Correlation Analysis Of Lamina Cribrosa Parameters With Retinal Nerve Fiber Layer Thickness And Visual Field In Chronic Primary Angle Closure Glaucoma

Objective:Optical coherence tomography(OCT)and Humphrey Field Analyzer were used to measure the parameters of lamina cribrosa,the thickness of peripapillary retinal nerve fiber layer(pRNFL)and the visual field damage in patients with chronic primary angle closure glaucoma(CPACG),and the differences of these parameters with different degrees of visual field damage were compared.Compared with healthy people,the correlation between lamina cribrosa parameters and pRNFL and visual field was analyzed,and the diagnostic ability of lamina cribrosa parameters as a structural index of glaucoma was evaluated.Methods:40 patients(60 eyes)with CPACG diagnosed in our hospital in November 2021 and August 2022 were selected as the experimental group and 15 normal subjects(20eyes)as the control group.All subjects were examined by slit lamp microscope,anterior chamber gonioscope,front mirror,best corrected visual acuity(BACV),intraocular pressure,OCT and visual field examination.The lamina cribrosa depth(LCD)and lamina cribrosa thickness(LCT)were measured on the image obtained by OCT using the Bruch’s membrane opening(BMO)as the reference plane,and the pRNFL thickness was calculated by the OCT software.The measurement indexes of pattern standard deviation(PSD)and mean defect(MD)were selected in the Humphrey Field Analyzer.According to the Hodapp-Parrish-Anderson staging standard,all patients in the experimental group were divided into three groups according to the MD value of visual field damage(<-6d B,6 d B≤MD≤-12 d B,>-12 d B),early,middle and advanced stages.Use statistics to process and analyze all data.Results:1.Comparison of lamina cribrosa parameters: compared with the control group,the LCD in the experimental group was deepened and the LCT was thinner,the difference was statistically significant(P<0.05).With the progress of visual field damage in glaucoma,these changes of LCD and LCT were gradually aggravated.2.The relationship between lamina cribrosa parameters and pPNFL thickness and visual field damage: There was a significant linear relationship between lamina cribrosa parameters(LCD and LCT)and pRNFL thickness and visual field MD(r>0.6,P<0.05).LCD has the strongest correlation with visual field MD(r=0.78,P<0.05).Among all parameters of lamina cribrosa,the correlation between LCD and pRNFL thickness and MD of visual field(r=0.76 and 0.78,P<0.05)was higher than that of LCT(r=0.66 and 0.71,P<0.05).3.Diagnostic ability of lamina cribrosa parameters for glaucoma: The lamina cribrosa parameters measured by EDI-OCT have a good diagnostic ability for glaucoma,and the diagnostic ability of LCT is slightly higher than that of LCD.The areas under the curve of LCD and LCT were 0.858 and 0.905,which were statistically significant(P<0.05).Conclusions:1.Compared with the normal control group,the LCD of patients with early CPACG deepened and LCT became thinner.With the progress of visual field damage,the structural parameters of the lamina cribrosa in patients with middle and advanced stages changed accordingly.As a structural index,lamina cribrosa parameters can provide basis for early diagnosis and follow-up of glaucoma patients.2.The parameters of lamina cribrosa measured by OCT are significantly correlated with the thickness of pRNFL and the MD of visual field.LCD and LCT can be used as a good indicator to evaluate glaucoma.3.The lamina cribrosa parameters measured by OCT have good diagnostic ability in primary glaucoma patients.As a widely used measuring instrument,OCT can provide a new measurement index for the assessment of glaucoma in clinical application.