Abstract
Purpose: :
To analyze the in vivo morphology of corneal cells and nerves in dry eye associated with primary and secondary Sjögren’s Syndrome (SS) and to study its relationship with the clinical evaluation.
Methods: :
Thirtyfive patients with SS (15 SSI and 20 SSII) and 20 age– and gender–matched control subjects were studied. Confocal microscopy was used to investigate corneal thickness, epithelial and stromal density and subbasal nerve number, tortuosity and reflectivity. These data were correlated with Schirmer’s test, BUT, corneal sensivity and corneal fluorescein staining score.
Results: :
Corneal central thickness was 514.74 ± 19.85 µm in the SS group and 550.00 ± 21.46 µm in the control group (P<0.0001, t–test); stromal central thickness was 456.62 ± 18.05µm in the SS group and 487.35 ± 20.40 µm in the control group (P<0.0001). The density of the superficial and basal epithelial cells was 985.05 ± 107.56 cells/mm2 and 6197.37 ± 180.34 cells/mm2 respectively in the SS group, 1488.55 ± 133.74 cells/mm2 and 5861.65 ± 260.40 cells/mm2 respectively in the control group (P<0.0001). The number of subbasal nerves was 3.34 ± 0.76 in the SS group, 5.10 ± 0.79 in the control group (P<0.0001). The average grade of nerve tortuosity was 2.62 ± 0.94 in the SS group and 1.20 ± 0.70 in the control group (P<0.0001). There were no statistically significant differences between the SSI and SSII confocal data. In the SS group, nerve number showed a significant correlation with Schirmer’s test (P<0.0001, Pearson) and with fluorescein staining score (P<0.01). A correlation was also found between the nerve tortuosity grade and fluorescein staining score (P<0.01) and between the nerve tortuosity grade and corneal sensivity (P<0.05).
Conclusions: :
Corneal thickness, cells and nerves show morphological changes in patients with dry eye associated with SS. The in vivo confocal study of these alterations can be important to better understand the complexity of the ocular surface morpho–functional unit and the potentials of terapeutical approaches aimed at the control of the phlogistic process and neuroprotection.
Keywords: cornea: tears/tear film/dry eye • cornea: clinical science