Study strongly links allergic conjunctivitis, meibomian gland duct distortion
"Although the exact mechanisms for the association between [allergic conjunctivitis] and meibomian gland duct distortion are unclear, inflammatory changes in the conjunctival tissue might induce pressure on the meibomian glands in the tarsus, which is stiff and has limited room for expansion," the study authors said. "Histologic examination of the distorted meibomian glands in patients with [allergic conjunctivitis] may be necessary to elucidate the mechanisms."
The study included 55 eyes of 55 patients with perennial allergic conjunctivitis and a comparator group comprising 47 eyes of 47 healthy subjects. The study group had a mean age of 32.3 years, while the control group a mean age of 32.8 years.
Patients underwent slit lamp examination with fluorescein staining, measurement of time to tear film breakup, superficial punctate keratopathy scoring, meibography, Schirmer testing and rating of meibomian expression.
Study results showed that meibomian gland duct distortion was identified in 45% of eyes with allergic conjunctivitis and 8.5% of healthy eyes; the difference was statistically significant (P < .0001). Eyes with allergic conjunctivitis had markedly higher meibum and superficial punctate keratopathy scores than the control eyes (P = .049 and P = .0076, respectively).
In addition, eyes with allergic conjunctivitis and meibomian gland duct distortion had appreciably higher meibomian expression scores than eyes with allergic conjunctivitis and no meibomian gland duct distortion; the difference was statistically significant (P = .0012).
No sizable between-group differences in meibography scores, tear film breakup time or Schirmer scores were identified, the authors said.
The authors have documented a significant increase in meibomian gland inspissation and difficulty in meibomian gland expression associated with allergic conjunctivitis. Both allergic conjunctivitis and meibomian gland disease are frequent causes of ocular surface disease. Their association helps explain why patients with allergic conjunctivitis may have extensive symptomatology with corneal and conjunctival staining. Based on this study I would suggest that patients with allergic conjunctivitis should be treated for their primary disease but the examination should also include a thorough lid evaluation for meibomian gland disease. Meibomian gland disease is a progressive disease. Early diagnosis and treatment can prevent permanent scarring and closure of the meibomian gland orifices.
– Eric D. Donnenfeld, MD
OSN Cornea/External Disease Board Member