A Population-Based Ultra-Widefield Digital Image Grading Study for Age-Related Macular Degeneration-Like Lesions at the Peripheral Retina

Ultra-Wide-Field OCT Measurements in Patients with Age-Related Macular Degeneration in Relation to Their Visual Function

BACKGROUND

Ultra-wide-field optical coherence tomography (UWF-OCT) devices have recently been introduced to clinical practice. The goal of this study was to compare choroidal and retinal thickness (CT and RT) in age-related macular degeneration (AMD) with a healthy control group using UWF-OCT Xephilio S1. Additionally, we sought to determine the relationship between the RT and CT of patients with AMD, measured in different sectors, and their visual acuity.

METHODS

The study included 104 eyes from 74 participants with dry AMD, 119 eyes from 86 participants with wet AMD, and 85 eyes from 53 healthy controls. Of the participants with wet AMD, 87 eyes received anti-VEGF treatment, 13 were treatment naïve, and 19 had incomplete data. The analyzed measurements were taken in the central area of 3 mm in diameter and two peripheral rings located between 3-9 mm and 9-18 mm diameters.

RESULTS

There was no significant variation in the RT in any sector between the three study groups. CT in dry and wet AMD cohorts was significantly lower compared to controls in every sector. Patients with treatment-naïve wet AMD did not demonstrate significant CT loss but had a tendency for lower CT values. Visual impairment in patients with AMD correlated with older age in both subgroups and with smaller RT in the dry AMD subgroup.

CONCLUSIONS

Values of RT and CT obtained at the mid- and far-periphery with UWF-OCT generally reflect the alterations observed in AMD in the central part of the posterior pole. Intravitreal anti-VEGF treatment might contribute to loss of choroidal tissue observed in AMD in every sector.

Comparison of Geographic Atrophy Measurements Between Blue-Light Heidelberg Standard Field and Green-Light Optos Ultrawide Field Autofluorescence

Purpose

This study compared geographic atrophy (GA) measurements in the macula using standard 30° field and ultrawide field (UWF) fundus autofluorescence (FAF) imaging.

Methods

Participants from Age-Related Eye Disease Study 2 (AREDS2) and Optos PEripheral RetinA (OPERA) studies with GA were included for comparison between standard field FAF with Heidelberg Spectralis and Optos 200Tx UWF FAF. Two time points 5 years apart were evaluated. GA area (mm2) was recorded in the macular area for both imaging types and in the peripheral field for UWF.

Results

Of 102 paired images (73 subjects), the mean (SD) baseline GA area was 5.32 (6.36) mm2 with standard and 4.79 (5.87) mm2 with UWF FAF (P < 0.001). The mean difference between the two modalities was 0.52 mm2 (95% confidence interval, -2.41 to 1.37). Progression of GA in 25 eyes over 5 years showed a median annual growth rate of 1.28 mm2 (range, 0.02 to 4.7) for standard and 1.34 mm2 (range, 0.04 to 5.3) for UWF FAF (P = 0.49).

Conclusions

The measurement of GA is larger on standard than on UWF FAF imaging. The observed difference may be due to image averaging and the use of blue versus green FAF. Similar GA progression with standard and UWF FAF suggests either may be used longitudinally, although not interchangeably. Further investigation is required with updated UWF technology.

Translational Relevance

With the increasing adoption of UWF imaging modalities, this study suggests that Optos UWF FAF may be used longitudinally as an alternative to standard field FAF to monitor GA.

Age-Related Macular Degeneration and Extramacular Drusen: Genetic Associations in the Coimbra Eye Study

Purpose

To explore the association between the genetics of age-related macular degeneration (AMD) and extramacular drusen (EMD) in patients with and without AMD.

Methods

We included 1753 eyes (912 subjects) with phenotypic characterization regarding AMD and EMD. Genetic sequencing and the genetic risk score (GRS) for AMD were performed according to the EYE-RISK consortium methodology. To test for differences in the GRS from EMD cases, AMD cases, and controls, a clustered Wilcoxon rank-sum test was used. The association of AMD, EMD, and the GRS was evaluated using logistic regression models adjusted for age and sex. Individual associations of common risk variants for AMD with EMD were explored.

Results

EMD were found in 755 eyes: 252 (14.4%) with AMD and 503 (28.7%) without. In total, 122 eyes (7.0%) had only AMD, and 876 (50.0%) were controls. EMD were strongly associated with AMD (odds ratio [OR], 3.333; 95% confidence interval [CI], 2.356-4.623; P < 0.001). The GRS was associated with an increased risk of AMD (OR, 1.416; 95% CI, 1.218-1.646; P < 0.001) but not with EMD. Individually, the common risk variants ARMS2 rs10490924 (P = 0.042), C3 rs2230199 (P = 0.042), and CETP rs5817082 (P = 0.042) were associated with EMD, after adjustment for AMD, sex, and age.

Conclusions

We found a strong association between EMD and AMD, suggesting a common pathogenesis. The GRS for AMD was not associated with EMD, but a partially overlapping genetic basis was suggested when assessing individual risk variants. We propose that EMD per se do not represent an increase in the global genetic risk for AMD.

Comparison of Standard 7-Field, Clarus, and Optos Ultrawidefield Imaging Systems for Diabetic Retinopathy (COCO Study)

Purpose

The purpose of this study was to compare diabetic retinopathy (DR) severity levels assessed from 7 standard-field stereoscopic color photographs on a 35° fundus camera to both Clarus and Optos ultrawidefield color images.

Design

Cross-sectional, comparative imaging study.

Participants

Participants with DR imaged at a single-center retina practice.

Methods

Participants were imaged on 3 cameras at a single visit with the Topcon 35° fundus camera, Clarus, and Optos. The DR Severity Scale (DRSS) level was determined within the 7-field (7F) area of each image set using the ETDRS scale. An additional global DRSS was assigned for both Clarus and Optos images using the entire visible retina. Weighted kappa (wκ) measured the agreement between cameras.

Main Outcome Measures

The primary outcome was a 3-way comparison of DRSS level within the 7F area imaged on the 3 cameras. Secondary outcomes included a comparison of the DRSS obtained with standard 7F imaging to the global DRSS of Clarus and Optos and a comparison of the global DRSS between Clarus and Optos only.

Results

Ninety-seven eyes (50 participants) were evaluated. Agreement within 1-step of ETDRS levels between standard 7F imaging and Clarus 7F was 90.1% (wκ = 0.65), and with Optos 7F in 85.9%, (wκ = 0.58). Agreement within 1-step between standard 7F imaging and Clarus global was 88.9% of eyes (wκ = 0.63), and Optos global was 85.7%, (wκ = 0.54). Agreement between Clarus and Optos global DR level within 1-step was 89.1% (wκ = 0.68). Intergrader agreement for the 7F ETDRS level was 96% for standard 7F imaging, 98% for Clarus, and 95.5% for Optos.

Conclusions

These findings suggest that when evaluating the 7F area on Clarus and Optos, DR severity grades are comparable to standard 7F imaging. However, it is important to understand the unique attributes and differences of each fundus camera when changing the type of system used in a clinical setting due to upgrading equipment. Additionally, if the facility has access to > 1 device, there should not be an exchange between cameras for the same patient.

Financial Disclosures

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

Recent Advances in Imaging Macular Atrophy for Late-Stage Age-Related Macular Degeneration

Age-related macular degeneration (AMD) is a leading cause of blindness worldwide. In late-stage AMD, geographic atrophy (GA) of dry AMD or choroidal neovascularization (CNV) of neovascular AMD eventually results in macular atrophy (MA), leading to significant visual loss. Despite the development of innovative therapies, there are currently no established effective treatments for MA. As a result, early detection of MA is critical in identifying later central macular involvement throughout time. Accurate and early diagnosis is achieved through a combination of clinical examination and imaging techniques. Our review of the literature depicts advances in retinal imaging to identify biomarkers of progression and risk factors for late AMD. Imaging methods like fundus photography; dye-based angiography; fundus autofluorescence (FAF); near-infrared reflectance (NIR); optical coherence tomography (OCT); and optical coherence tomography angiography (OCTA) can be used to detect and monitor the progression of retinal atrophy. These evolving diverse imaging modalities optimize detection of pathologic anatomy and measurement of visual function; they may also contribute to the understanding of underlying mechanistic pathways, particularly the underlying MA changes in late AMD.

Epidemiology of geographic atrophy and its precursor features of intermediate age-related macular degeneration

Globally age-related macular degeneration (AMD) is a leading cause of blindness with a significant impact on quality of life. Geographic atrophy (GA) is the atrophic late form of AMD and its prevalence increases markedly with age with around 1 in 5 persons aged 85 and above having GA in at least one eye. Bilateral GA leads to severe visual impairment thus posing a significant burden on patients, careers and health providers. The incidence and prevalence of GA varies across different geographic regions, with the highest rates in those of European ancestry. Although heterogeneity in definitions of GA and reporting strategy can explain some of the discrepancies, the data overall are consistent in showing a lower prevalence in other ethnicities such as those of Asian heritage. This is at present unexplained but thought to be due to the existence of protective factors such as differences in eye pigmentation, diet, environmental exposures and genetic variability. This review covers key aspects of the prevalence and incidence of the ocular precursor features of GA (large drusen, pigmentary abnormalities and reticular pseudo-drusen), the late stage of GA and factors that have been known to be associated with modifying risk including systemic, demographic, environment, genetic and ocular. Understanding the global epidemiology scenario is crucial for the prevention of and management of patients with GA.

Prevalence and risk factors for age-related macular degeneration in a population-based cohort study of older adults in Northern Ireland using multimodal imaging: NICOLA Study

PURPOSE

To report prevalence and risk factor associations for age-related macular degeneration (AMD) and AMD features from multimodal retinal grading in a multidisciplinary longitudinal population-based study of aging in Northern Ireland.

STUDY DESIGN

Population-based longitudinal cohort study.

METHODS

Retinal imaging at the Norther Ireland Cohort for the Longitudinal Aging Study health assessment included stereo Colour Fundus Photography (CFP) (Canon CX-1, Tokyo, Japan) and Spectral-Domain Optical Coherence Tomography (SD-OCT) ((Heidelberg Retinal Angopgraph (HRA)+OCT; Heidelberg Engineering, Heidelberg, Germany). Medical history and demographic information was obtained during a home interview. Descriptive statistics were used to describe the prevalence of AMD and individual AMD features. Multiple imputation followed by multiple regression modelling was used to explore risk factor associations including relationships with AMD genetic risk score.

RESULTS

Retinal images from 3386 participants were available for analysis. Mean age of the sample was 63.4 (SD 9.01, range: 36-99). Population weighted prevalence of AMD using colour grading in those over 55 years was: no drusen: 6 0.4%; drusen <63 μm: 15.9%; drusen 63-125 µm: 13.7%; drusen >125 µm or pigmentary changes: 8.3%; late AMD: 1.6%. Prevalence of AMD features in those over 55 years was: OCT drusen 27.5%, complete outer retinal pigment epithelium and outer retinal atrophy (cRORA) on OCT was 4.3%, reticular drusen 3.2% and subretinal drusenoid deposits 25.7%. The genetic risk score was significantly associated with drusen and cRORA but less so for SDD alone and non-significant for hyperpigmentation or vitelliform lesions.

CONCLUSIONS

Multimodal imaging-based classification has provided evidence of some divergence of genetic risk associations between classical drusen and SDD. Our findings support an urgent review of current AMD severity classification systems.

SPONTANEOUS REATTACHMENT OF RHEGMATOGENOUS RETINAL DETACHMENT: Observations of the Vitreoretinal Interface

PURPOSE

To describe the clinical characteristics and posterior vitreous findings of spontaneous reattachment of rhegmatogenous retinal detachment (SRRRD).

METHODS

Eighty-six eyes from 80 patients who were diagnosed with SRRRD (SRRRD group) and 92 eyes from 92 patients who had undergone successful scleral buckling for rhegmatogenous retinal detachment ( group for comparison) were included. Ultrawide field fundus imaging and spectral domain optical coherence tomography were performed to evaluate fundus characteristics and vitreoretinal interface.

RESULTS

A significant difference was found in the proportion of complete posterior vitreous attachment between the SRRRD and rhegmatogenous retinal detachment groups (44.2% vs. 19.6%, P < 0.001). The incidence of atypical epiretinal tissue (AET) in the SRRRD group was 14% (12 of 86 eyes), whereas none of the eyes in the rhegmatogenous retinal detachment group exhibited AET. In SRRRD eyes with AET, the visual acuity was lower (logarithm of the minimum angle of resolution, 0.51 ± 0.57 vs. 0.14 ± 0.15, P < 0.001), the mean age was higher (years, 61.7 vs. 39.4, P < 0.001), and the SRRRD lesion extent was wider (clock hours, 5.67 vs. 3.70, P = 0.004) than in SRRRD eyes without AET.

CONCLUSION

Compared with the rhegmatogenous retinal detachment group, the SRRRD group had a higher incidence of posterior vitreous attachment. Furthermore, AET was a significant comorbidity in the eyes with SRRRD, particularly in the elderly and the area of presumed reattachment over two quadrants and was related to worse functional outcomes.

A Prospective Audit Comparing Optos Widefield Imaging to Fundus Examination for Von Hippel-Lindau Retinal Screening

Background Von Hippel-Lindau (VHL) disease is an autosomal dominant multisystem disorder caused by germline mutations at chromosome 3p25-26 in the VHLtumour suppressor gene. Retinal manifestations include capillary haemangiomas that develop in up to 80% of gene carriers. Lifelong retinal surveillance involves yearly assessment usually by fundoscopy and often as part of a VHL multidisciplinary clinic. Optos ultra-widefield retinal imaging is now becoming more widely used in virtual retinal screening clinics. We aimed to assess discrepancies in the pickup rate of angioma and angiomatous-associated disease between slit-lamp fundoscopy and Optos ultra-widefield imaging. Methodology A total of 49 patients had both Optos ultra-widefield retinal imaging and slit-lamp fundoscopy over 16 months in VHL retinal surveillance clinics at the John Radcliffe Hospital, Oxford, UK. Optos images were analysed for image quality and presence of angioma(s) by a Consultant Ophthalmologist who was masked to the fundoscopy findings. The pickup rate was compared between slit-lamp fundoscopy and Optos imaging. Results In total, data on 94 eyes were collected. Of the total Optos retinal images, 12.8% were positive for angiomas compared to 11.7% from the slit-lamp examination. There was a discrepancy of 1.1% (one value) where the Optos image analysis suggested a possible angioma, which was not identified on slit-lamp examination. Optos imaging identified all angiomas in this cohort. Conclusions Optos imaging was non-inferior to slit-lamp examination in this sample of 94 eyes. In the current COVID-19 climate, reducing clinician-patient interaction is important. This research supports providing retinal imaging as an acceptable alternative to the yearly slit-lamp fundus examination.

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.

Exploring association between pseudoexfoliation syndrome and ocular aging

PURPOSE

Within a population-based follow-up study, to examine the 10-year incidence of pseudoexfoliation syndrome (PEX), possible risk factors for PEX and its association with ocular aging of the cornea, lens and retina.

METHODS

The baseline examination was conducted in 2006 on a random sample of 1,033 adult participants from Kaunas city (Lithuania) population of whom 631 had ophthalmic examination data at attendance of the 10-year follow-up in 2016. Detailed examination of the anterior and posterior segment of the eye was carried out. After diagnostic mydriasis PEX was diagnosed by the presence of typical grayish-white exfoliation material on the anterior capsule surface of the lens. The participants were divided to PEX and non-PEX groups.

RESULTS

PEX prevalence increased from 9.8 to 34.2% from baseline to 10-year follow-up. Nuclear cataract was common both in the PEX group (66.7%) and in those without PEX (72.2%), but this difference did not reach statistically significantly increased risk of developing cataract in those with PEX (OR 1.2; p = 0.61). Central corneal thickness (CCT) was thinner in the PEX group (529 ± 34 μm) and in the oldest group (525 ± 36 μm) (p < 0.001). Compared to baseline, corneal curvature (CC) became flatter in both groups (7.6 ± 0.27 vs 7.7 ± 0.26 mm; p < 0.001) during the follow-up, but the difference did not reach significance between groups. Corneal astigmatism was most commonly with-the-rule in both groups (37 (50.0%) vs 148 (68.5%); p > 0.05). Age, sex and PEX had no influence on age-related macular degeneration distribution.

CONCLUSION

The prevalence of PEX increased significantly with age in our population, with those with PEX having thinner and flatter corneae, but no difference in cataract and age-related macular degeneration characteristics.

Peripheral Manifestations in Age Related Macular Degeneration: A Review of Imaging and Findings

Purpose: To review novel findings in research with ultra-widefield imaging for analysis of peripheral manifestations in macular degeneration (AMD). We introduce the evolving widefield imaging modalities while summarizing the analytical techniques used in data collection of peripheral retinal findings thus far. Our review provides a summary of advancements to date and a commentary on future direction for AMD research. Methods: This is a literature review of all significant publications focused on the relationship between AMD and the retinal periphery conducted within the last two decades. Results and Conclusion: Promising research has been undertaken to elucidate peripheral retinal manifestations in macular degeneration using novel methodology. Advancements in ultra-widefield imaging and fundus autofluorescence have allowed us to elucidate peripheral retinal pigmentary changes, drusen deposition, and much more. Novel grid overlay techniques have been introduced to aid in analyzing these changes for pattern recognition and grouping of findings. This review discusses these findings in detail, providing evidence for the pan-retinal manifestations of AMD. Inter-study discordance in analytical approach highlights a need for more systematic future study.

Retinal phenotyping of variants of Alzheimer's disease using ultra-widefield retinal images

BACKGROUND

Posterior cortical atrophy (PCA) is the most common atypical variant of Alzheimer's disease (AD). Changes associated with PCA in the brain affect the visual cortex, but little is known about retinal changes in PCA. In this study, we explored retinal phenotypic variations in typical AD (tAD) and PCA.

METHODS

Retinal phenotyping was carried out on ultra-widefield (UWF) images of 69 control, 24 tAD, and 25 PCA participants.

RESULTS

Individuals with tAD (odds ratio [OR] = 2.76 [confidence interval (CI):1.24 to 6.10], P = .012) and PCA (OR = 3.40 [CI:1.25 to 9.22], P = .016) were more likely phenotyped as hard drusen. tAD (OR = 0.34 [CI:0.12 to 0.92], P = .035) were less likely to have soft drusen compared to control. Almost 3-fold increase in reticular pseudodrusen formation in tAD (OR = 2.93 [CI:1.10 to 7.76], P = .030) compared to control was estimated.

DISCUSSION

Studying the peripheral retina may contribute to a better understanding of differences in retinal phenotypes of different AD variants.

CLINICAL FEATURES OF PATCHY CHORIORETINAL ATROPHY IN PATHOLOGIC MYOPIA

PURPOSE

To reveal clinical features of patchy atrophy in pathologic myopia and investigate the status of the Bruch membrane and retinal pigment epithelium by swept-source optical coherence tomography.

METHODS

This study reviewed highly myopic patients who visited the high myopia clinic between January 2015 and February 2018. Wide-field photographs and wide-field fundus autofluorescence fundus images were used as the primary method for identifying PAs, and swept-source optical coherence tomography images were used for investigating the retinochoroid status of PAs.

RESULTS

Four hundred fifty-six PAs were detected in 137 eyes (118 patients). Patchy atrophys were located most often in the macular area (28.3%), followed by the inferior (25.9%), temporal (18.9%), nasal (14.5%), and superior (12.5%) region. All 210, PAs which had been fully or partially scanned by swept-source optical coherence tomography, showed a retinal pigment epithelium defect, and 174 (82.9%) PAs showed a Bruch membrane defect on the available scans. In 101 (82.8%) of 122 PAs with clearly detectable borders of the retinal pigment epithelium and Bruch membrane defect, the Bruch membrane defects were smaller than the retinal pigment epithelium defects. A dome-shape inward bulging of the sclera was observed in 10 PAs.

CONCLUSION

These morphological findings may provide a basis for exploring the biomechanical etiology of the PAs as part of the development of pathologic myopia.

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.

Ocular Imaging for Enhancing the Understanding, Assessment, and Management of Age-Related Macular Degeneration

Age-related macular degeneration (AMD) is a progressive neuro-retinal disease and the leading cause of central vision loss among elderly individuals in the developed countries. Modern ocular imaging technologies constitute an essential component of the evaluation of these patients and have contributed extensively to our understanding of the disease. A challenge with any review of ocular imaging technologies is the rapid pace of progress and evolution of these instruments. Nonetheless, for proper and optimal use of these technologies, it is essential for the user to understand the technical principles underlying the imaging modality and their role in assessing the disease in various settings. Indeed, AMD, like many other retinal diseases, benefits from a multimodal imaging approach to optimally characterize the disease. In this chapter, we will review the various imaging technologies currently used in the assessment and management of AMD.

Quantitative Comparison of Fundus Images by 2 Ultra-Widefield Fundus Cameras

PURPOSE

To compare the relative number of retinal pixels and retinal area imaged using the Optos P200DTx (Optos PLC) and Zeiss Clarus 500 (Carl Zeiss Meditec AG) ultra-widefield (UWF) fundus cameras.

DESIGN

Single-center retrospective cross-sectional analysis.

PARTICIPANTS

Seventy-eight eyes of 46 patients.

METHODS

Eyes were imaged with Optos P200DTx, single-capture, and Zeiss Clarus 500, 2 capture montages when possible, UWF fundus cameras. Relative number of pixels encompassing all foveal-centered retinal quadrants were measured. Retinal area was measured with Zeiss Clarus 500 images that were registered to the Optos P200DTx images. Patients and technicians were asked for preferences between the machines. Imaging session times were recorded.

MAIN OUTCOME MEASURES

Relative number of retinal pixels and retina area captured by each fundus camera.

RESULTS

Optos P200DTx consistently captured more relative pixels compared with Zeiss Clarus 500: 510.4 versus 355.6 (P < 0.001) in total with a similarly statistically significant trend in all 4 quadrants (P < 0.001 for each). For area calculation, 70 of the 78 images achieved successful registration. Optos captured a larger total retinal area: 765.6 versus 566.5 mm² (P < 0.001) with a similarly statistically significant trend in all 4 quadrants. In the subset of 52 of 70 registered and montaged Zeiss Clarus 500 images, similar results were found. For peripheral pathologic features, Optos P200DTx captured unique findings in 28 images, and Zeiss Clarus 500 captured unique findings 1 image (P < 0.001). Among the 48 imaging sessions in which technicians preferred Optos P200DTx for 28 sessions (58%) and Zeiss Clarus 500 for 20 (42%; P = 0.15). Among patients who responded with a preference, 24 preferred Optos P200DTx and 20 preferred Zeiss Clarus 500 (P = 0.52). Average imaging session time was 4.6 minutes (standard deviation, 3.0 minutes) for Optos P200DTx and 5.2 minutes (standard deviation, 3.0 minutes) for Zeiss Clarus 500 (P = 0.17).

CONCLUSIONS

In the current study, the Optos P200DTx captured statistically significantly more retinal area in all 4 quadrants compared with the Zeiss Clarus 500. No statistically significant difference was found in patient or technician preference or image acquisition time between devices.

Non-Mydriatic Ultra-Wide Field Imaging Versus Dilated Fundus Exam and Intraoperative Findings for Assessment of Rhegmatogenous Retinal Detachment

Background: to compare the extent of the detached retina and retinal tears location in rhegmatogenous retinal detachment (RRD) among non-mydriatic ultra-wide field (UWF) imaging, dilated fundus exam (DFE), and intraoperative evaluation. Methods: this retrospective chart review comprised 123 patients undergoing surgery for RRD. A masked retina specialist analyzed the UWF fundus images for RRD area, status of the macula, and presence and location of retinal breaks. The same variables were collected from a database including DFE and intraoperative recordings. Evaluation methods were compared. Results: mean age was 59.8 ± 14.9 years. Best-corrected visual acuity improved from 0.25 ± 0.3 (Snellen) to 0.67 ± 0.3 at 12 months (p = 0.009). The RRD description and assessment of macula status (34.5% macula-on) did not differ between UWF, DFE, and intraoperative examination. The inferior quadrant was involved most frequently (41.5%), followed by the superior (38.9%), temporal (27.8%) and nasal quadrant (14.8%). Intraoperative exam detected 96.7% of retinal tears compared with DFE (73.2%, p = 0.008) and UWF imaging (65%, p=0.003). UWF imaging and DFE did not differ significantly. Conclusion: RRD extent on DFE and UWF images was consistent with intraoperative findings. UWF and DFE detection of peripheral retinal tears was similar, but 25% of retinal breaks were missed until intraoperative evaluation.

Observation of the far peripheral retina of normal eyes by ultra-wide field fluorescein angiography

PURPOSE

The appearance of the far peripheral retina in normal eyes was observed using an Optos ultra-wide field fluorescein angiography imaging system.

METHODS

A cross-sectional study of ultra-wide field pseudocolor and angiography images obtained using the Optos 200Tx. Four different non-vascular and six vascular-associated fluorescence features in far peripheral retina were analyzed.

RESULTS

A total of 166 eyes in 83 patients met the inclusion criteria. The mean patient age was 40.78 ± 10.94 years (range: 20-65 years) with a female-to-male ratio of 0.98. Slight cataract were present in 64 eyes (38.55%), low to moderate myopia in 50 eyes (30.12%), and unspecified visual disturbances in 52 eyes (31.33%). Far peripheral retinas were found to have mottled florescent band in 42.17% eyes, ground glass hyperfluorescence in 84.34% eyes, granular hyperfluorescence in 12.65% eyes, local mottled fluorescence in 10.84% eyes, vascular anastomosis with a peripheral avascular area in 36.23% eyes, invisible capillary details in 50.67% eyes, vessels passing through the ora serrata in 16.98% eyes, late-phase slight leakage in 32.53% eyes, angiectasis in 18.67% eyes, and microaneurysm in 34.94% eyes.

CONCLUSION

Ultra-wide field fluorescein angiography revealed various fluorescence features in the periphery of normal eyes, providing a basis for interpreting normal and pathological changes in peripheral retina and an important reference for clinical work.

Ultra-widefield retinal imaging: an update on recent advances

The development of ultra-widefield retinal imaging has accelerated our understanding of common retinal diseases. As we continue to validate the diagnostic and prognostic significance of pathology in the retinal periphery, the ability to visualize and evaluate these features in an efficient and patient-friendly manner will become more important. Current interest in ultra-widefield imaging includes the development of potential biomarkers of disease progression and indicators of preclinical disease development. This article reviews the current ultra-widefield imaging systems and recent advances in their applications to clinical practice with a focus on diabetic retinopathy, retinal vein occlusion, uveitis, and pediatric retina.

Multimodal imaging characterization of peripheral drusen

PURPOSE

To provide an integrate multimodal imaging characterization of peripheral drusen in the eyes with and without macular signs of age-related macular degeneration (AMD) and to analyze their association with macular findings.

METHODS

In this retrospective, cross-sectional study, subjects with peripheral drusen were imaged with the Optos (Optos PLC, Dunfermline, Scotland, UK) and Spectralis devices to obtain referenced spectral domain optical coherence tomography (SD-OCT) images. Two experienced graders independently graded the ultra-widefield (UWF) pseudocolor and fundus autofluorescence (FAF) images for the presence of peripheral drusen and analyzed peripheral druse features using OCT. Main outcome measures included quantitative and qualitative assessment of peripheral drusen.

RESULTS

Fifty-seven eyes (30 subjects) were included in the analysis. Mean ± SD age was 77.6 ± 9.2 years (range 54-97 years). On pseudocolor images, graders identified the presence of drusen in all the enrolled eyes (Cohen's kappa was 1.0). On FAF images, Cohen's kappa was 0.71. In the topographical assessment, peripheral drusen were detected in 23 cases in the temporal region, in 40 cases in the nasal region, in 40 cases in the inferior region, and in 42 cases in the superior region. On SD-OCT images, peripheral drusen had a high reflective core in 97.1% of cases, while remaining drusen were characterized by a low reflective core. The macula was affected by early/intermediate AMD in 23 eyes (43.5%) and late AMD in 6 eyes (10.5%).

CONCLUSIONS

We provided an integrate multimodal imaging assessment of peripheral drusen in the eyes with and without AMD. Peripheral drusen were characterized by distinguished features that may suggest that these lesions constitute a distinct disease, rather than representing an expansion of AMD.

Ultra-wide-field fundus imaging of acute retinal necrosis: clinical characteristics and visual significance

OBJECTIVES

To investigate the clinical characteristics of acute retinal necrosis (ARN) with ultra-wide-field imaging (UWFI) and analyse their visual significance.

METHODS

Clinical and UWFI records of patients diagnosed with ARN at a single centre over 2 years were reviewed.

RESULTS

In 38 eyes of 35 patients, the clinical manifestations of ARN on UWFI included patchy (12 eyes) or fan-shaped necrotic lesions (26 eyes), retinal arterial obliteration (38 eyes), vitritis (38 eyes), retinal venous haemorrhage (19 eyes), and vitreous haemorrhage (6 eyes). Retinal detachment was associated with the number of retinal quadrants involved (β = 2.145, P = 0.005). LogMAR BCVA at last follow-up was associated with logMAR BCVA at presentation (β = 0.473, P = 0.004) and retinal detachment (β = 0.367, P = 0.020).

CONCLUSION

UWFI is useful for detecting retinal lesions in ARN, especially peripheral lesions or through opaque media, and provides valuable information concerning visual prognosis.

Lessons learned from quantitative fundus autofluorescence

Quantitative fundus autofluorescence (qAF) is an approach that is built on a confocal scanning laser platform and used to measure the intensity of the inherent autofluorescence of retina elicited by short-wavelength (488 nm) excitation. Being non-invasive, qAF does not interrupt tissue architecture, thus allowing for structural correlations. The spectral features, cellular origin and topographic distribution of the natural autofluorescence of the fundus indicate that it is emitted from retinaldehyde-adducts that form in photoreceptor cells and accumulate, under most conditions, in retinal pigment epithelial cells. The distributions and intensities of fundus autofluorescence deviate from normal in many retinal disorders and it is widely recognized that these changing patterns can aid in the diagnosis and monitoring of retinal disease. The standardized protocol employed by qAF involves the normalization of fundus grey levels to a fluorescent reference installed in the imaging instrument. Together with corrections for magnification and anterior media absorption, this approach facilitates comparisons with serial images and images acquired within groups of patients. Here we provide a comprehensive summary of the principles and practice of qAF and we highlight recent efforts to elucidate retinal disease processes by combining qAF with multi-modal imaging.

Peripheral Retinal Lesions in Eyes with Age-Related Macular Degeneration Using Ultra-Widefield Imaging: A Systematic Review with Meta-analyses

TOPIC

Age-related macular degeneration (AMD) is highly prevalent among the elderly. We systematically reviewed the literature to provide an overview of ultra-widefield imaging (UWFI) of peripheral retinal lesions in AMD.

CLINICAL RELEVANCE

Information regarding retinal characteristics and prevalence of AMD is based mainly on studies using color photography of the central retina, where early and potentially severe manifestations of the disease are found. However, this approach has the effect of neglecting the periphery. Studies using UWFI provide new evidence to show that clinical features associated with AMD are not exclusive to the area of the macula.

METHODS

Eligible studies had to detect lesions of the peripheral retina (based on the original definition of a standard macular grid, with the addition of 2 zones classed as peripheral) using UWFI in eyes with AMD. Ultra-widefield imaging included pseudocolor photography, fundus autofluorescence, fluorescein angiography, and indocyanine green angiography. Eligibility was restricted to human participants and studies written in English. We searched the bibliographic databases PubMed, the Cochrane Library, EMBASE, and the Web of Science on March 27, 2018. We calculated the prevalence of peripheral findings in eyes with AMD and performed similar meta-analyses on the healthy control group. A random-effects model was used because of possible study heterogeneity.

RESULTS

Twelve studies were eligible for the review, which included 3261 or more eyes. Studies were clinic based, apart from 1 study that was a random population sample of individuals 62 years of age or older. Studies were cross-sectional in nature, apart from 1 case-control study. The peripheral lesions most commonly observed were drusen, atrophy, and changes to the retinal pigment epithelium. In eyes with AMD, peripheral lesions were found in 82.7% of eyes (confidence interval, 78.4%-86.7%) compared with 33.3% of healthy eyes (confidence interval, 28.3%-38.5%).

CONCLUSIONS

Peripheral changes were found to be highly prevalent in eyes with AMD, supporting the claim that the disease is panretinal and not macula only. The clinical significance of peripheral lesions in AMD remains incompletely understood, and therefore, further UWFI studies are recommended.

Deep and Frequent Phenotyping study protocol: an observational study in prodromal Alzheimer's disease

INTRODUCTION

Recent failures of potential novel therapeutics for Alzheimer's disease (AD) have prompted a drive towards clinical studies in prodromal or preclinical states. However, carrying out clinical trials in early disease stages is extremely challenging-a key reason being the unfeasibility of using classical outcome measures of dementia trials (eg, conversion to dementia) and the lack of validated surrogate measures so early in the disease process. The Deep and Frequent Phenotyping (DFP) study aims to resolve this issue by identifying a set of markers acting as indicators of disease progression in the prodromal phase of disease that could be used as indicative outcome measures in proof-of-concept trials.

METHODS AND ANALYSIS

The DFP study is a repeated measures observational study where participants will be recruited through existing parent cohorts, research interested lists/databases, advertisements and memory clinics. Repeated measures of both established (cognition, positron emission tomography (PET) imaging or cerebrospinal fluid (CSF) markers of pathology, structural MRI markers of neurodegeneration) and experimental modalities (functional MRI, magnetoencephalography and/or electroencephalography, gait measurement, ophthalmological and continuous smartphone-based cognitive and other assessments together with experimental CSF, blood, tear and saliva biomarkers) will be performed. We will be recruiting male and female participants aged >60 years with prodromal AD, defined as absence of dementia but with evidence of cognitive impairment together with AD pathology as assessed using PET imaging or CSF biomarkers. Control participants without evidence of AD pathology will be included at a 1:4 ratio.

ETHICS AND DISSEMINATION

The study gained favourable ethical opinion from the South Central-Oxford B NHS Research Ethics Committee (REC reference 17/SC/0315; approved on 18 August 2017; amendment 13 February 2018). Data will be shared with the scientific community no more than 1 year following completion of study and data assembly.

Peripheral retinal findings in populations with macular disease are similar to healthy eyes

PURPOSE

Recent evidence suggests several macular diseases are associated with peripheral retinal changes. This study investigated the number, type and management consequences of peripheral retinal findings detected in patients attending a referral only, eye-care clinic, the Centre for Eye Health(CFEH) with macular disease.

METHODS

Records of 537 patients attending CFEH for a macular assessment were included in the study. Subjects were classified as having age-related macular degeneration (AMD), epiretinal membrane (ERM), central serous chorioretinopathy (CSCR), inherited macular dystrophy or no macular disease. Data extracted included reason for referral, macular findings, peripheral findings (based on examination by ultra-widefield scanning laser ophthalmoscopy), diagnosis and management.

RESULTS

After age-matching, the number of peripheral findings in subjects with AMD, ERM or CSCR was not significant different to normal subjects. The most common finding for all cohorts were non-specific, degenerative changes such as drusen or pigmentation (61-72%) except inherited macular dystrophy subjects who had mostly vascular findings (30%; p < 0.05). Subjects with AMD and ERM with peripheral findings were significantly more likely to be reviewed or referred to an ophthalmologist than discharged back to their community eye care provider compared to subjects without findings. However only 8% of subjects had altered management based specifically on peripheral findings suggesting the macular findings in most subjects dictated their management. For those with a change, it was significant (upgrade to referral to an ophthalmologist). Peripheral findings also flagged 5% of subjects with vascular findings for referral to their general practitioner (GP).

CONCLUSIONS

Overall, the percentage and distribution of peripheral retinal findings in some macular diseases was similar to normal subjects. However, subjects with peripheral findings appeared to have significant differences in management. Considering some common findings, such as peripheral drusen may be relevant to AMD pathogenesis and therefore affect management of this disease, assessment of the peripheral retina should not be overlooked when the clinical focus is on the posterior pole.

On the origin of proteins in human drusen: The meet, greet and stick hypothesis

Retinal drusen formation is not only a clinical hallmark for the development of age-related macular degeneration (AMD) but also for other disorders, such as Alzheimer's disease and renal diseases. The initiation and growth of drusen is poorly understood. Attention has focused on lipids and minerals, but relatively little is known about the origin of drusen-associated proteins and how they are retained in the space between the basal lamina of the retinal pigment epithelium and the inner collagenous layer space (sub-RPE-BL space). While some authors suggested that drusen proteins are mainly derived from cellular debris from processed photoreceptor outer segments and the RPE, others suggest a choroidal cell or blood origin. Here, we reviewed and supplemented the existing literature on the molecular composition of the retina/choroid complex, to gain a more complete understanding of the sources of proteins in drusen. These "drusenomics" studies showed that a considerable proportion of currently identified drusen proteins is uniquely originating from the blood. A smaller, but still large fraction of drusen proteins comes from both blood and/or RPE. Only a small proportion of drusen proteins is uniquely derived from the photoreceptors or choroid. We next evaluated how drusen components may "meet, greet and stick" to each other and/or to structures like hydroxyapatite spherules to form macroscopic deposits in the sub-RPE-BL space. Finally, we discuss implications of our findings with respect to the previously proposed homology between drusenogenesis in AMD and plaque formation in atherosclerosis.

The clinical relevance of visualising the peripheral retina

Recent developments in imaging technologies now allow the documentation, qualitative and quantitative evaluation of peripheral retinal lesions. As wide field retinal imaging, capturing both the central and peripheral retina up to 200° eccentricity, is becoming readily available the question is: what is it that we gain by imaging the periphery? Based on accumulating evidence it is clear that findings in the periphery do not always associate to those observed in the posterior pole. However, the newly acquired information may provide useful clues to previously unrecognised disease features and may facilitate more accurate disease prognostication. In this review, we explore the anatomy and physiology of the peripheral retina, focusing on how it differs from the posterior pole, recount the history of peripheral retinal imaging, describe various peripheral retinal lesions and evaluate the overall relevance of peripheral retinal findings to different diseases.

Determining Optimal Test Parameters for Assessing Dark Adaptation in People With Intermediate Age-Related Macular Degeneration

Purpose

The primary aim was to determine optimal test conditions for evaluating dark adaptation in intermediate age-related macular degeneration (iAMD) in order to minimize test time while maintaining diagnostic sensitivity.

Methods

People with AMD and age-similar controls were recruited (aged >55 years). Rod intercept time (RIT) was assessed after a 76%, 70%, and 65% rhodopsin bleach at 5° eccentricity and 76% and 70% bleach at 12°. Test order was randomized and a 30-minute washout period added between tests. Results were compared between control and iAMD groups and receiver operating characteristics (ROC) curves were constructed.

Results

A total of 26 participants with variable grades of macular health attended for two visits. There was a statistically significant difference in average RIT between the control and iAMD groups at 5° (median, IQR controls = 5.8 minutes, 3.8-7.5; iAMD = 20.6 minutes, 11.1-30.0; Mann-Whitney, P = 0.01) and at 12° (mean, controls: 4.54 minutes ± 2.12 SD, iAMD = 7.72 minutes ± 3.37 SD; independent samples t-test, P = 0.03) following a 76% bleach. Area under the ROC curves was 0.83 (confidence interval [CI]: 0.64-1.0) and 0.79 (CI: 0.59-0.99) for these two test conditions, respectively. Five participants (45%) in the iAMD group had RITs >20 minutes for 76% bleach at 5°, but none for any other test condition.

Conclusions

Nearly half of the participants with iAMD produced unacceptably long recovery times (>20 minutes) using a 76% bleach at 5° eccentricity. The 76% bleach at 12° provided almost equivalent separation between AMD and controls but recovery was achieved within 20 minutes.

Multimodal Imaging of Nonneovascular Age-Related Macular Degeneration

Nonneovascular (dry) AMD is a retinal disease with potential for significant central visual impairment. The hallmarks of this disease are macular drusen, RPE alterations, and geographic atrophy (GA). Classification schemes for nonneovascular AMD have evolved over the years as major advances in retinal imaging have enabled a greater understanding of disease pathophysiology. The original classifications of nonneovascular AMD were based on color fundus photography (CFP), while more modern schemes rely on a multimodal imaging approach. Effective diagnosis and management of nonneovascular AMD requires a thorough understanding of its multimodal imaging features as detailed in this review. Future imaging modalities and imaging biomarkers that may aid in diagnosis and management are also discussed.

Peripheral Changes Associated With Delayed Dark Adaptation in Age-related Macular Degeneration

PURPOSE

To study the association between peripheral changes in age-related macular degeneration (AMD) and dark adaptation (DA).

DESIGN

Prospective, cross-sectional study.

METHODS

We recruited patients with AMD and a control group (>50 years) without any vitreoretinal disease. Ultra-widefield (UWF) pseudocolor and fundus autofluorescence (FAF) were obtained, and were assessed by 2 graders for the presence of several peripheral changes in perimacular, midperipheral, and far-peripheral zones. All participants were also imaged with 7-field color fundus photographs used for AMD staging (Age-Related Eye Disease Study classification system). Both eyes of study participants were tested with a dark adaptation (DA) extended protocol (20 minutes). Multilevel mixed-effect models (accounting for correlated outcomes between 2 eyes) were used for analyses.

RESULTS

We included 128 eyes (n = 72 patients), 75% with AMD and the remainder controls. The presence of reticular pigmentary changes in the midperipheral (ß = 4.3, P = .012) and far-peripheral zones (ß = 8.4, P < .001) was associated with delayed rod-intercept times (RITs), even after adjusting for confounding factors. The presence, number, and extent of peripheral classic drusen did not show a similar association (P ≥ .148). The presence of a mottled decreased FAF pattern in the midperipheral zone was also associated with prolonged RITs (β = 4.4, P = .031).

CONCLUSION

Our results suggest an association between DA and the presence of peripheral reticular pigmentary changes, as well as the presence of a peripheral mottled decreased FAF pattern. This provides new insights on the clinical significance of peripheral changes in AMD, and their contribution to impairments on DA.

Peripheral Retinal Imaging Biomarkers for Alzheimer's Disease: A Pilot Study

PURPOSE

To examine whether ultra-widefield (UWF) retinal imaging can identify biomarkers for Alzheimer's disease (AD) and its progression.

METHODS

Images were taken using a UWF scanning laser ophthalmoscope (Optos P200C AF) to determine phenotypic variations in 59 patients with AD and 48 healthy controls at baseline (BL). All living participants were invited for a follow-up (FU) after 2 years and imaged again (if still able to participate). All participants had blood taken for genotyping at BL. Images were graded for the prevalence of age-related macular degeneration-like pathologies and retinal vascular parameters. Comparison between AD patients and controls was made using the Student t test and the χ2 test.

RESULTS

Analysis at BL revealed a significantly higher prevalence of a hard drusen phenotype in the periphery of AD patients (14/55; 25.4%) compared to controls (2/48; 4.2%) [χ2 = 9.9, df = 4, p = 0.04]. A markedly increased drusen number was observed at the 2-year FU in patients with AD compared to controls. There was a significant increase in venular width gradient at BL (zone C: 8.425 × 10-3 ± 2.865 × 10-3 vs. 6.375 × 10-3 ± 1.532 × 10-3, p = 0.008; entire image: 8.235 × 10-3 ± 2.839 × 10-3 vs. 6.050 × 10-3 ± 1.414 × 10-3, p = 0.004) and a significant decrease in arterial fractal dimension in AD at BL (entire image: 1.250 ± 0.086 vs. 1.304 ± 0.089, p = 0.049) with a trend for both at FU.

CONCLUSIONS

UWF retinal imaging revealed a significant association between AD and peripheral hard drusen formation and changes to the vasculature beyond the posterior pole, at BL and after clinical progression over 2 years, suggesting that monitoring pathological changes in the peripheral retina might become a valuable tool in AD monitoring.

CFH and ARMS2 genetic risk determines progression to neovascular age-related macular degeneration after antioxidant and zinc supplementation

Age-related macular degeneration (AMD) is the leading cause of severe vision loss in the elderly and has major economic and quality-of-life impact. Prophylactic high-dose zinc and antioxidant supplements treatments are typically recommended with the assumption of homogeneously distributed benefit and risk of developing neovascular AMD. We show that individual variation at complement factor H and age-related maculopathy susceptibility 2, genes which predispose to AMD, also determines the effectiveness of nutritional prophylaxis. Some individuals paradoxically experience worsening disease with treatment, while others experience greater than average benefit. These divergent responses are difficult to identify when treatment effects have long latency. Understanding individual variations in prophylactic treatment response should inform future research and optimize health outcomes.

We evaluated the influence of an antioxidant and zinc nutritional supplement [the Age-Related Eye Disease Study (AREDS) formulation] on delaying or preventing progression to neovascular AMD (NV) in persons with age-related macular degeneration (AMD). AREDS subjects (n = 802) with category 3 or 4 AMD at baseline who had been treated with placebo or the AREDS formulation were evaluated for differences in the risk of progression to NV as a function of complement factor H (CFH) and age-related maculopathy susceptibility 2 (ARMS2) genotype groups. We used published genetic grouping: a two-SNP haplotype risk-calling algorithm to assess CFH, and either the single SNP rs10490924 or 372_815del443ins54 to mark ARMS2 risk. Progression risk was determined using the Cox proportional hazard model. Genetics–treatment interaction on NV risk was assessed using a multiiterative bootstrap validation analysis. We identified strong interaction of genetics with AREDS formulation treatment on the development of NV. Individuals with high CFH and no ARMS2 risk alleles and taking the AREDS formulation had increased progression to NV compared with placebo. Those with low CFH risk and high ARMS2 risk had decreased progression risk. Analysis of CFH and ARMS2 genotype groups from a validation dataset reinforces this conclusion. Bootstrapping analysis confirms the presence of a genetics–treatment interaction and suggests that individual treatment response to the AREDS formulation is largely determined by genetics. The AREDS formulation modifies the risk of progression to NV based on individual genetics. Its use should be based on patient-specific genotype.

Novel grid combined with peripheral distortion correction for ultra-widefield image grading of age-related macular degeneration

Purpose

Eyes with age-related macular degeneration (AMD) often harbor pathological changes in the retinal periphery and perimacular region. These extramacular changes have not been well classified, but may be phenotypically and functionally relevant. The purpose of this study was to demonstrate a novel grid to systematically study peripheral retinal abnormalities in AMD using geometric distortion-corrected ultra-widefield (UWF) imaging.

Methods

This is a cross-sectional observational case series. Consecutive patients with AMD without any other coexisting vitreoretinal disease and control patients over age 50 without AMD or any other vitreoretinal disease were imaged using Optos 200 Tx. Captured 200° UWF images were corrected for peripheral geometric distortion using Optos transformation software. A newly developed grid to study perimacular and peripheral abnormalities in AMD was then projected onto the images.

Results

Peripheral and perimacular changes such as drusen, retinal pigment epithelium changes and atrophy were found in patients with AMD. The presented grid in conjunction with geometric distortion-corrected UWF images allowed for systematic study of these peripheral changes in AMD.

Conclusion

We present a novel grid to study peripheral and posterior pole changes in AMD. The grid is unique in that it adds a perimacular zone, which may be important in characterizing certain phenotypes in AMD. Our UWF images were corrected for geometric peripheral distortion to accurately reflect the anatomical dimensions of the retina. This grid offers a reliable and reproducible foundation for the exploration of peripheral retinal pathology associated with AMD.

Ultra-widefield fundus autofluorescence in age-related macular degeneration

Background

Establish accuracy and reproducibility of subjective grading in ultra-widefield fundus autofluorescence (FAF) imaging in patients with age-related macular degeneration (AMD), and determine if an association exists between peripheral FAF abnormalities and AMD.

Methods

This was a prospective, single-blinded case-control study. Patients were consecutively recruited for the study. Patients were excluded if there was a history of prior or active ocular pathology other than AMD or image quality was insufficient for analysis as determined by two independent graders. Control patients were those without any evidence of AMD or other ophthalmic disease apart from cataract. Using the Optos 200Tx (Optos, Marlborough, MA, USA), a ResMax central macula and an ultra-widefield peripheral retina image was taken for each eye in both normal color and short wavelength FAF. Ultra-widefield photographs were modified to mask the macula. Each ResMax and ultra-widefield image was independently graded by two blinded investigators.

Results

There were 28 AMD patients and 11 controls. There was a significant difference in the average age between AMD patients and control groups (80 versus 64, respectively P<0.001). There was moderate, statistically significant agreement between observers regarding image interpretation (78.4%, K = 0.524, P<0.001), and 69.0% (K = 0.49, P<0.001) agreement between graders for FAF abnormality patterns. Patients with AMD were at greater risk for peripheral FAF abnormalities (OR: 3.43, P = 0.019) and patients with FAF abnormalities on central macular ResMax images were at greater risk of peripheral FAF findings (OR: 5.19, P = 0.017).

Conclusion

Subjective interpretation of FAF images has moderate reproducibility and validity in assessment of peripheral FAF abnormalities. Peripheral FAF abnormalities are seen in both AMD and control patients. Those with AMD, poor visual acuity, and macular FAF abnormalities are at greater risk.

Quantifying Retinal Area in Ultra-Widefield Imaging Using a 3-Dimensional Printed Eye Model

PURPOSE

To study the effects of different axial lengths on ultra-widefield imaging to determine the presence of distortion in images despite software correction and calculate an enlargement factor based on angular location.

DESIGN

Experimental image analysis study.

STUDY OBJECTS

Three 3-dimensional printed model eyes simulating eyes with axial lengths of 22, 24, and 26 mm. Each model has a grid of rings 9° apart centered at the posterior pole.

METHODS

Single-center study performed at the National Institute for Health Research Moorfields Biomedical Research Centre (London, UK). Each model was imaged using Optos 200TX (Optos, Dunfermline, UK). Two images for each model eye that were corrected using V2 Vantage Pro software (Optos) were used for analysis and the average values obtained. Each image inter-ring area was measured using ImageJ to obtain a measured image area in pixel and square millimeters. This was compared with the true calculated object inter-ring area and an enlargement factor was determined.

MAIN OUTCOME MEASURES

Measured image inter-ring area in pixels and square millimeters. True calculated object inter-ring area in square millimeters.

RESULTS

The enlargement factor of the rings gradually increases toward the periphery with factors of 1.4 at 45° and 1.9 at the equator. The axial lengths did not affect the enlargement factor of the rings imaged in 3 different model eyes (P = 0.9512). The anterior equator exhibits a significant distortion despite the software correction.

CONCLUSION

The enlargement factor depends on angular location and not axial length. The enlargement factors can be used in clinical practice to more accurately measure area in ultra-widefield imaging.

Visual and Ocular Manifestations of Alzheimer's Disease and Their Use as Biomarkers for Diagnosis and Progression

Alzheimer's disease (AD) is the most common form of dementia affecting the growing aging population today, with prevalence expected to rise over the next 35 years. Clinically, patients exhibit a progressive decline in cognition, memory, and social functioning due to deposition of amyloid β (Aβ) protein and intracellular hyperphosphorylated tau protein. These pathological hallmarks of AD are measured either through neuroimaging, cerebrospinal fluid analysis, or diagnosed post-mortem. Importantly, neuropathological progression occurs in the eye as well as the brain, and multiple visual changes have been noted in both human and animal models of AD. The eye offers itself as a transparent medium to cerebral pathology and has thus potentiated the development of ocular biomarkers for AD. The use of non-invasive screening, such as retinal imaging and visual testing, may enable earlier diagnosis in the clinical setting, minimizing invasive and expensive investigations. It also potentially improves disease management and quality of life for AD patients, as an earlier diagnosis allows initiation of medication and treatment. In this review, we explore the evidence surrounding ocular changes in AD and consider the biomarkers currently in development for early diagnosis.

Comparison of intravitreal aflibercept and ranibizumab injections on subfoveal and peripapillary choroidal thickness in eyes with neovascular age-related macular degeneration

PURPOSE

We aimed to compare changes in subfoveal and peripapillary choroidal thickness (CT) after intravitreal aflibercept or ranibizumab injections for neovascular age-related macular degeneration (AMD).

METHODS

Medical records of 54 treatment-naïve, consecutive patients (54 eyes) who were diagnosed with neovascular AMD and received three monthly injections of aflibercept (21 eyes) or ranibizumab (33 eyes) were reviewed. Subfoveal and peripapillary CT were measured with images obtained using spectral domain optical coherence tomography at baseline and at three months.

RESULTS

Subfoveal CT decreased from 232.2 ± 94.4 μm at baseline to 207.1 ± 89.3 μm at three months in the aflibercept group (p < 0.001) and from 231.5 ± 102.9 μm to 220.0 ± 98.0 μm in the ranibizumab group (p = 0.006). The reduction was greater in the aflibercept group than in the ranibizumab group (p = 0.024). Peripapillary CT decreased from 157.2 ± 62.2 μm at baseline to 147.4 ± 62.2 μm at three months in the aflibercept group (p < 0.001). However, the change in peripapillary CT from 154.9 ± 46.5 μm at baseline to 152.3 ± 50.0 μm at three months was not significant in the ranibizumab group (p = 0.123).

CONCLUSIONS

Intravitreally injected aflibercept significantly decreased subfoveal CT more than ranibizumab. Choroidal thinning after aflibercept injection was not limited to the subfoveal area, but extended beyond the macula as well.

Validation of Concentric Rings Method as a Topographic Measure of Retinal Nonperfusion in Ultra-Widefield Fluorescein Angiography

PURPOSE

To validate the use of concentric rings as a method to measure topographic area of retinal nonperfusion in ultra-widefield angiography with the ischemic index method, which is the most frequently used method to measure nonperfusion in ultra-widefield angiography.

DESIGN

Validation study and reliability analysis.

METHODS

setting: Single-center study performed at National Institute for Health Research Moorfields Biomedical Research Centre, London, United Kingdom.

STUDY POPULATION

Twenty-eight ultra-widefield angiogram images of eyes with central retinal vein occlusion.

OBSERVATION PROCEDURE

The concentric rings method consists of 6 macula-centered concentric rings divided into 12 segments each. Each image was graded by 5 graders using both the concentric rings and the ischemic index methods.

MAIN OUTCOME MEASURES

Agreement between the 2 methods was calculated using the intraclass correlation coefficient. Intertest agreement, intergrader agreement, test-retest reliability, and the time taken to grade using these 2 methods were compared.

RESULTS

The intertest agreement between concentric rings method and ischemic index method was 0.965. The intergrader agreement was 0.910 for the concentric rings method and 0.898 with the ischemic index method. The test-retest reliability was 0.975 for the rings and 0.979 for the ischemic index. Average grading time per image was 187 s and 297 s for the concentric rings method and ischemic index method, respectively, P < .001.

CONCLUSION

The concentric rings method has an "almost-perfect" intergrader agreement and intertest agreement with the ischemic index method, with a shorter grading time.