Abstract
Purpose: :
To study with an integrated approach confocal (in vivo laser scan confocal microscopy - LSCM) features of the ocular surface in patients with primary Sjogren’s syndrome (SSI), non Sjogren’s syndrome dry eye (non-SSDE) and Meibomian gland disease (MGD).
Methods: :
15 patients with SSI, 15 with non-SSDE, 15 with MGD and 15 age- and gender-matched control subjects were consecutively enrolled. Each participant underwent a full eye exam and a LSCM examination of corneal apex (epithelial, stromal and inflammatory cells densities, sub-basal nerve plexus), bulbar and tarsal conjunctiva (epithelial and inflammatory cells densities), mucocutaneous junction - MCJ (epithelial densities) and meibomian glands - MGs (acini, orifices and secretion).
Results: :
All the analyzed superficial epithelia, except MCJ, showed reduced cells densities in each group compared to controls (P<0.001, LSD post hoc test), with the lowest one in SSI (P<0.001). MCJ superficial cells density was significantly decreased only in MGD (P<0.001). Basal epithelial density was increased in both SSI and non-SSDE compared to controls (P<0.001 and P<0.01, respectively) at the corneal apex, decreased in each group compared to controls (P<0.01) in the conjunctiva, not significantly different among the groups in the MCJ. Sub-basal dendritic cells density was significantly increased in both SSI and MGD compared to controls (P<0.001 and P<0.01, respectively) and in SSI compared to MGD (P<0.001). Conjunctival inflammatory cells density and MG confocal grading of inflammation were increased in each group compared to controls (P<0.001, LSD post hoc and Mann-Whitney U test, respectively), with the highest values in SSI. Sub-basal plexus showed less fibers and higher beadings density in each group compared to controls (P<0.001, LSD), and increased tortuosity in both SSI and MGD (P<0.001, Mann-Whitney U test).MG showed the lowest acinar density, the largest diameter of both acini and orifices (P≤0.001, LSD), and the highest secretion reflectivity (P<0.001, Mann-Whitney U test) in MGD patients.
Conclusions: :
LSCM allows to perform an in vivo, non-invasive, integrated evaluation of the ocular surface in dry eye. It provides, in a steady-state respectful manner, simultaneous information about several components of the ocular surface morpho-funcional unit, useful to clarify the pathogenetic processes of the different types of dry eye.
Keywords: cornea: tears/tear film/dry eye • imaging/image analysis: clinical • microscopy: confocal/tunneling