The amniotic membrane (AM) has a long history of use in the treatment of various diseases of the ocular surface. It contains pluripotent cells, highly organized collagen, anti-fibrotic and anti-inflammatory cytokines, immune-modulators, growth factors, and matrix proteins. It is used to promote corneal healing in severely damaged eyes. Recently, AM extract and AM extract eye drops have been successfully used in clinical applications, including dry eye and chemical burns. We provide an overview on the recent progress in the preparation, mechanisms of action, and use of AM extract/AM extract eye drops for corneal and external eye diseases.

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The recent emergence of the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its resultant human disease, COVID-19, will likely have a significant impact on the corneal tissue donor pool. Current recommendations from the United States and global eye bank associations call for the outright avoidance of tissues from donors recently infected with or exposed to COVID-19. This conservative recommendation is currently appropriate given the reported ocular sequelae, tear film viral detectability, and transmissibility of COVID-19. However, the rapidly increasing global prevalence and mortality of COVID-19 threatens the tenability of current tissue exclusion guidelines, and may necessitate their relaxation in the near future.

The corneal endothelium plays an integral role in regulating corneal hydration and clarity. Endotheliitis, defined as inflammation of the corneal endothelium, may disrupt endothelial function and cause subsequent visual changes. Corneal endotheliitis is characterized by corneal edema, the presence of keratic precipitates, anterior chamber inflammation, and occasionally limbal injection, neovascularization, and co-existing or superimposed uveitis. The disorder is classified into four subgroups: linear, sectoral, disciform, and diffuse. Its etiology is extensive and, although commonly viral, may be medication-related, procedural, fungal, zoological, environmental, or systemic. Not all cases of endothelial dysfunction leading to corneal edema are inflammatory in nature. Therefore, it is imperative that practitioners consider a broad differential for patients presenting with possible endotheliitis, as well as familiarize themselves with appropriate diagnostic and therapeutic modalities.