Meibomian Gland Function Status In Type 2 Diabetes Patients

Aim of the study:To study the characteristics of tear and meibomian gland in type 2 diabetic and characterize meibomian gland dysfunction in the pathogenesis of dry eye in type 2 diabetic.Methodology:This study is a prospective and case-control study of 198 eyes of 99 type 2 diabetic patients,they were divided into groups according to the severity of ocular symptoms and the level of glycosylated hemoglobin,diabetic duration and diabetic retinopathy.Another 160 eyes of 80 normal persons and 220 eyes of 110 nondiabetic patients with dry eye served as the control group.Every patient was examined with the following clinical tests and responded to questionnaire to identify their ocular surface disease index(OSDI),tear film breakup time(BUT),corneal fluorescein staining(FL),Schirmer ? test(SIT),lipid layer thickness(LLT);Lid margin abnormality score,meibomian gland dropout degree(meiboscore),meibum expression assessment and meibomian gland yielding secretion score.Principal Findings:Compared with the normal group,OSDI and corneal fluorescein staining score of type 2 diabetic group were significantly higher,BUT their tear volumes,the tear BUT and lipid layer thickness were very much decreased whereas four meibomian gland parameters were significantly increased(P<0.001).In contrast,relative to the nondiabetic dry eye group,the tear secretion volumes in type 2 diabetic group did not decrease;while their tear BUT,corneal fluorescein staining score and lipid layer thickness significantly decreased.Four meibomian gland parameters in the type 2 diabetic group were significantly higher than in the normal population and nondiabetic dry eye group.All meibomian gland parameters were positively associated with glycosylated hemoglobin levels(P<0.001)in type 2 diabetes patients.Even though patients that were under good metabolic control and had normal tear volume,their meibomian gland morphology and function were abnormal.However in the patients with poor glycemic control,both the tear volume significantly and the conditions of meibomian gland were significantly worse.Besides,the declines in diabetes patients' tear and meibomian gland parameters very significantly correlated with the disease course of the disease and Diabetic retinopathy progression(P<0.001).And the morphology and function of meibomian gland have been changed in no-diabetes retinopathy group.Conclusions:Type 2 diabetes patients had more severe ocular surface symptoms than nondiabetic patients.The ocular surface symptoms were very related to the level of glycosylated hemoglobin.In patients with good metabolic control,their meibomian gland morphology and function was abnormal BUT they had no aqueous tear volume deficiency.Meibomian gland dysfunction plays a key role in the pathogenesis of dry eye in type2 diabetic patients.And meibomian gland dysfunction were earlier than diabetic retinopathy.Therefore,the examination and evaluation of meibomian gland function is very important in the early diagnosis and treatment of diabetes-related dry eye.