ABSTRACT
To investigate associations between central visual function and inner retinal structure in primary open-angle glaucoma (POAG). This study enrolled 78 POAG patients and 58 healthy controls. POAG was classified into early glaucoma and moderate to advanced glaucoma. The following tests were performed on all participants: isolated-check visual evoked potential (icVEP) testing, 24–2 standard automated perimetry (SAP), and Cirrus optical coherence tomography (OCT) examinations. Signal-to-noise ratio (SNR) measures obtained from icVEP responses to isolated checks presented at four depths of modulation (DOMs; 8%, 14%, 22%, and 32%) were explored. Mean macular sensitivity (mMS) was assessed by calculating the mean sensitivities of central 12 SAP points. Ganglion cell layer+ inner plexiform layer thickness (GCL+IPLT) and peripapillary retinal nerve fiber layer thickness (pRNFLT) were measured by OCT scanning. For each group of subjects, linear relationships among the following measures were analyzed: SNR, mMS, GCL+IPLT, and pRNFLT. SNR, mMS, GCL+IPLT, and pRNFLT were all more significantly decreased in glaucoma than in controls (P<0.001). A significant positive association was found between SNR at 14% DOM and GCL+IPLT at the inferior sector in early glaucoma (r=0.465, P=0.004). In moderate to advanced glaucoma, significant correlations were found between SNR at 32% DOM and mean GCL+IPLT (r=0.364, P=0.023), superior GCL+IPLT (r=0.358, P=0.025), and mean pRNFLT (r=0.396, P=0.025). In addition, in moderate to advanced glaucoma, there were significant correlations between mMS and all relevant measures of retinal thickness (r=0.330−0.663, P<0.010). In early glaucoma, significant correlations were found between mean mMS and minimum GCL+IPLT (r=0.373, P=0.023), and between inferior mMS and superior GCL+IPLT (r=0.470, P=0.003). Linear models provided a good explanation for the relationship between SNR and inner retinal thickness (IRT), whereas nonlinear models better explained the relationship between mMS and IRT. In early glaucoma, both SNR and mMS were related moderately and significantly to IRT, whereas in moderate to advanced glaucoma, mMS was more strongly correlated with IRT than SNR.
ABSTRACT
@#AIM: To analyze the application value of optical coherence tomography(OCT)combined with isolated-check visual evoked potential(Ic-VEP)in the diagnosis and treatment of primary open angle glaucoma(POAG). <p>METHODS: Prospective cohort study. Totally 32 eyes of 32 suspected glaucoma cases, 30 eyes of 30 early POAG cases, 25 eyes of 25 moderate and late POAG cases were selected from the patients treated in our hospital from October 2014 to May 2018 were enrolled, and 30 eyes of 30 normal subjects were selected as control group. All subjects received OCT, Ic-VEP, visual field test, measurement results were analyzed.<p>RESULTS: The sensitivity and specificity of Ic-VEP in diagnose of early POAG was 83% and 93% respectively. The difference between the early POAG group and the suspected glaucoma group was no statistically significant in the signal-to-noise ratio of 8% SNR(<i>P</i>>0.05), but were statistically significant in other groups(<i>P</i><0.05). The differences of 16%SNR and 32%SNR between the control group and the moderate and late POAG group, the suspected glaucoma group and the moderate and late POAG group, the early POAG group and the moderate and late POAG group were statistically significant(<i>P</i><0.01), but were no statistically significant in other groups(<i>P</i>>0.05). The retinal nerve fiber layer(RNFL)thickness parameters in four groups became thinner with the aggravation of the disease, and the differences between the four groups were statistically significant(<i>P</i><0.05). The mean defect of the four groups decreased gradually, there were no significant differences between the suspected glaucoma group and the control group(<i>P</i>=0.08), the differences between the other groups were statistically significant(<i>P</i><0.05). The area under the ROC curve of 8%SNR, mean RNFL and MD in the suspected glaucoma group were 0.824, 0.846 and 0.661 respectively, the early POAG group of those were 0.898, 0.969, 0.889, respectively. <p>CONCLUSION: OCT and Ic-VEP have high diagnostic ability for the early changes of POAG and can evaluate the degree of optic nerve injury, which can be combined used for early diagnosis and efficacy evaluation of POAG.
ABSTRACT
<p><b>Background</b>Standard automated perimetry does not sufficiently detect early open-angle glaucoma (OAG) in the clinic. New visual function tests for early glaucoma damage are therefore needed. The present study evaluated whether an isolated-check visual evoked potential (icVEP) could be used to detect visual function abnormalities in early-stage OAG and to explore potential related factors.</p><p><b>Methods</b>This was a cross-sectional study. Thirty-seven OAG patients with early-stage visual field loss (mean deviation ≥ -6.00 dB) detected by the Humphrey Field Analyzer (30-2 SITA program) and 26 controls were included in this study. Optical coherence tomography (OCT) was used to detect retinal nerve fiber layer (RNFL) defects. The icVEP preferentially evaluates the magnocellular-ON pathway. VEPs were recorded and signal-to-noise ratios (SNRs) were derived based on multivariate analysis. Eyes that yielded an SNR ≤1 were considered abnormal. Receiver operating characteristic (ROC) curve analysis was used to estimate the accuracy of group classification. Correlations between SNRs and related factors were analyzed.</p><p><b>Results</b>Based on an SNR criterion of 1, the icVEP had a sensitivity of 62.2% and a specificity of 92.3% for diagnosing early-stage OAG with 74.6% classification accuracy. The ROC curve analysis, however, suggested that an SNR criterion of 0.93 would produce the highest classification accuracy (77.3%). Both RNFL thinning in the temporal superior quadrant on OCT and number of abnormal test points in the central 11° visual field (pattern deviation, P < 0.5%) significantly correlated with the SNR (P < 0.05).</p><p><b>Conclusions</b>The icVEP detected visual function abnormalities in approximately 3/5 of eyes with early-stage OAG with greater than 90% specificity. SNR correlated with both a decrease in RNFL thickness and severity of central visual field loss.</p>
ABSTRACT
Objective To explore the value of qualitative pattern of isolated-check visual evoked potential ( ic-VEP) in the early diagnosis of primary open-angle glaucoma ( POAG) , and to provide an objective and effective basis for the early diagnosis of clinical glaucoma. Methods Sixty-eight patients (82 eyes) with normal POAG were randomly selected. Forty-seven normal individuals (76 eyes) were as control group. Both groups were treated to analyze ic-VEP,the defect of the visual field, the thickness of the retinal nerve fiber layer ( RNFLT) , and the mult-ivariate correlation analysis between ic-VEP, the visual field and RNFLT was performed. The sensitivity and speci-ficity of ic-VEP in the diagnosis of POAG was analysis in this study. Results There were no significant differences in age, diopter and central corneal thickness between glaucoma group and normal control group. However, the in-traocular pressure ( IOP) , the visual field, RNFLT and ic-VEP between two groups were statistically different( P＜0.01) . The correlation analysis of ic-VEP Signal-to-noise ratio ( SNR) with diopter, IOP, the visual field and RN-FLT in the glaucoma group showed that ic-VEP SNR was significantly associated with IOP, the visual field and RN-FLT damage(P＜0.01). The sensitivity of ic-VEP to detect POAG was 90.2% and the specificity was 88.2% . Ic-VEP and the visual field, RNFLT had good consistency. Conclusion Ic-VEP has high sensitivity and accuracy in the diagnosis of primary open-angle glaucoma. Meanwhile ic-VEP SNR is associated with the damage of retinal nerve fiber layer and the visual field damage.