Dimensions Of Normal Lacrimal Gland In Females And Study On The Correlation Between Tear Secretion And Lacrimal Artery Hemodynamics

Part Ⅰ Ultrasound study of normal lacrimal gland in femalesObjective : The lesions of lacrimal glands are often accompanied by changes in the size of lacrimal glands.The enlargement of lacrimal glands is usually a manifestation of orbital diseases.In this study,two-dimensional ultrasound was used to observe the ultrasonographic manifestations of normal female lacrimal glands,and to explore the relationship between the size of normal female lacrimal glands and age.Materials and Methods : 128 healthy women from December 2016 to October 2017 were examined by conventional two-dimensional ultrasound.The subjects were in supine position.The ultrasound probe was placed in the lacrimal gland area on the lateral edge of the eyeball.Some of the eyeballs could be used as a sound transmission window.The direction of the ultrasound probe showed the longest diameter of the lacrimal gland,measured from the upper endto the lower end of the lacrimal gland,and the shortest diameter was perpendicular to the longest diameter at the widest point of the lacrimal gland.The lateral to medial margins of lacrimal glands were measured.Paired t-test and Pearson correlation analysis were used to study the relationship between lacrimal gland measurements and age.Results:The average age of 128 subjects was 47.27 ±17.21 years.The average length of the right lacrimal gland was 1.38 ±0.19 cm and that of the left lacrimal gland was 1.40±0.24 cm.The mean short diameter of the right lacrimal gland was 0.59 ±0.13 cm and that of the left lacrimal gland was 0.64±0.14 cm.The mean short diameter of left lacrimal gland was larger than that of right lacrimal gland(P < 0.05).There was no statistical difference between the long diameter of bilateral lacrimal gland.There was a negative linear correlation between the length and age of lacrimal glands in both eyes,but no significant correlation between the short diameter and age.Conclusion : Combined with the size of normal female lacrimal gland ultrasound,ultrasonography can be used as an assistant method for the diagnosis of lacrimal gland diseases.Ultrasound reference values of normal female lacrimal glands can help to distinguish between diseased and non-diseased lacrimal glands.Part Ⅱ Correlation between tear secretion and hemodynamics of lacrimal glandObjective:It is assumed that the decrease of blood flow in lacrimal gland tissue can directly cause the oxygen supply disorder of lacrimal gland,resulting in the decrease of lacrimal secretion,instability of lacrimal film,damage of ocular surface function and dry eye syndrome.The purpose of this study is to evaluate the relationship between lacrimal hemodynamic parameters and lacrimal secretion,to explore the correlation between lacrimal hemodynamic parameters and lacrimal gland function,and to explore the role of lacrimal hemodynamics in lacrimal secretion.Materials and Methods : 128 healthy female volunteers who underwent physical examination from December 2016 to October 2017 were included in this study.Tear secretion test(SIt)and tear film rupture time(BUT)were performed on each patient.The peak systolic velocity(PSV),end diastolic velocity(EDV)and resistance index(RI)of lacrimal artery were determined by ultrasound.The average values of lacrimal glands in both eyes were collected for statistical analysis.Pearson correlation was used to analyze the relationship among age,SIt,BUT,PSV,EDV and RI.Results:A total of 128 subjects were enrolled in this study,with an average age of 47.27 ± 17.21 years.The mean PSV,EDV and RI of normal female lacrimal artery were 14.01 ± 2.90 cm/s,5.35 ± 1.22 cm/s and 0.62 ± 0.06 respectively.SIt was negatively correlated with age and RI,and positively correlated with PSV and EDV(all P < 0.05).BUT was negatively correlatedwith age and RI,and positively correlated with PSV and EDV(all P < 0.05).Age was negatively correlated with PSV and EDV,and positively correlated with RI(all P < 0.05).Conclusion : With the increase of age,tear secretion decreases.The resistance index of lacrimal artery increased with age in females.Female lacrimal artery hemodynamic parameters are related to lacrimal gland secretion function,suggesting that the change of lacrimal gland blood supply may be one of the reasons for the decline of lacrimal gland secretion function.Ultrasound can detect the blood flow of lacrimal gland,which can indirectly monitor the lacrimal secretion function of lacrimal gland.