Tear film function in type 2 diabetic patients with retinopathy

To investigate whether diabetes mellitus is correlated with tear film dysfunction.

Tear film function tests including tear film breakup time (BUT), fluorescein staining, Schirmer I test, rose Bengal staining, total tear protein detection, tear sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and TMS-4 corneal topography were performed. A dry-eye questionnaire was used.

Compared with the control group and nonproliferative diabetic retinopathy (NPDR) group, in the proliferative diabetic retinopathy (PDR) group, the BUT and the value of the Schirmer I test were reduced significantly (p < 0.01); corneal fluorescein staining scores, the positive rate of rose Bengal staining and the surface regularity index (SRI) and surface asymmetry index (SAI) were higher (p < 0.01); concentrations of lactoferrin and tear-specific prealbumin were lower (p < 0.01, p < 0.05, respectively). In diabetic patients, the SRI and SAI were positively correlated with fluorescein staining scores (r = 0.754, 0.480, p < 0.01, respectively), and the dry-eye symptoms were significantly related to an abnormal BUT and Schirmer I test (p < 0.01, respectively).

The declined tear film function is severer in the patients with PDR than in those with NPDR. Besides the traditional methods, tear SDS-PAGE and TMS corneal topographic indices contribute to the discovery of tear film dysfunction in diabetic patients.