Association between the retinal vascular network and retinal nerve fiber layer in the elderly: The Montrachet study

Neuroretinal and Retinal Pigment Epithelium Changes and Susceptibility to Age-Related Macular Degeneration: Insights from the Longitudinal ALIENOR Study

PURPOSE

We assessed the associations of macular layer thicknesses, measured using spectral-domain (SD) OCT, with incident age-related macular degeneration (AMD) and AMD polygenic risk scores (PRSs).

DESIGN

Population-based cohort study.

PARTICIPANTS

A total of 653 participants from the ALIENOR study, with biennial eye imaging from 2009 through 2024.

METHODS

Macular layer thicknesses of 8 distinct layers were automatically segmented based on SD-OCT imaging. Total and pathway-specific PRSs were calculated from previous AMD genome-wide association studies summary statistics. Associations of macular layer thicknesses with incident intermediate and advanced AMD were analyzed using time-dependent Cox proportional hazards models. Associations of macular layer thicknesses with PRS were assessed using linear mixed models.

MAIN OUTCOME MEASURES

Incident intermediate and advanced AMD based on fundus color photographs and SD-OCT.

RESULTS

Mean age at first OCT examination of the 653 participants was 82.2 ± 4.2 years, 61.3% of which were women. In multivariable adjusted models, incident intermediate AMD was associated with thicker retinal pigment epithelium (RPE)-Bruch membrane (BM) complex in the 1-mm central circle (hazard ratio [HR], 1.13 for 1-μm increase; P = 8.08 × 10-4 with false discovery rate [FDR] correction). Incident advanced AMD was associated with thicker RPE-BM complex in both the central (HR, 1.09; PFDR = 0.005) and inner circle (1- to 3 mm; HR, 1.28; PFDR = 1.61 × 10-5). Over the study period, RPE-BM complex thickening in the inner circle was more pronounced in individuals with high total PRS (β = 0.06 μm/year for 1-standard deviation increase; PFDR = 1.61 × 10-10), high complement pathway PRS (β = 0.04 μm/year; PFDR = 3.23 × 10-5), high lipid pathway PRS (β = 0.03 μm/year; PFDR = 3.74 × 10-4), and ARMS2 (β = 0.03 μm/year, PFDR = 0.002). High total PRS and high complement-specific PRS were associated with thinner photoreceptor segment layer (PSL) at baseline and longitudinal thinning of the outer nuclear layer.

CONCLUSIONS

These findings highlight RPE-BM complex thickening in the pathophysiologic sequence of AMD. Further longitudinal studies are needed, in particular to determine the value of RPE-BM thickening and PSL thinning measured using SD-OCT for the clinical follow-up of patients with AMD.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Normative Variability in Retinal Nerve Fiber Layer Thickness: Does It Matter Where the Peaks Are?

Purpose

Retinal nerve fiber layer thickness (RNFLT), a glaucoma biomarker, has a wide normative range affecting its sensitivity and specificity for abnormality detection. The interindividual RNFLT peak location variability contribution to this wide normative range has not been directly evaluated. The purpose of this study is to assess the effect of RNFLT peak normalization (PN) on normative variability.

Methods

Circumpapillary RNFLT profiles at 1.7 mm radius from the optic nerve head (ONH) were re-sampled from optical coherence tomography (OCT) volumes (Cirrus HD-OCT, 200 × 200) obtained from one eye of 83 healthy individuals. Fovea-ONH axis (FOA) was calculated from corresponding scanning laser ophthalmoscope images. Supratemporal (ST) and infratemporal (IT) RNFLT peaks of each profile were aligned to respective average peak locations. Normative ranges were calculated by averaging individual profiles before and after PN (with and without FOA to horizontal image axis (HA) alignment).

Results

RNFLT-PN resulted in an overall decrease in coefficient of variation (CoV) of the normative range by 4.2% (P = 0.02). CoV was reduced by more than 10% in clock-hours 10 (11.9%), 8 (10.6%), 6 (10.4%) after PN, and 7 (16.3%), 10 (11.4%), and 12 (10.4%) after PN with FOA-HA alignment. RNFLT-PN corrected for abnormality categorization because of peak misalignment in RNFLT profiles of healthy and glaucoma suspect subjects.

Conclusions

RNFLT-PN reduces normative variability, especially in the ST and IT regions.

Translational Relevance

RNFLT-PN reduces normative variability and improves sectoral abnormality categorization, potentially leading to better sensitivity and specificity of RNFLT measure in glaucoma detection.

Dementia and glaucoma: Results from a Nationwide French Study between 2006 and 2018

PURPOSE

Glaucoma is the leading cause of irreversible blindness worldwide. The brain and eye share many characteristics, so the eye may provide an easy-access window on brain processes. The aim of the study was to evaluate the link between glaucoma as well as intraocular pressure (IOP)-lowering drops load and all-cause dementia.

METHODS

This was a nested case-control study based on the French national healthcare database from 1 January 2006 to 31 December 2018in individuals aged ≥60 years. We compared cases of incident all-cause dementia with 1:5 controls matched by date of case diagnosis (index date), age, sex, and income. We set a 5-year exposure to glaucoma period ending 2 years before the index date (lag-time period to avoid protopathic bias). The main outcome was glaucoma defined with hospitalization related to POAG and/or dispensations of IOP-lowering drops. The secondary outcome was the IOP-lowering drops load.

RESULTS

In total, 4810 incident all-cause dementia and 24 050 matched controls were analysed (median [IQR] age 82 [10] years; 66.6% women). The prevalence of glaucoma was 14.0% in controls and cases. Risk of all-cause dementia was not associated with glaucoma (crude OR, 1.02; 95% CI [0.93-1.11]; p = 0.7; adjusted OR, 0.99; 95% CI [0.91-1.09]; p = 0.9) or IOP-lowering drops load (p = 0.2).

CONCLUSION

The present study in general population ≥60 years old in France did not find any association between glaucoma and incident all-cause dementia.

A narrative review of retinal vascular parameters and the applications (Part I): Measuring methods

The retina is often used to evaluate the vascular health status of eyes and the whole body directly and noninvasively in vivo. Retinal vascular parameters included caliber, tortuosity and fractal dimension. These variables represent the density or geometric characteristics of the vascular network apart from reflecting structural changes in the retinal vessel system. Currently, these parameters are often used as indicators of retinal disease, cardiovascular and cerebrovascular disease. Advanced digital fundus photography apparatus and computer-assisted analysis techniques combined with artificial intelligence, make the quantitative calculation of these parameters easier, objective, and labor-saving.

Artificial intelligence in ophthalmology: an insight into neurodegenerative disease

PURPOSE OF REVIEW

The aging world population accounts for the increasing prevalence of neurodegenerative diseases such as Alzheimer's and Parkinson's which carry a significant health and economic burden. There is therefore a need for sensitive and specific noninvasive biomarkers for early diagnosis and monitoring. Advances in retinal and optic nerve multimodal imaging as well as the development of artificial intelligence deep learning systems (AI-DLS) have heralded a number of promising advances of which ophthalmologists are at the forefront.

RECENT FINDINGS

The association among retinal vascular, nerve fiber layer, and macular findings in neurodegenerative disease is well established. In order to optimize the use of these ophthalmic parameters as biomarkers, validated AI-DLS are required to ensure clinical efficacy and reliability. Varied image acquisition methods and protocols as well as variability in neurogenerative disease diagnosis compromise the robustness of ground truths that are paramount to developing high-quality training datasets.

SUMMARY

In order to produce effective AI-DLS for the diagnosis and monitoring of neurodegenerative disease, multicenter international collaboration is required to prospectively produce large inclusive datasets, acquired through standardized methods and protocols. With a uniform approach, the efficacy of resultant clinical applications will be maximized.

Asian Race and Primary Open-Angle Glaucoma: Where Do We Stand?

Primary open-angle glaucoma (POAG) is an optic neuropathy characterized by irreversible retinal ganglion cell damage and visual field loss. The global POAG prevalence is estimated to be 3.05%, and near term is expected to significantly rise, especially within aging Asian populations. Primary angle-closure glaucoma disproportionately affects Asians, with up to four times greater prevalence of normal-tension glaucoma reported compared with high-tension glaucoma. Estimates for overall POAG prevalence in Asian populations vary, with Chinese and Indian populations representing the majority of future cases. Structural characteristics associated with glaucoma progression including the optic nerve head, retina, and cornea are distinct in Asians, serving as intermediates between African and European descent populations. Patterns in IOP suggest some similarities between races, with a significant inverse relationship between age and IOP only in Asian populations. Genetic differences have been suggested to play a role in these differences, however, a clear genetic pattern is yet to be established. POAG pathogenesis differs between Asians and other ethnicities, and it may differ within the broad classification of the Asian race. Greater awareness and further research are needed to improve treatment plans and outcomes for the increasingly high prevalence of normal tension glaucoma within aging Asian populations.

Comparison of peripapillary retinal nerve fiber layer and macular thickness in non-diabetic chronic kidney disease and controls

Objective

This study aimed to compare the peripapillary retinal nerve fiber layer (pRNFL) thickness and macular thickness (MT) between patients with non-diabetic chronic kidney disease (NDCKD) and controls, as well as between different stages of NDCKD. We also evaluated the correlation between pRNFL thickness and MT with duration of NDCKD.

Methods

This was a comparative cross-sectional study. Subjects were divided into NDCKD and control groups. Both pRNFL thickness and MT, including center subfield thickness (CST), average MT as well as average ganglion cell-inner plexiform layer (GC-IPL) were measured using spectral-domain optical coherence tomography. One-way ANCOVA test was used to compare the differences in pRNFL and MT between NDCKD and controls, as well as between the different stages of NDCKD. Spearman rank-order correlation coefficients were employed to determine the effects of NDCKD duration on pRNFL thickness and MT.

Results

A total of 132 subjects were recruited, 66 with NDCKD and 66 controls. There was a statistically significant difference in superior (110.74 ± 23.35 vs 117.36 ± 16.17 μm, p = 0.022), nasal (65.97 ± 12.90 vs 69.35 ± 10.17 μm, p = 0.006), inferior quadrant (117.44 ± 23.98 vs 126.15 ± 14.75 μm, p = 0.006), average pRNFL (90.36 ± 14.93 vs 95.42 ± 9.87 μm, p = 0.005), CST (231.89 ± 26.72 vs 243.30 ± 21.05 μm, p = 0.006), average MT (268.88 ± 20.21 vs 274.92 ± 12.79 μm, p = 0.020) and average GC-IPL (75.48 ± 12.44 vs 81.56 ± 6.48, p = 0.001) values between the NDCKD group and controls. The superior quadrant (p = 0.007), nasal quadrant (p = 0.030), inferior quadrant (p = 0.047), average pRNFL (p = 0.006), average MT (p = 0.001) and average GC-IPL (p = 0.001) differed significantly between different stages of NDCKD. There was no correlation between pRNFL thickness and MT with duration of NDCKD.

Conclusion

CST, average MT, average GC-IPL thickness, average pRNFL and all quadrants of pRNFL except the temporal quadrant were significantly thinner in NDCKD patients compared to controls. These changes were associated with the severity of CKD, but not its duration.

An Evaluation of Choroidal and Retinal Nerve Fiber Layer Thicknesses Using SD-OCT in Children with Childhood IgA Vasculitis

Background: We aimed to evaluate choroidal and retinal nerve fiber layer (RNFL) thicknesses in children undergoing the childhood IgA vasculitis (IgAV). Methods: Fifty-two patients with IgAV aged 1−6 years and 54 healthy children were included. Cases’ age, sex, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), RNFL thicknesses, and choroidal thickness values were recorded. Results: Median foveal center choroidal thickness was 374.0 µm (315.0 to 452.0 µm) in the IgAV group and 349.5 µm (285.0 to 442.0 µm) in the control group (p = 0.001). Median average RNFL thickness was 110.0 µm (91.0 to 134.0 µm) in the IgAV group and 104.0 µm (89.0 to 117.0 µm) in the control group (p < 0.001). Choroidal and RNFL thicknesses were significantly greater in all quadrants in the IgAV group than in the control group. No correlation was determined between ESR or CRP and foveal center choroidal and average RNFL thicknesses. Conclusions: Our findings show that choroidal and RNFL thicknesses increased significantly in children undergoing childhood IgA vasculitis compared to the healthy control group. These findings show that the choroid and RNFL are also affected by the inflammatory process in IgAV, which is a systemic vasculitis. We think that the choroidal and RNFL thicknesses can be used as a biomarker for childhood IgAV.

Retinal Biomarkers for Alzheimer Disease: The Facts and the Future

ABSTRACT

Alzheimer disease (AD) is a significant cause of morbidity and mortality worldwide, with limited treatment options and considerable diagnostic challenges. Identification and validation of retinal changes that correlate with clinicopathologic features of AD could provide a noninvasive method of screening and monitoring progression of disease, with notable implications for developing new therapies, particularly in its preclinical stages. Retinal biomarkers that have been studied to date include structural changes in neurosensory retinal layers, alterations in vascular architecture and function, and pathologic deposition of proteins within the retina, which have all demonstrated variable correlation with the presence of preclinical or clinical AD. Evolution of specialized retinal imaging modalities and advances in artificial intelligence hold great promise for future study in this burgeoning field. The current status of research in retinal biomarkers, and some of the challenges that will need to be addressed in future work, are reviewed herein.

[Retinal vascular network: Changes with aging and systemic vascular disease (cardiac and cerebral)]

For over 10 years, the description of the retinal microvascular network has benefited from the development of new imaging techniques. Automated retinal image analysis software, as well as OCT angiography (OCT-A), are able to highlight subtle, early changes in the retinal vascular network thanks to a large amount of microvascular quantitative data. The challenge of current research is to demonstrate the association between these microvascular changes, the systemic vascular aging process, and cerebrovascular and cardiovascular disease. Indeed, a pathophysiological continuum exists between retinal microvascular changes and systemic vascular diseases. In the Montrachet study, we found that a suboptimal retinal vascular network, as identified by the Singapore I Vessel Assessment (SIVA) software, was significantly associated with treated diabetes and an increased risk of cardiovascular mortality. In addition, we supplemented our research on the retinal vascular network with the use of OCT-A. In the EYE-MI study, we showed the potential role of quantitative characterization of the retinal microvascular network by OCT-A in order to assess the cardiovascular risk profile of patients with a history of myocardial infarction. A high AHA (American Heart Association) risk score was associated with low retinal vascular density independently of hemodynamic changes. Thus, a better understanding of the association between the retinal microvasculature and macrovascular disease might make its use conceivable for early identification of at-risk patients and to suggest a personalized program of preventative care. The retinal vascular network could therefore represent an indicator of systemic vascular disease as well as an interesting predictive biomarker for vascular events.

Increased retinal venular calibre in acute infections

Population-based studies have demonstrated that increased retinal venular calibre is a risk factor for cardiac disease, cardiac events and stroke. Venular dilatation also occurs with diabetes, obesity, dyslipidemia and autoimmune disease where it is attributed to inflammation. This study examined whether the inflammation associated with infections also affected microvascular calibre. Participants with infections and CRP levels  >  100 mg/L were recruited from the medical wards of a teaching hospital and assisted to complete a demographic and vascular risk factor questionnaire, and to undergo non-mydriatic retinal photography (Canon CR5-45NM, Japan). They were then treated with appropriate antibiotics, and underwent repeat retinal imaging when their CRP levels had fallen to less than 100 mg/L. Retinal images were examined for arteriole and venular calibre using validated semi-automated software based on Knudtson's modification of the Parr-Hubbard formula (IVAN, U Wisconsin). Differences in inflammatory markers and calibre were examined using the paired t-test for continuous variables. Determinants of calibre were calculated from multiple linear regression analysis. Forty-one participants with respiratory (27, 66%), urinary (6, 15%), skin (5, 12%), or miscellaneous (3, 7%) infections were studied. After antibiotic treatment, participants' mean CRP levels fell from 172.9 ± 68.4 mg/L to 42.2 ± 28.2 mg/L (p < 0.0001) and mean neutrophil counts fell from 9 ± 4 × 109/L to 6 ± 3 × 109/L (p < 0.0001). The participants' mean venular calibre (CRVE) decreased from 240.9 ± 26.9 MU to 233.4 ± 23.5 MU (p = 0.0017) but arteriolar calibre (CRAE) was unchanged (156.9 ± 15.2 MU and 156.2 ± 16.0 MU, p = 0.84). Thirteen additional participants with infections had a CRP > 100 mg/L that persisted at review (199.2 ± 59.0 and 159.4 ± 40.7 mg/L, p = 0.055). Their CRAE and CRVE were not different before and after antibiotic treatment (p = 0.96, p = 0.78). Hospital inpatients with severe infections had retinal venular calibre that decreased as their infections resolved and CRP levels fell after antibiotic treatment. The changes in venular calibre with intercurrent infections may confound retinal vascular assessments of, for example, blood pressure control and cardiac risk.