Ocular manifestations of emerging viral diseases

Abstract

Emerging infectious diseases (EIDs) are an increasing threat to public health on a global scale. In recent times, the most prominent outbreaks have constituted RNA viruses, spreading via droplets (COVID-19 and Influenza A H1N1), directly between humans (Ebola and Marburg), via arthropod vectors (Dengue, Zika, West Nile, Chikungunya, Crimean Congo) and zoonotically (Lassa fever, Nipah, Rift Valley fever, Hantaviruses). However, specific approved antiviral therapies and vaccine availability are scarce, and public health measures remain critical. Patients can present with a spectrum of ocular manifestations. Emerging infectious diseases should therefore be considered in the differential diagnosis of ocular inflammatory conditions in patients inhabiting or returning from endemic territories, and more general vigilance is advisable in the context of a global pandemic. Eye specialists are in a position to facilitate swift diagnosis, improve clinical outcomes, and contribute to wider public health efforts during outbreaks. This article reviews those emerging viral diseases associated with reports of ocular manifestations and summarizes details pertinent to practicing eye specialists.

Fig. 1. Ebola retinal lesions.

A Colour fundus image, B corresponding OCT images showing discontinuities in the outer retinal layers, C multiple non-pigmented lesions and associated perilesional areas of dark without pressure. Source: Steptoe et al. [18] (CC-BY License).

Fig. 2. Rift Valley fever virus, fundus photograph, demonstrating active retinitis in the macular region and retinal haemorrhages.

Source: Khairallah [231] (CC-BY licence), original publication Al-Hazmi 2005.

Fig. 3. Dengue foveolitis in left eye.

A Fundus photograph showing orange-yellow central foveal lesion B OCT scan demonstrating focal thickening of the outer neurosensory retina and retinal pigment epithelium. Source: Khairallah [231] (CC-BY licence), original courtesy of Soon-Phaik Chee.

Fig. 4. West Nile virus retinopathy.

A Inflammatory vascular sheathing, B retinal necrosis, C multifocal chorioretinitis, D pigmented chorioretinal scars. Source: Hasburn [232] (CC-BY licence).

Fig. 5. Chikungunya, slit lamp anterior segment photos with 1+ cells and 2+ flare evident in the anterior chamber of both eyes.

A Pigmented keratic precipitates in the inferior cornea, B stellate keratic precipitates. Source: Mahendradas [233] (CC-BY Licence).

Fig. 6. Chikungunya, retinal manifestations.

A Fundus image of the left eye showing confluent area of retinal whitening suggestive of retinitis. B, C Fundus fluorescein angiography showing the posterior pole in early and late hypofluorescence, respectively. Source: Mahendradas [233] (CC-BY Licence).

Fig. 7. Influenza virus H1N1, severe ocular cases.

A Lower chemosis and severe conjunctival hyperaemia associated with significant eyelid oedema, B petechiae and significant upper sub-tarsal follicles. Source: Lopez-Pratz [234] (CC-BY Licence).