Analysis Of The Influencing Factors Of Spectral-domain Optical Coherence Tomography In The Diagnosis Of Primary Open Aangle Glaucoma

ObjectiveTo explore the influential factors of spectral domain optical coherence tomography(SD-OCT)in the diagnosis of primary open-angle glaucoma.MethodsEighty patients(80 eyes)with mild or moderate POAG who were admitted to our department from September 2015 to August 2019 were enrolled,of which 40 cases aged 20-39 years old and 40 aged 60-79 years old.Eighty health controls(80 eyes)were also included in the same period in our department,40 of them were 20-39 years old and 40 of them were 60-79 years old.All subjects received comprehensive ophthalmic examination.SD-OCT was used to measure the thickness of the peripapillary retinal nerve fiber layer(pRNFL),the macular average ganglion cell layer combined with the inner plexiform layer(GCL-IPL)and the macular minimum GCL-IPL thickness and the average cube thickness of the macular area.The best corrected vision acuity(BCVA),non-contact intraocular pressure,central corneal thickness(CCT),automatic static field of vision,fundus photography,slit lamp,computer optometry and gonioscopy wererecorded.SPSS 19.0 statistical software was used to analyze the above measurement parameters.The measurement data of normal distribution was expressed by mean ± standard deviation(x±s).The thickness of pRNFL was divided into five areas:average thickness,superior,nasal,inferior and temporal thickness.The mean GCL-IPL thickness of macular area,the minimum GCL-IPL thickness of macular area and the average cube thickness of macular area were compared among the four groups.The age,diopter,CCT,BCVA and the above-mentioned measurement parameters between the healthy control group and POAG group(4 groups)were compared by non paired t test,and the gender difference between the groups was compared by chi square test,P<0.05,which was statistically significant.The diagnostic accuracy of each parameter of peripapillary and macular area was compared by means of the area under the receiver operating characteristics(ROC)curve(AUC).The AUC summarizes the global value of the parameter,where values closer to 1 represent higher diagnostic discriminant ability.ResultsThe average and minimum GCL-IPL thickness decreased significantly with age in both health control and POAG groups(P<0.05,P<0.01).With the increase of age,the average macular cube thickness did not change significantly in the healthy control group and POAG group.In the heathy control group,age had no significant effect on the pRNFL thickness,and there was no significant difference(P>0.05).In the mild or moderate POAG group,the mean,superior,inferior and temporal thickness of pRNFL in 20-39 years old and 60-79 years old were thinner than those of the healthy control group,and the thickness of pRNFL in 60-79 years old group was thinner than that in 20-39 years old group(P<0.05,P<0.01).There was no significant difference in the nasal thickness of pRNFL between 20-39 and 60-79 years old in the mild or moderate POAG group(P>0.05),and there was no significant difference in the same age of the healthy control group(P>0.05).The parameters of optic disc and macular area were calculated by ROC curve analysis.The highest AUC value was inferior pRNFL thickness,AUC=0.943,followed by average pRNFL thickness,AUC=0.902,and the third was the thinnest GCL-IPL thickness in macular area,AUC=0.864.ConclusionUsing SD-OCT method,POAG can be detected early.The diagnosis accuracy of the inferior pRNFL is the highest and the influencing factors are few.It can be used as a sensitive index for early diagnosis of POAG.