Measurement and analysis of optic disc parameters in Mongolian and Han healthy subjects with or without family history of glaucoma / 中华眼底病杂志

ABSTRACT

Objective To measure optic disc parameters in Mongolian and Han healthy subjects with or without family history of glaucoma,to explore the causes of the differences and their significance in the diagnosis of early glaucoma.Methods Fifteen healthy Mongolian individuals (30 eyes),30 healthy Han individuals (60 eyes) with a family history of open-angle (30 eyes) or angle-closure (30 eyes) glaucoma,and 45 healthy Han individuals (90 eyes) without a family history of glaucoma were enrolled in this study.The 45 healthy Han individuals without a family history of glaucoma included three age-groups20 to 29 years old group,30 to 39 years old group and 40 to 49 years old group,each group have 15 subjects (30 eyes).Thirteen parameters were measured by Heidelberg retina tomography (HRT) for all subjects,including disc area,cup area,rim area,cup volume,rim volume,cup/disc area ratio,linear cup/disc ratio,mean cup depth,maximum cup depth,cup shape,disc height variation contour,mean retinal nerve fiber layer (RNFL) thickness and optic nerve fiber layer cross-sectional area.The results were analyzed and compared between the above groups.Results There was no statistically significant (t=0.791,P=0.132) of the height variation contour between Mongolian and Han without a family history of glaucoma (20 to 29 years old) group.The other parameters of Mongolian were smaller than Han without a family history of glaucoma (20 to 29 years old) group,but the difference was not statistically significant (t=-1.039,-0.799,-0.840,-1.108,-0.956,-0.695,-0.931,-1.099,-1.074,-0.580,-0.204,-1.425; P＞ 0.05).The parameters in Han with a family history of open-angle glaucoma group were bigger than Han without a family history of glaucoma (30 to 39 years old) group.The differences were statistically significant for disc area,cup area,rim area,cup volume,rim volume,cup area ratio,linear cup/disc ratio,mean cup depth,cup shape measure,nerve fiber layer cross-sectional area (t =4.758,3.187,2.544,2.674,1.798,3.676,2.721,2.715,2.510,2.373; P＜0.05),but were not statistically significant for maximum cup depth,disc height variation contour and mean RNFL thickness (t=1.649,1.565,0.767; P＞0.05).Most parameters in Han with a family history of angle-closure glaucoma group were the same as that in Han without a family history of glaucoma (40 to 49 years old) group,including cup area,rim area,cup volume,rim volume,cup/disc area ratio,linear cup/disc ratio,mean optic cup depth,maximum cup depth,cup shape,disc height variation contour,mean RNFL thickness,optic nerve fiber layer cross-section (t=1.201,1.697,1.000,0.516,0.740,-0.172,-0.070,-0.972,1.530,-0.390,-0.091,0.659; P＞ 0.05) ; but the difference of disc area between these 2 groups was statistically significant (t=2.224,P＜0.05).Conclusions The family history of glaucoma can change the optic disc parameters of healthy individuals,especially those with a family history of open-angle glaucoma.There is no difference of optic disc parameters between healthy Mongolian and Han subjects.