New method of screening for COVID-19 disease using sniffer dogs and scents from axillary sweat samples.

BACKGROUND: Early screening for COVID-19 is needed to limit the spread of the virus. The aim of this study is to test if the sniffer dogs can be successfully trained to identify subjects with COVID-19 for 'proof of concept' and 'non-inferiority' against PCR. We are calling this method, Dognosis (DN). METHODS: Four hundred and fifty-nine subjects were included, 256 (Group 'P') were known cases of COVID-19 (PCR positive, some with and some without symptoms) and 203 (Group 'C') were PCR negative and asymptomatic (control). Samples were obtained from the axillary sweat of each subject in a masked fashion. Two dogs trained to detect specific Volatile Organic Compounds for COVID-19 detection were used to test each sample. RESULTS: [DN] turned out positive (+) in all the cases that were PCR positive (100% sensitivity). On the other hand, [DN] turned positive (+) in an average of 12.5 cases (6.2%) that were initially PCR negative (apparent specificity of 93.8%). When the PCR was repeated, true specificity was 97.2%. These parameters varied in subgroups from 100% sensitivity and 99% specificity in symptomatic patients to 100% sensitivity and 93% specificity in asymptomatic patients. CONCLUSION: DN method shows high sensitivity and specificity in screening COVID-19 patients.

A rare case of occlusive juxtafoveolar retinal telangiectasias associated with lesions of the central nervous system: A cerebroretinal vasculopathy like phenotype without mutations in the TREX1 gene.

PURPOSE: To report a rare case of bilateral occlusive juxtafoveolar retinal telangiectasias associated with central nervous system lesions and renal impairment. OBSERVATIONS: A 47-year-old woman presented to clinic with subjective vision loss in the right eye with best-corrected visual acuity (BCVA) 20/80. Fundoscopic examination, fluorescein angiography (FA), and optical coherence tomography with adjunct angiography (OCT/OCT-A) revealed macular microhemorrhages, enlarged foveal avascular zones (FAZ), and occlusive juxtafoveal telangiectasis with pruning of the macular capillaries in both eyes. Patient subsequently developed memory loss, dizziness, nystagmus, and diplopia secondary to intermittent exotropia. She was found to have a two-millimeter aneurysm of the proximal posterior cerebellar artery along with several scattered white matter changes on brain magnetic resonance imaging (MRI). Genetic workup revealed no mutations in the TREX1 gene. With continued surveillance over 18 months, the patient's BCVA deteriorated to 20/200 OU and she developed mild renal impairment, without further CNS complications. CONCLUSION AND IMPORTANCE: Patients who present with vision loss secondary to occlusive juxtafoveolar telangiectasias should undergo imaging of the central nervous system (CNS) for architectural abnormalities in cerebral vasculature and white matter. Further investigation of patients with the Gass-Blodi type 3 macular telangiectasia - cerebroretinal vasculopathy phenotype is required to optimize management protocols for both retinal and CNS lesions. At this time, no interventions have demonstrated clear benefit in vision preservation or recovery.

Impact of AREDS in a developing country 5 years after publication of the study.

PURPOSE: The Age-Related Eye Disease Study (AREDS) is the only large-scale study to demonstrate a reduction in the risk of progression to end-stage age-related macular degeneration (AMD) when vitamin supplementation was given to patients with advanced forms of the disease. Our study assesses the impact of this study on vitamin supplementation in patients with advanced AMD from 5 years before publication of the AREDS results until 5 years after. METHODS: Medical records of patients with AMD presenting between September 1996 and October 2006 were reviewed. Patients were subclassified according to AREDS categories. The proportion of advanced cases on vitamin replacement before October 2001 was compared to that after October 2001. Since October 2001, the different reasons for abstinence were investigated and analyzed. RESULTS: Only 2403 patients of the 40,000 medical records reviewed met the AREDS AMD criteria. Of these, 137 patients verifying categories 3 and 4 were diagnosed prior to October 2001. Fourteen were on supplements then. Fifty-three patients complied with the represcribed vitamins during subsequent visits after October 2001, raising the percentage significantly to 48.9% (p<0.001). Also, from October 2001 until October 2006, an additional 76 patients verified categories 3 and 4. Fifty-three (69.7%) of them were on vitamins (p=0.001). Financial burden was the principal reason for abstinence in 67.7% of patients prescribed vitamins after October 2001. CONCLUSIONS: The results of AREDS had an impressive impact on prescribing supplements in AREDS category 3 and 4 patients in Lebanon. The main reason for noncompliance is financial.