Retinal Venule Coverage by Pericytes Decreases in Multiparous Mice in a Time-Dependent Manner Post-Delivery.

Structural changes in the retinal vasculature have been linked to increased cardiovascular risks and also change as a function of age. Because multiparity has been associated with poorer cardiovascular health scores, we hypothesized that changes in retinal vascular caliber would be observed in multiparous, compared to nulliparous, females and retired breeder males. Age-matched nulliparous (n = 6) and multiparous (n = 11, retired breeder females with 4 ± 1 litters), and male breeder (n = 7) SMA-GFP reporter mice were included for assessment of retinal vascular structure. Multiparous females had higher body mass, heart weight, and kidney weight compared to nulliparous mice, with lower kidney and higher brain weight compared to male breeders. There was no difference in number of retinal arterioles or venules, or arteriole or venule diameter among groups; however, venous pericyte density (number per venule area) decreased in multiparous vs. nulliparous mice and was negatively associated with the time since last litter and with age. Our results suggest that the time elapsed since delivery is an important factor to be considered in multiparity studies. Taken together, changes in vascular structure and potentially function, are time- and age-dependent. Ongoing and future work will determine whether structural changes are associated with functional consequences at the blood-retinal barrier.

Varicella Zoster Meningitis, Optic Neuritis Preceding the Development of Posterior Outer Retinal Necrosis, and Central Retinal Artery Occlusion in a HIV Patient.

Varicella-zoster virus (VZV) has been known to cause various eye disorders in both immunocompetent and immunocompromised patients. We present a case of a forty-nine-year-old female patient with acquired immunodeficiency syndrome (AIDS) who presented with headache, fever, and blurred vision. Cerebrospinal fluid (CSF) analysis was consistent with VZV meningitis. Magnetic resonance imaging (MRI) of the brain showed enhancement of the right optic nerve indicative of optic neuritis. She responded well to acyclovir and steroids and discharged on the same. Four weeks after discharge, she presented with sudden onset blindness in the left eye. A cerebral angiogram revealed left retinal artery occlusion and was treated with tissue plasminogen activator (tPA). Funduscopic examination showed patchy areas of necrosis in the periphery which were rapidly progressive, diagnostic of posterior outer retinal necrosis (PORN). She was started on ganciclovir and cidofovir and experienced significant improvement in her visual acuity.

Thyrotoxic periodic paralysis: case report and review of the literature.

INTRODUCTION: Thyrotoxic periodic paralysis (TPP) is a rare and potentially lethal complication of hyperthyroidism. It is characterized by sudden onset paralysis associated with hypokalemia. Management includes prompt normalization of potassium, which results in resolution of the paralysis. Definitive treatment of hyperthyroidism resolves TPP completely. CASE PRESENTATION: A 23-year-old African American male patient presented to the emergency room at the University of Mississippi Medical Center, USA in November 2016 with sudden onset quadriplegia. He also endorsed a history of weight loss, palpitations, heat intolerance and tremors. The patient reported similar episodes of quadriplegia in the past, which were associated with hypokalemia and resolved with normalization of potassium levels. Physical examination was significant for exophthalmos, smooth goiter with bruit consistent with the diagnosis of Graves' disease. Laboratory assessment showed severe hypokalemia, hypomagnesemia, suppressed thyroid stimulating hormone (TSH) and high free thyroxine (T4). Urine potassium creatinine ratio was less than one, indicating transcellular shift as the cause of hypokalemia. After normalization of potassium and magnesium, the paralysis resolved in 12 hours. He was started on methimazole. On follow up, the patient was clinically and biochemically euthyroid with no further episodes of paralysis. TAKE-AWAY LESSON: TPP is a rare and reversible cause of paralysis. Physicians need to be aware of the diagnostic and treatment modalities as delayed recognition in treatment could result in potential harm or unnecessary interventions.