Abstract
Purpose::
To analyze the in vivo morphology of corneal cells and nerves in rheumatoid arthritis (RA) patients with or without Sjögren’s syndrome (SS), and to investigate the correlations between corneal alterations and RA activity.
Methods::
Fifty patients with RA and 30 age- and gender matched control subjects were studied.SS was diagnosed according to the American-European Consensus Group criteria and the RA activity was evaluated by the Lansbury index (LI).Each partecipant completed a questionnaire for a standardized evaluation of dry eye symptomatology (Ocular Surface Disease Index) and underwent an ophthalmologic examination (including Schirmer test, corneal sensitivity, fluorescein staining and tear break-up time) and a confocal microscopic examination ( to investigate corneal and stromal thicknesses, cell density of different corneal layers, number of "activated keratocytes" and sub-basal nerves number, tortuosity, reflectivity and "bead-like formations").
Results::
16% of RA patients (8/50) were diagnosed with secondary SS. No statistically significant difference was found in LI and in clinical and confocal parameters between SS and non-SS patients. Significant differences were found between RA patients and control subjects for all the parameters studied, reflectivity excepted. A significant correlation was found between LI and Schirmer test analysing the entire RA group (P<0.05, Spearman) and the RA with SS group (P<0.05). LI showed a significant correlation also with the number of "bead-like formations" and the number of "activated keratocytes"; these correlations were found in the entire RA group (P<0.05 and P<0.05 respectively), in the RA with SS group (P<0.01 and P<0.05 respectively) and in the RA non-SS group (P<0.05 and P<0.05 respectively).
Conclusions::
RA patients show clinical and confocal corneal alterations. The number of "bead-like formations" and the number of "activated keratocytes" could be interpreted as confocal signs of ocular surface disease activity; their correlation with an index of systemic disease activity (LI), both in RA with SS and in RA without SS patients, could be an interesting element to better understand the pathogenetic mechanisms of dry eye in RA patients.
Keywords: cornea: tears/tear film/dry eye • cornea: clinical science