Changes in corneal nerve morphology and function in patients with dry eyes having type 2 diabetes

BACKGROUND Dry eye syndrome(DES)is a common disease with various clinical manifestations.DES had a significant association with diabetes.Blink reflex(BR)is also known as trigeminal nerve facial reflex.The stimulation of corneal nerves is one of the origins of BR stimulation.The parasympathetic fibers sent out through the facial nerve are the outlet of tear reflexes.BR can be used to assess the function of the corneal nerve closed-loop;however,whether the BR changes in these patients is unclear.AIM To understand the morphology and function of the corneal nerve in patients with dry eyes having diabetes or not.METHODS This study enrolled 131 patients who visited the inpatient and outpatient services of ophthalmology and endocrinology departments between January 2019 to August 2020 with subjective symptoms of dry eyes and non-dry eye reasons,as well as volunteers such as colleagues.The patients were divided into four groups:DEwDM,with dry eyes having type 2 diabetes mellitus(T2DM);DMnDE,with T2DM not having dry eyes;DEnDM,with dry eyes not having diabetes;and nDMnDE,with neither dry eyes nor diabetes.The tear film break-up time,Schirmer I test,in vivo confocal microscopy,and BR were performed.RESULTS The DEwDM,DMnDE,DEnDM,and nDMnDE groups included 56,22,33,and 20 patients,respectively.Sex and age were not statistically different among the four groups.The nerve fiber length(NFL)of patients in the DEwDM,DEnDM,and DMnDE groups reduced(P<0.001,P=0.014,and P=0.001,respectively).No significant difference in corneal nerve fiber density(NFD)(P=0.083)and corneal nerve branch density(NBD)(P=0.195)was found among the four groups.The R1 Latency of blink reflexes increased only in the DEwDM group(P=0.008,P=0.001,P<0.001,compared with the DMnDE,DEnDM,and nDMnDE groups,respectively).The NBD and R1 Latency were different between DEwDM and DEnDM groups in patients with moderate and severe dry eyes.CONCLUSION The corneal nerve morphology changed in patients with dry eyes or diabetes,or with both,while the function of corneal nerve closed-loop reduced only in those with dry eyes and diabetes.

Efficacy observation of acupuncture for dry eye syndrome of lung-yin deficiency pattern

Objective:To observe the clinical efficacy of combining two needling manipulations,Er Long Xi Zhu(two dragons playing with a pearl)and Guo Yan Re(heat produced to reach the eyes),in treating dry eye syndrome(DES)of lung-yin deficiency pattern.Methods:Fifty-six eligible DES patients of lung-yin deficiency were randomized into an observation group and a control group,with 28 cases in each group.Same acupoints were selected in the two groups:Cuanzhu(BL 2),Sizhukong(TE 23),Taiyang(EX-HN 5)and Fengchi(GB 20)were chosen as the major points and Feishu(BL 13)and Chize(LU 5)as the adjuvant.Er Long Xi Zhu and Guo Yan Re needling manipulations were applied in the observation group while twirling reinforcing manipulation was used in the control group.Treatment was conducted once per day in both groups,for two sets of 15 consecutive days at a 2-day interval.Changes in the symptom score,tear break-up time(BUT)and tear production were observed afterwards,and the clinical efficacy was also compared between the two groups.Results:The total effective rate was 92.8%in the observation group,higher than 71.4%in the control group,and the between-group difference was statistically significant(P<0.05).After treatment,the symptom score,tear BUT and tear production showed significant improvements in both groups(all P<0.05);the symptom score,BUT and tear production in the observation group were significantly different from those in the control group(all P<0.05).Conclusion:Given the same acupoint selection,combining Er Long Xi Zhu and Guo Yan Re needling manipulations can produce more significant clinical efficacy than twirling reinforcing manipulation in treating DES of lung-yin deficiency pattern.