Meibomian gland dysfunction and keratopathy are associated with dry eye disease in aniridia

Aims To investigate the aetiology and characteristics of dry eye disease (DED) in a Nordic cohort of patients with congenital aniridia. Methods Thirty-four Norwegian and one Danish subject with congenital aniridia and 21 healthy controls were examined. All subjects underwent an extensive dry eye examination, including evaluation of meibomian glands (MGs) by meibography, measurement of tear production and tear film osmolarity and grading of vital staining of the ocular surface. Moreover, slit-lamp biomicroscopy was undertaken, including grading of aniridia-associated keratopathy (AAK). Results Mean tear film osmolarity was significantly higher (314 +/- 11 mOsmol/L) in patients with aniridia compared with the healthy control group (303 +/- 11 mOsmol/L, p=0.002). Vital staining score was higher in the aniridia group (4.3 +/- 3.0) compared with healthy controls (2.4 +/- 1.6, p=0.02). The degree of staining correlated positively with the stage of AAK (r=0.44, p=0.008) and negatively with corneal sensitivity (r=-0.45, p=0.012). Number of expressible MGs was lower in aniridia subjects (2.9 +/- 1.6) than in controls (4.0 +/- 1.3, p=0.007). MG loss, staged from 0 to 3, was higher in the aniridia group than in the control group, both in upper eyelid (0.86 +/- 0.89 vs 0.10 +/- 0.31, p=0.001) and lower eyelid (0.94 +/- 0.73 vs 0.30 +/- 0.47, p=0.003). Computerised analyses showed thinning (p=0.004) and lower density (p<0.001) of the MGs compared with the healthy population. Conclusions Patients with congenital aniridia demonstrate increased tear film osmolarity, ocular surface staining, loss of MGs and lower MG expressibility. We conclude that meibomian gland dysfunction and keratopathy are related to development of DED in aniridia.