Photodiagnosis and Photodynamic Therapy

This study is rooted in the observation that retinal lesions, such as cotton-wool exudates, microbleeds, vascular occlusions, and vasculitis, can occur in a minority of patients infected with Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2), the virus responsible for COVID-19, due to its neurotropism, endothelial tropism, and the systemic inflammatory reaction it causes. Since COVID-19 presents with varied and challenging clinical manifestations beyond the commonly affected respiratory system, and given the ability of the virus to cause neurological and vascular issues, the assessment of the retina offers a unique opportunity to analyze these systemic effects. Retinal imaging, particularly color retinography, is an effective tool to document these lesions. Therefore, this study was undertaken to utilize portable color retinography (specifically the Eyer® camera) to identify and document retinal changes in patients with mild and moderate COVID-19 symptoms who were admitted to an isolation ward, aiming to contribute to the understanding of the virus's ocular impact, while also highlighting the utility of portable and cost-effective devices in such isolated clinical settings.

The viral RNA was extracted using the QIAmp Viral RNA Mini Kit (QIAGEN) for RT-qPCR according to the manufacturer’s protocols. Viral RNA of SARS-CoV-2 was detected by TaqMan®-based Real-Time PCR (Promega) using a Center for Disease Control (CDC) protocol with two primer/probe sets which amplify the virus nucleocapsid (N) gene (2019-nCoV_N1 and 2019-nCoV_N2). The Human RNase P (RP) primer/probe set was included to detect the gene in control samples. [8,28] The results were analyzed in QuantStudio 3 software v1.5.1 (Thermo Fisher Scientific, USA) and interpreted as a cycle quantification value (Ct) less than or equal to 40 as positive and Ct greater than 40 as negative. [8] After pupil dilation, the Eyer® portable fundus camera (Phelcom Technologies®) was used for color retinography of the posterior pole. Patients who did not agree to participate in the study and those for whom good images were not possible, either due to non-collaboration or because of opaque medium, were excluded. Facts about ocular complaints during COVID-19, ocular history and comorbidities of each patient were investigated. Patients admitted to the intensive care unit were not evaluated.

During July 2021, 30 male and 21 female patients with ophthalmologic manifestations related to SARS-CoV-2 were enrolled and evaluated in this study. Patient ages ranged from 21 to 83 years (mean age: 47 years). Systemic Arterial Hypertension (SAH) was identified in 21 (41.2 %) and Diabetes Mellitus (DM) in 12 (23.5 %) patients. Aroundhalf of the patients (26/51; 50.9 %) had already presented with ophthalmologic complaints prior to COVID-19 infection including the necessity of wearing glasses, visual loss, glaucoma, presbyopia and myopia. Of the 51 patients, 6 (11.7 %) presented ophthalmologic concerns. Thirty-four (66.6 %) had alterations in the retinography; ten (19.6 %) had Intraretinal Hemorrhages (IRH); one (1.9 %) Cottom-Wool Exudates (CWE) and seven (13.7 %) had Venous Dilatations (VeD), as shown in Fig.. Thirteen patients (25.4 %) had vascular tortuosity and six (11.7 %) had pathological arteriovenous crossings; other findings are described in Table 1. Among the patients with altered retinography,only three (8.8 %) had reported ophthalmologic complaints. All were taking 6 mg/day dexamethasone and were being treated with prophylactic anticoagulation and oxygen therapy. Furthermore, six patients (11.7 %) reported worsening visual acuity however, none of these patients had ocular findings that justified their complaint.

Portable color retinography is useful in evaluating hospitalized patients isolated on wards due to COVID-19 infection. The findings should not be directly attributed to the disease without further evidence, as they may be due to comorbidities, medications used during treatment, the immunological response against the infection or incidental findings. More studies are needed to better understand the results and should include larger sample sizes, longitudinal patient follow-up and multimodal assessment with the addition of methods, when possible, such as fluorescein retinography, fluorescein angiography, optical coherence tomography and optical coherence tomography angiography. On the other hand, using these last four technologies, in addition to the high cost, requires that the patient is healthy enough to be able to move around and be examined in a clinic where the equipment is installed, since they are not portable. Therefore, any assistive technology that is developed to provide portable, quality healthcare to patients in isolated situations, such as riverside populations, isolated native populations and populations without access to medical care, is always very welcome.