Correlation Of Optic Disc Parameters With Retinal Nerve Fiber Layer Thickness And Visual Field Defects In Primary Angle Closure Glaucoma

Objective:To investigate the correlation between optic disc parameters,circumpapillary retinal nerve fiber layer thickness(cp RNFLT)and visual field defects in primary angle closure glaucoma(PACG)patients.To compare the consistency of optic disc parameters measured by KOWA nonmyd WX stereo fundus camera with those measured by Heidelberg Retina Tomograph-III(HRT-III)in PACG patients.Methods:Seventy-four patients(74 eyes)with PACG who attended the second hospital of Jilin University from October 2021 to October 2022 were selected for this study.The total cases were divided into 35 cases(35 eyes)in the APACG group and 39 cases(39eyes)in the CPACG group according to the glaucoma diagnostic criteria established by the Glaucoma Group of the Chinese Academy of Ophthalmology.The optic disc parameters were measured with KOWA nonmyd WX stereo fundus camera and Heidelberg retinal tomograph(HRT-III).Mean cp RNFLT was measured by spectral domain optical coherence tomography(SD-OCT)and mean deviation(MD)values were measured by Humphrey field analyzer(HFA).For each patient group,the relationship between optic disc parameters,mean cp RNFLT,and MD values were analyzed using Pearson correlation.The intraclass correlation coefficients(ICC)were selected to evaluate the consistency between KOWA nonmyd WX stereo fundus camera and HRT-III in measuring various optic disc parameters in PACG patients.Fisher’s z test was used to compare the difference in correlation coefficients between the structural and functional damage of the optic nerve measured in the APACG and CPACG groups Results:1.Among the optic disc parameters measured with the KOWA nonmyd WX stereo fundus camera in PACG patients,the vertical cup-to-disc ratio,cup-to-disc area ratio,and rim area were significantly correlated with the mean cp RNFLT(P < 0.05),and the correlation between rim volume and the mean cp RNFLT was not statistically significant(P > 0.05).Vertical cup-to-disc ratio,cup-to-disc area ratio,rim area,cup area,and cup volume were significantly correlated with MD values(P < 0.05),and the correlation between rim volume and MD values was not statistically significant(P > 0.05).Among the optic disc parameters measured by HRT-III,the cup-to-disc area ratio,rim area,rim volume were significantly correlated with the mean cp RNFLT(P < 0.05),and the cupto-disc area ratio,rim area,cup volume,cup area and rim volume were significantly correlated with MD value(P < 0.05).The mean cp RNFLT was significantly correlated with MD value(P < 0.01).2.The optic disc parameters measured by KOWA nonmyd WX stereo fundus camera in PACG patients were consistent with those measured by HRT-III(P < 0.05).There was high consistency between the rim area,cup area,and cup-to-disc area ratios measured by the two apparatus,medium consistency between the cup volume,and low consistency between the rim volume.3.The vertical cup-to-disc ratio,cup-to-disc area ratio,cup volume,rim area,and cup area of optic disc parameters in APACG group were significantly correlated with MD values(P < 0.05),and the correlation between rim volume and MD values was not statistically significant(P>0.05).In APACG group the mean cp RNFLT was significantly correlated with the MD values(P < 0.01).The vertical cup-to-disc ratio,cup-to-disc area ratio,cup area,and rim area of the optic disc parameters in CPACG group were significantly correlated with the MD values(P < 0.01),and the correlation between rim volume and MD values was not statistically significant(P>0.05).The mean cp RNFLT in CPACG group was significantly correlated with the MD values(P< 0.01).4.The correlation coefficients of vertical cup-to-disc ratio,cup-to-disc area ratio and cup area of optic disc parameters with MD values were significantly stronger in CPACG group than in APACG group(P < 0.05).The correlation coefficients of the mean cp RNFLT with MD values were significantly stronger in CPACG group than in APACG group(P < 0.05).Conclusion:1.The optic disc parameters such as vertical cup-to-disc ratio,cup-to-disc area ratio and rim area in PACG patients were correlated with the mean cp RNFLT measured by SD-OCT and MD values detected by HFA.2.There was consistency between the optic disc parameters measured by KOWA nonmyd WX stereo fundus camera and those measured by HRT-III.3.The correlation between structural and functional damage of the optic nerve was stronger in the CPACG group than in the APACG group.4.The optic disc parameters measured by KOWA nonmyd WX stereo fundus camera can be used as an important basis for PACG diagnosis and monitoring of disease progression.