Circumpapillary ganglion cell complex thickness to diagnose glaucoma: A pilot study

Ganglion Cell Complex Analysis: Correlations with Retinal Nerve Fiber Layer on Optical Coherence Tomography

The aim of this review is to analyze the correlations between the changes in the ganglion cell complex (GCC) and the retinal nerve fiber layer (RNFL) on optical coherence tomography in different possible situations, especially in eyes with glaucoma. For glaucoma evaluation, several studies have suggested that in the early stages, GCC analysis, especially the thickness of the infero and that of the inferotemporal GCC layers, is a more sensitive examination than circumpapillary RNFL (pRNFL). In the moderate stages of glaucoma, inferior pRNFL thinning is better correlated with the disease than in advanced cases. Another strategy for glaucoma detection is to find any asymmetry of the ganglion cell-inner plexiform layers (GCIPL) between the two macular hemifields, because this finding is a valuable indicator for preperimetric glaucoma, better than the RNFL thickness or the absolute thickness parameters of GCIPL. In preperimetric and suspected glaucoma, GCC and pRNFL have better specificity and are superior to the visual field. In advanced stages, pRNFL and later, GCC reach the floor effect. Therefore, in this stage, it is more useful to evaluate the visual field for monitoring the progression of glaucoma. In conclusion, GCC and pRNFL are parameters that can be used for glaucoma diagnosis and monitoring of the progression of the disease, with each having a higher accuracy depending on the stage of the disease.

A Comparison Among Microperimetry, Standard Automated Perimetry and Spectral Domain Optical Coherence Tomography in the Evaluation of the Macula in Glaucoma Eyes with Hemifield Defects

Introduction

To evaluate the correlation between macular integrity assessment (MAIA) and standard automated perimetry (SAP) in detecting macular function damage in glaucoma and to explore the relationship between macular structure and functional damage by using spectral domain optical coherence tomography (SD-OCT).

Methods

This was a cross-sectional study. Seventy patients with glaucoma, with hemifield defects verified by Humphrey 24-2 examination, and 60 normal subjects underwent Humphrey 10-2 and MAIA expert 10-2 examinations. Patients with glaucoma with normal hemifields, as detected by SAP, were divided into a normal hemifield group and a visual field (VF) defect group. The difference in the retina and ganglion cell complex (GCC) thicknesses was analyzed between the abnormal and normal hemifields.

Results

Among the 70 glaucoma eyes, the results of MAIA and SAP were consistent for 66 (66/70, 94.3%). The others showed SAP hemifield defects, while MAIA was normal (4/70, 5.7%). There was a good correlation of the mean sensitivity between MAIA and SAP (P < 0.001). There also was a good correlation between the mean threshold of MAIA and the mean deviation (MD) of SAP (P = 0.008, r = 0.507). Among the patients with glaucoma with a normal hemifield, MAIA showed abnormal results in 50 eyes (50/66, 75.8%), which was consistent with the changes in the inner retina and GCC thicknesses. Meanwhile, MAIA showed normal results; there were no significant differences between patients with glaucoma and the normal group in the thicknesses of the inner retina and GCC.

Conclusion

MAIA and SAP have good consistency in detecting macular dysfunction. MAIA can also identify abnormal VFs in the macular regions that may not be detected by SAP, which is consistent with the changes in the GCC thicknesses, suggesting that there may be central VF damage in patients with glaucoma that has not been previously identified.

Can We Corroborate Peripapillary RNFL Analysis with Macular GCIPL Analysis? Our 2-Year Experience at a Single-Centre Tertiary Healthcare Hospital Using Two OCT Machines and a Review of Literature

Purpose

To determine whether macular volume and macular GCA measurements in patients are comparable to their RNFL thickness parameters.

Materials and Methods

The cross-sectional, observational study was conducted on 1380 eyes with 460 each, into three groups. Group I: patients with healthy eyes. Group II: patients diagnosed as pre-perimetric glaucoma. Group III: patients with diagnosed perimetric glaucoma. After patients were selected on the basis of inclusion and exclusion criteria, baseline standard ophthalmic examination was done by the same operator under the same settings, including SD-OCT using both the Spectralis SD-OCT and the Cirrus SD-OCT as elaborated below.

Statistical Analysis

Data were checked for normality before statistical analysis using Shapiro-Wilk test. Normally distributed continuous variables were compared using ANOVA. For all statistical tests, a p < 0.05 was taken to indicate a significant difference. Receiver operating characteristic (ROC) curves were used to define the ability RNFL and GCC parameters to distinguish perimetric and preperimetric glaucomatous eyes from control eyes.

Results

There was a statistically significant difference in the average, superior, inferior RNFL thickness and average, superior, inferior GCIPL thickness between Group I and Group II (p<0.001), between Group I and Group III (p<0.001) and also between Group II and Group III (p<0.001). The statistical significance was also reflected in their AUROCs.

Conclusion

Mean, superior, inferior GCIPL thickness along with macular volume analysis can substantiate RNFL analysis for diagnosis, serial monitoring and follow-up of glaucoma patients and suspects.

Development of a Spatial Model of Age-Related Change in the Macular Ganglion Cell Layer to Predict Function From Structural Changes

PURPOSE

To develop location-specific models of normal, age-related changes in the macular ganglion cell layer (GCL) from optical coherence tomography (OCT). Using these OCT-derived models, we predicted visual field (VF) sensitivities and compared these results to actual VF sensitivities.

DESIGN

Retrospective cohort study.

METHODS

Single eyes of 254 normal participants were retrospectively enrolled from the Centre for Eye Health (Sydney, Australia). Macular GCL measurements were obtained using Spectralis OCT. Cluster algorithms were performed to identify spatial patterns demonstrating similar age-related change. Quadratic and linear regression models were subsequently used to characterize age-related GCL decline. Forty participants underwent additional testing with Humphrey VFs, and 95% prediction intervals were calculated to measure the predictive ability of structure-function models incorporating cluster-based pooling, age correction, and consideration of spatial summation.

RESULTS

Quadratic GCL regression models provided a superior fit (P value <.0001-.0066), establishing that GCL decline commences in the late 30s across the macula. The equivalent linear rates of GCL decline showed eccentricity-dependent variation (0.13 μm/yr centrally vs 0.06 μm/yr peripherally); however, average, normalized GCL loss per year was consistent across the 64 macular measurement locations at 0.26%. The 95% prediction intervals describing predicted VF sensitivities were significantly narrower across all cluster-based structure-function models (3.79-4.99 dB) compared with models without clustering applied (5.66-6.73 dB, P < .0001).

CONCLUSIONS

Combining spatial clustering with age-correction based on regression models allowed the development of robust models describing GCL changes with age. The resultant superior predictive ability of VF sensitivity from ganglion cell measurements may be applied to future models of disease development to improve detection of early macular GCL pathology.

Circumpapillary structure-function relationships with microperimetry and spectral domain optical coherence tomography in glaucoma: a pilot study

Purpose

To compare the relationships between circumpapillary microperimetry (MP)-sensitivity measurements and various circumpapillary retinal thickness parameters in healthy and primary open-angle glaucoma (POAG) eyes.

Methods

In 14 eyes of 14 healthy subjects and 22 early–moderate POAG eyes of 22 patients, circumpapillary optical coherence tomography thickness measurements (RS-3000 Advance OCT, NIDEK) of the retinal nerve fiber layer (cpRNFL), total retina (cpTR), and ganglion cell complex (cpGCC) and outer retina (cpOR) and circumpapillary MP-sensitivity measurements (MP-3 microperimeter, NIDEK) were made in 12 sectors of identical circumpapillary circles. The structure-function relationship was investigated in each sector.

Results

Statistically significant correlations with circumpapillary MP-sensitivity values were found for cpRNFL in five sectors, cpTR in nine sectors, cpGCC in nine sectors, and cpOR in three sectors. The structure-function relationship was strong (r=0.4–0.69) in three sectors for cpRNFL, in six for cpTR, in four for cpGCC, and in one for cpOR. The relationship was very strong (r>0.7) in one sector for cpRNFL, cpTR, and cpGCC, and in no sectors for cpOR. The very strong relationships all occurred in sector 5 (inferotemporal sector).

Conclusion

In our pilot study, the circumpapillary structure-function relationship was more extensive for cpTR thickness and cpGCC thickness than for cpRNFL thickness, which suggests that the former parameters may require greater attention in structure-function research into glaucoma.

A new strategy to interpret OCT posterior pole asymmetry analysis for glaucoma diagnosis

AIM

To detect early glaucoma by optical coherence tomography (OCT) posterior pole asymmetry analysis.

METHODS

Totally 39 eyes from 39 healthy subjects, 40 eyes from 40 mild glaucoma patients, 33 eyes from 33 moderate glaucoma patients and 41 eyes from severe glaucoma patients were included in this study. All subjects underwent posterior pole asymmetry analysis (PPAA) of OCT and the posterior pole area was divided into three zones. Means, standard deviations and 95% confidence intervals of each zone asymmetry in control group were assessed. Retina thickness asymmetry (RTA) of different stage of glaucoma were compared for each zone, and receiver operating characteristic (ROC) curves were made to test the efficacy of strategies using different zones to discriminate glaucomatous eyes from the healthy ones.

RESULTS

In a healthy population, RTA of the centre zone showed the minimal mean value (3.085 µm), standard deviation (1.756), and the narrowest 95% confidence interval (from 2.360 to 3.810 µm). It was only in the center zone that RTA exhibited significant difference between control and moderate glaucoma group (P<0.01), as well as control and severe glaucoma group (P<0.00001). The strategy utilized in the center zone had the strongest diagnostic capability (zone 3 AUROC=0.816, P=0.0016) in comparison to that of the periphery area (zone 1 AUROC=0.675, P=0.0016; zone 2 AUROC=0.623, P=0.0197), the whole posterior pole involved interpreting strategy showed inferior diagnostic power than the centre zone dependent strategy (z=2.851, P=0.0044).

CONCLUSION

Utilizing the posterior pole centre zone to interpret OCT PPAA results are more effective than making use of the whole posterior pole map.

Genetic Polymorphisms of Cytotoxic T-Lymphocyte Antigen 4 in Primary Biliary Cholangitis: A Meta-Analysis

Background and Aim

The connection between gene polymorphisms of cytotoxic T-lymphocyte-associated protein 4 (CTLA4) and primary biliary cholangitis (PBC) is still vague and blurred. The purpose of this study is to precisely estimate the association of the polymorphisms of CTLA4 with the risk of PBC by using a meta-analysis.

Methods

PubMed and the Chinese National Knowledge Infrastructure (CNKI) database were used to search correlative literatures, and the documents which were about the relationships between the polymorphisms of CTLA4 (rs231775, rs231725, rs3087243, and rs5742909) and PBC were collected as of June 2016. The strength of correlation based on odds ratios (ORs) and its 95% confidence intervals (95%CIs) was computed by STATA.

Results

Generally, in rs231775, a significant risk was found in G allele, the value of OR was 1.32, and its 95%CI was 1.19 to 1.47. The same situation was found in A allele of rs231725, the value of OR was 1.33, and its 95%CI was 1.22 to 1.45. As genotypic level, different genotypic models were also found to have obvious relevance with PBC in rs231775 and rs231725. No obvious connections were found in other SNPs.

Conclusion

This study indicated that the polymorphisms of rs231775 and rs231725 would be the risk factors of PBC.