region of the HO-1 gene, which is related to the level of gene transcription, is associated with disease severity of IgA nephropathy. The subjects comprised 916 patients with IgA nephropathy and gene data. Renal impairment was defined as an estimated glomerular filtration rate less than 60 mL/min/1.73 m(2) at diagnosis. The short (S: <23), medium (M: 23-28), and long (L: >28) (GT) repeats in the HO-1 gene was determined. The frequencies of S/S, S/M, M/M, S/L, L/M, and L/L genotypes were 7.2%, 6.9%, 3.1%, 30.8%, 22.7%, and 29.4%, respectively. The baseline characteristics were not different. In the S/S genotypic group, the renal impairment rate was 18.2%, which was lower than 32.2% in the group with M/M, L/M, or L/L genotype. The odds ratio of renal impairment in S/S genotype, compared to that in M/M, L/M, or L/L genotype, was 0.216 (95% confidence interval, 0.060-0.774, p=0.019). The HO-1 gene promoter length polymorphism was related to the renal impairment of IgA nephropathy at diagnosis, which is an important risk factor for mortality in IgA nephropathy patients.

The association between the vascular endothelial growth factor-to-cancer antigen 125 ratio in peritoneal dialysis effluent and the epithelial-to-mesenchymal transition in continuous ambulatory peritoneal dialysis.

We examined peritoneal growth factors, mesothelial mass, and epithelial-to-mesenchymal transition (EMT) in response to peritoneal exposure to peritoneal dialysate with standard and low concentrations of glucose degradation products (GDPs). We randomized 56 incident continuous ambulatory peritoneal dialysis (CAPD) patients to receive either low-GDP (30 patients) or high-GDP (standard) peritoneal dialysis (PD) solution (26 patients). The effects of the PD solutions on EMT and peritoneal growth factors in overnight dialysate effluent were compared at 1, 6, and 12 months. Assessment of EMT was performed after human peritoneal mesothelial cells (HPMCs) were cultured from overnight effluent. The low-GDP solution group showed significantly higher dialysate levels of cancer antigen 125 (CA125), fibronectin, transforming growth factor beta(TGFbeta)-induced gene product (betaig-h3), and interleukin-6 (IL-6), but the rate of EMT was significantly lower in the low-GDP solution group during the initial 12 months of CAPD treatment. After adjusting peritoneal growth factors for dialysate CA125 concentration, the low-GDP solution group showed significantly lower ratios of fibronectin/CA125, betaig-h3/CA125, IL-6/CA125, TGFbeta/CA125, and vascular endothelial growth factor (VEGF)/CA125 than did patients in the high-GDP (standard) solution group. Factors associated with higher EMT were the type of solution (high in GDPs), the mass of HPMCs (low CA125), and higher VEGF/CA125. Adjustment of dialysate VEGF for effluent CA125 revealed a significant association with EMT. It suggests that fibroblastoid transition from HPMCs could be affected by the intraperitoneal VEGF per unit mass of HPMCs.

The effect of low glucose degradation product dialysis solution on epithelial-to-mesenchymal transition in continuous ambulatory peritoneal dialysis patients.

BACKGROUND: Human peritoneal mesothelial cells (HPMCs) undergo a transition from an epithelial phenotype to a mesenchymal phenotype (EMT) during peritoneal dialysis (PD). That transition may be directly related to failure of peritoneal membrane function. OBJECTIVE: In a randomized prospective controlled study, we investigated the effect of low glucose degradation product (GDP) dialysis solution on the transition of HPMCs. METHODS: Among new continuous ambulatory PD patients, 60 patients completed a 12-month protocol (low-GDP solution group, n = 32; high-GDP solution group, n = 28). At the 1st, 6th, and 12th months, HPMCs drained from overnight effluent were cultured on T25. When they had nearly reached confluence, cell scores were measured blindly by the same person (score 1 = cobblestone-shaped HPMCs, score 2 = mixed, score 3 = fibroblast dominant). Cell scores and clinical indices, including peritoneal markers, were compared between the low-GDP and high-GDP groups at the 1st, 6th, and 12th months. The factors associated with EMT were analyzed with generalized estimating equations using STATA 7.0 (STATA Corp., College Station, Texas, USA). In addition, vimentin and cytokeratin 8/18 stains were used to verify EMT in cultured cells and peritoneal specimens in some patients. RESULTS: (1) The low-GOP group showed higher dialysate cancer antigen 125 levels from the 1st to 12th months (55.4 +/- 24.8 vs 8.8 +/- 1.7, 56.7 +/- 28.1 vs 22.1 +/- 11.3, and 54.2 +/- 28.2 vs 24.6 +/- 16.5 U/mL, at the 1st, 6th, and 12th months, respectively; all p = 0.000). (2) The low-GOP group showed lower cell scores at the 1st, 6th, and 12th months (1.22, 1.22, and 1.56 vs 1.61, 1.75, and 2.14; p < 0.05, p < 0.01, and p < 0.01, respectively). (3) At the 12th month, the number of fibroblast-dominant cultures (score 3) was significantly lower in the low-GOP group [4/32 (12.5%) patients vs 14/28 (50%), p < 0.05]. (4) Both cobblestone-shaped HPMCs and fibroblastoid cells were positively stained with cytokeratin and vimentin. (5) There were many cytokeratin- and vimentin-positive cells in the submesothelial area in the peritoneal biopsy specimens. (6) The consistent factor associated with EMT was only high-GOP solution (60 patients, n = 178, beta coefficient 0.312, p = 0.000; 46 patients, n = 137, beta coef: 0.228, p = 0.000) and not numbers of peritonitis episodes, duration of angiotensin-converting enzyme inhibitor and/or angiotensin receptor blocker medication, or diabetes. CONCLUSION: Low-GDP solution showed beneficial effects such as rapid remesothelialization and less EMT in the peritoneum with time on PD.

Low glucose degradation products dialysis solution modulates the levels of surrogate markers of peritoneal inflammation, integrity, and angiogenesis: preliminary report.

The presence of glucose degradation products (GDPs) in peritoneal dialysis (PD) fluids has many adverse effects, namely clinically significant abdominal pain or discomfort during infusion, inhibition of cell proliferation, impairment of inflammatory cell function, cytotoxicity, and the induction of vascular endothelial growth factor (VEGF). In a prospective, randomized, controlled trial comparing a low GDP PD solution (pH 7.0, two compartment bag: low GDP) to conventional PD solution (pH 5.5: high GDP), the overnight dialysate levels of the markers of inflammation/wound healing (hyaluronic acid (HA)), mesothelial cell mass/membrane integrity (cancer antigen 125 (CA125)), and angiogenesis (VEGF) were assessed over a 12-month period. Twenty-six newly commencing continuous ambulatory peritoneal dialysis (CAPD) patients were randomly assigned to either the Low GDP group (n = 16) or the High GDP group (n = 10). Standard peritoneal permeability analysis for membrane transport characteristics and dialysis adequacy with nutritional status (serum albumin, nPCR) were evaluated at 1, 6, and 12 months. In patients treated with high GDP solution, there was significant increase in VEGF with time (time = 1 month, 67.2 +/- 10.8; time = 6 months, 189.8 +/- 90.2; and time = 12 months, 169.3 +/- 83.1 pg/mg of protein; P < 0.05). There was no significant change of VEGF with time in the low GDP group. Significantly higher concentrations of CA125 (65.5 +/- 10.4 vs. 19.7 +/- 2.6 at 1 month, P < 0.0001; 66.6 +/- 9.8 vs. 29.7 +/- 5.0 at 6 months, P < 0.01; 68.7 +/- 10.5 vs. 30.7 +/- 10.0 U/mL at 12 months, P < 0.01) and lower concentrations of HA (114.6 +/- 18.8 vs. 254.3 +/- 69.2 at 1 month, P < 0.05; 417.5 +/- 57.2 vs. 1277.5 +/- 367.9 ng/mg of protein at 12 month, P < 0.05) were observed in the low GDP group compared with the high GDP group. In conclusion, continuous therapy with the low GDP solution modulates the levels of surrogate markers of peritoneal inflammation, integrity and angiogenesis. The results strongly suggest that the use of a low GDP solution would be beneficial to maintain the function and structural integrity of the peritoneal membrane.