In praise of povidone-iodine application in ophthalmology.

Polyvinyl pyrrolidone or povidone-iodine (PVP-I) is a water-soluble complex formed by the combination of iodine and a water-soluble polymer, polyvinyl pyrrolidone. This complex exerts bactericidal, fungicidal, and virucidal action by gradually releasing free iodine at the site of application to react with pathogens. In ophthalmology, PVP-I is used as a disinfectant and antiseptic agent for preoperative preparation of the skin and mucous membranes and for treating contaminated wounds. PVP-I has been shown to reduce effectively the risk of endophthalmitis in various ocular procedures, including cataract surgery and intravitreal injections; however, it has also been used in the treatment of conjunctivitis, keratitis, and endophthalmitis, with promising results especially in low-resource situations. PVP-I has been associated with complications such as postoperative eye pain, persistent corneal epithelial defects, ocular inflammation, and an attendant risk of keratitis. In cases of poor PVP-I tolerance, applying PVP-I at lower concentrations or using alternative antiseptics such as chlorhexidine should be considered. We provide an update on the efficacy of PVP-I in the prophylaxis and treatment of conjunctivitis, keratitis, and endophthalmitis and a comprehensive analysis of the current literature regarding the use of PVP-I in the management of these ocular conditions. Also, PVP-I-related adverse effects and toxicities and its alternatives are discussed. The goal is to present a thorough evaluation of the available evidence and to offer practical recommendations for clinicians regarding the therapeutic usage of PVP-I in ophthalmology.

SARS-CoV-2 and Acute Cerebrovascular Events: An Overview.

Since the coronavirus disease 2019 (COVID-19) pandemic, due to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, accumulating evidence indicates that SARS-CoV-2 infection may be associated with various neurological manifestations, including acute cerebrovascular events (i.e., stroke and cerebral venous thrombosis). These events can occur prior to, during and even after the onset of COVID-19's general symptoms. Although the mechanisms underlying the cerebrovascular complications in patients with COVID-19 are yet to be fully elucidated, the hypercoagulability state, inflammation and altered angiotensin-converting enzyme 2 (ACE-2) signaling in association with SARS-CoV-2 may play key roles. ACE-2 plays a critical role in preserving heart and brain homeostasis. In this review, we discuss the current state of knowledge of the possible mechanisms underlying the acute cerebrovascular events in patients with COVID-19, and we review the current epidemiological studies and case reports of neurovascular complications in association with SARS-CoV-2, as well as the relevant therapeutic approaches that have been considered worldwide. As the number of published COVID-19 cases with cerebrovascular events is growing, prospective studies would help gather more valuable insights into the pathophysiology of cerebrovascular events, effective therapies, and the factors predicting poor functional outcomes related to such events in COVID-19 patients.