Association Between Ocular Trauma and Activation of Ocular Toxoplasmosis.

PURPOSE: To evaluate the association between ocular trauma and activation of ocular toxoplasmosis. METHODS: Retrospective review of 686 patients with ocular toxoplasmosis and its association with trauma to the eye or the head within 1 week of activation. RESULTS: Ten patients with a history of trauma and activation of ocular toxoplasmosis were detected (10/686; 1.45%). Nine patients showed a primary focus of retinitis without a previous scar and one patient had a recurrent form of ocular toxoplasmosis. From these 10 patients, Toxoplasma IgG was positive in eight of them. The median age of the patients was 35.8 years-old (range 17 to 65). CONCLUSIONS: These cases suggest that trauma can be associated with activation of retinal bradyzoite cysts in ocular toxoplasmosis.

COMPARISON OF 2D AND 3D VIDEO DISPLAYS FOR TEACHING VITREORETINAL SURGERY.

PURPOSE: To compare medical students' learning uptake and understanding of vitreoretinal surgeries by watching either 2D or 3D video recordings. METHODS: Three vitreoretinal procedures (tractional retinal detachment, exposed scleral buckle removal, and four-point scleral fixation of an intraocular lens [TSS]) were recorded simultaneously with a conventional recorder for two-dimensional viewing and a VERION 3D HD system using Sony HVO-1000MD for three-dimensional viewing. Two videos of each surgery, one 2D and the other 3D, were edited to have the same content side by side. One hundred UMass medical students randomly assigned to a 2D group or 3D, then watched corresponding videos on a MacBook. All groups wore BiAL Red-blue 3D glasses and were appropriately randomized. Students filled out questionnaires about surgical steps or anatomical relationships of the pathologies or tissues, and their answers were compared. RESULTS: There was no significant difference in comprehension between the two groups for the extraocular scleral buckle procedure. However, for the intraocular TSS and tractional retinal detachment videos, the 3D group performed better than 2D (P < 0.05) on anatomy comprehension questions. CONCLUSION: Three-dimensional videos may have value in teaching intraocular ophthalmic surgeries. Surgical procedure steps and basic ocular anatomy may have to be reviewed to ensure maximal teaching efficacy.

VITREOMACULAR ADHESION EVOLUTION WITH AGE IN HEALTHY HUMAN EYES.

PURPOSE: To quantify the changes in vitreomacular interactions that occur with normal aging in normal eyes. METHODS: Spectral domain optical coherence tomography (SD-OCT, Spectralis; Heidelberg Engineering, Heidelberg, Germany) foveal scans of subjects with best corrected visual acuity better than 20/40 and no ocular pathology were included in the study. Each scan was analyzed to determine the status of vitreoretinal interface: complete vitreous adhesion, partial posterior vitreous detachment (PVD) with persistent vitreomacular adhesion (VMA), or complete PVD. Area of VMA was delineated using the Spectralis drawing tool and calculated in mm for each scan. Subjects, aged 10 years to 97 years, were divided into 9 age groups according to decade of life. RESULTS: Five hundred and sixty-six SD-OCT scans were analyzed. Area of VMA (mm) decreased sigmoidally (R = 0.99) with each decade of life. With aging, percentage of PVD increased while percentage of complete adhesion decreased. Males were found to have significantly larger area of VMA (mm) compared with females in the fifth through eighth decades of life, P < 0.05. CONCLUSION: Vitreomacular interface interactions throughout life are age and gender dependent. This adds to our current understanding of the normal aging process undergone by the vitreous, thereby providing assistance in the clinical differentiation between normal and pathologic vitreomacular interactions.

DIABETES ALTERS THE MAGNITUDE OF VITREOMACULAR ADHESION.

PURPOSE: To quantify the changes in vitreomacular interactions that occur with aging in diabetic eyes in comparison with age-matched control eyes. METHODS: Spectral-domain optical coherence tomography (Spectralis; Heidelberg Engineering) foveal scans of diabetic patients, without evidence of cystoid macular edema, were included. Twenty-five raster foveal scans were performed on every subject. Area of vitreomacular adhesion was delineated using the Spectralis drawing tool and calculated in square millimeter. Data collected included gender, race, best-corrected visual acuity, and posterior vitreous detachment status. Subjects were divided into age groups according to decade of life. RESULTS: Spectral-domain optical coherence tomography scans from 141 diabetic patients were analyzed. Area of vitreomacular adhesion (mm) showed a hyperbolic decline in diabetic patients (35.5 ± 0, 35.0 ± 3, 34.0 ± 3, 33.9 ± 5, 33.7 ± 6, 29.0 ± 11, 23 ± 15, 13 ± 15). With aging, incidence of posterior vitreous detachment increased and incidence of complete attachment decreased. CONCLUSION: Diabetes affects the magnitude of attachment of the vitreous gel to the macula that results in stronger and longer lasting attachment of the gel throughout life. Gender differences were not noticed in diabetic patients, suggesting that vitreomacular adhesion remains robust in both genders in diabetes despite aging.

A Sema3C Mutant Resistant to Cleavage by Furin (FR-Sema3C) Inhibits Choroidal Neovascularization.

In age-related macular degeneration (AMD), abnormal sub retinal choroidal neovascularization (CNV) is a major cause of blindness. FR-sema3C is a point mutated form of semaphorin-3C that is resistant to cleavage by furin like pro-protein convertases (FPPC). We have found in previous work that FR-sema3C functions as an anti-angiogenic factor. In this study we investigated the possible use of FR-sema3C as an inhibitor of CNV. FR-sema3C inhibits VEGF as well as PDGF-BB signal transduction in endothelial cells and to less extent bFGF induced signal transduction using a mechanism that does not depend upon the binding of VEGF like the drugs that are currently the mainstay treatment for AMD. CNV was induced in eyes of C57 black mice by laser photocoagulation. Intravitreal injection of FR-Sema3C or aflibercept (VEGF-trap) was then used to inhibit CNV formation. Invading choroidal vessels were visualized a week later by injection of FITC-dextran into the circulation, followed by the measurement of the area of the invading blood vessels. Injection of 0.1 µg FR-Sema3C inhibited CNV by 55% (P<0.01) and was as effective as 5 µg aflibercept. FR-sema3C did not display any adverse effects on retinal function following its injection into eyes of healthy mice as assessed by optokinetic reflex (OKR) and Electro-retinogram (ERG) criteria. Furthermore, FR-sema3C did not induce apoptosis in the retina as determined by TUNEL nor was there any discernable structural damage to the retina as assessed by several immuno-histochemical criteria. Our results suggest that FR-sema3C could perhaps be used for the treatment of AMD, and that it may perhaps be of benefit to patients that do not respond well to current treatments relying on VEGF sequestering agents.

Fusarium and Aspergillus mycotoxins contaminating wheat silage for dairy cattle feeding in Uruguay

Abstract Wheat is one of the most important cultivated cereals in Uruguay for human consumption; however, when harvest yields are low, wheat is usually used in ensiling for animal feeding. Ensiling is a forage preservation method that allows for storage during extended periods of time while maintaining nutritional values comparable to fresh pastures. Silage is vulnerable to contamination by spoilage molds and mycotoxins because ensilage materials are excellent substrates for fungal growth. The aim of the study was to identify the mycobiota composition and occurrence of aflatoxins and DON from wheat silage. A total of 220 samples of wheat were collected from four farms in the southwest region of Uruguay were silage practices are developed. The main fungi isolated were Fusarium (43%) and Aspergillus (36%), with Fusarium graminearum sensu lato and Aspergillus section Flavi being the most prevalent species. Aflatoxin concentrations in silo bags ranged from 6.1 to 23.3 µg/kg, whereas DON levels ranged between 3000 µg/kg and 12,400 µg/kg. When evaluating aflatoxigenic capacity, 27.5% of Aspergillus section Flavi strains produced AFB1, 5% AFB2, 10% AFG1 and 17.5% AFG2. All isolates of F. graminearum sensu lato produced DON and 15-AcDON. The results from this study contribute to the knowledge of mycobiota and mycotoxins present in wheat silage.

A SEMA3E mutant resistant to cleavage by furins (UNCL-SEMA3E) inhibits choroidal neovascularization.

Abnormal subretinal choroidal neovascularization (CNV) is a major cause of blindness in exudative age-related macular degeneration (AMD). Current anti-angiogenic treatments by VEGF sequestering agents have been successful, but a significant proportion of patients do not respond well to these treatments, and the response of others diminishes over time, suggesting that additional anti-angiogenic agents that function by separate mechanisms may be of use to such patients. We have previously found that a point mutated form of semaphorin-3E resistant to cleavage by furin like pro-protein convertases (UNCL-Sema3E) displays potent anti-angiogenic properties. We therefore determined if UNCL-Sema3E has potential as an inhibitor of CNV formation. We chose to study UNCL-Sema3E rather than wild type sema3E because unlike full length sema3E, the major p61-Sema3E peptide that is produced by cleavage of sema3E with furin like pro-protein convertases activates signal transduction mediated by the ErbB2 receptor and can promote tumor metastasis in addition to its anti-angiogenic activity. UNCL-Sema3E inhibited efficiently vascular endothelial growth factor-A (VEGF), platelet derived growth factor (PDGF) and basic fibroblast growth factor (bFGF) signaling in human umbilical vein derived endothelial cells (HUVEC) and to a lesser extent hepatocyte growth factor (HGF) signal transduction. CNV that was induced in the eyes of C57 black mice by laser photocoagulation was inhibited by 65% (P < 0.01) following a single bolus intra-vitreal injection of 5 µg UNCL-Sema3E. This inhibitory effect was similar to the inhibition produced by a single bolus intra-vitreal injection of 5 µg aflibercept. A similar inhibition of CNV was observed following the injection of UNCL-Sema3E into the eyes of Long-Evans rats. However, a higher dose of UNCL-Sema3E (125 µg), partially due to the larger volume of the vitreous cavity of rats, was required to achieve maximal inhibition of CNV. Injection of UNCL-Sema3E into eyes of healthy mice did not have any adverse effect on retinal function as assessed by optic kinetic reflex (OKR) or by electroretinogram (ERG) assays nor did UNCL-Sema3E injection affect the structure of the retina as determined using histology. To conclude, our results suggest that UNCL-Sema3E may be useful for the treatment of exudative AMD, which does not respond well to conventional anti-VEGF therapy.