The Partnership for Research on Ebola Virus in Liberia (PREVAIL) recently conducted a clinical research study where Ebola survivors and their close contacts benefitted from eye cataract removal surgeries.
The study, called PREVAIL 7, sought to address the issues of safety for participants to undergo cataract surgery and to define the post-surgical care needed to achieve the best vision outcomes. It also aimed to understand whether the Ebola virus disease (EVD) persists in eye tissues of survivors with cataracts. This information will also help determine how best to ensure the safety of the surgical team when performing eye surgery on Ebola survivors.
People with cataracts have difficulty seeing because the lens of the eye, which reflects light and allows them to see clearly, has become cloudy. Cataracts are the leading cause of reversible blindness in the world, and surgery is the only known effective cure. Twenty million people worldwide live with blindness in both eyes due to cataracts. A cataract surgery is one of the most cost-effective surgical interventions worldwide.
The study, which is still following the participants, has two major goals: (1) to determine the proportion of EVD survivors with viral persistence in ocular (eye) tissues, and (2) to compare the amount of inflammation between survivors and control patients at one month and three months after cataract surgery.
In addition, the investigators aim to assess whether the vision outcomes in Ebola survivors differ from those in other patients, whether age and gender play a role in their outcomes, and whether structural changes in the eye from Ebola infection impact these outcomes.
For the study, PREVAIL enrolled 24 Ebola survivors whose blood tested positive for the presence of EVD antibodies and 10 close contacts whose blood showed no evidence of EVD exposure. All survivors and close contacts had visually significant cataracts, which means that the cataracts caused their best vision with the help of eyeglasses can only see at a 20-foot distance what a person with normal vision can see at a 40-foot distance.
Participants in the study were drawn from the PREVAIL eye care sub-studies under the Ebola Natural History Study known as PREVAIL 3. Participants were over 14 years old, and only one eye of a survivor could be a candidate for the surgery. Pregnant women were excluded because of the effect the procedure could have on an unborn fetus.
The research is a joint collaboration of multiple organizations spanning academic, government, faith-based, private, and non-governmental organizations from four countries. These organizations included the U.S. National Institutes of Health, Johns Hopkins University, Emory University, LVPrasad/the Liberian Eye Center at JFK Hospital under Dr. Kumar Nishant, New Sight Eye Center under Mr. Robert Dolo, ELWA Hospital, Samaritan’s Purse, John Snow Inc., and the Liberian Ministry of Health.
Two U.S.-based surgeons, Dr. Daniel Gradin and Dr. Benjamin Roberts, donated one week of their time to Samaritan’s Purse to perform the surgeries. They were chosen because of their rigorous training and extensive experience in Kenya and South Sudan performing similar cataract surgeries.
At ELWA Hospital, under the direction of Dr. John Fankhauser, deployed the innovative Baylor Smart Pod—a small field clinic—for testing the aqueous fluid of the eye in Ebola virus. The Baylor pod is a portable treatment unit that can be quickly built and rapidly deployed in emergency responses. This pod provided clinical safety for participants, staff, and surgeons. ELWA provided housing at Camp Lawana, adjacent to the staff housing, and provided food, lodging, and security before and after surgery for all participants.
Since June 2015, the PREVAIL 3 Natural History Eye Sub-Study has enrolled about 2,100 Ebola survivors and close contacts and followed them prospectively to shed light on the ocular complications of EVD.