Optical coherence tomography evidence of macular ganglion cell-inner plexiform layer thinning in eyes with subretinal drusenoid deposits

Vascular changes in optical coherence tomography angiography unveiling the depths of dry age-related macular degeneration: a review

INTRODUCTION

Recent advancements in imaging techniques, particularly optical coherence tomography angiography (OCTA), have transformed our understanding of retinal microvascular changes in various ocular diseases, including dry age-related macular degeneration (AMD). Our literature review summarizes key findings on retinal vascular alterations in dry AMD as observed with OCTA, highlighting their implications for disease progression and management.

AREAS COVERED

Studies reveal significant changes in dry AMD patients, affecting the superficial and deep capillary plexuses as well as the choroid. These alterations include decreased vascular and flow density, variations in the foveal avascular zone, reduced choriocapillaris perfusion, and alterations in choroidal vascularity and thickness. Such changes reflect the complex vascular pathology of dry AMD and serve as potential biomarkers for monitoring disease progression. Variability in study results underscores the importance of considering AMD stage, sample size, follow-up duration, imaging protocols, and standardization.

EXPERT OPINION

OCTA in dry AMD is primarily research-focused due to technical and methodological challenges. Its adoption in clinical practice requires standardized protocols and improved software. With future advancements and a better understanding of disease pathology, OCTA could become a routine part of dry AMD management, especially as new therapies emerge that utilize OCTA for assessing dry AMD progression.

Alterations of the Ganglion Cell Complex in Age-Related Macular Degeneration: An Amish Eye Study Analysis

PURPOSE

To compare the ganglion cell complex (GCC) thickness in eyes with age-related macular degeneration (AMD) vs healthy controls in an elderly Amish population.

DESIGN

Prospective cross-sectional study.

METHODS

This is a post hoc analysis of the family-based prospective study of Amish subjects. Study subjects underwent imaging with the Cirrus HD-OCT (Carl Zeiss Meditec Inc) using a macular cube protocol of 512 × 128 scans (128 horizontal B-scans, each comprising 512 A-scans) over a 6 mm × 6 mm region centered on the fovea. The ganglion cell analysis algorithm calculated the GCC thickness by segmenting the outer boundaries of the retinal nerve fiber layer (RNFL) and inner plexiform layer (IPL) in all B-scans of the volume, with the region between these boundaries representing the combined thickness of the ganglion cell layer (GCL) and the IPL. A number of parameters were used to evaluate the GCC thickness: the average GCC thickness, minimum (lowest GCC thickness at a single meridian crossing the elliptical annulus), and sectoral (within each of 6 sectoral areas: superior, superotemporal, superonasal, inferior, inferonasal, and inferotemporal). The stage of AMD was graded on color fundus photographs in accordance with the Beckman Initiative for Macular Research classification system.

RESULTS

Of 1339 subjects enrolled in the Amish eye study, a total of 1294 eyes of 1294 subjects had all required imaging studies of sufficient quality and were included in the final analysis. Of these, 798 (62%) were female. Following age adjustment, the average GCC thickness was significantly (P < .001) thinner in AMD subjects (73.71 ± SD; 13.77 µm) compared to normals (77.97 ± 10.42 µm). An independent t test showed that the early AMD (75.03 ± 12.45 µm) and late AMD (61.64 ± 21.18 µm) groups (among which eyes with geographic atrophy [GA] had the lowest thickness, of 58.10 ± 20.27 µm) had a statistically significant lower GCC thickness compared to eyes without AMD. There was no significant differences in average GCC thickness between early AMD and intermediate AMD (76.36 ± 9.25 µm) eyes.

CONCLUSIONS

The GCC thickness in AMD eyes is reduced compared to normal eyes; however, the relationship is complex, with the greatest reduction in late AMD eyes (particularly eyes with GA) but no difference between early and intermediate AMD eyes.

Central macular choriocapillaris impairment as a manifestation of microvascular disease in eyes with subretinal drusenoid deposits

BACKGROUND/OBJECTIVES

Microvascular alterations and choroidal impairment are emerging as a pathologic pathway in age-related macular degeneration (AMD). This study aimed to evaluate the central macular choriocapillaris (CC) in eyes with subretinal drusenoid deposits (SDD) and the retinal microvasculature in patients with early AMD phenotypes.

SUBJECTS/METHODS

This was an institutional, multicentric observational cross-sectional study. Ninety-nine eyes of 99 subjects; 33 eyes with SDD only, 33 eyes with conventional drusen (CD) only, and 33 eyes of healthy age-matched subjects were included. Comprehensive ophthalmologic examination and optical coherence tomography angiography (OCTA) was performed. The central macular flow area of the CC was analysed in the SDD group and the vessel density of the retinal superficial capillary plexus (SCP) and deep capillary plexus (DCP) was analysed in the SDD and CD groups using automated OCTA output parameters.

RESULTS

The flow area of the CC in the SDD group was significantly reduced (p ≤ 0.001) with respect to the healthy control group. There was a trend of reduction of vessel density of the SCP and the DCP in the SDD and CD group with respect to controls, although this did not reach statistical significance.

CONCLUSIONS

OCTA data in the present report corroborate the role of vascular damage in early AMD with CC impairment in the central macular area in eyes with SDD.

Retinal and choroidal changes in AMD: A systematic review and meta-analysis of spectral-domain optical coherence tomography studies

Optical coherence tomography is a noninvasive imaging technology using the optical reflectivity of tissues that is capable of detecting quantitative and qualitative biomarkers of age-related macular degeneration (AMD) that cannot be similarly recognized in conventional imaging. We systematically searched PubMed and Embase databases to identify relevant articles to this subject. A fixed-effect or random-effect model was applied for the meta-analysis based on the heterogeneity level. In addition, subgroup analyses, meta-regression, publication bias, and quality assessment were also performed. Twenty-five studies with 1,632 cases and 1,445 healthy controls in total were included. Our results revealed that, when compared to controls, AMD subjects showed a significantly lower thickness in the choroid at 500 µm temporal, 1,500 µm nasal, and temporal to the fovea, subfoveal choroid, average peripapillary retinal nerve fiber layer, and average macular ganglion cell complex (GCC); however, average and central choroidal thickness 500 µm nasal, 1,000 µm nasal and temporal to the fovea, central and parafoveal macular GCC, retinal nerve fiber layer, and inner plexiform layer, and central macular thickness did not change significantly. Various regional analyses showed several other significant differences. The findings of the current study confirm that some retinal layers are altered in AMD patients compared to healthy controls. Thus, future studies are required to derive more definitive conclusions.

Choroidal Vasculature Changes in Age-Related Macular Degeneration: From a Molecular to a Clinical Perspective

The contribution of choroidal vasculature to the pathogenesis of age-related macular degeneration (AMD) has been long debated. The present narrative review aims to discuss the primary molecular and choroidal structural changes occurring with aging and AMD with a brief overview of the principal multimodal imaging modalities and techniques that enable the optimal in vivo visualization of choroidal modifications. The molecular aspects that target the choroid in AMD mainly involve human leukocyte antigen (HLA) expression, complement dysregulation, leukocyte interaction at Bruch’s membrane, and mast cell infiltration of the choroid. A mechanistic link between high-risk genetic loci for AMD and mast cell recruitment has also been recently demonstrated. Recent advances in multimodal imaging allow more detailed visualization of choroidal structure, identifying alterations that may expand our comprehension of aging and AMD development.

Inner Retinal Layer Thickness Alterations in Early Age Related Macular Degeneration in Eyes with Subretinal Drusenoid Deposits or Conventional Drusen

The purpose of this study was to evaluate central and parafoveal inner retinal layer thickness in patients with subretinal drusenoid deposits (SDD) or conventional drusen (CD). Participants underwent comprehensive ophthalmoscopic examination. Evidence of SDD or CD was evaluated with near infrared reflectance and spectral domain optical coherence tomography. Quantification of subfoveal lesions was made through a qualitative analysis of vertical and horizontal SD-OCT scans centered on the fovea. Inner retinal layer macular thickness measurements were obtained for central circles with 1, 3, and 5 mm diameter. Continuous variables were compared by the analysis of covariance (ANCOVA) with post-hoc Tukey HSD correction for multiple comparison analysis. Fifty-five patients were included in the study; 18 eyes with SDD alone, 19 eyes with CD alone, and 18 eyes of healthy age-matched subjects. Eight eyes with SDD (44%) and 13 eyes with CD (68%) had subfoveal lesions. There was significant reduction in the inner retinal layer thickness in the central 1mm area and in the superior 3 mm area in the SDD and CD group compared to controls. In conclusion the inner retinal layer is thinner in the central macula and in the superior parafovea in eyes.

Ten-Year Outcomes of Intravitreal Bevacizumab for Myopic Choroidal Neovascularization: Analysis of Prognostic Factors

The current standard treatment of myopic choroidal neovascularisation (mCNV) is intravitreal injection of VEGF antagonists. This study was proposed to assess efficacy and safety of intravitreal bevacizumab (IVB) for the treatment of mCNV across a 10-year follow-up. Thirty eyes of thirty patients with treatment-naïve mCNV who underwent IVB and were followed up with for a minimum of ten years were recruited for the present retrospective cohort study. All participants were treated with three monthly IVB at baseline and then evaluated and treated under pro re nata (PRN) schedule. Outcome measures were to determine BCVA changes over years and identify the predictive factors of both final visual outcome and need for retreatment. Analysis of the main involved prognostic factors with correlations among variables is reported. Visual acuity remained stable at 10-year follow-up (p = 0.001) with the greatest improvement at 2 years (p < 0.0001) in all CNV locations. Baseline BCVA correlated positively with final BCVA (β = 0.88, p < 0.0001, R²: 0.75). No predictive factors for the need of additional injections were identified. Retinal and choroidal thickness significantly reduced over time but without correlation with the number of injections. CNV max height and area significantly decreased at 10 years (p < 0.0001 and p = 0.003, respectively), with complete regression of mCNV lesion in 40% of subjects. Intravitreal bevacizumab resulted as long-term effective and safe therapy for mCNV with sustained results at 10 years.

Macular Thickness in Intermediate Age-Related Macular Degeneration Is Influenced by Disease Severity and Subretinal Drusenoid Deposit Presence

Purpose

To investigate how macular thickness varies with intermediate age-related macular degeneration (iAMD) severity and the presence of subretinal drusenoid deposits (SDDs).

Methods

A longitudinal prospective study of 143 participants >50 years of age with no to intermediate AMD who were followed with multimodal imaging and functional testing. Participants were stratified by iAMD severity according to imaging features. Macular thicknesses measurements over the central circles with 1-mm, 3-mm, and 6-mm diameters obtained from ocular coherence tomography imaging were compared across severity categories using cross-sectional (143 eyes) and longitudinal (subset of 77 eyes followed for 4 years) multivariate analyses.

Results

Compared with control eyes without large drusen or SDDs (Group 0), central maculas of lower risk eyes with unilateral large drusen (Group 1) were thicker (P = 0.014), whereas higher risk eyes with SDDs (Group SDD) were thinner (P = 0.02) in cross-sectional multivariate analyses. In longitudinal analyses, maculas with SDDs thinned more rapidly over 4 years relative to control eyes (P = 0.0058), which did not show significant thinning. More rapid central macular thinning was associated with worse baseline best-corrected visual acuity (BCVA) (P = 0.016) and more rapid BCVA decline (P = 0.0059).

Conclusions

Macular thickness in iAMD varies with disease severity, showing small increases in eyes with large drusen and decreases in eyes with SDDs. Active processes possibly related to neuroinflammation and neurodegeneration may be contributory. Longitudinal central macular thickness evaluation is an accessible outcome measure relevant to functional measures and is potentially useful for iAMD interventional studies.

Characteristics of the inner retinal layer in the fellow eyes of patients with unilateral exudative age-related macular degeneration

OBJECTIVE

To investigate the thicknesses of the ganglion cell-inner plexiform layer (GC-IPL) and retinal nerve fiber layer (RNFL) of the fellow eyes of patients with unilateral exudative age-related macular degeneration (AMD).

METHODS

A total of 107 patients with unilateral exudative AMD [34 of typical choroidal neovascularization (tCNV), Group A; 73 of polypoidal choroidal vasculopathy (PCV), Group B] and 73 normal control eyes (Group C) were included. Drusen and subretinal drusenoid deposits were assessed in all participants using fundus photography, autofluorescence, and optical coherence tomography (OCT). The GC-IPL and RNFL thicknesses were measured using Cirrus HD-OCT and compared among groups. Linear regression analyses were used to evaluate the factors associated with GC-IPL thicknesses.

RESULTS

The average GC-IPL thicknesses of Groups A, B, and C were 77.09 ± 3.87, 80.10 ± 6.61, and 80.88 ± 6.50 μm, respectively (p = 0.022). Sectoral GC-IPLs and central macular thicknesses (CMTs) were significantly different among groups (all, p <0.05), whereas none of the RNFL parameters differed significantly (all, p >0.05). Multivariate linear regression analyses revealed that age (p <0.001), CMT (p <0.001), and tCNV (p = 0.013) were significantly associated with average GC-IPL thickness, and the rate of reduction of GC-IPL thickness with increasing age in the fellow eyes of tCNV patients was higher than those in the PCV and control groups.

CONCLUSIONS

Unilateral tCNV patients exhibited statistically significant reduction of the GC-IPL thickness in the fellow eyes, compared to values of the fellow eyes of unilateral PCV patients or control patients. RNFL values trended to be lower but did not reach statistical significance.

The Effect of Topical Bromfenac on Intraretinal and Subretinal Fluid in Neovascular Age-Related Macular Degeneration

Purpose:

To report the effect of topical bromfenac, a non-steroidal anti-inflammatory drug (NSAID), in a case of neovascular age-related macular degeneration (AMD).

Methods:

An 85-year-old woman presented with a complaint of visual acuity reduction in the right eye. Comprehensive ophthalmological examination and retinal imaging were performed.

Results:

Best corrected visual acuity was 2/100. Fundus examination showed reticular pseudodrusen and a small hemorrhage in the fovea. Fluorescein angiography showed an active neovascular membrane. Spectral-domain optical coherence tomography (SD-OCT) confirmed diagnosis and revealed subretinal and intraretinal fluid. The patient refused recommended intravitreal anti-vascular endothelial growth factor treatment and received topical bromfenac 0.09% twice daily. Follow-up with SD-OCT showed subretinal followed by intraretinal fluid reduction at 16 weeks after treatment.

Conclusion:

Short-term reduction of subretinal and intraretinal fluid was observed with topical bromfenac monotherapy in neovascular AMD.

Longitudinal Changes in Ganglion Cell-Inner Plexiform Layer of Fellow Eyes in Unilateral Neovascular Age-Related Macular Degeneration

PURPOSE

To determine longitudinal changes in the ganglion cell-inner plexiform layer (GC-IPL) thickness of the fellow eyes of patients with neovascular age-related macular degeneration (AMD).

DESIGN

Prospective cohort study.

METHODS

Patients with unilateral neovascular AMD, unilateral polypoidal choroidal vasculopathy (PCV), and control subjects were included. After the initial visit, GC-IPL thickness was measured twice more with at least a 1-year interval between examinations using spectral domain optical coherence tomography.

RESULTS

Twenty-seven fellow eyes of patients with unilateral choroidal neovascularization (CNV), 33 fellow eyes of patients with unilateral PCV, and 35 eyes of control subjects were enrolled. The GC-IPL thickness of the fellow eyes was 78.41 ± 9.23, 81.20 ± 5.52, and 81.60 ± 3.83 μm in the CNV, PCV, and control groups, respectively, and they showed a significant change over time (P < .001, P = .001, and P = .003, respectively). The reduction rate of GC-IPL thickness was -0.88, -0.41, and -0.31 μm per year in the fellow eyes of the CNV, PCV, and control groups, respectively (CNV > PCV, control, P < .001). In a linear mixed model determination of factors associated with GC-IPL reduction in the fellow eyes of the CNV group, the interaction between baseline GC-IPL thickness and duration showed a significant result (P < .001).

CONCLUSIONS

The fellow eyes of patients with neovascular AMD showed a greater reduction rate of GC-IPL thickness compared with fellow eyes of patients with unilateral PCV and control subjects. In patients with unilateral neovascular AMD, fellow eyes with a thicker GC-IPL at baseline showed a greater reduction in GC-IPL thickness over time.