PREVAIL VII: Cataract Surgery in Ebola Survivors

Objective: Zaire ebolavirus is a single-stranded RNA virus associated with high morbidity and mortality. The most recent epidemic of Ebola virus disease (EVD) in West Africa resulted in over 11,000 deaths and disabling sequelae among survivors, among which eye complications are highly represented. Chronic intraocular inflammation and viral persistence may result in posterior synechiae and cataract formation, resulting in loss of visual acuity and requiring surgical intervention to resolve. Approximately one out of ten Ebola survivors present with cataract, most of whom will require intraocular surgery during their lifetime, and many of whom require intervention in the near future to regain quality of life. For survivors who are blind from cataract, cataract extraction is necessary to restore visual function, allow reintegration into society and facilitate performance of activities of daily living.

However, surgical parameters among Ebola survivors are unknown, including whether Ebola viral RNA persists in aqueous humor, whether additional anti-inflammatory medication is needed, and the expected degree of improvement in visual function. Moreover, sites of viral persistence are unknown, and it is unclear if lens tissues removed during cataract surgery may harbor virus in Ebola-affected eyes. We propose following EVD survivors and control subjects undergoing cataract surgery to determine visual outcomes among Ebola survivors and explore detection of the presence of virus in lens tissues. The data will inform both future surgical intervention and aid in the understanding of the pathophysiology of Ebola-associated eye disease.

Study Population: Up to 60 Ebola survivors and up to 60 controls will be enrolled. The accrual ceiling is 120 participants.

Design: This is a prospective, natural history study to evaluate the persistence of Ebola viral RNA in the eyes of Ebola survivors and assess the response to cataract surgery in survivors as compared to controls. EVD survivors will first undergo assessment of aqueous humor for the presence of viral RNA. Survivors testing negative for viral RNA and control subjects will undergo clinically indicated cataract surgery. Subjects will be evaluated 1 day, 1 week, 1 month, and 3, 6, 9 and 12 months after surgery for safety and visual outcome assessments, and more often as clinically indicated.

Outcome Measures: The primary outcomes are: 1) the proportion of EVD survivors with evidence of persistence of Ebola viral RNA in ocular tissue and 2) the comparison of amount of intraocular inflammation, as measured by average grade of anterior chamber cell by SUN criteria, between EVD survivors and controls at 1 month and 3 months following cataract surgery. Secondary outcomes include: 1) the proportion of survivors with at least 20/40 best corrected visual acuity (BCVA) after cataract surgery, relative to controls; 2) impact the of covariates, age and gender on viral persistence and cataract outcomes; 3) post-operative optical coherence tomography results in EVD survivors.