Abstract
Purpose: :
To investigate and assess subclinical corneal and eyelid tissue inflammation in patients with refractory symptoms despite notable improvement in objective signs post-treatment for meibomian gland dysfunction (MGD).
Methods: :
In vivo confocal microscopy (IVCM; 800x) was performed on the cornea, palpebral conjunctiva and MGs with HRT3/RCM (Heidelberg Engineering, Heidelberg, Germany) on five patients (mean age: 41.6 +/-14.5 years) post-LipiFlow treatment for chronic MGD and related dry eye symptoms. Images were analyzed for signs of inflammation undetected by slit-lamp examination (50x). Symptoms were evaluated using two questionnaires, the Standard Patient Evaluation for Eye Dryness (SPEED) and the Ocular Surface Disease Index (OSDI). The objective signs which improved post-LipiFlow were MG function and tear break-up time.
Results: :
IVCM demonstrated that all patients had subclinical inflammation of the palpebral conjunctival epithelium, substantia propria, periglandular and intraglandular areas, as well as subepithelial conjunctival fibrosis. High inflammatory cell (IC) density in the conjunctival epithelium was associated with increased stromal IC density and periglandular inflammation. Three patients also had increased corneal (IC) density. The superficial corneal epithelia had heterogeneous epithelial cell size, increased hyperreflectivity, and decreased cell density. Further, increased symptom severity was associated with decreased subbasal corneal nerve density, increased beading, hyperreflectivity and dendritic cell density.
Conclusions: :
IVCM permits visualization of otherwise undetectable inflammation within the ocular surface and eyelid tissue. IVCM provides a metric beyond the magnification of the slit-lamp and offers immediate potential to explain the presence of symptoms in the absence of obvious signs and, conversely, the presence of signs in the absence of symptoms.
Keywords: eyelid • cornea: clinical science • cornea: tears/tear film/dry eye