Comparison of diode laser trans-scleral cyclophotocoagulation versus implantation of a 350-mm2 Baerveldt glaucoma drainage device for the treatment of glaucoma in dogs (a retrospective study: 2010-2016).

OBJECTIVE: To compare outcomes following trans-scleral cyclophotocoagulation (TSCP) and 350-mm2 Baerveldt implantation in the treatment of canine refractory glaucoma. DESIGN: Retrospective case study. CASE SELECTION: Client owned dogs undergoing surgical treatment of glaucoma within a veterinary referral hospital. PROCEDURES: Eighty-six glaucoma surgeries were performed on 83 eyes (69 dogs) diagnosed with primary or secondary glaucoma. Medical records were retrieved, and baseline data, surgery, medications, intraocular pressures (IOPs), vision, and complications were extracted. RESULTS: Fifty-four eyes (44 dogs) were treated with TSCP and placement of an anterior chamber suture shunt; 28 eyes (24 dogs) were implanted with a Baerveldt glaucoma drainage device (GDD); and four eyes (4 dogs) underwent GDD implantation after failure of TSCP to manage IOP. Following TSCP, IOP control (<20 mmHg) and vision retention occurred in 81.5% and 42.6%, respectively, for 16.1 ± 1.36 months. Following GDD implantation, 71.4% maintained IOP <20 mmHg and 69.6% maintained vision for 11.0 ± 0.94 months. IOP control without loss of vision was more likely following Baerveldt implantation (17/28; 60.7%) than TSCP (19/54; 35.2%) (P = 0.027). One eye had functional vision restored following GDD placement. IOP control without adjunctive medications was more likely following Baerveldt implantation (P = 0.02). CONCLUSIONS: In this study, eyes treated with Baerveldt GDD implantation were more likely to maintain IOP control and retain vision compared to eyes treated with TSCP and placement of an anterior chamber suture shunt. Lack of formal randomization, inconsistencies in surgical techniques and TSCP protocols, and potential unmeasured confounders must be considered when extrapolating from this retrospective study.

Use of a 350-mm2 Baerveldt glaucoma drainage device to maintain vision and control intraocular pressure in dogs with glaucoma: a retrospective study (2013-2016).

OBJECTIVE: To evaluate the 350-mm2 Baerveldt glaucoma drainage device (GDD) in dogs with refractory glaucoma when modifications to address postoperative hypotony (extraluminal ligature; intraluminal stent) and the fibroproliferative response (intraoperative Mitomycin-C; postoperative oral colchicine and prednisolone) are implemented as reported in human ophthalmology. DESIGN: Retrospective case series. ANIMALS: Twenty-eight client-owned dogs (32 eyes) including seven dogs (nine eyes) with primary glaucoma and 21 dogs (23 eyes) with secondary glaucoma. METHODS: The medical records of all dogs undergoing placement of a 350-mm2 Baerveldt GDD at a veterinary ophthalmology referral service between 2013 and 2016 were reviewed. Signalment, diagnosis, duration and previous treatment of glaucoma, previous intraocular surgery, IOP, visual, and surgical outcomes were recorded. RESULTS: IOP was maintained <20mmHg in 24 of 32 (75.0%) eyes. Fourteen eyes (43.8%) required no adjunctive treatments to maintain this IOP control. Fewer doses of glaucoma medication were required following surgery. Vision was retained in 18 of 27 (66.7%) eyes with vision at the time of surgery. No eyes that were blind at the time of surgery (n = 5) had restoration of functional vision. Complications following surgery included hypotony (26/32; 81.3%), intraocular hypertension (24/32; 75.0%), and fibrin formation within the anterior chamber (20/32; 62.5%). The average follow-up after placement of the GDD was 361.1 days (median 395.6 days). CONCLUSION: Efforts to minimize postoperative hypotony and address the fibroproliferative response following placement of a 350-mm2 Baerveldt GDD showed an increased success rate to other reports of this device in dogs and offers an alternative surgical treatment for controlling intraocular pressure in dogs with glaucoma.

Primary congenital glaucoma outcomes: lessons from 23 years of follow-up.

PURPOSE: To determine in primary congenital glaucoma whether age of presentation influences surgical success, the degrees of angle surgery needed to achieve glaucoma control, and whether there are critical ages where glaucoma progresses, requiring further surgical management. DESIGN: Retrospective cohort study. METHODS: The medical records of patients with primary congenital glaucoma over a 23-year period were reviewed: 192 procedures were performed on 117 eyes (70 patients). The number and age of angle procedures and final visual acuity was analyzed. Surgical success was defined as stable intraocular pressure and optic disc appearance. RESULTS: Procedures involving 83 of the 110 eyes (75.5%) undergoing angle surgery were successful, with 2-, 4-, 6-, and 10-year success rates of 92%, 86%, 84%, and 75%, respectively. Subgroup analysis (<3 months; 3-6 months; >6 months) comparing age of diagnosis to visual outcome (<20/200, 20/200-20/40, >20/40) was significant (P = .04). The age at first operation (P = .94), the number of angle operations (P = .43), and their effect on angle surgery success was not significant. Seven of 192 operations were performed after the age of 8 years (3.6%). After the initial angle surgeries within the first year of life, the third procedure occurred at a median age of 2.4 years (interquartile ratio [IQR] 0.6-3.8 years) and the fourth procedure occurred at a median age of 5.3 years (IQR 2.5-6.1 years). CONCLUSIONS: Children diagnosed at <3 months of age had a visual outcome of <20/200 despite successful glaucoma control. Age of presentation did not affect surgical success. A total of 78.9% of cases undergoing primary trabeculotomy were controlled with 1 operation: 4 clock hours of angle (120 degrees). Analysis of glaucoma progression suggests critical ages where further glaucoma surgery is required at around 2 and 5 years of age.

Immunomodulatory effects of bone marrow-derived mesenchymal stem cells on pro-inflammatory cytokine-stimulated human corneal epithelial cells.

PURPOSE: To investigate the modulatory effect of rat bone marrow mesenchymal stem cells (MSC) on human corneal epithelial cells (HCE-T) stimulated with pro-inflammatory cytokines interferon gamma (IFN-γ) and tumor necrosis factor alpha (TNF-α) in an in vitro co-cultured model. METHODS: HCE-T alone and co-cultured with MSC were stimulated with IFN-γ/TNF for 24 and 48 hours or left untreated. The expression of intracellular adhesion molecule (ICAM)-1, human leukocyte antigen ABC, DR and G (HLA-ABC, HLA-DR, HLA-G) were investigated by flow cytometry. Subcellular localization of nuclear factor-kappa B (NF-κB) and expression of indoleamine 2,3-dioxygenase (IDO) were assessed by immunofluorescence staining and western blot. The concentration of transforming growth factor beta 1 (TGF-ß1) in the conditioned media from different cultures was evaluated by enzyme-linked immunosorbent assay. NF-κB and TGF-ß1 signaling pathway blocking experiments were performed to analyze associations between the expression of cell surface molecules and the NF-κB transcription pathway, and the expression of IDO and TGF-ß1 signaling pathway. RESULTS: IFN-γ/TNF treatment significantly up-regulated expression of ICAM-1, HLA-ABC, and induced de novo expression of HLA-DR and IDO on HCE-T cultured alone, while HLA-G expression remained unaffected. Up-regulation was significantly inhibited by co-culture with MSC. Increased TGF-ß1 secretion was detected in 48 h IFN-γ/TNF-stimulated MSC monocultures and HCE-T/MSC co-cultures. MSC attenuated the activation of cytokine-induced NF-κB and IDO induction. Blockade of NF-κB transcription pathway by BMS-345541 significantly reduced the up-regulation of ICAM-1, HLA-ABC, HLA-DR and IDO expression, while blockade of TGF-ß1 signaling pathways reversed the modulatory effect of MSC on IDO expression. CONCLUSIONS: MSC reduced the expression of adhesion and immunoregulatory molecules on pro-inflammatory cytokine-stimulated HCE-T via the NF-κB transcription pathway. MSC attenuated expression of IDO through both NF-κB transcription and TGF-ß1 signaling pathways. Co-culture of HCEC with MSC therefore provides a useful in vitro model to study the anti-inflammatory properties of MSC on corneal epithelium.

The importance of electrophysiology in revealing a complete homozygous deletion of KCNV2.

Visual electrophysiology is an important ancillary investigation in children with poor vision and nystagmus. Cone dystrophy with supranormal rod electroretinogram (KCNV2 retinopathy) has pathognomonic electrophysiology findings that, if identified, direct molecular genetic testing. We report the case of a 6-year-old boy with typical electrophysiology findings of KCNV2 retinopathy but with abnormal cone dysfunction compared to other patients with mutations in KCNV2. Molecular genetic testing revealed complete homozygous deletion of KCNV2. To our knowledge, this is the first such report. The greater cone dysfunction seen in this case suggests a phenotypic link to the genetic changes.

Multifocal blue-on-yellow visual evoked potentials in early glaucoma.

OBJECTIVE: To determine the sensitivity and specificity of blue-on-yellow multifocal visual evoked potentials (mfVEPs) in early glaucoma. DESIGN: Cross-sectional study. PARTICIPANTS: Fifty patients with a confirmed diagnosis of early glaucoma and 60 normal participants. METHODS: Black-and-white mfVEPs and blue-on-yellow mfVEPs were recorded using the Accumap version 2.0 (ObjectiVision Pty. Ltd., Sydney, Australia). All patients also underwent achromatic standard automated perimetry (SAP). MAIN OUTCOME MEASURES: Multifocal VEP amplitude and latency values in glaucoma patients were analyzed and compared with those of the normal controls. RESULTS: Based on the definition of visual field defect, in the group of glaucomatous eyes with SAP defects, amplitude of blue-on-yellow mfVEP was abnormal in all 64 cases (100% sensitivity), whereas black-and-white mfVEP missed 5 cases (92.2% sensitivity). Generally, larger scotomata were noted on blue-on-yellow mfVEP compared with black-and-white mfVEP for the same eyes. There was high topographic correspondence between SAP and amplitude of blue-on-yellow mfVEP and significant (P<0.0001) correlation between them (correlation coefficient, 0.73). Abnormal amplitude was detected in 3 of 60 eyes of control subjects (95% specificity). There was, however, no correlation between visual field defect and latency delay in glaucoma patients. Although there was a significant difference between averaged latency of control and glaucoma eyes, values considerably overlapped. CONCLUSIONS: The blue-on-yellow mfVEP is a sensitive and specific tool for detecting early glaucoma based on amplitude analysis.

Multifocal visual evoked potential analysis of inflammatory or demyelinating optic neuritis.

OBJECTIVE: To determine the sensitivity of multifocal visual evoked potentials (mVEP) in optic neuritis of an inflammatory or demyelinating nature. DESIGN: Cross-sectional study. PARTICIPANTS: Sixty-four patients participated who had a confirmed diagnosis of optic neuritis (ON) (past and acute). Based on the McDonald multiple sclerosis (MS) criteria, 25 patients (27 eyes with ON) were deemed to have isolated optic neuritis and thus not have MS (i.e., the not-MS group), and 19 patients (24 eyes with ON) had a diagnosis of MS (i.e., the MS group). The remaining 20 patients (25 eyes with ON) were at a high risk of MS, but diagnostic evaluation was equivocal, and thus were classified as the possible MS group. A control group of 20 normal patients was enrolled. TESTING: The mVEP test was performed using the Accumap. All ON patients had recent magnetic resonance imaging scans of the brain and spinal cord. MAIN OUTCOME MEASURES: Multifocal visual evoked potentials amplitude and latency values were analyzed within each group and were compared with the normal controls. RESULTS: No abnormality was recorded on mVEP in the control group. Of all the ON eyes, 74 (97.3%) were abnormal on mVEP testing. Amplitude values were abnormal in 92.6% of not-MS eyes, 92.0% of possible MS eyes, and 100% of those with MS, and latency was abnormal in 33.3%, 76.0%, and 100%, respectively. There was a significant difference in the mVEP latency z-scores among all ON groups (P<0.01; Kruskal-Wallis test). Although distribution graphs of latency z-scores in the not-MS and MS groups had single peaks and were clearly separate from each other, the latency z-score distribution within the possible MS group in postacute patients was bimodal, with each peak corresponding to the distribution of the not-MS and MS group, respectively. The mVEP latency z-scores had a sensitivity and specificity of 100% in detecting patients with ON due to MS when compared with normal patients. CONCLUSIONS: The mVEP test is a sensitive and specific tool for detecting optic neuritis. There was a significant difference in latency analysis findings between patient groups as classified according to the McDonald MS criteria. Latency results suggest a role in identifying a patient's risk for future MS.

In vitro targeting of NG2 antigen by 213Bi-9.2.27 alpha-immunoconjugate induces cytotoxicity in human uveal melanoma cells.

PURPOSE: To examine uveal melanoma cell lines for the expression of human melanoma proteoglycan (NG2) using monoclonal antibody (mAb) 9.2.27 and subsequently to assess the in vitro specificity and cytotoxicity of mAb 9.2.27 conjugated to the alpha-particle-emitting radioisotope 213bismuth (213Bi-9.2.27) for uveal melanoma cells. METHODS: Immunocytochemistry and flow cytometry were used to examine OCM-1, OCM-3, OCM-8, OMM-1, Mel202 and 92-1 melanoma cell lines for NG2 expression. Melanoma cells were treated with test (213Bi-9.2.27) or control (213Bi-A2) alpha-immunoconjugates (AICs). The specific cytotoxicity of 213Bi-9.2.27 AIC was evaluated using an MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfenyl)-2H-tetrazolium, inner salt) assay. Cell death was also assessed using TUNEL. RESULTS: OCM-1, OCM-8, OMM-1, and Mel202 cells strongly expressed NG2. OCM-3 cells showed moderate expression and 92-1 cells were NG2-negative. 213Bi-9.2.27 specifically killed NG2-positive OCM-1, OCM-8, and OMM-1 cells in a concentration-dependent manner. D0 values for 37% cell survival of NG2-positive OCM-1, OCM-8, and OMM-1 cells were 5.8, 5.0, and 5.6 microCi, respectively, and the value was 43.4 muCi for NG2-negative 92-1 cells. CONCLUSIONS: The specific cytotoxicity of 213Bi-9.2.27 AIC for NG2-positive, but not NG2-negative, cells suggests NG2 is a suitable target for alpha-immunotherapy in uveal melanoma. 213Bi-9.2.27 AIC used directly or as adjunct therapy may be a promising new agent for treating NG2-positive uveal melanomas or metastases.

Effect of pupil size on multifocal pattern visual evoked potentials.

The purpose of this study was to investigate the influence of pupil diameter on the amplitude and latency of multifocal visual evoked potentials (mfVEP). The multifocal objective perimeter (Accumap; Objectivision) was used to stimulate the visual field at 56 sites extending to 32 degrees using a pseudo-random pattern stimulus. The mfVEP were recorded using bipolar occipital electrodes, 7 min/eye. Ten normal subjects were recruited from the community and one eye was randomly selected for testing. The mfVEP were recorded at four different pupil diameters (2 mm, 4 mm, 6 mm, 8 mm), obtained by applying tropicamide (0.5%) or pilocarpine (2%) in different dilutions. Appropriate refractive correction was provided to overcome cycloplegia and achieve a visual acuity of 6/7.5 or better. Analysis revealed that at most pupil diameters the normalized full field amplitude did not show significant variation, except at the most miotic pupil diameter (2 mm), where the amplitude became reduced, based on 2-way anova and Tukey's T method. There was, however, significant correlation between latency and pupil area (correlation coefficient: upper field -0.63, lower field -0.76). The results suggest that even in the presence of mydriatics or miotics, the mfVEP test can be used to assess diseases that affect amplitude, provided near correction is used. The interpretation of latency, however, must be made with caution, as a borderline conduction defect with a dilated pupil may appear normal.

Immunoglobulin superfamily expression in primary retinoblastoma and retinoblastoma cell lines.

Retinoblastoma (Rb) is the most common intraocular tumor of childhood. In this study we examined primary Rb specimens and Rb cell lines for the expression of immunoglobulin superfamily (IgSF) antigens: MHC class I and II (MHC-I and MHC-II), neural cell adhesion molecule (NCAM), intercellular adhesion molecule-1 (ICAM-1), and Thy-1, which play an important role in immune system and tumor cell interactions. MHC-I and-II, ICAM-1 (CD54), NCAM (CD56), and Thy-1 (CDw90) immunoreactivity was studied in eight primary Rb biopsy specimens using immunohistochemistry, three using immunoelectron microscopy, and six Rb cell lines using flow cytometry (FCM). Parenchymal and vascular-associated cells, phenotypically similar to retinal microglia, strongly expressed MHC-II immunoreactivity and were distributed throughout primary Rb specimens. However, MHC-II expression on Rb cell lines was similar to nonspecific control levels. Tumor cells in primary Rb specimens displayed high NCAM, moderate Thy-1, and low MHC-I and ICAM-1 immunolabeling. Tumor vasculature expressed low to moderate MHC-I and ICAM-1 immunoreactivity and moderate Thy-1 immunoreactivity. NCAM was not detected on the vasculature of primary Rb specimens. Rb cell lines displayed variable expression of Thy-1, ICAM-1, and MHC-I. NCAM was highly expressed on five of six Rb cell lines. The high levels of constitutive NCAM immunoreactivity on Rb tumor cells confirm the neuroectodermal origins of this tumor. Additionally, the variable expression of Thy-1 may suggest separate neural lineages or differences in the maturational status ofsome Rb tumors. The presence of a population of infiltrating MHC-II-positive cells in primary Rb tumors has implications for immunomodulation of Rb growth.

Effects of post-mortem delay and storage duration on the expression of GFAP in normal human adult retinae.

Glial fibrillary acidic protein (GFAP) is an established marker of retinal glia and has been shown to be modulated by several cytokines and retinal pathology. The influence of a number of factors, including post-mortem delay, storage duration and retinal pathology, on the distribution and morphology of macroglia and GFAP antigenicity was examined in human retina. The effects of these parameters on GFAP expression were estimated using immunohistochemistry, confocal microscopy and image analysis. Changes in expression of antigenicity were analysed in human retinal cryosections at three levels: constitutive,aberrant and total. The results indicated that short-term and long-term storage duration had no significant effect on GFAP immunoreactivity at all three levels of expression (P > 0.2).However, a significant increase in GFAP immunoreactivity and distribution at all three levels of expression was associated with prolonged post-mortem delay (> 30 h) (P < 0.05). This study highlights the importance of rigorous matching of post-mortem delay between control specimens in histological studies of human retinae. The study further demonstrates the utility of Eye Bank retinae fixed and stored in 2% paraformaldehyde, provided that appropriate controls are applied.