Quantitative contrast sensitivity test to assess visual function in central serous chorioretinopathy

BACKGROUND

To characterise the contrast sensitivity function (CSF) in central serous chorioretinopathy (CSCR) compared with healthy controls using novel computerised contrast sensitivity (CS) testing with active learning algorithms.

METHODS

Prospective observational study measuring CSF in CSCR eyes and controls using the Manifold Platform (Adaptive Sensory Technology, San Diego, California). Mixed effects multivariate regression models were used. Outcomes included area under the log CSF (AULCSF), CS thresholds at 1, 1.5, 3, 12 and 18 cycles per degree (cpd) and best-corrected visual acuity (BCVA). Associations of contrast outcomes with structural findings on optical coherence tomography (OCT) and subjective symptomatology were investigated.

RESULTS

Forty CSCR eyes and 89 controls were included with median BCVA logarithm of median angle of resolution 0.10 (20/25) versus 0.00 (20/20), respectively (p=0.01). When accounting for age, CSCR was associated with significantly reduced median AULCSF (p=0.02, β=-0.14) and reduced CS thresholds at 6 cpd (p=0.009, β=-0.18), 12 cpd (p<0.001, β=-0.23) and 18 cpd (p=0.04, β=-0.09), versus controls. Within the CSCR group, subjectively perceived visual impairment (N=22) was associated with significantly decreased CS thresholds at all spatial frequencies and in AULCSF compared with asymptomatic CSCR eyes (N=18). Ellipsoid zone attenuation and subfoveal fluid on OCT were associated with decreased AULCSF and CS thresholds specifically at 3, 6 and 12 cpd, whereas presence of extrafoveal fluid at 1.5 and 3 cpd.

CONCLUSION

Contrast sensitivity is significantly reduced in CSCR, and strongly correlates with subjective visual impairment. Different structural biomarkers correlate with contrast thresholds reductions at different spatial frequencies.

Peripapillary Choroidal Vascularity and Visual Correlates in Non-Arteritic Anterior Ischemic Optic Neuropathy Using Swept-Source Optical Coherence Tomography

Introduction

The peripapillary choroid shares a blood supply with and is directly apposed to the optic nerve, and therefore may contribute to the pathogenesis of non-arteritic anterior ischemic optic neuropathy (NAION). Prior studies evaluating peripapillary choroidal thickness (PCT) or choroidal vascularity index (CVI; the ratio of the perfused area to total choroid area) have produced mixed results. None investigated the relationship between PCT and CVI or demonstrated functional correlates. We hypothesized that greater PCT and lower CVI would correlate with visual function in patients presenting with NAION.

Methods

Seventeen eyes with NAION (9 acute, 8 non-acute) and 6 unaffected "fellow" eyes in 13 patients, and 18 eyes in 18 age-matched control subjects were imaged using swept-source optical coherence tomography (SS-OCT) prospectively between 2017-2018. Mean PCT and CVI measurements were compared across groups and with respect to corresponding automated perimetric performance at the same visit.

Results

Analysis of variance showed significantly greater PCT (NAION: 278 ± 65 μm, Fellow: 221 ± 50 μm, Control: 158 ± 27 μm, p<0.001) and lower CVI (NAION: 0.35 ± 0.03, Fellow: 0.35 ± 0.04, Control: 0.38 ± 0.02, p<0.005) in patients with NAION compared to control subjects. Bonferroni-corrected pairwise comparisons showed greater PCT and lower CVI in NAION-affected eyes compared to control eyes (p values<0.008), and no significant differences in PCT or CVI between NAION and fellow eyes (p values>0.06). PCT was negatively correlated with CVI among unaffected fellow eyes (r=-0.8, p<0.05), but not among acute NAION eyes (r=-0.1, p>0.7), non-acute NAION eyes (r=0.1, p>0.7), or controls (r=-0.3, p>0.2). Nasal CVI was positively correlated with mean deviation scores in non-acute NAION (r=0.8, p<0.02), but not among fellow unaffected eyes (r=0.8, p>0.05) or acutely affected NAION eyes (r=-0.3, p>0.4). Mean and temporal PCT correlated with pattern standard deviation scores among unaffected fellow eyes (r=0.8, p<0.04; r=0.9, p<0.03), but not among acute NAION eyes (r=-0.2, p>0.5; r=-0.1, p>0.7) or non-acute NAION eyes (r=0.1, p>0.7; r=0.05, p>0.9).

Conclusion

NAION and unaffected fellow eyes demonstrate increased choroidal thicknesses and reduced vascular density. Perimetric performance is directly associated with vascular density among non-acutely affected eyes with NAION. Ongoing work will provide further insights into these structure-function relationships with pathogenic and pathophysiologic relevance.

The Value of Musculoskeletal Ultrasound for Evaluation of Postinfectious Lyme Arthritis

BACKGROUND

Inflammatory arthritis is the most common late manifestation of untreated Lyme disease in the United States. While antimicrobial therapy is effective in resolving swelling and pain for 90% of patients, many patients have persistent inflammation, termed postinfectious Lyme arthritis (PILA). Current outcome measures for Lyme arthritis have several limitations, as improvement is considered a dichotomous outcome based solely on physical examination. There is growing interest in the use of ultrasonography to better define outcomes in inflammatory arthritis, and this is particularly relevant for conditions such as late Lyme arthritis and PILA, which are monoarticular or oligoarticular. We describe results from a series of 5 patients who underwent ultrasound evaluations leading to a diagnosis of PILA.

METHODS

This is a case series describing 5 patients with PILA who were referred for evaluation and treatment of symptomatic joints.

RESULTS

Musculoskeletal ultrasound showed significant joint pathology, even in cases with minimal clinical findings. Synovitis, effusions, enthesitis/tendinopathy, and bone erosions were seen and helped confirm the presence of ongoing inflammatory arthritis.

CONCLUSIONS

Marked inflammatory change-with synovitis, enthesitis and erosions-can be seen in selected patients with PILA. Systematic sonographic evaluation of patients with PILA is needed to further evaluate pathology and treatment response.

Remote Imaging Capture with Widefield Swept-Source OCT Angiography During the COVID-19 Pandemic

Purpose

The COVID-19 pandemic has had a widespread impact on the health sector worldwide, both in the clinical and research subsector. This has necessitated for the invention of protocols compliant with social distancing policies to efficiently tackle the current needs. Our aim is to describe a novel remote imaging technique, which helped us continue our research with widefield swept-source optical coherence tomography angiography (WF SS-OCTA).

Patients and Methods

As a part of this cross-sectional observational study from August 2020 to September 2020 at Massachusetts Eye and Ear (MEE), we used our institute approved remote desktop, outside of MEE, to gain full access to the on-site WF SS-OCTA device in the imaging room for the purpose of remote imaging. With only the patient being in the imaging room, effective communication was established via video conferencing on an encrypted tablet computer device for the entire procedure.

Results

We imaged four patients with various retinal pathologies, aged 32–69 years. All images obtained were of high quality and signal strength (median score 9/10 for both) and all patients reported a highly satisfactory, comfortable, and safe experience amidst the COVID-19 pandemic.

Conclusion

This novel method is better for remote imaging compared to the previously described techniques as it is time and cost effective, requires limited resources without compromising the image quality or patient satisfaction and adheres to the various guidelines for infection control, most importantly social distancing. As a paradigm shift, this can also be employed in future for setups with limited staff like busy emergency departments or a rural setup with limited access or difficult commute, in the “new-normal” era.

Quantifying Retinal Microvascular Morphology in Schizophrenia Using Swept-Source Optical Coherence Tomography Angiography

BACKGROUND

Retinovascular changes are reported on fundus imaging in schizophrenia (SZ). This is the first study to use swept-source optical coherence tomography angiography (OCT-A) to comprehensively examine retinal microvascular changes in SZ.

METHODS

This study included 30 patients with SZ/schizoaffective disorder (8 early and 15 chronic) and 22 healthy controls (HCs). All assessments were performed at Beth Israel Deaconess Medical Center and Massachusetts Eye and Ear. All participants underwent swept-source OCT-A of right (oculus dextrus [OD]) and left (oculus sinister [OS]) eye, clinical, and cognitive assessments. Macular OCT-A images (6 × 6 mm) were collected with the DRI Topcon Triton for superficial, deep, and choriocapillaris vascular regions. Microvasculature was quantified using vessel density (VD), skeletonized vessel density (SVD), fractal dimension (FD), and vessel diameter index (VDI).

RESULTS

Twenty-one HCs and 26 SZ subjects were included. Compared to HCs, SZ patients demonstrated higher overall OD superficial SVD, OD choriocapillaris VD, and OD choriocapillaris SVD, which were primarily observed in the central, central and outer superior, and central and outer inferior/superior, respectively. Early-course SZ subjects had significantly higher OD superficial VD, OD choriocapillaris SVD, and OD choriocapillaris FD compared to matched HCs. Higher bilateral (OU) superficial VD correlated with lower Positive and Negative Syndrome Scale (PANSS) positive scores, and higher OU deep VDI was associated with higher PANSS negative scores.

CONCLUSIONS AND RELEVANCE

These results suggest the presence of microvascular dysfunction associated with early-stage SZ. Clinical associations with microvascular alterations further implicate this hypothesis, with higher measures being associated with worse symptom severity and functioning in early stages and with lower symptom severity and better functioning in later stages.

Dual Task Performance Is Associated with Amyloidosis in Cognitively Healthy Adults

BACKGROUND

Preclinical Alzheimer's disease (AD) provides an opportunity for the study and implementation of interventions and strategies aimed at delaying, mitigating, and preventing AD. While this preclinical state is an ideal target, it is difficult to identify efficiently and cost-effectively. Recent findings have suggested that cognitive-motor dual task paradigms may provide additional inference.

OBJECTIVES

Investigate the relationship between dual task performance and amyloidosis, suggestive of preclinical Alzheimer's disease and whether dual task performance provides additional information beyond a cognitive composite, to help in the identification of amyloidosis.

DESIGN

Cross-sectional.

SETTING

Outpatient specialty brain health clinical research institution in the United States.

PARTICIPANTS

52 cognitively healthy adults.

MEASUREMENTS

The data included demographics, amyloid standardized uptake value ratio obtained via florbetapir-PET, neuropsychological testing, apolipoprotien E genotype, and dual task performance measures. Data were analyzed via hierarchal multiple linear regression or logistic regression, controlling for age, education, and apolipoprotien E genotype. Receiver operating characteristic curves were plotted, and sensitivity and specificity calculated via 2x2 contingency tables.

RESULTS

There was a moderate relationship (rs>.30) between motor and cognitive dual task effects and amyloid standardized uptake value ratio (ps<.042). A strong relationship (r=.58) was found between combined dual task effect, a measure of automaticity derived from dual task performance, and amyloid standardized uptake value ratio (p<.001). Additionally, combined dual task effect showed promise in its unique contributions to amyloid standardized uptake value ratio, accounting for 7.8% of amyloid standardized uptake value ratio variance beyond cognitive composite scores (p=.018). Additionally, when incorporated into the cognitive composite, combined dual task effect resulted in improved diagnostic accuracy for determining elevated amyloid standardized uptake value ratio, and increased the sensitivity and specificity of the cognitive composite.

CONCLUSSION

Dual task performance using the combined dual task effect, a measure of automaticity, was a moderate predictor of cerebral amyloidosis, which suggests that it has utility in the screening and diagnosis of individuals for preclinical AD. Additionally, when combined with the cognitive composite, the combined dual task effect improves diagnostic accuracy. Further research is warranted.

Three-dimensional telesurgery and remote proctoring over a 5G network

Purpose

To present 2 cases of vitreoretinal surgery performed on a three-dimensional (3D) heads-up display surgical platform with real-time transfer of 3D video over a fifth-generation (5G) cellular network.

Methods

An epiretinal membrane peel and tractional retinal detachment repair performed at Massachusetts Eye and Ear in April 2019 were broadcast live to the Verizon 5G Lab in Cambridge, MA.

Results

Both surgeries were successful. The heads-up digital surgery platform, combined with a 5G network, allowed telesurgical transfer of high-quality 3D vitreoretinal surgery with minimal degradation. Average end-to-end latency was 250 ms, and average round-trip latency was 16 ms. Fine surgical details were observed remotely by a proctoring surgeon and trainee, with real-time communication via mobile phone.

Conclusions

This pilot study represents the first successful demonstration of vitreoretinal surgery transmitted over a 5G network. Telesurgery has the potential to enhance surgical education, provide intraoperative consultation and guidance from expert proctors, and improve patient outcomes, especially in remote and low-resource areas.

Stages of Lyme Arthritis

BACKGROUND/HISTORICAL PERSPECTIVE

Lyme arthritis was described in 1977, after an apparent outbreak of juvenile idiopathic arthritis in Lyme, Connecticut. The evolution of the disease has been meticulously described with presentation dependent on disease duration and previous therapy.

SUMMARY INTEGRATING PUBLISHED LITERATURE

Erythema migrans is typically the first manifestation. Untreated patients often develop early disseminated disease, characterized by migratory polyarthralgia, potentially with cardiac and/or neurologic sequelae. If untreated, most patients develop late Lyme arthritis, characterized as a monoarthritis or oligoarthritis, typically involving the knees. Serologies are strongly positive at this stage; if positive, Lyme PCR from synovial fluid confirms the diagnosis. Doxycycline is recommended for late Lyme arthritis, although amoxicillin or ceftriaxone may be considered.Initial antibiotic therapy for late Lyme arthritis is insufficient for a subset of patients. However, serologies and synovial fluid PCR are not useful at determining whether infection persists after oral therapy. As such, ceftriaxone is recommended in patients with inadequate response to doxycycline or amoxicillin.Approximately 10% of patients have persistent arthritis despite antimicrobial therapy, termed postinfectious Lyme arthritis, which is thought to be related to prolonged inflammation and unique microbial and host interaction. Therapy at this stage relies on immunosuppression and/or synovectomy.

MAJOR CONCLUSIONS AND FUTURE RESEARCH

Lyme arthritis provides unique insights into the complex interplay between microbes and host immunity. The progression from localized erythema migrans to early disseminated disease and late Lyme arthritis allows insight into arthritis initiation, and the study of postinfectious Lyme arthritis allows further insight into mechanisms of arthritis persistence.

Association of Patient Characteristics With Delivery of Ophthalmic Telemedicine During the COVID-19 Pandemic

Importance

Telemedicine has been shown to have had reduced uptake among historically marginalized populations within multiple medical specialties during the COVID-19 pandemic. An evaluation of health disparities among patients receiving ophthalmic telemedical care during the pandemic is needed.

Objective

To evaluate disparities in the delivery of ophthalmic telemedicine at Massachusetts Eye and Ear (MEE) during the COVID-19 pandemic.

Design, Setting, and Participants

This retrospective, cross-sectional study analyzed clinical visits at a single tertiary eye care center (MEE) from January 1 to December 31, 2020. Patients who had ophthalmology and optometry clinical visits at the MEE during the study period were included.

Exposures

Telemedicine vs in-person clinical encounters.

Main Outcomes and Measures

Variables associated with use of ophthalmic telemedicine during the study period.

Results

A total of 2262 telemedicine ophthalmic encounters for 1911 patients were included in the analysis. The median age of the patients was 61 (interquartile range, 43-72) years, and 1179 (61.70%) were women. With regard to race and ethnicity, 87 patients (4.55%) identified as Asian; 128 (6.70%), as Black or African American; 23 (1.20%), as Hispanic or Latino; and 1455 (76.14%), as White. On multivariate analysis, factors associated with decreased receipt of telemedical care included male sex (odds ratio [OR], 0.86; 95% CI, 0.77-0.96), Black race (OR, 0.69; 95% CI, 0.56-0.86), not speaking English (OR, 0.63; 95% CI, 0.48-0.81), educational level of high school or less (OR, 0.83; 95% CI, 0.71-0.97), and age (OR per year of age, 0.99; 95% CI, 0.989-0.998). When comparing telephone- and video-based telemedicine visits, decreased participation in video-based visits was associated with age (OR per year of age, 0.96; 95% CI, 0.94-0.98), educational level of high school or less (OR, 0.54; 95% CI, 0.29-0.99), being unemployed (OR, 0.28; 95% CI, 0.12-0.68), being retired (OR, 0.22; 95% CI, 0.10-0.42), or having a disability (OR, 0.09; 95% CI, 0.04-0.23).

Conclusions and Relevance

The findings of this cross-sectional study, though limited to retrospective data from a single university-based practice, suggest that historically marginalized populations were less likely to receive ophthalmic telemedical care compared with in-person care during the first year of the COVID-19 pandemic in the US. Understanding the causes of these disparities might help those who need access to virtual care.

Retrospective Analysis of Retinal Imaging in COVID-19 Positive Patients at a Tertiary Eye Care Center

PURPOSE

Since the start of the COVID-19 pandemic, numerous authors have published data demonstrating retinal changes found in patients with COVID-19. However, others have debated the significance of these findings and the effects of COVID-19 on the retina remain uncertain. This study aims to better understand retinal findings in patients with COVID-19.

PATIENTS AND METHODS

A retrospective review of patients with a history of a positive COVID-19 polymerase chain reaction test was performed between March 1st, 2020 and October 31st, 2020. Patients were included if they presented within 90 days of their first positive COVID-19 test and underwent color fundus photography and/or OCT of the macula. All images were reviewed by two independent graders who assessed the presence of retinal heme, cotton wool spots, vascular sheathing, and disc edema, as well as hyper-reflective changes, intra-retinal fluid, and sub-retinal fluid on OCT.

RESULTS

A total of 119 eyes from 61 patients were included. Among 83 eyes which underwent OCT of the macula, inner retinal hyper-reflective changes were seen in 16.9% (n=14), outer retinal hyper-reflective changes in 18.1% (n=15), intra-retinal fluid in 28.9% (n=24), and sub-retinal fluid in 14.5% (n=12). Among 48 eyes which underwent color fundus photography, retinal hemorrhage was seen in 27.1% (n=13), optic disc edema in 2.1% (n=1), and cotton wool spots in none of the eyes. Sub-analysis of 70 eyes from 41 patients with no alternative retinal pathology to potentially explain the above findings revealed none of the above exam findings on OCT of the macula (n=35), fundus photography (n=28), or documented exam (n=66).

CONCLUSION

While a number of patients seen after COVID-19 infection demonstrated retinal findings, all could be explained by pre-existing retinal conditions. In a sub-group of eyes without pre-existing retinal disease, we did not identify any retinal findings that could be associated with COVID-19.

Temporal Trends in the Treatment of Proliferative Diabetic Retinopathy

Purpose

Design

Participants

Methods

Main Outcome Measures

Results

Conclusions

Widefield Swept-Source OCTA in Vogt-Koyanagi-Harada Disease

Herein, the authors describe an initial case report of widefield swept-source optical coherence tomography angiography (SS-OCTA) in Vogt-Koyanagi-Harada (VKH) disease. When compared to fluorescent angiography, indocyanine green angiography, and enhanced-depth OCT - upon which the revised criteria for VHK are based - widefield SS-OCTA enables detection of vitreous inflammation, noninvasive identification of characteristic areas of flow void at the level of choriocapillaris in the acute phase and may be a novel valuable tool not only for noninvasive diagnosis and monitoring of disease progression, persistence, resolution, and recurrence to guide therapy in VKH disease in the future. [Ophthalmic Surg Lasers Imaging Retina. 2020;51:407-412.].

Measuring Contrast Sensitivity Function With Active Learning in Retinal Vein Occlusion: A New Endpoint of Visual Function

BACKGROUND AND OBJECTIVE

To characterize contrast sensitivity function (CSF) in patients with retinal vein occlusion (RVO) compared to age-matched controls using novel computerized contrast sensitivity (CS) testing with active learning algorithms.

PATIENTS AND METHODS

CSF was prospectively measured in RVO patients with visual acuity (VA) greater than 20/200 and age-matched controls using the novel Manifold Contrast Vision Meter implementing quantitative CSF testing. Outcomes included area under the Log CSF (AULCSF), contrast acuity (CA), and CS thresholds at 1, 1.5, 3, 12, and 18 cycles per degree (cpd). A sub-analysis was performed on RVO eyes with good acuity (VA ≥ 20/30).

RESULTS

Twenty-two eyes with RVO and 63 control eyes were included. Mean AULCSF (± standard deviation) in RVO eyes was 0.817 (0.28) compared to 1.217 (0.28) in controls (P < .0001). Mean contrast acuity in the RVO group was 1.054 (0.19) versus 1.286 ± 0.16 in controls (P < .0001). For individual spatial frequencies, CS loss at 6.0 cpd was most prominent in the RVO group. In 10 RVO eyes with VA of 20/30 or greater, mean AULCSF was 0.978 versus 1.217 in control eyes. (P = .008).

CONCLUSIONS

CSF in eyes with RVO was found to be significantly reduced compared to age-matched controls. CSF seems to be a promising visual function endpoint with potential applications in clinical practice and future clinical trials. [Ophthalmic Surg Lasers Imaging Retina. 2020;51:392-400.].

Active Learning of Contrast Sensitivity to Assess Visual Function in Macula-off Retinal Detachment

PURPOSE

To characterize the contrast sensitivity function (CSF) in patients with successful repair of macula-off rhegmatogenous retinal detachment (RD) using an adaptive computerized contrast testing device.

METHODS

CSF was prospectively measured in macula-off RD patients following successful repair and age-matched controls at W. K. Kellogg Eye Center and Massachusetts Eye and Ear, employing the active learning device Manifold Contrast Vision Meter (Adaptive Sensory Technology, San Diego, CA). Outcome measures included average area under the CSF curve (AULCSF), CS thresholds at 1-18 cycles per degree (cpd) and best correctd visual acuity (BCVA) in RD eyes fellow eyes and controls. A sub-analysis was performed in eyes with BCVA of 20/30 or better.

RESULTS

Twenty-three macula-off RD eyes status post repair, fellow healthy eyes and 45 age-matched control eyes underwent CSF testing. The mean BCVA of the 23 RD eyes was 0.250 logMAR, significantly reduced compared to fellow eyes 0.032 (p<0.001) and controls 0.026 (p< 0.00001). There was a statistically significant reduction in AULCSF in RD eyes compared to the fellow eyes (p<0.0001) and to age-matched controls (Z-score -0.90, p<0.0001) and CSF reduction across all spatial frequencies. In the 15 RD eyes with BCVA of 20/30 or better, the mean CSF was significantly reduced compared to fellow eyes (p=0.0158) and controls (p=0.0453).

CONCLUSIONS

CSF in macula-off RD eyes following repair was significantly reduced compared to fellow eyes and age-matched controls. CSF seems to be a promising visual function endpoint with potential applications in the clinical practice and future clinical trials.

Measuring the Contrast Sensitivity Function in Non-Neovascular and Neovascular Age-Related Macular Degeneration: The Quantitative Contrast Sensitivity Function Test

Age-related macular degeneration (AMD) affects various aspects of visual function compromising patients' functional vision and quality of life. Compared to visual acuity, contrast sensitivity correlates better with vision-related quality of life and subjectively perceived visual impairment. It may also be affected earlier in the course of AMD than visual acuity. However, lengthy testing times, coarse sampling and resolution, and poor test-retest reliability of the existing contrast testing methods have limited its widespread adoption into routine clinical practice. Using active learning principles, the qCSF can efficiently measure contrast sensitivity across multiple spatial frequencies with both high sensitivity in detecting subtle changes in visual function and robust test-retest reliability, emerging as a promising visual function endpoint in AMD both in clinical practice and future clinical trials.

Quantitative autofluorescence: Review of Current Technical Aspects and Applications in Chorioretinal Disease

Purpose: In this review we discuss the broad clinical application of qAF and provide a descriptive summary of the phenotypic findings of different chorioretinal pathologies.Background: Quantitative Fundus autofluorescence (qAF) is a novel developing technology that can aid in diagnosis and longitudinal disease monitoring by measuring and comparing autofluorescence intensities. Fundus autofluorescence (FAF) is a noninvasive imaging method that creates a density map of the fluorophores of the ocular fundus and provides both functional and topographic anatomic information about retinal cells. Fluorophores are molecules that have the ability to temporarily absorb irradiated light, and emit a small amount of light of a different wavelength. Different endogenous fluorophores can be found in the ocular fundus. Changes in accumulation of retinal fluorophores usually indicate retinal pathology and create characteristic patterns of hyper-autofluorescence and hypo-autofluorescence that help establish a diagnosis.Conclusion: qAF allows a safe non-invasive visualization of the retina, enables a standard for AF intensities comparison and aids to the understanding of the genotype-phenotype correlations.

Association of Human Plasma Metabolomics with Delayed Dark Adaptation in Age-Related Macular Degeneration

The purpose of this study was to analyze the association between plasma metabolite levels and dark adaptation (DA) in age-related macular degeneration (AMD). This was a cross-sectional study including patients with AMD (early, intermediate, and late) and control subjects older than 50 years without any vitreoretinal disease. Fasting blood samples were collected and used for metabolomic profiling with ultra-performance liquid chromatography-mass spectrometry (LC-MS). Patients were also tested with the AdaptDx (MacuLogix, Middletown, PA, USA) DA extended protocol (20 min). Two measures of dark adaptation were calculated and used: rod-intercept time (RIT) and area under the dark adaptation curve (AUDAC). Associations between dark adaption and metabolite levels were tested using multilevel mixed-effects linear modelling, adjusting for age, gender, body mass index (BMI), smoking, race, AMD stage, and Age-Related Eye Disease Study (AREDS) formulation supplementation. We included a total of 71 subjects: 53 with AMD (13 early AMD, 31 intermediate AMD, and 9 late AMD) and 18 controls. Our results revealed that fatty acid-related lipids and amino acids related to glutamate and leucine, isoleucine and valine metabolism were associated with RIT (p < 0.01). Similar results were found when AUDAC was used as the outcome. Fatty acid-related lipids and amino acids are associated with DA, thus suggesting that oxidative stress and mitochondrial dysfunction likely play a role in AMD and visual impairment in this condition.

Artificial Intelligence (AI) and Retinal Optical Coherence Tomography (OCT)

Ophthalmology has been at the forefront of medical specialties adopting artificial intelligence. This is primarily due to the "image-centric" nature of the field. Thanks to the abundance of patients' OCT scans, analysis of OCT imaging has greatly benefited from artificial intelligence to expand patient screening and facilitate clinical decision-making.In this review, we define the concepts of artificial intelligence, machine learning, and deep learning and how different artificial intelligence algorithms have been applied in OCT image analysis for disease screening, diagnosis, management, and prognosis.Finally, we address some of the challenges and limitations that might affect the incorporation of artificial intelligence in ophthalmology. These limitations mainly revolve around the quality and accuracy of datasets used in the algorithms and their generalizability, false negatives, and the cultural challenges around the adoption of the technology.

Wide Field Swept Source Optical Coherence Tomography Angiography for the Evaluation of Proliferative Diabetic Retinopathy and Associated Lesions: A Review

Retinal imaging remains the mainstay for monitoring and grading diabetic retinopathy. The gold standard for detecting proliferative diabetic retinopathy (PDR) requiring treatment has long been the seven-field stereoscopic fundus photography and fluorescein angiography. In the past decade, ultra-wide field fluorescein angiography (UWF-FA) has become more commonly used in clinical practice for the evaluation of more advanced diabetic retinopathy. Since its invention, optical coherence tomography (OCT) has been an important tool for the assessment of diabetic macular edema; however, OCT offered little in the assessment of neovascular changes associated with PDR until OCT-A became available. More recently, swept source OCT allowed larger field of view scans to assess a variety of DR lesions with wide field swept source optical coherence tomography (WF-SS-OCTA). This paper reviews the role of WF-SS-OCTA in detecting neovascularization of the disc (NVD), and elsewhere (NVE), microaneurysms, changes of the foveal avascular zone (FAZ), intraretinal microvascular abnormalities (IRMA), and capillary non-perfusion, as well as limitations of this evolving technology.