Peripapillary vessel density correlates with visual field mean sensitivity in highly myopic eyes

Peripheral Superficial Retina Vascular Density and Area of Radial Peripapillary Capillaries Changes in Myopic Individuals: A Wide-Field OCT Angiography Study

Purpose

Using swept-source optical coherence tomography (SS-OCT) to explore the effect of high myopia on superficial retina vascular density (SVD) of the peripheral region and the area of radial peripapillary capillaries (RPCs).

Methods

In this cross-sectional study, a total of 91 volunteers (34 male subjects and 57 female subjects) were recruited and 34 individuals in the high myopic group (group A) and 57 individuals in the low myopic group (group B). Using the wide-field OCT-angiography (OCTA; 24 × 20 mm, 120 degrees angular field) compared the peripheral SVD and the area of RPC between the two groups and investigated its correlation with ocular axial length and diopter.

Results

Peripheral SVD of group B around the supratemporal (SVD1), supranasal (SVD2), infratemporal (SVD3), and infranasal (SVD4) directions were significantly higher than those of group A (all P < 0.05). The RPC area of group B around the supranasal (RPC2) and infranasal (RPC4) were significantly larger than that of group A (all P < 0.01). Ocular axial length and diopter were significantly correlated with SVD2 and SVD4 (all P < 0.05), and they also have a significant correlation with the supratemporal (RPC1), RPC2, and RPC4 (all P < 0.05).

Conclusions

Peripheral SVD was decreased and the RPC area was mainly reduced on the nasal side in the high myopic group. Peripheral SVD and area of RPC are significantly correlated with ocular axial length and diopter.

Translational Relevance

The wide-field OCTA can be used for new detection of myopia's impact on the retinal peripheral SVD and area of peripapillary RPC, offering new insights into the progression of myopia.

Exome-wide association study identifies KDELR3 mutations in extreme myopia

Extreme myopia (EM), defined as a spherical equivalent (SE) ≤ -10.00 diopters (D), is one of the leading causes of sight impairment. Known EM-associated variants only explain limited risk and are inadequate for clinical decision-making. To discover risk genes, we performed a whole-exome sequencing (WES) on 449 EM individuals and 9606 controls. We find a significant excess of rare protein-truncating variants (PTVs) in EM cases, enriched in the retrograde vesicle-mediated transport pathway. Employing single-cell RNA-sequencing (scRNA-seq) and a single-cell polygenic burden score (scPBS), we pinpointed PI16 + /SFRP4+ fibroblasts as the most relevant cell type. We observed that KDELR3 is highly expressed in scleral fibroblast and involved in scleral extracellular matrix (ECM) organization. The zebrafish model revealed that kdelr3 downregulation leads to elongated ocular axial length and increased lens diameter. Together, our study provides insight into the genetics of EM in humans and highlights KDELR3's role in EM pathogenesis.

Optic neuropathy in high myopia: Glaucoma or high myopia or both?

Due to the increasing prevalence of high myopia around the world, structural and functional damages to the optic nerve in high myopia has recently attracted much attention. Evidence has shown that high myopia is related to the development of glaucomatous or glaucoma-like optic neuropathy, and that both have many common features. These similarities often pose a diagnostic challenge that will affect the future management of glaucoma suspects in high myopia. In this review, we summarize similarities and differences in optic neuropathy arising from non-pathologic high myopia and glaucoma by considering their respective structural and functional characteristics on fundus photography, optical coherence tomography scanning, and visual field tests. These features may also help to distinguish the underlying mechanisms of the optic neuropathies and to determine management strategies for patients with high myopia and glaucoma.

Analysis of the relationship between axial length, optic disc morphology, and regional variations in retinal vessel density in young adults with healthy eyes

Purpose

To investigate the relationship between optic disc morphology, axial length, and regional distribution of retinal vessels in healthy eyes of young adults.

Methods

Nine hundred and two healthy eyes were enrolled in this university-based, cross-sectional study. Spectral-domain optical coherence tomography angiography was used to measure the parapapillary retinal vessel density. We automated the process of calculating optic disc tilt and rotation by using a program written in Python. Relationships between optic disc rotation, optic disc tilt, parapapillary vessel density, and other ocular parameters were analyzed using regression models.

Results

As axial length increased, optic disc morphology became more tilted and rotated inferiorly. The superficial vessel density (SVD) and radial peripapillary capillary density (RPCD) gradually decreased in all regions except for the temporal quadrant. Increased temporal SVD (OR [95% CI] = 1.081 [1.039, 1.124], p < 0.001), reduced nasal SVD (OR [95% CI] = 0.898 [0.861, 0.937], p < 0.01), and short relative lens position (OR [95% CI] = 0.126 [0.032, 0.495], p = 0.003) were significantly associated with the presence of a tilted optic disc. Inferior disc rotation was associated with decreased superior deep vessel density (DVD) and increased inferior DVD and temporal DVD after adjusting for sex and axial length.

Conclusion

The tilted and rotated optic discs were associated with the distribution of SVD and DVD, respectively. We should fully consider the influence of optic disc morphology on parapapillary vessel density in eyes with myopia.

Association of macular vessel density and ganglion cell complex thickness with central visual field progression in glaucoma

BACKGROUND/AIMS

To evaluate the association of macular vessel density (VD) and ganglion cell complex (GCC) thickness with 10-2 central visual field (CVF) progression in glaucoma.

METHODS

In this retrospective cohort study, patients with glaucoma from Diagnostic Innovation in Glaucoma Study with≥five 10-2 visual field (VF) tests and 3-year follow-up before optical coherence tomography (OCT) and OCT angiography (OCTA) imaging were included. Whole-image GCC thickness (wiGCC) and superficial VD (wiVD) were obtained from 6*6 macula scans. The association of wiVD and wiGCC with past rate of 10-2 VF mean deviation worsening, and with past CVF progression (defined using clustered linear regression criteria) was evaluated using linear mixed models after adjusting for confounders.

RESULTS

From 238 eyes (141 patients), 25 eyes (11%) of 16 patients were CVF progressors. In the multivariable analysis of the association between OCT/OCTA parameters and past rate of 10-2 CVF worsening, lower wiVD (β=-0.04 (-0.05, -0.02); p<0.001; R2=0.32) and wiGCC (β=-0.01 (-0.01, 0.00); p=0.004; R2=0.21) were significantly associated with faster CVF worsening. For the association between OCT/OCTA parameters and past CVF progression, the multivariable analysis showed that a lower wiVD was significantly associated with increased odds of past CVF progression (OR=1.23 (1.06, 1.44) per 1% lower; p=0.008), while wiGCC did not show correlation.

CONCLUSIONS

Lower macular VD and GCC were associated with faster worsening of CVF, and lower macular VD was associated with increased odds of CVF progression. Assessment of macular OCT and OCTA may help detect glaucoma eyes with CVF progression.

Influence of Refractive Error on Circumpapillary Structure-Function Versus Vessel Density-Function Relationships in Open Angle Glaucoma

PRCIS

In Japanese open angle glaucoma (OAG) eyes correlation of 30-degree visual field mean deviation (MD) and visual field index (VFI) with circumpapillary vessel density is systematically stronger than that with circumpapillary retinal nerve fiber layer thickness (RNFLT), and is preserved in myopia and high myopia.

PURPOSE

The purpose of this study was to investigate the influence of refractive error on the relationship between circumpapillary retinal nerve fiber layer thickness (cpRNFLT) and circumpapillary vessel density (cpVD), respectively, and global visual field parameters in Japanese open angle glaucoma (OAG) eyes.

MATERIAL AND METHODS

One eye of 81 Japanese OAG patients (spherical equivalent refractive error: +3.0 to -9.0 D) underwent 360-degree cpRNFLT and cpVD measurements with Cirrus HD 5000-AngioPlex optical coherence tomography and 30-2 Humphrey visual field testing for mean deviation (MD) and visual field index (VFI) within 1 month. Correlations were determined for the whole population and each refractive error subgroups, separately: emmetropia/hyperopia (n=24), mild (n=18), moderate (n=20), and high myopia (n=19).

RESULTS

For the total population, significant strong to very strong correlations were found between MD, VFI, and both cpRNFLT and cpVD, respectively, with consistently higher r -values for cpVD (highest r -values: 0.532 for cpRNFLT, P <0.001; 0.722 for cpVD, P <0.001). Of the refractive subgroups, statistically significant correlations between cpRNFLT and the visual field parameters were maintained only in the hyperopia/emmetropia and moderate myopia groups. In contrast, statistically significant, strong to very strong correlations between cpVD and both MD and VFI, always exceeding the corresponding r -values found for cpRNFLT were found in all refractive subgroups, with r -values ranging between 0.548 ( P =0.005) and 0.841 ( P <0.001).

CONCLUSIONS

Our results suggest that in Japanese OAG eyes the relationship of MD and VFI with cpVD is strong. It is systematically stronger than that with cpRNFLT and preserved in each conventional refractive error category including high myopia.

Neuroprotection in Glaucoma: Basic Aspects and Clinical Relevance

Glaucoma is a neurodegenerative disease that affects primarily the retinal ganglion cells (RGCs). Increased intraocular pressure (IOP) is one of the major risk factors for glaucoma. The mainstay of current glaucoma therapy is limited to lowering IOP; however, controlling IOP in certain patients can be futile in slowing disease progression. The understanding of potential biomolecular processes that occur in glaucomatous degeneration allows for the development of glaucoma treatments that modulate the death of RGCs. Neuroprotection is the modification of RGCs and the microenvironment of neurons to promote neuron survival and function. Numerous studies have revealed effective neuroprotection modalities in animal models of glaucoma; nevertheless, clinical translation remains a major challenge. In this review, we select the most clinically relevant treatment strategies, summarize preclinical and clinical data as well as recent therapeutic advances in IOP-independent neuroprotection research, and discuss the feasibility and hurdles of each therapeutic approach based on possible pathogenic mechanisms. We also summarize the potential therapeutic mechanisms of various agents in neuroprotection related to glutamate excitotoxicity.