Retinal vessel shift and its association with axial length elongation in a prospective observation in Japanese junior high school students

Compartmental analysis of retinal vascular parameters and thickness in myopic eyes using SS-OCTA

Background

This study aimed to comprehensively explore the thickness and topographic distributions of retinal vessel alterations of different myopic eyes by using swept-source OCT angiography (SS-OCTA).

Methods

One hundred myopes were included in this observational cross-sectional study. All participants underwent a series of ocular examinations of biometrical parameters, including spherical equivalent refraction (SER), axial length (AL), intraocular pressure (IOP), curvature radius (CR), and others. Retinal parameters like vessel density (VD) of different compartments of papillary and peripapillary sectors were measured by SS-OCTA, respectively. Two sample-independent T-test was applied to identify intraocular differences in retinal biometrical indicators between groups, and correlation analysis was used to explore potential relationships between AL/CR ratio and some ocular variables.

Results

For high myopic participants, they exhibited a lower vessel density, a lower small vessel density, and a lower flow area, especially in the superficial layer and the nerve fiber layer (RNFL), along with a thinner superficial layer, RNFL and retina. More alterations were proved in nasal peripapillary sectors in high myopes. We also explored their hidden relationship with AL/CR ratio. We found that in non-high myopes, the thickness of the whole retina, RNFL and the superficial layer were all negatively correlated with AL/CR ratio in the papillary and peripapillary zone. In contrast, the vessel density and flow area of several vessel layers were positively correlated. However, there wasn't so much significance found in high myopic eyes.

Conclusion

Retinal vessel microstructure was more easily affected in highly myopic eyes, especially in superficial blood vessels, and compartmental analysis showed that alterations in nasal peripapillary sectors were more evident. Additionally, we highlighted hidden correlations between AL/CR ratio and blood flow characteristics of specific vascular layers, which could serve as sensitive biometrical indicators of early retinal damages.

Axial elongation in nonpathologic high myopia: Ocular structural changes and glaucoma diagnostic challenges

Axial elongation continues in highly myopic adult eyes, even in the absence of pathologic changes such as posterior staphyloma or chorioretinal atrophy. This ongoing axial elongation leads to structural changes in the macular and peripapillary regions, including chorioretinal thinning, reduced vascular perfusion and optic disc tilting and rotation, among others. These alterations can affect the acquisition and interpretation of optical coherence tomography, optical coherence tomography angiography and fundus photographs, potentially introducing artifacts and diminishing the accuracy of glaucoma diagnosis in highly myopic eyes. In this review, we compared the progression patterns of axial elongation across populations with varying demographic characteristics, genetic and environmental backgrounds and ocular features. We also discussed the implications of axial elongation-induced ocular structural changes for diagnosing glaucoma in nonpathologic high myopia. Finally, we highlighted the prospects for enhancing the diagnostic efficacy of glaucoma in nonpathologic highly myopic populations.

Retinal vascular arcade angle as a biomarker for visual improvement after epiretinal membrane surgery

OBJECTIVES

To investigate the changes in the temporal vascular angles after epiretinal membrane (ERM) surgery and utilize the angles to predict visual outcomes.

METHODS

A total of 168 eyes from 84 patients with unilateral ERM who underwent vitrectomy were enrolled from a single institution. The angles of temporal venous (anglevein) and arterial arcades (angleartery) were measured on fundus photographs. The relationships between the angles and the best-corrected visual acuity (BCVA) were explored and multivariable logistic models and receiver operating characteristic (ROC) curves were analyzed to identify the factors that predicted visual outcomes.

RESULTS

At baseline, both angleartery and anglevein were narrower in the eyes with ERM than the fellow eyes (p < 0.001 and 0.007) but had no correlation with the baseline BCVA (p = 0.754 and 0.804). Postoperatively, the angleartery and anglevein significantly widened (both p < 0.001) and a greater BCVA improvement was associated with a greater widening of the angleartery (p = 0.029) and anglevein (p = 0.050). Multivariable logistic analyses found a narrower baseline angleartery compared to the fellow eye had a higher chance for BCVA improvement ≧ 2 lines (Odds ratio = 0.97; 95% CI, 0.94-0.99; p = 0.016). ROC curve showed the baseline difference in the angleartery between bilateral eyes predicted BCVA improvement ≧ 2 lines (area under the curve = 0.74; p = 0.035), and a 0.73 sensitivity and 0.80 specificity with a cut-off value of -27.19 degrees.

CONCLUSIONS

The retinal vascular angles widened after ERM surgery and the fundus photograph-derived angles may serve as a highly-accessible biomarker to predict postoperative visual outcomes.

A New Vessel-Based Method to Estimate Automatically the Position of the Nonfunctional Fovea on Altered Retinography From Maculopathies

Purpose

The purpose of this study was to validate a new automated method to locate the fovea on normal and pathological fundus images. Compared to the normative anatomic measures (NAMs), our vessel-based fovea localization (VBFL) approach relies on the retina's vessel structure to make predictions.

Methods

The spatial relationship between the fovea location and vessel characteristics is learnt from healthy fundus images and then used to predict fovea location in new images. We evaluate the VBFL method on three categories of fundus images: healthy images acquired with different head orientations and fixation locations, healthy images with simulated macular lesions, and pathological images from age-related macular degeneration (AMD).

Results

For healthy images taken with the head tilted to the side, the NAM estimation error is significantly multiplied by 4, whereas VBFL yields no significant increase, representing a 73% reduction in prediction error. With simulated lesions, VBFL performance decreases significantly as lesion size increases and remains better than NAM until lesion size reaches 200 degrees2. For pathological images, average prediction error was 2.8 degrees, with 64% of the images yielding an error of 2.5 degrees or less. VBFL was not robust for images showing darker regions and/or incomplete representation of the optic disk.

Conclusions

The vascular structure provides enough information to precisely locate the fovea in fundus images in a way that is robust to head tilt, eccentric fixation location, missing vessels, and actual macular lesions.

Translational Relevance

The VBFL method should allow researchers and clinicians to assess automatically the eccentricity of a newly developed area of fixation in fundus images with macular lesions.