Optical Coherence Tomography Angiography-Based Quantitative Assessment of Morphologic Changes in Active Myopic Choroidal Neovascularization During Anti-vascular Endothelial Growth Factor Therapy

PREDICTIVE ROLES OF QUANTITATIVE OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY FEATURES IN PROGNOSIS OF MYOPIC CHOROIDAL NEOVASCULARIZATION

PURPOSE

To explore the predictive roles of the morphologic features of neovascularization in the prognosis of myopic choroidal neovascularization.

METHODS

In this retrospective case series study, quantitative morphologic features of neovascularization were obtained from the optical coherence tomography angiography images. According to the number of anti-vascular endothelial growth factor injections administered within 1 year, the eyes were classified into a stable group (≤2 injections) or an unstable group (>2 injections). Best-corrected visual acuity was recorded before the treatment and at the 1-year follow-up.

RESULTS

Overall, 50 eyes with treatment-naive myopic choroidal neovascularization were included; 26 in the stable group and 24 in the unstable group. Multivariate analysis showed that the eyes in the unstable group were associated with a larger lesion area (odds ratio = 2.596, P = 0.012), higher junction density (odds ratio = 1.611, P = 0.014), and higher end point density (odds ratio = 1.435, P = 0.023).The area under the receiver operating characteristic curve of the multivariate model was 0.865, with 91.7% sensitivity and 65.4% specificity. The final best-corrected visual acuity was significantly correlated with the lesion area (β = 0.152, P = 0.032) after adjusted for age, sex, and baseline best-corrected visual acuity.

CONCLUSION

Lesions with larger areas and higher end point and junction densities tended to have more frequent anti-vascular endothelial growth factor injections and worse visual outcomes in eyes with myopic choroidal neovascularization.

Vascular Aging and Damage in Patients with Iron Metabolism Disorders

Vascular aging is a physiological, multifactorial process that involves every type of vessel, from large arteries to microcirculation. This manifests itself as impaired vasomotor function, altered secretory phenotype, deteriorated intercellular transport function, structural remodeling, and aggravated barrier function between the blood and the vascular smooth muscle layer. Iron disorders, particularly iron overload, may lead to oxidative stress and, among other effects, vascular aging. The elevated transferrin saturation and serum iron levels observed in iron overload lead to the formation of a non-transferrin-bound iron (NTBI) fraction with high pro-oxidant activity. NTBI can induce the production of reactive oxygen species (ROS), which induce lipid peroxidation and mediate iron-related damage as the elements of oxidative stress in many tissues, including heart and vessels' mitochondria. However, the available data make it difficult to precisely determine the impact of iron metabolism disorders on vascular aging; therefore, the relationship requires further investigation. Our study aims to present the current state of knowledge on vascular aging in patients with deteriorated iron metabolism.

Advances in OCT Imaging in Myopia and Pathologic Myopia

Advances in imaging with optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA) technology, including the development of swept source OCT/OCTA, widefield or ultra-widefield systems, have greatly improved the understanding, diagnosis, and treatment of myopia and myopia-related complications. Anterior segment OCT is useful for imaging the anterior segment of myopes, providing the basis for implantable collamer lens optimization, or detecting intraocular lens decentration in high myopic patients. OCT has enhanced imaging of vitreous properties, and measurement of choroidal thickness in myopic eyes. Widefield OCT systems have greatly improved the visualization of peripheral retinal lesions and have enabled the evaluation of wide staphyloma and ocular curvature. Based on OCT imaging, a new classification system and guidelines for the management of myopic traction maculopathy have been proposed; different dome-shaped macula morphologies have been described; and myopia-related abnormalities in the optic nerve and peripapillary region have been demonstrated. OCTA can quantitatively evaluate the retinal microvasculature and choriocapillaris, which is useful for the early detection of myopic choroidal neovascularization and the evaluation of anti-vascular endothelial growth factor therapy in these patients. In addition, the application of artificial intelligence in OCT/OCTA imaging in myopia has achieved promising results.

Predicting lesion shrinkage in eyes with myopic choroidal neovascularization from features on optical coherence tomography angiography

PURPOSE

To identify baseline morphological predictors of lesion shrinkage in eyes with myopic choroidal neovascularization (mCNV) treated with anti-vascular endothelial growth factor (VEGF).

METHODS

This retrospective study included 46 eyes (41 consecutive patients) with active mCNV receiving anti-VEGF treatment. Optical coherence tomography angiography (OCTA) was performed at baseline and 1 year after treatment. Quantitative features were obtained from OCTA images using AngioTool software. Eyes were classified as "high-shrinkage" or "low-shrinkage" according to the median relative change in lesion area. Baseline quantitative morphological features associated with mCNV shrinkage were identified in univariate and multivariate analyses.

RESULTS

The mCNV area was significantly smaller after 1 year (P=0.013), with a median relative change of -16.5%. The relative change in mCNV area was -48.3% in high-shrinkage eyes (n=23) and -5.2% in low-shrinkage eyes (n=23). High-shrinkage eyes had a smaller mCNV area (P=0.013), shorter total vessel length (P=0.023), and higher endpoint density (P<0.001). Multivariate analysis showed significant associations of high shrinkage with endpoint density (β=-0.037, P=0.043) and previous anti-VEGF treatment (β=0.216, P=0.029).

CONCLUSION

Morphological features of neovascularization detected by OCTA can predict lesion shrinkage in eyes with mCNV receiving anti-VEGF therapy. Higher endpoint density contributed to shrinkage, particularly of treatment-naive lesions.

Performance Assessment of Two Different Approaches of Measuring Skeletonized Radial Peripapillary Capillary Vessel Density in Glaucoma Patients

Objective

To compare performance assessment of two methods of measuring radial peripapillary capillary (RPC) vessel density (VD) after skeletonization using MATLAB and Image J in glaucoma clinical setting.

Methods

Seventy-three eyes of 73 glaucoma patients from Beijing Tongren Hospital were included in this prospective study. Original images of RPC were obtained using optical coherence tomography angiography. Two approaches were executed before measuring. Method 1 (M1) required image sharpening, removal of big vessels, and skeletonization. Method 2 (M2) required skeletonization and removal of major vessels. Each method was executed twice. Repeatability and correlations with glaucomatous parameters were assessed. Factors associated with retinal nerve fiber layer thickness (RNFLT) and visual field mean deviation (MD) were analyzed.

Results

Average VD was 13.86 ± 2.73 and 7.50 ± 2.50% measured by M1 and M2. Percentage of total elimination of the major vessels was 36.99 and 100% by M1 and M2, respectively. The intrasession and intersession reproducibility was higher by M2 (ICC = 0.979, ICC = 0.990) than by M1 (ICC = 0.930, ICC = 0.934). VD measured by M2 showed stronger correlations with glaucomatous parameters than by M1. By stepwise multiple linear regression, thinner RNFLT was associated with smaller VD measured by M2 (B = 4.643, P < 0.001). Worse MD was associated with smaller VD measured by M1 (B = 1.079, P = 0.015).

Conclusion

The VD measured by M2 showed better reproducibility and higher correlation with glaucomatous structural parameters. Image sharpning helps display of hazy vasculature in glaucoma, which may reflect visual function better. Researchers should carefully choose image processing methods according to their research object.

Novel Findings of Retinal and Choroidal Features Utilizing Optical Coherence Tomography Angiography Analysis in Patients With Autoimmune Posterior Uveitis

Purpose: To analyze the quantitative parameters acquired by optical coherence tomography angiography (OCTA) in patients with autoimmune posterior uveitis. Methods: OCTA images of 65 eyes affected with uveitis and 65 normal control (NC) eyes were obtained. The central macular thickness (CMT), retinal thicknesses, foveal avascular zone (FAZ) area, foveal density 300 μm (FD300), and vascular density (VD) were compared among acute uveitic eyes, chronic uveitic eyes, and NC eyes. VDs were evaluated in the choriocapillaris, outer retina, optic disk, whole and parafovea superficial capillary plexus (SCP), and whole and parafovea deep capillary plexus (DCP). Correlation analysis was used to analyze the relationship between LogMAR best-corrected visual acuity (BCVA) and quantitative parameters from OCTA. Results: Compared with NC eyes, the CMT and retinal thicknesses were increased significantly in eyes with uveitis (p < 0.05, respectively). No significant difference was observed in the FAZ area. FD300, VDs in the optic disk, SCP, and DCP both in whole image and parafovea, choriocapillaris were significantly decreased in uveitis eyes (p < 0.05, respectively) compared with NC eyes, only the acute group had decreased VD of the outer retina and choriocapillaris compared with the NC group (p < 0.05). Moreover, quantitative parameters of OCTA showed a significant correlation with LogMAR BCVA in the patients with uveitis. Whole VD DCP was the best predictive factor for BCVA in the patients with uveitis. Conclusion: Quantitative measurement by OCTA is a promising strategy for objective assessment of autoimmune posterior uveitis.