ABSTRACT
Background: Amblyopia is the interocular visual acuity difference of two lines or more with the best correction in both eyes. It is treated with ocular occlusion therapy, but its success depends on neuroplasticity, and thus is effective in children but not adults. Transcranial Direct Current Stimulation (tDCS) is suggested to increase neuroplasticity. Objective: To determine if combined intervention of bilateral tDCS and ocular occlusion improves visual function in adults with amblyopia. Methods: A double-blind randomized, controlled pilot trial was conducted in 10 volunteers with amblyopia. While applying ocular occlusion and performing a reading task, participants received bilateral tDCS (n = 5) or sham stimulation (n = 5), with the anodal tDCS electrode in the contralateral visual cortex and the cathodal in the ipsilateral visual cortex in relation to the amblyopic eye. Visual function (through visual acuity, stereopsis, and contrast sensitivity tests) and visual evoked potential (with checkerboard pattern stimuli presentation) were evaluated immediately after. Results: A total of 30 min after treatment with bilateral tDCS, visual acuity improved by 0.16 (± 0.025) LogMAR in the treatment group compared with no improvement (-0.02 ± 0.02) in five controls (p = 0.0079), along with a significant increase in the amplitude of visual evoked potentials of the amblyopic eye response (p = 0.0286). No significant changes were observed in stereopsis and contrast sensitivity. No volunteer reported any harm derived from the intervention. Conclusion: Our study is the first to combine anodal and cathodal tDCS for the treatment of amblyopia, showing transient improved visual acuity in amblyopic adults.
ABSTRACT
INTRODUCTION: Mesenteric and portal venous thromboses are rare diseases with high mortality rates and are strongly associated with hepatic cirrhosis, and abdominal inflammatory or tumoral processes, but in some cases can be the first sign of myeloproliferative neoplasm (MPN) or hereditary thrombophilia. JAK2V617F mutation detection is an important diagnostic tool for MPN patients. The aim of this study was to describe the JAK2V617F mutation prevalence on Chilean patients suffering from a primary splanchnic venous thrombosis (SVT), in order to assess how it relates to primary MVT and PVT in our specific population. METHODS: A retrospective observational study was conducted in patients referred to the University of Chile Clinical Hospital with mesenteric and/or portal venous thrombosis diagnosis over a 7-year period. Patients with primary thrombosis underwent hereditary thrombophilia study and JAK2V617F mutation screening. RESULTS: A total of 123 patients had splanchnic venous thrombosis (mesenteric and/or portal) as their main discharge diagnosis. Sixty patients (49%) had primary mesenteric or portal venous thrombosis (no attributable secondary cause). Hereditary thrombophilia and MPN were diagnosed in 21.6% and 43.3% of SVT patients, respectively. Twenty SVT patients remained without an etiologic diagnosis. In MPN patients, almost all had the JAK2V617F mutation (92.3%). About 16% of patients who had positive JAK2V617F mutation did not meet diagnostic criteria for MPN. CONCLUSIONS: In this Chilean cohort, half of mesenteric or portal venous thrombosis showed no secondary cause. In this group, the main causes were MPN and hereditary thrombophilia. Nearly, all MPN patients had JAK2V617F mutation, but there was a group of patients having JAK2V617F mutation but did not meet MPN criteria.
