EyeWorld India December 2018 Issue

69 EWAP NEWS & OPINION December 2018 Does current research provide insights to help with treatment of common eye problems? G rowing knowledge about the human mi- crobiome has provided insights into bowel disease, autoimmune conditions, glycemic control, and a variety of other areas. “The human microbiome has benefited from probiotic research that preceded it, as it provided a basis to go and examine the micro- bial contents of human sites,” said Gregor Reid, PhD , chair of hu- man microbiology and probiotics, Lawson Health Research Institute, and professor of microbiology & immunology and surgery, Univer- sity of Western Ontario, London, Canada. Dr. Reid has studied probi- otics for 35 years. “The Human Microbiome Project told us exactly what we expected, that humans harbor many microbes and the composi- tion differs in all of us, while many functions are shared,” Dr. Reid explained. Yet are there any implications within microbiome research for eye health? Although the number of stud- ies is still small, some researchers are discovering more about the ocular microbiome and its effects Eyeing the ocular microbiome by Vanessa Caceres EyeWorld Contributing Writer on dry eye disease, uveitis, infec- tion, and other ocular conditions. Last month, EyeWorld described how human microbiome research has slowly moved its way into ocu- lar research. This month, EyeWorld shares more examples of studies that focus on the eye’s microbiome and specific implications, both present and future, for ophthal- mology. Here is a sampling of the research underway to investigate the ocular microbiome and its ef- fects on specific eye diseases and conditions. Dry eye and MGD A pilot study that evaluated the effects of probiotic supplementa- tion on the tear film found that the strains were effective in reduc- ing dry eye syndrome, according to Chisari et al. 1 They used a mix of Saccharomyces boulardii MUCL 53837 and Enterococcus faecium LMG S-28935 and after a run-in period, randomized patients into a control group (n=30) receiving a substitute tear and a treatment group (n=30) receiving the substi- tute tear and the probiotic. Schirm- er test I and II test results improved in the treatment group, and there was a reduction in bacterial growth strains. In a prospective, cross-sec- tional study by Watters et al. that focused on meibomian gland dysfunction (MGD), 157 partici- pants were classified as normal or as having mild or moderate to severe MGD. 2 Lid margin swabs both before and after gland expres- sion were isolated and identified. Both participants with and with- out MGD showed a similar mi- crobiome; there also was a higher incidence of Staphylococcus aureus than anticipated across all severity groups. “Similarity in microbiome profile, irrespective of meibomian gland dysfunction severity, ante- rior blepharitis presence, or contact lens wear suggests potential for commonality in treatment,” the researchers wrote. Rhinoconjunctivitis A group of individuals using probiotics had an improvement in rhinoconjunctivitis-specific quality of life during allergy season. 3 Spe- cifically, researchers tested Lactoba- cillus gasseri KS-13, Bifidobacterium bifidum G9-1, and Bifidobacterium longum MM-2 as a probiotic capsule compared with placebo to meas- ure the effects on the Mini Rhi- noconjunctivitis Quality of Life Questionnaire (MRQLQ). There were 173 participants in the study. There was an improvement in the MRQLQ global score from baseline to pollen peak in the probiotic group (–0.68) compared with the placebo group (–0.19; P=0.0092). The associated mechanism for how the probiotics helped patients was unclear to researchers. Glaucoma The findings of a study from Astafurov et al. suggested that the oral microbiome may contribute to glaucoma pathophysiology. 4 The researchers used mouthwash specimens from glaucoma and control subjects and analyzed them for the amount of bacteria. Also in the study, low-dose subcutaneous lipopolysaccharide (LPS) was given in two separate animal models of glaucoma to determine a possible pathogenic mechanism. Research- ers also assessed glaucomatous neu- rodegeneration in the retina and optic nerve 2 months later and an- alyzed changes in gene expression of toll-like receptor (TLR) 4 sign- aling pathway and complement along with microglial numbers and morphology in the retina and optic nerve. They found that patients “ The opportunity to reduce inflammation, improve healing, and potentially deliver treatments for various conditions exists, but it will require low doses to be used, and only after safety is assured. ” - Gregor Reid, PhD continued on page 70