Higher bacterial diversity on the ocular surface may contribute to the increased frequency of certain eye infections in people who wear contact lenses, a group of New York University researchers has hypothesized.
Contact lens (CL) wearers had 3 times the usual proportion of Methylobacterium, Lactobacillus, Acinetobacter, and Pseudomonas on their conjunctivas than did a control group who did not wear CLs, the researchers reported at the annual meeting of the American Society for Microbiology.1
Using metagenomic analysis with specialized RNA sequencing, the scientists determined the bacterial makeup of 250 samples, swabbed from the conjunctiva, eyelid skin, and lenses of CL wearers and controls.
In CL wearers, there was greater similarity between the conjunctival microbiota and that of the lower eyelid skin than found in the controls. Further, bacteria on the lenses resemble more closely those of the skin than of the conjunctiva.
Relationship to infections. Although the results are intriguing, the sample sizes were small (9 test and 11 control subjects), and it is too early to know what causes these microbial alterations and what their connection, if any, is to contact lens–related corneal infections, said Lisa Park, MD, a coauthor of the study.
“This study suggests that organisms involved in eye infections may originate from the skin,” said Dr. Park, associate professor of ophthalmology at NYU. “Handling contact lenses may be transferring skin bacteria to the ocular surface, which emphasizes the importance of hand hygiene to prevent eye infections.”
She added that the group plans to test more patients and to examine cofactors, such lens material and wearing patterns.
1 Shin H et al. Poster presented at: annual meeting of the American Society for Microbiology; May 31, 2015; New Orleans.
Relevant financial disclosures—Dr. Park: None.
For full disclosures and disclosure key, see below.
More from this month's News in Review