Abstract: Inflammatory cells in the epithelium in DES

Changes in corneal epithelial layer inflammatory cells in aqueous tear-deficient dry eye.
Invest Ophthalmol Vis Sci. 2009 Jul 23. [Epub ahead of print] Lin H, Li W, Dong N, Chen W, Liu J, Chen L, Yuan H, Geng Z, Liu Z.
Zhongshan Ophthalmic Center, 54 Xianlie South Road, Guangzhou, Guangdong, 510080, China; Eye Institute and affiliated Xiamen Eye Center of Xiamen University, Xiamen, Fujian, China.

Purpose. To investigate the morphology, distribution, and density of inflammatory cells in the corneal epithelium of aqueous tear-deficient dry eye.

Methods. Thirty-two patients with non-Sjögren's syndrome dry eye (NSS), 14 patients with Sjögren's syndrome related dry eye (SS), and 33 healthy volunteers were studied. In vivo laser scanning confocal microscopy investigated both Langerhans cell (LCs) and leukocyte, distribution and density in the peripheral and central corneal epithelium. LC morphology was also evaluated. Multi-factor regression analysis assessed if there is a correlation between clinical manifestations and inflammatory cells densities.

Results. LCs were present in both central (34.9+/-5.7 cells/mm2) and peripheral (90.7+/-8.2 cells/mm2) parts of the normal corneal epithelium. Moreover, LCs density increased dramatically in the central corneal epithelium in patients with NSS (89.8+/-10.8 cells/mm2 ) and SS (127.9+/-23.7 cells/mm2). The ratio of LCs with obvious processes was much higher in dry eye patients than in healthy volunteers. LCs density also increased in peripheral corneal epithelium in patients with SS, but not NSS. Leukocytes density in normal corneal epithelium was very low, while they increased in the central corneal epithelium (4.6+/-1.0 cells/mm2) in NSS, and in both central (49.0+/-12.9 cells/mm2) and peripheral (84.2+/-36.8 cells/mm2) corneal epithelium in SS. Densities of LCs and leukocytes showed significant correlation with the severity of clinical evaluation.

Conclusions: The LCs and leukocyte changes in the corneal epithelium suggest their involvement in aqueous tear-deficient dry eye pathophysiology. In vivo dynamic assessment of central corneal inflammatory cell density might serve as an indicator of dry eye severity and provide new insight for dry eye treatment.