Documentation of intraretinal retinal pigment epithelium migration via high-speed ultrahigh-resolution optical coherence tomography

Predictive factors of age-related macular degeneration with poor response to three loading doses of anti-vascular endothelial growth factor

PURPOSE

To evaluate the predictive factors of neovascular age-related macular degeneration (nAMD) with poor response to three loading doses of intravitreal bevacizumab (IVB).

METHODS

A retrospective cohort study was performed on nAMD patients three loading IVB initial treatment. The patients were divided into two groups, without residual fluid on optical coherence tomography (OCT) images (Group 1) and with residual fluid (Group 2). Demographic data, OCT findings, and morphological features of macular neovascularization (MNV) in optical coherence tomography angiography (OCTA) were recorded.

RESULTS

The study included one hundred thirty-six eyes of 120 patients (Group 1: n = 66 eyes, Group 2: n = 70 eyes). Central macular thickness, presence of intraretinal fluid, subretinal fluid, hyperreflective foci-band, pigment epithelial detachment (PED), and prechoroidal cleft were similar between the two groups. Pre-injection central choroidal thickness (CCT) was 214.17 ± 50.28 µm in Group 1 and 247.40 ± 60.55 µm in Group 2 (p = 0.021). PED width (p = 0.028) and PED area (p = 0.042) were statistically significantly higher in Group 1. When the morphology of MNV in OCTA was examined, branching (p = 0.736), loops (p = 0.442), peripheral arcade (p = 0.600), hypointense halo (p = 0.779), sea fan (p = 0.250), medusa (p = 0.255), pruned vascular tree pattern (p = 0.148), capillary fringe (p = 0.683) were similar in both groups. The presence of a closed circuit pattern was significantly higher in Group 2 (p = 0.028).

CONCLUSION

Initial CCT and closed circuit pattern MNV were higher in IVB-resistant cases. It was observed that PEDs with large bases and areas responded significantly better to loading therapy. The presence of a closed-circuit pattern was an independent risk factor for poor response to loading therapy. Retrospectively registered.

REGISTRATION NUMBER

2011-KAEK-25 2023/05-08.

NONEXUDATIVE INTRARETINAL FLUID IN INTERMEDIATE AGE-RELATED MACULAR DEGENERATION

BACKGROUND

To describe the occurrence of nonexudative intraretinal fluid (IRF) in intermediate age-related macular degeneration.

METHODS

A retrospective study was designed to include consecutive cases with intermediate age-related macular degeneration associated with IRF. A multimodal imaging approach was used to confirm diagnosis of IRF in intermediate age-related macular degeneration. Multimodal imaging included color fundus photograph, fundus autofluorescence, fluorescein angiography, indocyanine green angiography, optical coherence tomography, and optical coherence tomography angiography.

RESULTS

Ten eyes of 10 patients (2 male and 8 female patients, ages 68-80 years) showing IRF in intermediate age-related macular degeneration were included in the study. The mean best-corrected visual acuity was 20/40 Snellen equivalent. Multimodal imaging including fluorescein angiography/indocyanine green angiography and optical coherence tomography demonstrated the absence of macular neovascularization in all cases; optical coherence tomography-angiography did not detect any abnormal flow signal associated with IRF. Seven of 10 patients developed IRF in correspondence of pigment epithelium detachment. Three of 10 patients presented IRF in correspondence of an area of nascent geographic atrophy.

CONCLUSION

Nonexudative intraretinal fluid in intermediate age-related macular degeneration is a novel, distinctive feature that is characterized by the presence of IRF with no evidence of macular neovascular lesions. The authors described different phenotypes of IRF in intermediate age-related macular degeneration. The definite diagnosis of this condition requires further studies with thorough application of multimodal imaging.

Structural OCT and OCT angiography biomarkers associated with the development and progression of geographic atrophy in AMD

BACKGROUND

Geographic atrophy (GA) is an advanced, irreversible, and progressive form of age-related macular degeneration (AMD). Structural optical coherence tomography (OCT) and OCT angiography (OCTA) have been largely used to characterize this stage of AMD and, more importantly, to define biomarkers associated with the development and progression of GA in AMD.

METHODS

Articles pertaining to OCT and OCTA biomarkers related to the development and progression of GA with relevant key words were used to search in PubMed, Researchgate, and Google Scholar. The articles were selected based on their relevance, reliability, publication year, published journal, and accessibility.

RESULTS

Previous reports have highlighted various OCT and OCTA biomarkers linked to the onset and advancement of GA. These biomarkers encompass characteristics such as the size, volume, and subtype of drusen, the presence of hyperreflective foci, basal laminar deposits, incomplete retinal pigment epithelium and outer retinal atrophy (iRORA), persistent choroidal hypertransmission defects, and the existence of subretinal drusenoid deposits (also referred to as reticular pseudodrusen). Moreover, biomarkers associated with the progression of GA include thinning of the outer retina, photoreceptor degradation, the distance between retinal pigment epithelium and Bruch's membrane, and choriocapillaris loss.

CONCLUSION

The advent of novel treatment strategies for GA underscores the heightened need for prompt diagnosis and precise monitoring of individuals with this condition. The utilization of structural OCT and OCTA becomes essential for identifying distinct biomarkers associated with the initiation and progression of GA.

Longitudinal Evaluation of the Distribution of Intraretinal Hyper-Reflective Foci in Eyes with Intermediate Age-Related Macular Degeneration

PURPOSE

Intraretinal hyper-reflective foci (IHRF) are optical coherence tomography (OCT) risk factors for progression of age-related macular degeneration (AMD). In this study we assess the change in the number and distribution of IHRF over two years.

METHODS

The axial distribution of IHRF were quantified in eyes with intermediate AMD (iAMD) at baseline and 24 months, using a series of 5 sequential equidistant en face OCT retinal slabs generated between the outer border of the internal limiting membrane (ILM) and the inner border of the retinal pigment epithelium (RPE). Following thresholding and binarization, IHRF were quantified in each retinal slab using ImageJ. The change in IHRF number in each slab between baseline and month 24 was calculated.

RESULTS

Fifty-two eyes showed evidence of IHRF at baseline, and all continued to show evidence of IHRF at 24 months (M24). The total average IHRF count/eye increased significantly from 4.67 ± 0.63 at baseline to 11.62 ± 13.86 at M24 (p < 0.001) with a mean increase of 6.94 ± 11.12 (range: - 9 to + 60). Overall, at M24, 76.9% eyes showed an increase in IHRF whereas 15.4% of eyes showed a decrease (3 eyes [5.7%] showed no change). There was a greater number of IHRF and a greater increase in IHRF over M24 in the outer slabs.

CONCLUSIONS

IHRF are most common in the outer retinal layers and tend to increase in number over time. The impact of the distribution and frequency of these IHRF on the overall progression of AMD requires further study.

HYPERREFLECTIVE FOCI NOT SEEN AS HYPERPIGMENTARY ABNORMALITIES ON COLOR FUNDUS PHOTOGRAPHS IN AGE-RELATED MACULAR DEGENERATION

PURPOSE

To investigate the prognostic value of quantifying optical coherence tomography (OCT)-defined hyperreflective foci (HRF) that do not correspond to hyperpigmentary abnormalities (HPAs) on color fundus photographs (CFPs)-HRF (OCT+/CFP-) -when considered in addition to HPA extent, for predicting late age-related macular degeneration development. This study sought to understand the impact of HRF (OCT+/CFP-) extent on visual sensitivity.

METHODS

Two hundred eighty eyes from 140 participants with bilateral large drusen underwent imaging and microperimetry at baseline, and then 6-monthly for 3-years. The extent of HPAs on CFPs and HRF (OCT+/CFP-) on OCT was quantified at baseline. Predictive models for progression to late age-related macular degeneration, accounting for drusen volume and age, were developed using HPA extent, with and without HRF (OCT+/CFP-) extent. The association between HPA and HRF (OCT+/CFP-) extent with sector-based visual sensitivity was also evaluated.

RESULTS

Incorporating HRF (OCT+/CFP-) extent did not improve the predictive performance for late age-related macular degeneration development ( P ≥ 0.32). Increasing HPA and HRF (OCT+/CFP-) extent in each sector were independently and significantly associated with reduced sector-based visual sensitivity ( P ≤ 0.004).

CONCLUSION

The addition of HRF (OCT+/CFP-) extent to HPA extent did not improve the prediction of late age-related macular degeneration development. HRF (OCT+/CFP-) extent was also independently associated with local reductions in visual sensitivity, after accounting for HPAs.

Assessment of intraretinal hyperreflective foci using multimodal imaging in eyes with age-related macular degeneration

PURPOSE

This study aimed to investigate the correspondence between intraretinal hyperreflective foci (IHRF) identified on optical coherence tomography (OCT) B-scans with hyperpigmentation on colour fundus photography (CFP) or hyperreflectivity on infrared reflectance (IR) images in eyes with age-related macular degeneration (AMD).

METHODS

Flash CFP, IR images and OCT B-scans obtained at the same visit were evaluated. Individual IHRF identified on OCT B-scans were assessed for the qualitative presence or absence of a hypotransmission tail into the choroid. The corresponding IR image obtained at the time of OCT acquisition was analysed for the presence or absence of hyperreflectivity in this region. The IR images were manually registered to the CFP image, and CFP images were inspected for the presence or absence of hyperpigmentation at the location of IHRF.

RESULTS

From 122 eyes, a total of 494 IHRF were evaluated. For the primary analysis of qualitative presence or absence of hyperpigmentation on CFP and hyperreflectivity on IR at the locations corresponding to IHRF on OCT, 301 (61.0%) of the IHRFs demonstrated evidence of hyperpigmentation on CFP, while only 115 (23.3%) showed evidence of hyperreflectivity on IR. The qualitative determination of the presence or absence of an abnormality on CFP or IR were significantly different (p < 0.0001). 327 (66.2%) of the IHRF showed hypotransmission, and 80.4% of these IHRF showed hyperpigmentation on CFP, though only 23.9% (p < 0.0001) demonstrated hyperreflectivity on IR.

CONCLUSIONS

Less than two-thirds of IHRF evident on OCT manifest as hyperpigmentation on colour photos, though IHRF with posterior shadowing are more likely to be evident as pigment. IR imaging appears to be even more poorly sensitive for visualizing IHRF.

Optical Coherence Tomography Features of Macular Hyperpigmented Lesions without Intraretinal Hyperreflective Foci in Age-Related Macular Degeneration

PURPOSE

To evaluate the optical coherence tomography (OCT) features of hyperpigmented lesions in the absence of intraretinal hyperreflective foci (IHRF) on OCT in eyes with age-related macular degeneration (AMD).

METHODS

We retrospectively analyzed OCT images of eyes with intermediate AMD (iAMD) and macular hyperpigmentation (HP) on color fundus photograph (CFP) but without IHRF on OCT in the corresponding location. The most prominent or definite HP was selected for analysis. The infrared reflectance (IR) image registered with the CFP, and the location corresponding to the HP lesion were defined on the IR image. The location of the HP on the corresponding OCT B-scan was assessed for retinal pigment epithelium (RPE) elevation, acquired vitelliform lesion (AVL), abnormal retinal pigment epithelium + basal lamina (RPE + BL) band reflectivity, RPE + BL band thickening, as well as interdigitation zone (IZ), ellipsoid zone (EZ) and external limiting membrane (ELM) disruption.

RESULTS

49 eyes (39 patients) were included in this study. Forty-six (94%) of the hyperpigmented lesions showed a thickened RPE + BL band. RPE + BL band reflectivity was increased in 37 (76%) of the lesions. RPE + BL band thickening, however, was not correlated with RPE + BL band reflectivity (p-value = 0.31). Either thickening or hyperreflectivity of the RPE + BL band was present in all cases. Twenty (41%) lesions had evidence of ELM disruption, 42 (86%) demonstrated EZ disruption and 48 (98%) had IZ disruption. Five (10%) HPs demonstrated AVL. Among cases with RPE elevation (15 cases, 31%), 10 were classified as drusen, 2 as drusenoid PEDs, and 3 as fibrovascular PEDs.

CONCLUSIONS

Thickening and/or hyperreflectivity of the RPE + BL band commonly correspond to regions of macular hyperpigmentation without IHRF in eyes with iAMD.

Sialic Acid Mimetic Microglial Sialic Acid-Binding Immunoglobulin-like Lectin Agonism: Potential to Restore Retinal Homeostasis and Regain Visual Function in Age-Related Macular Degeneration

Age-related macular degeneration (AMD), a leading cause of visual loss and dysfunction worldwide, is a disease initiated by genetic polymorphisms that impair the negative regulation of complement. Proteomic investigation points to altered glycosylation and loss of Siglec-mediated glyco-immune checkpoint parainflammatory and inflammatory homeostasis as the main determinant for the vision impairing complications of macular degeneration. The effect of altered glycosylation on microglial maintained retinal para-inflammatory homeostasis and eventual recruitment and polarization of peripheral blood monocyte-derived macrophages (PBMDMs) into the retina can explain the phenotypic variability seen in this clinically heterogenous disease. Restoring glyco-immune checkpoint control with a sialic acid mimetic agonist targeting microglial/macrophage Siglecs to regain retinal para-inflammatory and inflammatory homeostasis is a promising therapeutic that could halt the progression of and improve visual function in all stages of macular degeneration.

Relationship between the distribution of intra-retinal hyper-reflective foci and the progression of intermediate age-related macular degeneration

PURPOSE

To assess the relationship between the distribution of intra-retinal hyper-reflective foci (IHRF) on optical coherence tomography (OCT) and progression of intermediate age-related macular degeneration (iAMD) over 2 years.

METHODS

Cirrus OCT volumes of the macula of subjects enrolled in the Amish Eye Study with 2 years of follow-up were evaluated for the presence of iAMD and IHRF at baseline. The IHRF were counted in a series of 5 sequential en face slabs from outer to inner retina. The number of IHRF in each slab at baseline and the change in IHRF from baseline to year 2 were correlated with progression to late AMD at 2 years.

RESULTS

Among 120 eyes from 71 patients with iAMD, 52 eyes (43.3%) of 42 patients had evidence of both iAMD and IHRF at baseline. Twenty-three eyes (19.0%) showed progression to late AMD after 2 years. The total IHRF count increased from 243 at baseline to 604 at 2 years, with a significant increase in the IHRF number in each slab, except for the innermost slab 5 which had no IHRF at baseline or follow-up. The IHRF count increased from 121 to 340 in eyes that showed progression to late AMD. The presence of IHRF in the outermost retinal slabs 1 and 2 was independently associated with a significant risk of progression to late AMD. A greater increase in IHRF count over 2 years in these same slabs 1 and 2 was also associated with a higher risk of conversion to late AMD.

CONCLUSIONS

The risk of progression to late AMD appears to be significantly associated with the distribution and extent of IHRF in the outermost retinal layers. This observation may point to significant pathophysiologic differences of IHRF in inner versus outer layers of the retina.

Endpoints for clinical trials in ophthalmology

With the identification of novel targets, the number of interventional clinical trials in ophthalmology has increased. Visual acuity has for a long time been considered the gold standard endpoint for clinical trials, but in the recent years it became evident that other endpoints are required for many indications including geographic atrophy and inherited retinal disease. In glaucoma the currently available drugs were approved based on their IOP lowering capacity. Some recent findings do, however, indicate that at the same level of IOP reduction, not all drugs have the same effect on visual field progression. For neuroprotection trials in glaucoma, novel surrogate endpoints are required, which may either include functional or structural parameters or a combination of both. A number of potential surrogate endpoints for ophthalmology clinical trials have been identified, but their validation is complicated and requires solid scientific evidence. In this article we summarize candidates for clinical endpoints in ophthalmology with a focus on retinal disease and glaucoma. Functional and structural biomarkers, as well as quality of life measures are discussed, and their potential to serve as endpoints in pivotal trials is critically evaluated.

Hyperreflective foci distribution in eyes with dry age-related macular degeneration with subretinal drusenoid deposits

PURPOSE

To investigate the distribution of hyperreflective foci (HRF) in eyes with dry age-related macular degeneration (AMD).

METHODS

We retrospectively reviewed optical coherence tomography (OCT) images of 58 dry AMD eyes presenting HRF. The distribution of HRF according to the early treatment diabetic retinopathy study area was analyzed according to the presence of subretinal drusenoid deposits (SDDs).

RESULTS

We classified 32 eyes and 26 eyes into the dry AMD with SDD group (SDD group) and dry AMD without SDD group (non-SDD group), respectively. The non-SDD group had higher prevalence and density of HRF at the fovea (65.4% and 1.71 ± 1.48) than the SDD group (37.5% and 0.48 ± 0.63, P = 0.035 and P < 0.001, respectively). However, the prevalence and density of HRF in the outer circle area of the SDD group (81.3% and 0.11 ± 0.09) were greater than those of the non-SDD group (53.8% and 0.05 ± 0.06, p = 0.025 and p = 0.004, respectively). The SDD group showed higher prevalence and mean densities of HRF in the superior and temporal area than in the non-SDD group (all, p < 0.05).

CONCLUSION

HRF distributions in dry AMD varied according to the presence of SDDs. This might support that the degenerative features may be different between dry AMD eyes with and without SDDs.

Longitudinal evaluation of the distribution of intraretinal hyper-reflective foci in eyes with intermediate age-related macular degeneration

Purpose

Intraretinal hyper-reflective foci (IHRF) are optical coherence tomography (OCT) risk factors for progression of age-related macular degeneration (AMD). In this study we assess the change in the number and distribution of IHRF over two years.

Methods

The axial distribution of IHRF were quantified in eyes with intermediate AMD (iAMD) at baseline and 24 months, using a series of 5 sequential equidistant en face OCT retinal slabs generated between the outer border of the internal limiting membrane (ILM) and the inner border of the retinal pigment epithelium (RPE). Following thresholding and binarization, IHRF were quantified in each retinal slab using ImageJ. The change in IHRF number in each slab between baseline and month 24 was calculated.

Results

Fifty-two eyes showed evidence of IHRF at baseline, and all continued to show evidence of IHRF at 24 months (M24). The total average IHRF count/eye increased significantly from 4.67 ± 0.63 at baseline to 11.62 ± 13.86 at M24 (p<0.001) with a mean increase of 6.94 ± 11.12 (range: - 9 to + 60). Overall, at M24, 76.9% eyes showed an increase in IHRF whereas 15.4% of eyes showed a decrease (4 eyes [7.6%] showed no change). There was a greater number of IHRF and a greater increase in IHRF over M24 in the outer slabs.

Conclusions

IHRF are most common in the outer retinal layers and tend to increase in number over time. The impact of the distribution and frequency of these IHRF on the overall progression of AMD requires further study.

Kallistatin Deficiency Induces the Oxidative Stress-Related Epithelial-Mesenchymal Transition of Retinal Pigment Epithelial Cells: A Novel Protagonist in Age-Related Macular Degeneration

Purpose

Retinal pigment epithelium (RPE) dysfunction induced by oxidative stress-related epithelial-mesenchymal transition (EMT) of RPE is the primary underlying mechanism of age-related macular degeneration (AMD). Kallistatin (KAL) is a secreted protein with an antioxidative stress effect. However, the relationship between KAL and EMT in RPE has not been determined. Therefore we aimed to explore the impact and mechanism of KAL in oxidative stress-induced EMT of RPE.

Methods

Sodium iodate (SI) was injected intraperitoneally to construct the AMD rat model and investigate the changes in RPE morphology and KAL expression. KAL knockout rats and KAL transgenic mice were used to explain the effects of KAL on EMT and oxidative stress. In addition, Snail overexpressed adenovirus and si-RNA transfected ARPE19 cells to verify the involvement of Snail in mediating KAL-suppressed EMT of RPE.

Results

AMD rats induced by SI expressed less KAL in the retina, and KAL knockout rats showed RPE dysfunction spontaneously where EMT and reactive oxygen species (ROS) production increased in RPE. In contrast, KAL overexpression attenuated EMT and ROS levels in RPE, even in TGF-β treatment. Mechanistically, Snail reversed the beneficial effect of KAL on EMT and ROS reduction. Moreover, KAL ameliorated SI-induced AMD-like pathological changes.

Conclusions

Our findings demonstrated that KAL inhibits oxidative stress-induced EMT by downregulating the transcription factor Snail. Herein, KAL knockout rats may be an appropriate animal model for observing spontaneous RPE dysfunction for AMD-like retinopathy, and KAL may represent a novel therapeutic target for treating dry AMD.

Fairness and generalizability of OCT normative databases: a comparative analysis

PURPOSE

In supervised Machine Learning algorithms, labels and reports are important in model development. To provide a normality assessment, the OCT has an in-built normative database that provides a color base scale from the measurement database comparison. This article aims to evaluate and compare normative databases of different OCT machines, analyzing patient demographic, contrast inclusion and exclusion criteria, diversity index, and statistical approach to assess their fairness and generalizability.

METHODS

Data were retrieved from Cirrus, Avanti, Spectralis, and Triton's FDA-approval and equipment manual. The following variables were compared: number of eyes and patients, inclusion and exclusion criteria, statistical approach, sex, race and ethnicity, age, participant country, and diversity index.

RESULTS

Avanti OCT has the largest normative database (640 eyes). In every database, the inclusion and exclusion criteria were similar, including adult patients and excluding pathological eyes. Spectralis has the largest White (79.7%) proportionately representation, Cirrus has the largest Asian (24%), and Triton has the largest Black (22%) patient representation. In all databases, the statistical analysis applied was Regression models. The sex diversity index is similar in all datasets, and comparable to the ten most populous contries. Avanti dataset has the highest diversity index in terms of race, followed by Cirrus, Triton, and Spectralis.

CONCLUSION

In all analyzed databases, the data framework is static, with limited upgrade options and lacking normative databases for new modules. As a result, caution in OCT normality interpretation is warranted. To address these limitations, there is a need for more diverse, representative, and open-access datasets that take into account patient demographics, especially considering the development of supervised Machine Learning algorithms in healthcare.

Subretinal Pseudocysts: A Comprehensive Analysis of this Novel OCT Finding

INTRODUCTION

In current clinical practice, several optical coherence tomography (OCT) biomarkers have been proposed for the assessment of severity and prognosis of different retinal diseases. Subretinal pseudocysts are subretinal cystoid spaces with hyperreflective borders and only a few single cases have been reported thus far. The aim of the study was to characterize and investigate this novel OCT finding, exploring its clinical outcome.

METHODS

Patients were evaluated retrospectively across different centers. The inclusion criterion was the presence of subretinal cystoid space on OCT scans, regardless of concurrent retinal diseases. Baseline examination was set as the first time the subretinal pseudocyst was identified by OCT. Medical and ophthalmological histories were collected at baseline. OCT and OCT-angiography were performed at baseline and at each follow-up examination.

RESULTS

Twenty-eight eyes were included in the study and 31 subretinal pseudocysts were characterized. Out of 28 eyes, 16 were diagnosed with neovascular age-related macular degeneration (AMD), 7 with central serous chorioretinopathy, 4 with diabetic retinopathy, and 1 with angioid streaks. Subretinal and intraretinal fluid were present in 25 and 13 eyes, respectively. Mean distance of the subretinal pseudocyst from the fovea was 686 µm. The diameter of the pseudocyst was positively associated with the height of the subretinal fluid (r = 0.46; p = 0.018) and central macular thickness (r = 0.612; p = 0.001). At follow-up, subretinal pseudocysts disappeared in most of the reimaged eyes (16 out of 17). Of these, two patients presented retinal atrophy at baseline examination and eight patients (47%) developed retinal atrophy at follow-up. Conversely, seven eyes (41%) did not develop retinal atrophy.

CONCLUSION

Subretinal pseudocysts are precarious OCT findings, usually disclosed in a context of subretinal fluid, and are probably transient alterations within the photoreceptor outer segments and retinal pigment epithelium (RPE) layer. Despite their nature, subretinal pseudocysts have been associated with photoreceptor loss and incomplete RPE definition.

Detection of macular atrophy in age-related macular degeneration aided by artificial intelligence

INTRODUCTION

Age-related macular degeneration (AMD) is a leading cause of irreversible visual impairment worldwide. The endpoint of AMD, both in its dry or wet form, is macular atrophy (MA) which is characterized by the permanent loss of the RPE and overlying photoreceptors either in dry AMD or in wet AMD. A recognized unmet need in AMD is the early detection of MA development.

AREAS COVERED

Artificial Intelligence (AI) has demonstrated great impact in detection of retinal diseases, especially with its robust ability to analyze big data afforded by ophthalmic imaging modalities, such as color fundus photography (CFP), fundus autofluorescence (FAF), near-infrared reflectance (NIR), and optical coherence tomography (OCT). Among these, OCT has been shown to have great promise in identifying early MA using the new criteria in 2018.

EXPERT OPINION

There are few studies in which AI-OCT methods have been used to identify MA; however, results are very promising when compared to other imaging modalities. In this paper, we review the development and advances of ophthalmic imaging modalities and their combination with AI technology to detect MA in AMD. In addition, we emphasize the application of AI-OCT as an objective, cost-effective tool for the early detection and monitoring of the progression of MA in AMD.

Optical Coherence Tomography Biomarkers for Conversion to Exudative Neovascular Age-related Macular Degeneration

PURPOSE

To identify optical coherence tomography (OCT) biomarkers, including thin and thick double-layer sign (DLS) for the progression from intermediate AMD (iAMD) to exudative macular neovascularization (MNV) over 24 months.

DESIGN

Retrospective cohort study.

METHODS

Setting: Retina consultants of Texas.

PATIENT POPULATION

458 eyes of 458 subjects with iAMD in at least 1 eye with 24 months of follow-up data.

MAIN OUTCOMES MEASURES

The following biomarkers were assessed at baseline: high central drusen volume (≥0.03 mm³), intraretinal hyper-reflective foci (IHRF), subretinal drusenoid deposits, hyporeflective drusen cores, thick DLS, thin DLS, and central choroidal thickness. A binary logistic regression was computed to investigate the association between baseline OCT covariates and the conversion to exudative MNV within 24 months. In addition, fellow eye status was also included in the model.

RESULTS

During follow-up, 18.1% (83 of 458) of eyes with iAMD progressed to exudative MNV. Thick DLS, IHRF, and fellow eye exudative MNV were found to be independent predictors for the development of exudative MNV within 2 years. The baseline frequencies, odds ratios, 95% confidence intervals, and P values for these biomarkers were as follows: thick DLS (9.6%, 4.339, 2.178-8.644; P < .001), IHRF (36.0%, 2.340, 1.396-3.922; P = 0.001), and fellow eye exudative MNV (35.8%, 1.694, 1.012-2.837; P = .045).

CONCLUSIONS

Thick DLS, IHRF, and fellow eye exudative MNV were associated with an increased risk of progression from iAMD to exudative MNV. These biomarkers, which are readily identified by the review of OCT volume scans, may aid in risk prognostication for patients and for identifying patients for early intervention trials.

Hyper-Reflective Foci in Intermediate Age-Related Macular Degeneration: Spatial Abundance and Impact on Retinal Morphology

Purpose

The purpose of this study was to analyze spatially resolved structural changes at retinal locations in presence (+) or absence (-) of hyper-reflective foci (HRF) in eyes with subretinal pigment epithelium (RPE) drusen in intermediate age-related macular degeneration (iAMD).

Methods

Patients with IAMD (n = 40; mean age = 69.7 ± 9.2 [SD] years) and healthy controls (n = 27; 64.2 ± 9.0) underwent spectral-domain optical-coherence-tomography imaging and fundus-controlled perimetry testing. After reviewing retinal layer segmentation, presence of HRF was annotated and retinal layer thicknesses (RLTs) extracted using ImageJ. Localized RLTs were compared between +HRF and -HRF positions. Univariate mixed linear models were used to investigate associations among RLT, HRF presence, and HRF size.

Results

In iAMD eyes, a mean of 11.1 ± 12.5 HRF were detected with a peak abundance at 0.5 to 1.5 mm eccentricity to the fovea. At +HRF positions, outer nuclear layer (ONL; P = 0.0013, average difference = -12.4 µm) and retinal pigment epithelium drusen complex (RPEDC; P < 0.0001, +45.6 µm) thicknesses differed significantly compared to -HRF positions, even after correcting for accompanying drusen-related RPEDC layer thickening (P = 0.01). Mixed linear models revealed a significant association between increasing HRF area and decreasing ONL (association score = -0.17, P < 0.0001; 95% confidence interval [CI] = -0.22 to -0.11), and inner photoreceptor segments (IS) layer thicknesses (-0.08, P = 0.005; 95% CI = -0.14 to -0.03). Spearman rank correlation analysis yielded a significant correlation between total HRF area and mesopic (P = 0.015), but not scotopic (P = 0.305) retinal sensitivity losses.

Conclusions

Descriptive analysis of this study demonstrated a predominant distribution of HRF at a foveal eccentricity of 0.5 to 1.5 mm, whereas further refined topographic analysis revealed a significant ONL layer thinning in presence of HRF even after correction for sub-RPE drusen presence compared to lesions in absence of HRF. Longitudinal studies are further needed to analyze the prognostic impact as well as the role of HRF presence in the context of iAMD.

Characteristics and Spatial Distribution of Structural Features in Age-Related Macular Degeneration: A MACUSTAR Study Report

PURPOSE

To report the prevalence and topographic distribution of structural characteristics in study participants with age-related macular degeneration (AMD) and controls in the cross-sectional study part of the MACUSTAR study (ClinicalTrials.gov Identifier: NCT03349801).

DESIGN

European, multicenter cohort study.

SUBJECTS

Overall, 301 eyes of 301 subjects with early (n = 34), intermediate (n = 168), and late AMD (n = 43), as well as eyes without any AMD features (n = 56).

METHODS

In study eyes with intermediate AMD (iAMD), the presence of structural AMD biomarkers, including pigmentary abnormalities (PAs), pigment epithelium detachment (PED), refractile deposits, reticular pseudodrusen (RPD), hyperreflective foci (HRF), incomplete/complete retinal pigment epithelium (RPE), and outer retinal atrophy (i/cRORA), and quiescent choroidal neovascularization (qCNV) was systematically determined in the prospectively acquired multimodal retinal imaging cross-sectional data set of MACUSTAR. Retinal layer thicknesses and the RPE drusen complex (RPEDC) volume were determined for the total study cohort in spectral-domain (SD) OCT imaging using a deep-learning-based algorithm.

MAIN OUTCOME MEASURES

Prevalence and topographic distribution of structural iAMD features.

RESULTS

A total of 301 study eyes of 301 subjects with a mean (± standard deviation) age of 71.2 ± 7.20 years (63.1% women) were included. Besides large drusen, the most prevalent structural feature in iAMD study eyes were PA (57.1%), followed by HRF (51.8%) and RPD (22.0%). Pigment epithelium detachment lesions were observed in 4.8%, vitelliform lesions in 4.2%, refractile deposits in 3.0%, and qCNV in 2.4%. Direct precursor lesions for manifest retinal atrophy were detected in 10.7% (iRORA) and 4.2% (cRORA) in iAMD eyes. Overall, the highest RPEDC volume with a median of 98.92 × 10^-4 mm³ was found in iAMD study eyes. Spatial analysis demonstrated a predominant distribution of RPD in the superior and temporal subfields at a foveal eccentricity of 1.5 to 2 mm, whereas HRF and large drusen had a distinct topographic distribution involving the foveal center.

CONCLUSIONS

Detailed knowledge of the prevalence and distribution of structural iAMD biomarkers is vital to identify reliable outcome measure for disease progression. Longitudinal analyses are needed to evaluate their prognostic value for conversion to advanced disease stages.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found after the references.

Hyperreflective Foci in Age-Related Macular Degeneration are Associated with Disease Severity and Functional Impairment

PURPOSE

To analyze presence of hyperreflective foci (HRF) across different age-related macular degeneration (AMD) severities and examine its correlation with other structural and functional AMD features.

DESIGN

Longitudinal, single-center, case-control study.

PARTICIPANTS

One hundred and fifty-eight participants aged > 50 years old with varying AMD severities (including no AMD).

METHODS

Color fundus imaging was used to assess AMD severity and hyperpigmentation (PGM) presence. Subretinal drusenoid deposits (SDD) and HRF were detected on OCT volumes. The correlations of HRF with additional AMD features were evaluated using linear and logistic mixed-effects models. One study eye per participant underwent dark adaptation (DA) testing to measure rod intercept time (RIT) for structure function associations. Eyes were followed longitudinally and changes in AMD severity and RIT were measured relative to HRF presence.

MAIN OUTCOME MEASURES

The primary outcome was presence of HRF, which was compared with presence of other AMD features and DA impairment.

RESULTS

One hundred and fifty-eight participants (median baseline age of 73.1 [interquartile range (IQR) = 66-79] years) contributing 1277 eye visits were included. Hyperreflective foci (HRF) were detected more frequently in higher AMD severities. Hyperreflective-foci presence was significantly associated with PGM presence (odds ratio 832.9, P < 0.001) and SDD presence (odds ratio 9.42, P = 0.017). Eyes with HRF demonstrated significantly longer DA (median 27.1 [IQR = 16-40] minutes) than those without HRF (13.5 [10-22] minutes) but less than eyes with SDD only (40 [28-40] minutes). Highest RIT values were found in eyes with both HRF and SDD (40.0 [40-40] minutes). Age and HRF explained a similar proportion of RIT variability as age and SDD. Eyes that developed HRF demonstrated baseline RITs closer to eyes with HRF at baseline, compared with eyes that never developed HRF (29.1 [16-40], 38.5 [22-40] versus 13.1 [10-22] minutes; Kruskal-Wallis P < 0.001).

CONCLUSIONS

The progressively increased presence of HRF in higher AMD severities, and its correlation with previously associated AMD biomarkers, suggests HRF is an important OCT feature adding to the understanding of disease progression. Hyperreflective foci presence was associated with delays in DA, indicating HRF is a marker for visual cycle impairment.

FINANCIAL DISCLOSURE

Proprietary or commercial disclosure may be found after the references.

Fundus autofluorescence and optical coherence tomography biomarkers associated with the progression of geographic atrophy secondary to age-related macular degeneration

OBJECTIVES

To investigate the impact of qualitatively graded and deep learning quantified imaging biomarkers on growth of geographic atrophy (GA) secondary to age-related macular degeneration.

METHODS

This prospective study included 1062 visits of 181 eyes of 100 patients with GA. Spectral-domain optical coherence tomography (SD-OCT) and fundus autofluorescence (FAF) images were acquired at each visit. Hyperreflective foci (HRF) were quantitatively assessed in SD-OCT volumes using a validated deep learning algorithm. FAF images were graded for FAF patterns, subretinal drusenoid deposits (SDD), GA lesion configuration and atrophy enlargement. Linear mixed models were calculated to investigate associations between all parameters and GA progression.

RESULTS

FAF patterns were significantly associated with GA progression (p < 0.001). SDD was associated with faster GA growth (p = 0.005). Eyes with higher HRF concentrations showed a trend towards faster GA progression (p = 0.072) and revealed a significant impact on GA enlargement in interaction with FAF patterns (p = 0.01). The fellow eye status had no significant effect on lesion enlargement (p > 0.05). The diffuse-trickling FAF pattern exhibited significantly higher HRF concentrations than any other pattern (p < 0.001).

CONCLUSION

Among a wide range of investigated biomarkers, SDD and FAF patterns, particularly in interaction with HRF, significantly impact GA progression. Fully automated quantification of retinal imaging biomarkers such as HRF is both reliable and merited as HRF are indicators of retinal pigment epithelium dysmorphia, a central pathogenetic mechanism in GA. Identifying disease markers using the combination of FAF and SD-OCT is of high prognostic value and facilitates individualized patient management in a clinical setting.

Factors associated with the recurrence of choroidal neovascularization in pathologic myopia

Purpose

To investigate the factors associated with the recurrence of pathologic myopia choroidal neovascularization (PM-CNV).

Methods

Forty-eight eyes of 48 patients with PM-CNV treated with conbercept at least 6 months of follow-up were included. Appearance of ellipsoid zone (EZ) and retinal pigment epithelium (RPE) observed on optical coherence tomography (OCT). Hyperreflective foci (HRF) height measured on OCT. Observation of CNV shape on OCT-angiography (OCTA). PM-CNV area measured on OCTA. To observe relationship between these factors and best corrected visual acuity (BCVA) and PM-CNV recurrence.

Results

The 48 patients (48 eyes) with PM-CNV were divided into two groups: yielding a group of 20 eyes with type 1 and a group of 28 eyes with type 2. The BCVA of type 1 was better than type 2 before and after treatment (P < 0.005). Smaller HRF height (P < 0.001) and CNV area (P < 0.001) for type 1 than type 2. The appearance of EZ and RPE were intact (P < 0.001). Spearman correlation analysis found that final BCVA was significantly associated with baseline BCVA, HRF height, and appearance of EZ (P < 0.05). Binary logistics regression analysis revealed that PM-CNV recurrence was significantly correlated not only HRF height and CNV area, but also with appearance of EZ, and RPE (P < 0.05).

Conclusion

PM-CNV had a higher recurrence ratio. Baseline BCVA and clinical features play an important role for vision prognosis. Factors associated with PM-CNV recurrence include HRF height, CNV area, and changes in EZ and RPE structure.

Effect of OCT B-Scan Density on Sensitivity for Detection of Intraretinal Hyperreflective Foci in Eyes with Age-Related Macular Degeneration

PURPOSE

To evaluate the impact of reducing the density of B-scans in an optical coherence tomography (OCT) volume on the sensitivity for detecting intraretinal hyperreflective foci (IHRF) in eyes with intermediate age-related macular degeneration (AMD).

METHODS

A total of 165 eyes with intermediate AMD and IHRF were evaluated in this retrospective analysis. For each case, Cirrus HD-OCT volumes were imported into the reading center 3 D-OCTOR software. The number of IHRF cases was assessed based on all 128 B-scans (spaced 47 μm apart), using a categorical scale (graded as 1-4, 5-9, 10-14, 15-19, and >20). Additionally, the B-scan densities in the volume were lowered to 64 B-scans (spaced 94 μm apart), 43 B-scans (spaced 140 μm apart), and 32 B-scans (spaced 188 μm apart). The number of eyes with any IHRF and the numerical category of IHRF in the eye were used to compare the sensitivity at each reduced B-scan density against the reference 128 B-scan volume.

RESULTS

In the primary analysis for the qualitative presence or absence of any IHRF, the sensitivity decreased to 98.2% (p = .32) with 64 B-scans, 92.7% (p = .001) with 43 B-scans, and 75.2% (p = .001) with 32 B-scans, compared with the 128 B-scan reference. With regard to the number of IHRF per eye, there was a significant difference (with a lower level chosen on the scale) when the B-scan density was reduced to 43 or 32 B-scans (p = .002 and p < .001, respectively).

CONCLUSION

Increasing the inter-B-scan spacing from 47 to 188 microns significantly reduced the ability to accurately determine whether IHRF were present in an eye. An increase in inter-B-scan spacing to 140 microns was associated with a significant misclassification of the IHRF quantity. These findings may be relevant in the design of OCT scanning protocols for studies utilizing these biomarkers for AMD progression.

Longitudinal Evaluation of Visual Function Impairments in Early and Intermediate Age-Related Macular Degeneration Patients

Purpose

To evaluate visual function (VF) changes in early and intermediate age-related macular degeneration (eAMD and iAMD) over 24 months.

Design

Prospective, observational natural history study.

Participants

Participants were enrolled at the Duke Eye Center.

Methods

A total of 101 subjects (33 with eAMD, 47 with iAMD, and 21 normal controls) were recruited. Visual function (VF) tests included best-corrected visual acuity (BCVA), low- luminance visual acuity (LLVA), microperimetry (MP), cone contrast tests (CCTs), and dark adaptation (DA). Mixed-effect model repeated measures based on absolute values and change from baseline identified VF tests differentiating AMD from controls and revealing longitudinal VF decline when controlling for covariates (baseline value, age, coronary artery disease, dry eye, and phakic status). Nine AMD genetic risk variants, combinations of these (genetic burden score), reticular pseudodrusen (RPD), and hyperreflective foci (HRF) were tested as predictors of diagnosis and VF performance.

Main Outcome Measures

Longitudinal changes in VF metrics over 24 months.

Results

A total of 70 subjects completed the 2-year visit (22 with eAMD, 31 with iAMD, and 17 controls). Percent reduced threshold (PRT) on MP and CCT red significantly distinguished iAMD versus controls after 12 and 24 months, respectively. Cone contrast test red, PRT, and absolute threshold (AT) on MP showed significant longitudinal deterioration of VF in iAMD versus baseline at 12 months and onward, however, with a reduced rate of worsening. The DA data confirmed a preexisting functional deficit in iAMD at baseline and revealed an increasing proportion of poorly performing iAMD subjects in DA over the study period. None of the other VF measures showed consistent significant changes among the normal, early, and intermediate groups or over time. The genetic burden score was significantly associated with AMD diagnosis (relative risk for iAMD = 1.64, P < 0.01) and DA (r = 0.42, P = 0.00005). Reticular pseudodrusen and HRF showed moderate associations with DA and weak to moderate associations with MP variables.

Conclusions

In iAMD, MP variables, CCT red, and DA revealed slow and nonlinear functional decline over 24 months. A structure-function relationship in eAMD and iAMD stages was demonstrated among HRF, RPD, and DA, possibly modified by genetic risk factors. These structural and functional features represent potential end points for clinical trials in iAMD.

Risk Factors for Progression of Age-Related Macular Degeneration: Population-Based Amish Eye Study

Objective: To evaluate the optical coherence tomography (OCT)-based risk factors for progression to late age-related macular degeneration (AMD) in a population-based study of elderly Amish. Methods: A total of 1332 eyes of 666 consecutive subjects who completed a 2-year follow-up visit were included in this multicenter, prospective, longitudinal, observational study. Imaging features were correlated with 2-year incidence of late AMD development. Odds ratios for imaging features were estimated from logistic regression. Baseline OCT images were reviewed for the presence of drusen volume ≥0.03 mm3 in the central 3 mm ring, intraretinal hyperreflective foci (IHRF), hyporeflective drusen cores (hDC), subretinal drusenoid deposits (SDD), and drusenoid pigment epithelium detachment (PED). Subfoveal choroidal thickness, drusen area, and drusen volume within 3 and 5 mm circles centered on the fovea were also assessed. Results: Twenty-one (1.5%) of 1332 eyes progressed to late AMD by 2 years. The mean age of the study subjects was 65 ± 10.17 (±SD) years and 410 subjects were female. Univariate logistic regression showed that drusen area and volume in both 3 mm and 5 mm circles, subfoveal choroidal thickness, drusen volume ≥ 0.03 mm3 in the 3 mm ring, SDD, IHRF, and hDC were all associated with an increased risk for development of late AMD. The multivariate regression model identified that drusen volume in the 3 mm ring (OR: 2.59, p = 0.049) and presence of IHRF (OR: 57.06, p < 0.001) remained as independent and significant risk factors for progression to late AMD. Conclusions: This population-based study confirms previous findings from clinic-based studies that high central drusen volume and IHRF are associated with an increased risk of progression to late AMD. These findings may be of value in risk-stratifying patients in clinical practice or identifying subjects for early intervention clinical trials.

Depth-resolved visualization and automated quantification of hyperreflective foci on OCT scans using optical attenuation coefficients

An automated depth-resolved algorithm using optical attenuation coefficients (OACs) was developed to visualize, localize, and quantify hyperreflective foci (HRF) seen on OCT imaging that are associated with macular hyperpigmentation and represent an increased risk of disease progression in age related macular degeneration. To achieve this, we first transformed the OCT scans to linear representation, which were then contrasted by OACs. HRF were visualized and localized within the entire scan by differentiating HRF within the retina from HRF along the retinal pigment epithelium (RPE). The total pigment burden was quantified using the en face sum projection of an OAC slab between the inner limiting membrane (ILM) to Bruch's membrane (BM). The manual total pigment burden measurements were also obtained by combining manual outlines of HRF in the B-scans with the total area of hypotransmission defects outlined on sub-RPE slabs, which was used as the reference to compare with those obtained from the automated algorithm. 6×6 mm swept-source OCT scans were collected from a total of 49 eyes from 42 patients with macular HRF. We demonstrate that the algorithm was able to automatically distinguish between HRF within the retina and HRF along the RPE. In 24 test eyes, the total pigment burden measurements by the automated algorithm were compared with measurements obtained from manual segmentations. A significant correlation was found between the total pigment area measurements from the automated and manual segmentations (P < 0.001). The proposed automated algorithm based on OACs should be useful in studying eye diseases involving HRF.

Does outer retinal layer thickness correlate with the central visual field indices in early dry age-related macular degeneration?

PURPOSE

Age-related macular degeneration (ARMD) is the leading cause of irreversible blindness worldwide and Nepal is one among them. We aimed to determine the relationship between outer retinal layer thickness parameters with central visual field indices in early dry ARMD cases among Nepalese population.

MATERIALS AND METHODS

The subjects for this descriptive, cross-sectional study comprised 40 patients with early dry ARMD from the ophthalmology department of a tertiary level hospital of Nepal. The retinal layer thickness was measured with spectral-domain optical coherence tomography (SD-OCT), and the visual field indices were assessed using the 10-2 protocol of Humphrey visual field analyzer (HFA). Thus, the retinal layer structures correlated with visual field indices among our population.

RESULTS

Among our early dry ARMD population, the foveal threshold (FT) was found to be significantly correlated with retinal pigment epithelium (RPE) elevation (P < 0.01, r = -0.541), outer segment (OS) length (P = 0.02, r = 0.465), and inner segment ellipsoid (ISe) band disruption (P = 0.01, r = -0.499), but not with presence of hyperreflective foci (P = 0.464), RPE thickness (P = 0.612), and central macular thickness (P = 0.214). However, no significant correlation between mean deviation and pattern standard deviation of visual field with retinal layer thickness parameters was identified.

CONCLUSION

In early dry ARMD, a reduced FT is significantly correlated with the integrity of the ISe band, thinning of OS length, and drusen-associated RPE elevation. The results highlight the utility of both SD-OCT retinal layer measurement and central visual field testing by HFA in ARMD to monitor the progression of the disease.

Long Term Time-Lapse Imaging of Geographic Atrophy: A Pilot Study

Geographic atrophy (GA), the late stage of age-related macular degeneration, is a major cause of visual disability whose pathophysiology remains largely unknown. Modern fundus imaging and histology revealed the complexity of the cellular changes that accompanies atrophy. Documenting the activity of the disease in the margins of atrophy, where the transition from health to disease occurs, would contribute to a better understanding of the progression of GA. Time-lapse imaging facilitates the identification of structural continuities in changing environments. In this retrospective pilot study, we documented the long-term changes in atrophy margins by time-lapse imaging of infrared scanning laser ophthalmoscopy (SLO) and optical coherence tomography (OCT) images in 6 cases of GA covering a mean period of 32.8 months (range, 18–72). The mean interval between imaging sessions was 2.4 months (range, 1.4–3.8). By viewing time-lapse sequences we observed extensive changes in the pattern of marginal hyperreflective spots, which associated fragmentation, increase and/or disappearance. Over the entire span of the follow-up, the most striking changes were those affecting hyperreflective spots closest to margins of atrophy, on the non-atrophic side of the retina; a continuum between the successive positions of some of the hyperreflective spots was detected, both by SLO and OCT. This continuum in their successive positions resulted in a subjective impression of a centrifugal motion of hyperreflective spots ahead of atrophy progression. Such mobilization of hyperreflective spots was detected up to several hundred microns away from atrophic borders. Such process is likely to reflect the inflammatory and degenerative process underlying GA progression and hence deserves further investigations. These results highlight the interest of multimodal time-lapse imaging to document cell-scale dynamics during progression of GA.

Kir4.2 Potassium Channels in Retinal Pigment Epithelial Cells In Vitro: Contribution to Cell Viability and Proliferation, and Down-Regulation by Vascular Endothelial Growth Factor

Dedifferentiation and proliferation of retinal pigment epithelial (RPE) cells are characteristics of retinal diseases. Dedifferentiation is likely associated with changes of inwardly rectifying potassium (Kir) channels. The roles of Kir4.2 channels in viability, and proliferation of cultured RPE cells were investigated. Gene expression levels were determined using qRT-PCR. RPE cells expressed Kir2.1, 2.2, 2.4, 3.2, 4.1, 4.2, 6.1, and 7.1 mRNA. Kir4.2 protein was verified by immunocytochemistry and Western blotting. Kir4.2 mRNA in cultured cells was upregulated by hypoxia (hypoxia mimetic CoCl₂ or 0.2% O₂) and extracellular hyperosmolarity (addition of high NaCl or sucrose). Kir4.2 mRNA was suppressed by vascular endothelial growth factor (VEGF), blood serum, and thrombin whereas platelet-derived growth factor (PDGF), basic fibroblast growth factor (bFGF), and transforming growth factor-β1 (TGF-β1) increased it. Hyperosmotic Kir4.2 gene expression was mediated by TGF-β1 receptor signaling while hypoxic gene transcription was dependent on PDGF receptor signaling. VEGF receptor-2 blockade increased Kir4.2 mRNA level under control, hyperosmotic, and hypoxic conditions. SiRNA-mediated knockdown of Kir4.2 decreased the cell viability and proliferation under control and hyperosmotic conditions. Kir4.2 channels play functional roles in maintaining the viability and proliferation of RPE cells. Downregulation of Kir4.2 by VEGF, via activation of VEGF receptor-2 and induction of blood-retinal barrier breakdown, may contribute to decreased viability of RPE cells under pathological conditions.

Hyperreflective Foci in Diabetic Macular Edema with Subretinal Fluid: Association with Visual Outcomes after Anti-VEGF Treatment

INTRODUCTION

Objectives of the study were to describe the hyperreflective foci (HRF) on optical coherence tomography angiography in diabetic macular edema (DME) with subretinal fluid (SRF) and explore the association of HRF in the outer retina with photoreceptor integrity and visual outcomes after anti-vascular endothelial growth factor (anti-VEGF) treatment.

METHODS

We retrospectively reviewed 46 eyes (36 patients) with DME treated with anti-VEGF drugs. The following parameters, including best-corrected visual acuity (BCVA), central macular thickness (CMT), the height of SRF, the number of HRF in the superficial capillary plexus, deep capillary plexus, and the outer retina, as well as the integrity of external limiting membrane (ELM) and ellipsoid zone (EZ), were evaluated and compared between the baseline and after 2 monthly injections of anti-VEGF drugs. The relationship between the HRF in the outer retina and the integrity of ELM and EZ, as well as BCVA, was analyzed.

RESULTS

BCVA was significantly improved in DME after anti-VEGF treatment; however, for the subgroup of DME patients with SRF, visual acuity remained unchanged after anti-VEGF treatment (p < 0.05 vs. p = 0.375). The number of HRF (p < 0.05), CMT (p < 0.001), and SRF height (p < 0.001) were significantly reduced, accompanied with partial restoration of ELM and EZ integrity after anti-VEGF injection. The HRF in the outer retina was correlated with the final ELM (p = 0.036) and EZ (p = 0.004) status. The final BCVA was significantly better in eyes with intact ELM (p = 0.002) and EZ at final visit (p < 0.001).

CONCLUSION

The number of HRF in outer retina was negatively associated with the microstructural restoration of ELM and EZ, as well as the visual outcome in DME patients with SRF after anti-VEGF treatment.

Multimodal Imaging, OCT B-Scan Localization, and En Face OCT Detection of Macular Hyperpigmentation in Eyes with Intermediate Age-Related Macular Degeneration

Purpose

Multimodal imaging was used to identify and characterize the cause of hyperpigmentation seen on color fundus images (CFIs) of eyes with intermediate age-related macular degeneration (iAMD).

Design

Retrospective review of a prospective study.

Participants

Patients with iAMD.

Methods

Color fundus images with macular hyperpigmentation were compared with same-day images obtained using fundus autofluorescence (FAF), near infrared reflectance (NIR), and swept-source (SS) OCT imaging. Two SS OCT en face slabs were generated: a retinal slab to identify hyperreflective foci within the retina and a slab from beneath the retinal pigment epithelium (RPE; the sub-RPE slab) that was used to detect regions that cause decreased light transmission into the choroid, also known as hypotransmission defects. All images were registered to allow for qualitative comparisons by 2 independent graders.

Main Outcome Measures

Comparison between foci of macular hyperpigmentation seen on CFIs with the detection of these regions on FAF, NIR, and SS OCT en face images.

Results

Compared with CFIs, FAF imaging seemed to be the least sensitive method for the detection of hyperpigmentation, whereas NIR and SS OCT imaging reliably detected these hyperpigmented areas. Although NIR imaging detected most of the hyperpigmentation seen in CFIs, SS OCT imaging detected all the areas of hyperpigmentation and anatomically localized these areas by using both en face and B-scan images. En face OCT slabs of the retina and sub-RPE region were registered to the CFIs, and areas of hyperpigmentation were shown to correspond to hyperreflective foci in the retina and regions of thickened RPE seen on OCT B-scans. Although both hyperpigmentation and early atrophic lesions appeared bright on NIR imaging, en face SS OCT imaging was able to distinguish these lesions because hyperpigmentary changes appeared dark and early atrophic lesions appeared bright on the sub-RPE slab.

Conclusions

En face OCT imaging in conjunction with OCT B-scans were able to identify and localize the hyperpigmentation seen in CFIs reliably. This hyperpigmentation was not only associated with intraretinal hyperreflective foci, but also corresponded to areas with a thickened RPE.

Masking of macular neovascular membranes by subretinal hyperreflective material on optical coherence tomography angiography

PURPOSE

The purpose of this study was to determine whether subretinal hyperreflective material (SHRM) may mask the detection of macular neovascular membranes (MNV) on optical coherence tomography angiography (OCTA).

METHODS

In this observational study, eyes with active neovascular age-related macular degeneration (nAMD), co-existing SHRM & intraretinal or subretinal fluid or hemorrhage on structural OCT, underwent OCTA & fundus fluorescein angiography (FFA) imaging. 6 × 6 mm choriocapillaris and outer retinal slabs on OCTA were examined to determine the presence of MNV underneath the SHRM. The corresponding area on FFA was used as a reference arm to confirm activity.

RESULTS

Thirty eyes of thirty patients with SHRM and active nAMD were recruited. All eyes failed to show a MNV in the choriocapillaris & avascular slabs of the OCTA underneath the SHRM, but showed active hyperfluorescent MNVs that increased in size and intensity in the late stages of FFA. In one eye, parts of a MNV under the SHRM were undetectable due to signal attenuation, while parts extending beyond the SHRM were detected on the choriocapillaris en face slab with flow on the B scan.

CONCLUSIONS

SHRM may act as a reflecting surface that limits the passage of light waves in OCTA, creating areas of signal attenuation and diminishing its ability to detect underlying MNVs.

Long-Term Analysis of Clinical Features and Treatment Outcomes of Inflammatory Choroidal Neovascularization

PURPOSE

To investigate the long-term clinical features and treatment outcomes of patients with inflammatory choroidal neovascularization (CNV) treated with intravitreal anti-vascular endothelial growth factor (anti-VEGF).

DESIGN

Retrospective, interventional, consecutive case series.

METHODS

Sixty-five eyes of 65 patients with inflammatory CNV treated with anti-VEGF injections and followed up at least 12 months were included. Retrospective chart review was conducted at a single tertiary referral center.

RESULTS

Study participants were followed up for 60.6 ± 42.8 (range, 16-160) months. Mean age was 33.4 ± 10.8 years, and mean refractive error was -3.94 ± 1.35 D in spherical equivalent. Final best-corrected visual acuity (BCVA) was 0.21 ± 0.20 logMAR after treatment. Patients were treated with bevacizumab (76.9%), ranibizumab (4.6%), aflibercept (3.1%), and drug combinations (15.4%). Systemic corticosteroid or immunosuppressant use was not correlated with visual outcome, required number of anti-VEGF injections, and recurrence. Commonly occurring optical coherence tomography (OCT) features included ellipsoid zone disruption, choroidal hypertransmission, retinal pigment epithelium atrophy or absence (RPEA), intraretinal hyperreflective foci (HRF), choroidal vessel engorgement, focal choroidal excavation, and irregular vascular loops (on OCT angiography). RPEA after treatment (β = 0.238, P = .036) and BCVA (β = 0.267, P = .029) showed significant correlation with final BCVA. A total of 28 patients (43.1%) experienced recurrence; intraretinal HRF after treatment was the single risk factor for recurrence (odds ratio = 2.712, P = .031).

CONCLUSIONS

Inflammatory CNV recurrence showed higher rates over time after anti-VEGF treatment than previously reported, even though the overall visual outcome was good. Baseline BCVA and RPEA after treatment are significant predictors for visual outcome. Intraretinal HRF after anti-VEGF treatment suggests the potential risk of recurrence.

Morphologic and Microvascular Differences Between Macular Neovascularization With and Without Subretinal Fibrosis

Purpose

To evaluate morphologic and microvascular differences between eyes with and without subretinal fibrosis (SF) caused by neovascular age-related macular degeneration (nAMD).

Methods

Patients with nAMD with a minimum history of 12 months of anti-VEGF treatment were prospectively included in this cross-sectional study. Patients were imaged using standard imaging, swept-source optical coherence tomography angiography for quantitative microvascular analysis and polarization-sensitive OCT as an ancillary method for automated SF segmentation. The presence of reticular pseudodrusen, hyperreflective foci (HRF), and outer retinal tubulation (ORT) were also evaluated.

Results

Sixty eyes of 60 participants (37 female) with nAMD and a mean 3.1 (±2.7)-year history of anti-VEGF treatment were included, 20 (33%) of which were diagnosed with SF. Eyes with SF had a higher prevalence of ORT (P < 0.001) and a lower prevalence of HRF (P = 0.004) than eyes without SF. Fifty eyes were analyzed quantitatively for microvascular biomarkers. Eyes with SF had a larger greatest vascular caliber (P = 0.001) and greatest linear diameter (P = 0.042), a larger microvascular neovascularization (MNV) area (P = 0.026), larger vessel area (P = 0.037), higher number of vessel junctions (P = 0.025), longer total vessel length (P = 0.027), higher number of vessel endpoints (P = 0.007), and higher endpoint density (P = 0.047).

Conclusions

This multimodal imaging approach demonstrated in vivo microvascular and morphological differences in eyes with and without SF. Eyes with SF tend to have larger MNV lesions with thicker vessels and are often associated with the presence of ORT.

Translational Relevance

This study points out imaging biomarkers in patients with SF, which may help identifying high-risk patients.

Progressive Dysmorphia of Retinal Pigment Epithelium in Age-Related Macular Degeneration Investigated by Fluorescence Lifetime Imaging

Purpose

The purpose of this study was to observe changes of the retinal pigment epithelium (RPE) on the transition from dysmorphia to atrophy in age-related macular degeneration (AMD) by fluorescence lifetime imaging ophthalmoscopy (FLIO).

Methods

Multimodal imaging including color fundus photography (CFP), optical coherence tomography (OCT), fundus autofluorescence (FAF) imaging, and FLIO was performed in 40 eyes of 37 patients with intermediate AMD and no evidence for geographic atrophy or macular neovascularization (mean age = 74.2 ± 7.0 years). Twenty-three eyes were followed for 28.3 ± 18.3 months. Seven eyes had a second follow-up after 46.6 ± 9.0 months. Thickened RPE on OCT, hyperpigmentation on CFP, hyper-reflective foci (HRF) on OCT, attributed to single or clustered intraretinal RPE, were identified. Fluorescence lifetimes in two spectral channels (short-wavelength spectral channel [SSC] = 500–560 nm, long-wavelength spectral channel [LSC] = 560–720 nm) as well as emission spectrum intensity ratio (ESIR) of the lesions were measured by FLIO.

Results

As hyperpigmented areas form and RPE migrates into the retina, FAF lifetimes lengthen and ESRI of RPE cells increase. Thickened RPE showed lifetimes of 256 ± 49 ps (SSC) and 336 ± 35 ps (LSC) and an ESIR of 0.552 ± 0.079. For hyperpigmentation, these values were 317 ± 68 ps (p < 0.001), 377 ± 56 ps (P < 0.001), and 0.609 ± 0.081 (P = 0.001), respectively, and for HRF 337 ± 79 ps (P < 0.001), 414 ± 50 ps (P < 0.001), and 0.654 ± 0.075 (P < 0.001).

Conclusions

In the process of RPE degeneration, comprising different steps of dysmorphia, hyperpigmentation, and migration, lengthening of FAF lifetimes and a hypsochromic shift of emission spectra can be observed by FLIO. Thus, FLIO might provide early biomarkers for AMD progression and contribute to our understanding of RPE pathology.

Hypoxic and osmotic expression of Kir2.1 potassium channels in retinal pigment epithelial cells: Contribution to vascular endothelial growth factor expression

Retinal pigment epithelial (RPE) cells express different subtypes of inwardly rectifying potassium (Kir) channels. We investigated whether human and rat RPE cells express genes of strongly rectifying Kir2 channels. We also determined the hypoxic and hyperosmotic regulation of Kir2.1 gene expression in cultured human RPE cells and the effects of siRNA-mediated knockdown of Kir2.1 on VEGFA expression, VEGF secretion, proliferation, and viability of the cells. Extracellular hyperosmolarity was induced by addition of NaCl or sucrose. Hypoxia and chemical hypoxia were produced by cell culture in 0.25% O₂ and addition of CoCl₂, respectively. Gene expression levels were evaluated by real-time RT-PCR. Rat RPE cells contained Kir2.1, Kir2.2, Kir2.3, and Kir2.4 gene transcripts while human RPE cells contained Kir2.1, Kir2.2, and Kir2.4 transcripts. Immunocytochemical data may suggest that Kir2.1 protein in cultured human cells is expressed in both perinuclear and plasma membranes. Kir2.1 gene expression and Kir2.1 protein level in human cells increased under hypoxic and hyperosmotic conditions. The expression of the Kir2.1 gene was mediated in part by diverse intracellular signal transduction pathways and transcription factor activities under both conditions; the hyperosmotic, but not the CoCl₂-induced Kir2.1 gene expression was dependent on intracellular calcium signaling. Autocrine/paracrine activation of purinergic receptors contributed to Kir2.1 gene expression under hyperosmotic (P2Y₁, P2Y₂, P2X₇) and CoCl₂-induced conditions (P2Y₂, P2X₇). Exogenous VEGF, TGF-β1, and blood serum decreased Kir2.1 gene expression. Inhibition of VEGF receptor-2 increased the Kir2.1 gene expression under control conditions and in CoCl₂-simulated hypoxia, and decreased it under high NaCl conditions. Knockdown of Kir2.1 by siRNA inhibited the CoCl₂-induced and hyperosmotic transcription of the VEGFA gene and caused a delayed decrease of the constitutive VEGFA gene expression while VEGF protein secretion was not altered. Kir2.1 knockdown stimulated RPE cell proliferation under control and hyperosmotic conditions without affecting cell viability. The data indicate that Kir2.1 channel activity is required for the expression of the VEGFA gene and inhibits the proliferation of RPE cells. Under control and hypoxic conditions, the extracellular VEGF level may regulate the production of VEGF via its inhibitory effect on the Kir2.1 gene transcription; this feedback loop may prevent overproduction of VEGF.

Shot-noise limited, supercontinuum-based optical coherence tomography

We present the first demonstration of shot-noise limited supercontinuum-based spectral domain optical coherence tomography (SD-OCT) with an axial resolution of 5.9 μm at a center wavelength of 1370 nm. Current supercontinuum-based SD-OCT systems cannot be operated in the shot-noise limited detection regime because of severe pulse-to-pulse relative intensity noise of the supercontinuum source. To overcome this disadvantage, we have developed a low-noise supercontinuum source based on an all-normal dispersion (ANDi) fiber, pumped by a femtosecond laser. The noise performance of our 90 MHz ANDi fiber-based supercontinuum source is compared to that of two commercial sources operating at 80 and 320 MHz repetition rate. We show that the low-noise of the ANDi fiber-based supercontinuum source improves the OCT images significantly in terms of both higher contrast, better sensitivity, and improved penetration. From SD-OCT imaging of skin, retina, and multilayer stacks we conclude that supercontinuum-based SD-OCT can enter the domain of shot-noise limited detection.

Association between Inflammatory Factors in the Aqueous Humor and Hyperreflective Foci in Patients with Intractable Macular Edema Treated with Antivascular Endothelial Growth Factor

Background

To evaluate the correlations between the inflammatory factors in the aqueous humor and hyperreflective foci (HRF) in patients with intractable macular edema treated with antivascular endothelial growth factor (anti-VEGF).

Methods

This study included 17 patients with intractable macular edema (ME) treated with anti-VEGF agents. Inflammatory factors in the aqueous humor were measured by the Cytometric Beads Array before injection, and the numbers of HRF pre- and post-anti-VEGF treatment were counted from four different directions (90 degrees, 45 degrees, 180 degrees, and 135 degrees) in the SD-OCT images, respectively, before treatment and one month after treatment. The correlations between inflammatory factors and the numbers of HRF were assessed.

Results

The numbers of HRF were reduced significantly after anti-VEGF treatment. The change in the HRFs at the 90-degree location was significantly positively correlated with IL-8 and VCAM-1. The change of all HRFs was significantly positively correlated with IL-8. The HRFs before the treatment also had a positive correlation with IL-8 and VCAM-1.

Conclusion

After anti-VEGF treatment, the numbers of HRF in intractable ME declined greatly. The higher the levels of IL-8 and VCAM-1 before treatment, the more significant the reduction of HRF after anti-VEGF treatment, which indicated that HRF could be an effective noninvasive imaging indicator for evaluating the effect of anti-VEGF on intractable macular edema. The OCT images at the 90-degree location could better show the inflammatory reaction of patients and also had better clinical significance for the prognosis evaluation of ME associated with inflammation.

CNGB1-related rod-cone dystrophy: A mutation review and update

Cyclic nucleotide-gated channel β1 (CNGB1) encodes the 240-kDa β subunit of the rod photoreceptor cyclic nucleotide-gated ion channel. Disease-causing sequence variants in CNGB1 lead to autosomal recessive rod-cone dystrophy/retinitis pigmentosa (RP). We herein present a comprehensive review and analysis of all previously reported CNGB1 sequence variants, and add 22 novel variants, thereby enlarging the spectrum to 84 variants in total, including 24 missense variants (two of which may also affect splicing), 21 nonsense, 19 splicing defects (7 at noncanonical positions), 10 small deletions, 1 small insertion, 1 small insertion-deletion, 7 small duplications, and 1 gross deletion. According to the American College of Medical Genetics and Genomics classification criteria, 59 variants were considered pathogenic or likely pathogenic and 25 were variants of uncertain significance. In addition, we provide further phenotypic data from 34 CNGB1-related RP cases, which, overall, are in line with previous findings suggesting that this form of RP has long-term retention of useful central vision despite the early onset of night blindness, which is valuable for patient counseling, but also has implications for it being considered a priority target for gene therapy trials.

Topography of choriocapillaris flow deficit predicts development of neovascularization or atrophy in age-related macular degeneration

PURPOSE

To evaluate the relationship between choriocapillaris (CC), flow deficits (FD), and structural optical coherence tomography (OCT) biomarkers, and the progression of intermediate age-related macular degeneration (iAMD) to complete retinal pigment epithelial and outer retinal atrophy (cRORA) or macular neovascularization (MNV).

METHODS

Consecutive patients with iAMD were sequentially reviewed to define three equal sized groups: progressed to MNV, progressed to cRORA, or remained stable over 12 months of follow-up. Odds ratios for progression to cRORA and MNV were estimated by logistic regression for intraretinal hyperreflective foci (IHRF), hyporeflective drusen cores (hDC), subretinal drusenoid deposits (SDDs), high central drusen volume, fellow eye with late AMD, and peripheral and central CC FD.

RESULTS

Thirty iAMD eyes from 30 patients were enrolled into each group. The CC FD was greater in the peripheral sectors of the macula of eyes which progressed to cRORA compared to the other two groups (P < 0.0001). The central CC FD was also significantly impaired in eyes that progressed to cRORA or MNV compared to eyes that did not progress (P = 0.001 and P = 0.02, respectively). CC FD in the peripheral macula was significantly and independently associated with the development of cRORA, while CC FD in the center was significantly and independently associated with the development of MNV.

CONCLUSIONS

While the CC is diffusely impaired throughout the macula in iAMD eyes that progress to cRORA, it is relatively spared in the more peripheral macula among eyes which progress to MNV. These differential findings may have implications for the pathophysiology of the different late-stage manifestations of AMD.

Histopathology of Age-Related Macular Degeneration and Implications for Pathogenesis and Therapy

Aging is associated with a number of histological changes in the choroid, Bruch's membrane, RPE, and neuroretina. Outside of the normal physiologic aging spectrum of changes, abnormal deposits such as basal laminar deposits, basal linear deposits, and soft drusen are known to be associated with AMD. Progression of AMD to advanced stages involving geographic atrophy, choroidal neovascularization, and/or disciform scars can result in debilitating vision loss. Knowledge of the angiogenic pathway and its components that stimulate neovascularization has led to the development of a new paradigm of intravitreal anti-VEGF pharmacotherapy in the management of neovascular AMD. Currently however, there are no available treatments for the modification of disease progression in non-neovascular AMD, or for the treatment of geographic atrophy. Further understanding of the histopathology of AMD and the molecular mechanisms that contribute to pathogenesis of the disease may reveal additional therapeutic targets.

CHORIOCAPILLARIS FLOW DEFICITS AS A RISK FACTOR FOR PROGRESSION OF AGE-RELATED MACULAR DEGENERATION

PURPOSE

To evaluate the association between choriocapillaris (CC) flow deficits and structural optical coherence tomography biomarkers and the progression of intermediate age-related macular degeneration (iAMD) to complete retinal pigment epithelial and outer retinal atrophy.

METHODS

Retrospective analysis of consecutive patients with iAMD with a minimum follow-up of 12 months. Odds ratios of intraretinal hyperreflective foci, hyporeflective drusen cores, subretinal drusenoid deposits, the presence of drusen volume ≥0.03 mm3 within a central 3-mm circle, fellow eye with late stage of AMD, and CC flow deficits at baseline and months of follow-up were estimated from logistic regression.

RESULTS

A total of 112 eyes with iAMD were included. Eyes that progressed were significantly more likely to show intraretinal hyperreflective foci, hyporeflective drusen cores, and drusen volume ≥0.03 mm3. The CC flow deficit was also significantly greater in eyes that developed complete retinal pigment epithelial and outer retinal atrophy. Intraretinal hyperreflective foci, hyporeflective drusen cores, drusen volume ≥0.03 mm3, and higher CC flow deficits were significantly and independently associated with the development of complete retinal pigment epithelial and outer retinal atrophy.

CONCLUSION

The CC flow deficit was significantly greater in iAMD eyes that progressed to complete retinal pigment epithelial and outer retinal atrophy and remained an independent risk factor when structural optical coherence tomography biomarkers were considered. CC flow deficits may be useful for enhancing risk stratification and prognostication of patients with iAMD.

Drusen ooze: Predictor for progression of dry age-related macular degeneration

BACKGROUND

To evaluate natural history of drusen ooze and its role as a predictor for progression of dry age-related macular degeneration (AMD) longitudinally.

METHODS

Multi-centric retrospective observational case series of 72 eyes (72 patients) with dry AMD with a minimum follow-up of 4 years. Drusen types were identified on volume scans on optical coherence tomography (OCT) and were characterized for occurrence of drusen ooze at baseline until last visit. Drusen ooze was defined as hyperreflective dots overlying a collapsing drusen or pseudodrusen, or hyperreflective RPE above drusen or isoreflective dots at the level of outer nuclear layer. The consequent incidence of incomplete retinal pigment epithelium and outer retinal atrophy (iRORA), complete retinal pigment epithelium and outer retinal atrophy (cRORA), and neovascular AMD (nAMD) were evaluated statistically.

RESULTS

In total, 72 eyes with a mean follow-up of 68.89 (± 25.57 months) were studied. At presentation, 11 eyes (15.3%) had a single drusen type, whereas 61 eyes (84.7%) had mixed drusen. Reticular pseudodrusen were most common (84.7%) followed by soft drusen (66.6%). Drusen ooze was seen in 47 eyes (65.2%) at presentation. The presence of drusen ooze at baseline (p < 0.01) and baseline best corrected visual acuity (BCVA) (p = 0.04) significantly correlated with development of iRORA and cRORA. In total, 14 eyes progressed from iRORA to cRORA over a mean follow up of 29.14 (± 24.33) months. Odds of progression to iRORA or cRORA were 20.3 times greater for eyes with drusen ooze at baseline (95% C.I., 4.4-94.2).

CONCLUSIONS

In dry AMD, drusen ooze is a useful sign for predicting progression to iRORA and cRORA over time.

Predicting retinal pigment epithelium remodelling and its functional impact

PURPOSE

To identify predictive factors for RPE tear remodelling and its correlation with functional and morphological outcomes.

METHODS

Retrospective longitudinal study of patients with retinal pigment epithelium (RPE) tears secondary to age-related macular degeneration (AMD). Imaging was performed using spectral-domain optical coherence tomography (SD-OCT) and fundus autofluorescence (FAF). RPE layer integrity in the RPE-denuded area was examined with SD-OCT, and variation in the RPE-denuded homogeneous hypofluorescent area was examined with FAF over time for each case (eye). Patients were divided in two groups, according to the presence (Rem) or absence (No Rem) of evidence of RPE tear remodelling. Data were collected at three different time points: at baseline (at diagnosis of exudative AMD), at RPE tear diagnosis, and at the last available follow-up. Using SD-OCT, the following parameters were evaluated: type of CNV, type of PED and its dimensions, presence of subretinal (SRF) or intraretinal (IRF) fluid, central retinal thickness (CRT), presence and location of hyperreflective dots, and dimension and location of RPE tear.

RESULTS

This study included 32 eyes from 31 patients (19 female and 12 male), with RPE tears secondary to AMD. RPE remodelling after tear development was evident in 17 (53.1%) eyes after 7 [1-59] months. Anatomical recovery was associated with a younger age at RPE tear diagnosis (73 ± 7 vs. 81 ± 7 years old, p=0.01), smaller and narrower retinal pigment epithelial detachment (PED) at tear diagnosis (height 369 vs. 602 μm, p=0.02; width 2379 vs. 3378 μm, p=0.04), and the presence of SRF at tear diagnosis (94% vs. 53%, p=0.02). After adjusting for other covariates, a younger age at RPE tear diagnosis maintained significant association with RPE tear remodelling. RPE tear remodelling did not correlate with a better visual outcome at last follow-up (43 ± 22.8 vs. 34 ± 23.8 ETDRS letters, p=0.30). Final VA was directly proportional to VA at tear diagnosis (r= 0.654; p<0.001) and correlated negatively with PED width at tear diagnosis (r = -0.388; p=0.03).

CONCLUSION

RPE remodelling was evident in half of our sample and was associated with a younger age, smaller and narrower PED at RPE tear diagnosis, and presence of SRF also at tear diagnosis. Nevertheless, this structural recovery did not result in a better functional outcome.

ULTRAWIDEFIELD PSEUDOCOLOR RETINAL IMAGING VERSUS REAL-COLOR FUNDUS PHOTOGRAPHY FOR DETECTION OF INTRARETINAL PIGMENT MIGRATION IN AGE-RELATED MACULAR DEGENERATION

PURPOSE

To compare pseudocolor Optos ultrawidefield (UWF) retinal images with conventional real-color fundus photography (CFP) for detecting macular hyperpigmentary changes in intermediate age-related macular degeneration.

METHODS

This retrospective study included 50 patients diagnosed with intermediate age-related macular degeneration. All patients underwent Optos imaging and CFP. The overall accuracy to visualize hyperpigmentation and its morphologic features was graded by two independent readers using a standardized grid. Structural and en face optical coherence tomography images were correlated with UWF and CFP images to determine spatial correspondence of pigment clumping on fundus images and hyperreflective foci on optical coherence tomography.

RESULTS

One hundred eyes of 50 patients had hyperpigmentary changes on funduscopic examination and were included. The intragraders and intergraders agreements were high for all measurements (P < 0.001). At least one hyperpigmentary changes within the standardized grid was detected in 93% using CFP and 100% using UWF camera (P = 0.02). The total area of hyperpigmentation measured on UWF images was significantly higher than on CFP images (P < 0.001). There was a significant correlation between the presence of hyperpigmentary changes on both CFP and UWF images and hyperreflective foci on structural optical coherence tomography (P < 0.001).

CONCLUSION

Ultrawidefield fundus images allow high detection and accurate quantification of macular hyperpigmentary changes in intermediate age-related macular degeneration compared with conventional CFP.

Evaluation of retinal pigment epithelium changes in serous pigment epithelial detachment in age-related macular degeneration

The purpose of this study was to quantitatively evaluate retinal pigment epithelium (RPE) changes in serous pigment epithelial detachment (PED) among patients with age-related macular degeneration by means of prototype multi-contrast optical coherence tomography (OCT), which is capable of simultaneous collection of OCT angiography, polarization-sensitive OCT, and standard OCT images. We evaluated 26 eyes of 21 patients with serous PED. RPE-melanin OCT images were calculated from the multi-contrast OCT dataset and compared with near-infrared autofluorescence images. An active RPE lesion was defined as an area of thickened RPE-melanin (≥ 70 μm; RPE₇₀) on RPE-melanin OCT. Each PED area was divided into peak and slope regions. RPE₇₀ area ratios were compared with the maximum PED height, PED area, PED volume, and slope area ratio (area of slope region/area of whole PED). RPE-melanin OCT images were consistent with near-infrared autofluorescence images. The RPE₇₀ area ratio in the slope region was significantly negatively correlated with the slope area ratio. Development of active RPE lesions in the slope region was correlated with the PED configuration. Multi-contrast OCT is useful for objective evaluation of changes in the RPE in patients with age-related macular degeneration.

OPTICAL COHERENCE TOMOGRAPHY BIOMARKERS FOR REDUCTION OF DRUSENOID PIGMENT EPITHELIUM DETACHMENT

PURPOSE

To identify the optical coherence tomography biomarkers that can collectively predict the probability of collapse or reduction of drusenoid pigment epithelium detachment (PED).

METHODS

This consecutive observational case series reviewed the clinical data of 24 eyes with non-neovascular drusenoid PED. Among the study population, 17 eyes showed collapse or reduction of drusenoid PED. The mean follow-up duration was 44.8 ± 24.6 months. Optical coherence tomography-derived parameters were analyzed at baseline, at the last available visit before reduction of PED, at the first available visit after reduction of PED, and at the final visit.

RESULTS

The mean subfoveal choroidal thickness showed a significant decrease after PED reduction and at the most recent visit (P = 0.015). Migration of retinal pigment epithelium cells was detected in 15 (88.2%) after PED reduction; however, there was no significance in the frequency of migration of retinal pigment epithelium cells at each time point (P = 0.392). Non-neovascular subretinal fluid was detected in 7 (41.2%) before PED reduction, 2 (11.8%) after PED reduction, and 2 (11.8%) at the final visit. Interestingly, subretinal fluid appeared more frequently just before reduction of PED (P = 0.029).

CONCLUSION

We found evidence of non-neovascular subretinal fluid and choroidal thinning before reduction in PED. This finding might be useful for detection and prediction of the progression of drusenoid PED.