Abstract
Purpose :
The etiology of meibomian gland dysfunction (MGD) remains unclear. We assessed the association between the commensal ocular microflora burden (colony forming units-cfu) and symptoms of dry eye using two Dry Eye Questionnaires.
Methods :
186 subjects (110 females) aged 25-66 years with normal ocular and systemic history were recruited. The Ocular Surface Disease Index (OSDI) and McMonnies dry eye questionnaires were completed (in random order). Ocular swabs were collected from left eye lower lid margin. Conventional cultivation was used for bacterial isolation and identification. Independent student t-test was applied to measure microbial recovery of the eyelid margin between two groups of independent variables. Two-way ANOVA was performed for interaction of age groups and sex on cfu. Association between questionnaire scores and cfu was determined using Pearson’s correlation and one-way ANOVA
Results :
OSDI categorization of dry eye groups were as follows: normal (score 0-12, n=114), mild (score 13-22, n=42), moderate (score 23-32, n=21) and severe (score 33-100, n=8). McMonnies categorization of dry eye groups were as follows: normal (score <10, n = 98), marginal dry eye (score 10-20, n= 76) and pathological dry eye (score >20, n =12). Cfu ranged from 0 to 1500 cfu/swab. Most common species were Propionibacterium spp. (59%) and Staphylococcus epidermidis (36%). Average cfu were higher in males than females (162±156 vs 105± 187 cfu per swab; p< 0.05) and in older females (≥45 yr) than younger (155 ± 187 vs 64 ± 82 cfu per swab, p<0.05). There were weak negative correlations between cfu and both dry eye questionnaire scores. McMonnies categories showed significant differences in cfu (p=0.035) but there was no consistent trend in cfu vs dry eye symptoms severity score.
Conclusions :
We have previously shown a correlation between bacterial burden and signs of MGD and hence sought to determine if bacterial burden correlates with dry eye symptoms. Neither OSDI nor McMonnies questionnaire showed strong correlation with bacterial burden, in keeping with the generally reported poor correlation between MGD signs and dry eye symptoms.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.