Abstract
Purpose :
The purpose of this study is to determine the composition and stability of the ocular surface microbiome (OSM) in patients with severe OSD including SJS, ocular graft versus host disease (oGVHD), and dry eye disease (DED). In a prior study, we found that the OSM of healthy eyes consisted of Lactobacillus/Streptococcus and Corynebacterium. We hope to develop a more complete understanding of disease-dependent ocular surface changes.
Methods :
Two groups were studied: A) patients seen in the outpatient center with SJS, oGVHD, and DED; and B) patients admitted to the burn unit for acute SJS management. A conjunctival swab (COPAN ESwab) was used to sample the inferior fornix of each eye. Outpatient samples were taken every 4-6 weeks for a total of 3 samples and inpatient samples were taken weekly for the duration of their admission. Sample DNA was amplified and underwent 16S rRNA sequencing to determine the OSM composition.
Results :
For the 24 outpatient eyes with SJS, Corynebacterium was the predominant bacteria (n=10), followed by Staphylococcus (n=4) and Pseudomonas (n=3). For the 20 outpatient eyes with oGVHD, Corynebacterium was the predominant bacteria (n=6), followed by Pseudomonas (n=5). For the 16 outpatient eyes with DED, Lactobacillus was the predominant bacteria (n=4), followed by Pseudomonas (n=3) and Staphylococcus (n=3) (Table 1).
To date, outpatient swabs at a second time point were taken from 6/12 SJS, 3/10 oGVHD, and 3/8 DED patients. 11/12 of the SJS eyes, 5/6 oGVHD eyes, and 6/6 of DED eyes showed a change in the dominant bacteria (Table 1). Patients with a different predominant bacterium between their 2 eyes at a single time point were seen in all 3 OSD groups.
Initially, both eyes of Inpatient 1 were Stenotrophomonas-predominant while both eyes of Inpatient 2 were Lactobacillus-predominant (Table 2). The right eye of Inpatient 2 maintained Lactobacillus as the predominant bacteria over the course of all 4 samples while the left eye had a different predominant bacterium at each time point with a Stenotrophomonas-predominant final sample.
Conclusions :
Different OSDs have a distinct OSM and treatment could play a role in altering the OSM. OSM changes to Corynebacterium at the second time point was seen in 7/11 SJS eyes and 4/6 DED eyes suggesting that over the course of treatment, the OSM may be changing to a profile seen in healthy eyes.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.