Comparing Rim Area By HRT-III With P-ERG In The Early Diagosis Of POAG

Primary open-angle glaucoma(POAG),the most common form among blacks and whites,causes insidious asymptomatic progressive bilateral visual loss that is often not detected until extensive field loss has already occurred.Therefore early diagnosis of glaucoma is the key to prevention and curing of the disease.The pattern of visual field loss are characteristic of POAG.But Dr. Quigley noted that only when the retinal ganglion cells(RGCs)are atrophied more than 50%did the vision field changed,while 20%RGCs had already apoptosis when the photosensitivity of retina decreased 5dB. Recently,increasing methods provide more sensitive and objective evidences for the early diagnosis of glaucoma,such as Heidelberg Retina Tomography(HRT),OCT,Electrophysiology,GDx VCC,and so on.The confocal scanning laser ophthalmoscope(Heidelberg Retina Tomography[HRT];Heidelberg Engineering,Heidelberg,Germany) obtains topographic imaging of the optic disk and peripapillary retina with a high degree of discrimination between healthy and glaucomatous eyes. The disadvantages of HRT-Ⅱrecently were amended in the newer version of the HRT software(HRT—Ⅲ),which includes an expanded normative database including subjects of European,African,and Indian ancestry (Sinai MJ,et al.IOVS 2006;47:ARVO E-Abstract 4350).The HRT—Ⅲalso includes an automated,operator-independent classifying procedure of the optic disk,the glaucoma probability score(GPS)classification. Zelefsky and associates found increased sensitivity using the HRT-ⅢThe objective of the study was to observe the diagnostic ability of pattern electroretinogram(P-ERG)and rim area measured by Heidelberg Retina TomographyⅢ(HRT-Ⅲ)in the primary open-angle glaucoma(POAG).Methods 25 Patients(25 eyes)in the early stage of POAG,25 Patients(25 eyes)with suspected POAG,25 normal controls were enrolled in the study,and they were measured with P-ERG and HRT-Ⅲ.The abnormal rates of P-ERG and HRT-Ⅲwere compared,and the correlation between rim area and P-ERG was investigated.Results In the early stage POAG group,the abnormal rates of P-ERG was 72%,much more than HRT-Ⅲ(32%)significantly;In the suspected POAG group,the abnormal rates of P-ERG was 60%,while the rate of HRT-Ⅲwas 20%;In the normal group,the abnormal rates of P-ERG and HRT-Ⅲdid not have a significant difference,with the abnormal rate of 12%and 20%. Conclusions The abnormal rates of P-ERG was much higher than HRT-Ⅲin the early diagnosis of POAG,and the rim area have a positive correlation with P-ERG.P-ERG combined with HRI-Ⅲmay be a useful method to early diagnosis of POAG.Besides,in order to serve the patients,the disadvantages and advantages of HRT-Ⅲand P-ERG ought to be evaluated and summarized in the coming years.