Chapters authored
The Eye and the Chikungunya Virus
Ocular involvement in chikungunya virus (CHIKV) infection can be present as mild and vision-threatening ocular complications with unilateral or bilateral compromise in both gender and all ages. Precise prevalence and incidence are unknown, but ocular involvement of CHIKV infection is uncommon. Anterior uveitis is the most common syndromic manifestation; nevertheless the infection could manifest posterior segment repercussion, such as retinitis which is the other most usual clinical manifestation. At the beginning of the systemic disease, main ophthalmologic symptoms are conjunctival injection, retro-ocular pain, and photophobia. Ocular pathogenesis of CHIKV infection is not totally clarified; however, findings related to an immune dysregulation and proinflammatory processes are the most accepted theories. The diagnosis of CHIKV is based on polymerase chain reaction, virus isolation, or detection of viral antigens which should be used before the eighth day of systemic illness. After 8 days, chikungunya serologic tests such as IgM ELISA/rapid tests or IgG paired must be used. Actual management is focused according to the clinical context of each patient. While in most instances recovery of vision to normal occurs, CHIKV infection can result in blindness, the visual prognosis depends on various factors, but the common one is the early onset of corticosteroid treatment.
Part of the book: Current Topics in Chikungunya
The Eye and the Zika Virus
Ocular involvement in Zika virus (ZIKV) infection can be present both in adults and infants as acquired and congenital diseases respectively. Through experimental studies, there has been clarified important mechanisms of ocular pathogenesis that allow the establishment of potential objectives for antiviral drugs development. The spread of the virus at the ocular level could be hematogenous or axonal, however the hematogenous route through the choroid is suggested as the most important initial mechanism for infection. Ocular manifestations vary according to the age of presentation, being mild and self-limited in adults and potentially devastating in children, related to congenital Zika syndrome (CZS). Ocular diagnosis is made based in clinical features and contact/travel history to countries of epidemiological importance; fundoscopy, optical coherence tomography, fluoresceinic/green indocianine angiography, cultures, serological and molecular tests are useful diagnostic tools. Ocular management is focused according to the clinical context of each patient. Prevention is carried out in a comprehensive manner and further research is directed to vaccine development and specific antiviral treatment. Proper attention requires a multidisciplinary team in order to reach complete visual evaluation and early rehabilitation.
Part of the book: Current Concepts in Zika Research