Impact of optical coherence tomography angiography on the non-invasive diagnosis of neovascular age-related macular degeneration

Comparison of macular thickness in diabetic patients acquired from optical coherence tomography mode and optical coherence tomography angiography mode in Cirrus HD-OCT 5000

PURPOSE

To compare macular thickness obtained using two different modes of image acquisitions with Cirrus HD-OCT 5000.

METHODS

Patients with diabetes were recruited and macular thickness were obtained using optical coherence tomography (OCT) mode and optical coherence tomography angiography (OCTA) mode. The OCT mode involved a Macular Cube (512×128 pixels) centred on the fovea covering a 6 × 6 mm2 macular region. The OCTA acquisition involved scanning of a 6 × 6 mm² scan (350×350 pixels) centred on the fovea. Data was exported and compared according to the Early Treatment Diabetic Retinopathy Study (ETDRS) subfields. Fixation deviation was defined as the deviation of the foveal point from the grid center in the OCT scan and OCTA scan.

RESULTS

Eighty-six diabetic patients were recruited had similar macular thickness in all ETDRS subfield except the superior outer sector. The 95 % limits of agreement between the two modes were within 9.7μm to -9.0μm. It took longer to complete each OCTA mode (median of 7.4 s) than the OCT mode (median time of 5.8 s) (Wilcoxon test, p < 0.001), but OCTA generated a smaller fixation deviation (median 68.8μm) than the OCT mode (median 103.0μm) (Wilcoxon test, p = 0.014).

CONCLUSIONS

Improved fixation in OCTA compared with OCT was evident, likely because of the faster scanning speed and higher sampling density of OCTA. Macular thickness was found similar. There appears no requirement to obtain macular thickness measurements using a separate OCT mode. This approach can reduce patient chair time, improve patient comfort, and streamline the clinical workflow.

Real-world outcomes of anti-VEGF therapy in treatment-naïve neovascular age-related macular degeneration diagnosed on OCT angiography: the REVEAL study

PURPOSE

To compare the 12 months visual and anatomical outcomes of treatment-naïve neovascular age-related macular degeneration (nAMD) patients diagnosed by optical coherence tomography angiography (OCT-A) compared with fluorescein angiography (FA)/indocyanine green angiography (ICGA), after anti-VEGF treatment in a real-world setting.

METHODS

Monocentric, observational, parallel-group study of nAMD patients diagnosed with either FA/ICGA or non-invasive OCT-A methods. Patients were treated with a fixed dosing regimen of intravitreal ranibizumab or aflibercept and followed up for 12 months. Primary outcomes were the 12 months functional (BCVA) and anatomical (CST reduction) gains between the two groups. The stratification of BCVA and CST gains by type of neovascular lesion and by anti-VEGF treatment was also assessed.

RESULTS

Seventy-two patients received FA/ICGA for the initial diagnosis of nAMD, while 73 received OCT-A. Overall, the mean BCVA gain at 12 months was 11.5 ± 9.6 letters. There were no statistically significant differences between the invasive and non-invasive imaging groups in BCVA gain (p = 0.87) or CST reduction (p = 0.76). No statistically significant outcome differences between different lesion types and the two drugs were observed.

CONCLUSION

In a real-world setting, nAMD patients diagnosed with OCT-A showed meaningful improvements in visual and anatomical parameters during 12 months of treatment, without significant differences with those diagnosed by invasive modalities.

Diagnostic Value of Optical Coherence Tomography Angiography for Choroidal Neovascularization in Age-Related Macular Degeneration: A Systematic Review and Meta-Analysis

OBJECTIVE

This study aims to evaluate the diagnostic value of optical coherence tomography angiography (OCTA) in detecting the choroidal neovascularization (CNV) in age-related macular degeneration (AMD).

METHODS

A systematic review and meta-analysis was performed by searching Pubmed, Science Direct, Embase, and Web of Science. The pooled sensitivity and specificity with 95% confidence intervals (CIs), area under the summary receiver operator characteristic curve (sROC), and the total accurate classification rate were used to evaluate OCTA's diagnostic value of CNV in AMD patients.

RESULTS

Seven studies involving 517 eyes were included in the analysis. The mean age of subjects in each study ranged from 58.5 years to 81.7 years. Fluorescein angiography was applied as the gold standard in 5 studies. There were 350 eyes diagnosed with CNV, OCTA detected 301 eyes correctly, while among the 167 eyes without CNV, OCTA identified 150 correctly. The total accurate classification rate was 87.23%. The Spearman's rank correlation coefficient was 0.5, indicating that there was no significant threshold effect in the current study (S = 8, p = 0.103). The pooled sensitivity and pooled specificity were 0.89 (95% CI: 0.82, 0.94) and 0.96 (95% CI: 0.85, 1.00), respectively. The area under sROC was up to 0.911.

CONCLUSION

The specificity of OCTA for the detection of CNV in AMD patients is extremely high; however, the sensitivity still needs to be improved. In general, the meta-analysis revealed that OCTA had a high diagnostic value for the detection of CNV in AMD patients.