ABSTRACT
Background Exfoliation syndrome is a systemic disease with abnormal accumulation of extracellular matrix.Oxidative stress and imbalance between matrix metalloproteinases(MMPs) and tissue inhibitor of matrix metalloproteinases(TIMPs)may play an important role in the pathogenesis of exfoliation syndrome.Researches showed that the incidence of exfoliation syndrome is higher in Uyghur nationality than that in Han nationality.However,whether the imbalance of serum MMPs and TIMPs is associated with pathogenesis of different ethnic groups is unclear.Objective The aim of the study was to discuss the change of serum MMP-9 and TIMP-2 in Uyghur patients.Methods This study protocol was approved by Ethic Committee of Xinjiang Medical University and followed Declaration of Helsinki.A prospective cohort study was performed.Forty Uyghur nationality (46 eyes) with exfoliation syndrome were collected from March 2012 to May 2013 in Affiliated First Hospital of Xinjiang Medical University and First People Hospital of Kashi.Forty cases(40 eyes)age-and gender-matched normal volunteers were included in the same duration.The peripheral blood was collected under the informed consent.Serum MMP-9 and TIMP-2 levels were detected by ELISA,and the results between the two groups were compared using independent samples t test.Results Slit-lamp examination found that part of pigmentation was depigmented and white dandrufflike substance attached in the pupil margin in all the patients,and stripping white dandruff-like substance was deposited in the front surface of the lens capsule which distributed in 3 zones.The pupils were disk-shaped pupil,and the surrounding area was the ring granular and the middle was transparent area without ablative material after dilation.Serum MMP-9 levels were (57.88±18.63)μg/L in the exfoliation syndrome group and (9.35±2.78)μg/L in the normal control group;serum TIMP-2 levels were (17.36±4.66) μg/L in the exfoliation syndrome group and (25.73±3.59) μg/L in the control group.The ratios of MMP-9/TIMP-2 were 3.57± 1.45 in the exfoliation syndrome group and 0.37±0.11 in the control group,with statistically significant differences in serum MMP-9 and TIMP-2 levels as well as ratio of MMP-9/TIMP-2 between the two groups(t=11.52,-6.36,9.87,all at P=0.00).Conclusions The upregulation of serum MMP-9 and downregulation of serum TIMP-2 are found in Uyghur patients with exfoliation syndrome.It is verified that the imbalance of serum MMP-9 and TIMP-2 contributes to the pathogenesis of exfoliation syndrome in Uyghur patients.