Abstract
Purpose :
To characterize the role of meibomian gland dysfunction (MGD) in pathogenesis of dry eye in type 2 diabetics
Methods :
198 eyes of 99 diabetic patients (DM) and the age and sex-matched 160 eyes of 80 dry eye patients without DM (DE) were recruited, with 220 eyes of 110 normal subjects served as control group (NC). Each subject was examined with an OSDI questionnaire, tear film breakup time (BUT), Schirmer I test (SIT), corneal fluorescein staining (FL), lipid layer thickness (LLT), and meibomian gland (MG) parameters including lid margin abnormality, meibomian gland dropout, property of meibum and meibomian gland yielding secretion. Glycosylated hemoglobin (HbA1c) level and the duration of diabetes were also recorded. Data was statistically analyzed using SPSS software.
Results :
The tear volumes in the DM group were 9.59±3.17 mm, very closed to the normal cut-off value (10 mm) and significantly higher than that of DE group (5.61±2.36 mm, P<0.05). However, the BUT and LLT were significantly lower, and the values of all MG parameters were significantly higher in DM group than the DE and NC groups. 118 eyes (59.6 %) of diabetic patients were diagnosed with dry eye (OSDI≥13 and BUT <10 s) as DM+DE group, while others without dry eye serves as DM-DE group. Interestingly, the tear volume, BUT and LLT in the DM-DE group were significantly higher (P<0.01), and the values of all MG parameters and FL scores were significantly lower (P<0.01) in DM-DE group than DM+DE group. More importantly, the values of four MG parameters were significantly higher in DM-DE group than NC group, although the OSDI were below 13 in both group. This suggested the MGD emerged before ocular discomfort developed. Furthermore, the HbA1c levels were correlated with OSDI, BUT, LLT, FL scores, and the four MG parameters (P<0.001) in type 2 diabetics. However, even in the patients with HbA1c <7%, SIT >10mm and OSDI <13, the scores of MG parameters were higher than those in normal controls. In addition, the duration of diabetes was positively correlated with the values of MG parameters (P<0.001).
Conclusions :
MGD is a major cause of dry eye syndrome in type 2 diabetics without obvious aqueous tear deficiency. The tear function and MG parameters were correlated with HbA1c level and diabetic duration. MGD, which appears before the development of ocular discomfort, may be an early sign and the critical factor of dry eye in type 2 diabetics.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.