Impact of the COVID-19 Pandemic on Ophthalmic Practice. Historical Aspects and Clinical Examples

Abstract
This article presents data on clinical ophthalmological manifestations of COVID-19 described in the literature, clinical examples that we met in pandemic conditions, COVID-19 including early and late manifestations, as well as references to studies conducted decades ago and aimed to evaluate the effects of coronavirus infection on the visual organ. The purpose of the most studies was to study the effect of COVID-19 on the visual organ indicate that the most common ophthalmological manifestation of this disease is conjunctivitis, which occurs in 3–10 % of cases. Our observations showed that patients with COVID-19, when applying for an appointment with an ophthalmologist after 1–3 months, make complaints about the feeling of dryness, discomfort in the eyes, itching and redness of the eyelids. These complains arose immediately after the illness and persisted during the above terms. This phenomenon can be explained by the fact that any inflammatory process occurring on the eye surface disrupts the process of lacrimation and leads to the emergence of dry eye syndrome. It is necessary to pay close attention to complaints from the visual organ not only in patients with COVID-19 in the early stages of the disease, but also in the coming months after stopping the acute pathological process. As studies have shown, coronavirus can involve the posterior segment of the eye in the pathological process, since this virus has a retinotropic effect. This hypothesis can be confirmed by the reports of several authors who studied with optical coherence tomography (OCT) the state of the retina 11–33 days after the onset of symptoms in patients with COVID-19. OCT data indicate the presence of hyperreflexive zones at the level of the ganglion cell layer and the plexiform layer, the severity of these zones being greater in the papillomacular bundle region. In addition, cases of thromboembolic complications affecting the vascular system of the eye are described. Considering the fact that in the development of thromboembolism of the central artery and retinal vein, therapy is as effective as possible in the first hours from the beginning of this pathological process development, close attention should be paid to patients’ complaints to visual impairment occurred against the background of coronavirus infection. The data presented in this article open up a range of possibilities for conducting new scientific research that will help to preserve the vision and health of our patients as effectively as possible.