En Face Depth Resolved OCTA Monitoring of Macular Outer Retinal Deposits in a Case of Multifocal Choroiditis Mimicking Syphilitic Uveitis.

PURPOSE: Multifocal choroiditis (MFC) is a rare inflammatory condition characterized by retinal and choroidal lesions that may present similarly to ocular pathology of various etiologies. Here we present a case of MFC mimicking syphilitic uveitis with unique en face optical coherence tomography angiography (OCTA) imaging characteristics. METHODS: Case report. RESULTS: A 61-year-old woman presented with blurry vision, floaters and multiple whitish subretinal deposits on en face swept-source OCTA in the left eye. Fluorescent treponemal antibody test absorption was positive which led to the initial diagnosis of syphilitic uveitis and subsequent treatment with intravenous penicillin. During follow-up, OCTA of the left eye revealed the development of new choroidal neovascular membrane and new punched-out lesions in the posterior pole. The patient was eventually diagnosed with MFC and treated with aflibercept injections. CONCLUSIONS: Immune-mediated uveitis can simulate infectious and neoplastic uveitis. En face OCTA is unique imaging modality that allowed for the complete characterization and monitoring of the sub-macular deposits. This expands the clinical spectrum of multifocal choroiditis.

Widefield, Swept-Source Optical Coherence Tomography Angiography Metrics as Predictors of Anti-VEGF Treatment in Retinal Vein Occlusions.

BACKGROUND AND OBJECTIVE: Our objective was to assess baseline widefield swept-source optical coherence tomography angiography (WF SSOCTA) microvascular metrics as predictors for the number of anti-vascular endothelial growth factor (VEGF) injections and visual acuity (VA) at 12-months follow-up in patients with retinal vein occlusion (RVO). PATIENTS AND METHODS: This was a prospective study including 49 RVO eyes from 49 patients who had not received an anti-VEGF injection for at least 3 months prior to imaging. Microvascular metrics from 6×6-mm and 12×12-mm angiograms were assessed using linear regression models, adjusting for age. RESULTS: Reductions in the vessel density (VD) and vessel skeletonized density (VSD) vascular metrics were associated both with a higher number of anti-VEGF injections at all follow-up time points and reduced VA 12 months after imaging in all RVO eyes. CONCLUSIONS: WF SS-OCTA VD and VSD micro-vascular metrics at baseline can prognosticate VA and number of anti-VEGF injections required at 3, 6, and 12 months in RVO eyes. [Ophthalmic Surg Lasers Imaging Retina 2024;55:xx-xx.].

Assessment of Microvascular Changes After Rhegmatogenous Retinal Detachment Repair Using Wide-Field Swept-Source Optical Coherence Tomography Angiography.

BACKGROUND AND OBJECTIVE: Our objective was to evaluate retinal microvascular changes and visual outcomes following rhegmatogenous retinal detachment (RRD) repair using wide-field swept-source optical coherence tomography angiography (WF SS-OCTA). PATIENTS AND METHODS: The study included 116 eyes of 111 patients with macula-off (n = 68) or macula-on (n = 48) RRD treated with a single successful procedure, 79 fellow eyes, and 183 eyes of control patients imaged with WF SS-OCTA (3 ×3, 6 ×6, and 12 ×12 mm images). Mixed-effects multiple linear regression models were used for statistical analysis. RESULTS: Vessel density (VD) and vessel skeletonized density (VSD) of the superficial capillary plexus (3 ×3 mm scans) and full-thickness retina (12 ×12 mm) were significantly reduced in RRD eyes compared to fellow and control eyes. Decreased VSD and VD in all layers (3 ×3 mm and 6 ×6 mm) were significantly associated with greater preoperative extent of retinal detachment (P < 0.05) and poorer postoperative best-corrected visual acuity (BCVA) in RRD eyes (P < 0.05). Macula-off status was associated with increased foveal avascular zone irregularity (12 ×12 mm, P = 0.02). CONCLUSIONS: Decreased VD on WF SS-OCTA is associated with poorer postoperative BCVA following RRD repair. [Ophthalmic Surg Lasers Imaging Retina 2024;55:XX-XX.].

Quantitative Contrast Sensitivity Function and the Effect of Aging in Healthy Adult Eyes: A Normative Database.

BACKGROUND AND OBJECTIVE: We sought to establish normative quantitative contrast sensitivity function (qCSF) values in healthy adult eyes and investigate the effect of age on qCSF. PATIENTS AND METHODS: Healthy eyes underwent qCSF testing (adaptive sensory technology) and Snellen's visual acuity (VA). Descriptive statistics and mixed-effects multivariable linear regressions were evaluated. RESULTS: A total of 334 eyes (290 patients) with median age 61 years (range 21 to 88) had qCSF values as follows: area under the log contrast sensitivity function curve: 1.18; contrast acuity: 1.32; contrast sensitivity (CS) at 1 cycle per degree (cpd): 1.32; CS at 1.5 cpd: 1.37; CS at 3 cpd: 1.38; CS at 6 cpd: 1.20; CS at 12 cpd: 0.69; CS at 18 cpd: 0.22. Linear reductions in qCSF values per decade of age ranged from -0.02 to -0.07 vs 0.01 for visual acuity (VA). Age had a greater effect on the majority of qCSF values than VA (beta standardized regression coefficient ranged from -0.309 to -0.141 for qCSF values vs 0.177 for VA). CONCLUSIONS: We herein establish a normative database for qCSF and quantify the effect of age on qCSF values, adding evidence towards the validation of qCSF as a clinical endpoint. [Ophthalmic Surg Lasers Imaging Retina 2024;55:212-219.].

Semi-automated algorithm using directional filter for the precise quantification of non-perfusion area on widefield swept-source optical coherence tomography angiograms.

Background: The clinical application of optical coherence tomography angiography (OCTA) has been well documented in literature with its promising potential in dye-less evaluation of various retinal vascular pathologies. Recent advances in OCTA help us gather wider field of view with 12 mm × 12 mm and montage compared to the standard dye-based scans, which has a higher accuracy and sensitivity in detection of peripheral pathologies. The aim of this study is to build a semi-automated algorithm to precisely quantify the non-perfusion areas (NPAs) on widefield swept-source optical coherence tomography angiography (WF SS-OCTA). Methods: All subjects underwent imaging on 100 kHz SS-OCTA device acquiring 12 mm × 12 mm angiograms centered on fovea and optic disc. After a comprehensive literature review, a novel algorithm using FIJI (ImageJ) was designed to calculate the NPAs (mm2) after excluding the threshold and segmentation artifact areas from the total field of view. Segmentation and threshold artifacts were first removed from enface structure images using the spatial variance and mean filter respectively. Vessel enhancement was achieved by using 'Subtract Background' followed by directional filter. The cut off for Huang's fuzzy black and white thresholding was defined from the pixel values based of the foveal avascular zone. Then, the NPAs were calculated using the 'Analyze Particles' command with a minimum size of ~0.15 mm2. Finally, the artifact area was subtracted from to give the corrected NPAs. Results: Our cohort had 44 eyes of 30 control patients and 107 eyes of 73 patients with diabetes mellitus (both median age 55 years, P=0.89). Of 107 eyes, 21 eyes had no evidence of diabetic retinopathy (DR), 50 eyes had non-proliferative DR and 36 eyes had proliferative DR. The median NPA was 0.20 (0.07-0.40) in controls, 0.28 (0.12-0.72) in no DR, 5.54 (3.12-9.10) in non-proliferative DR and 13.38 (8.73-26.32) in proliferative DR eyes. Using mixed effects-multiple linear regression analysis adjusting for age, there was significant progressive increase in NPA with increasing DR severity. Conclusions: This is one of the first study to use the directional filter for WFSS-OCTA image processing which is known to be superior to other Hessian based multiscale, linear, and non-linear filters especially for vascular analysis. Our method could greatly refine and streamline the calculation of signal void area proportion, while being much quicker and accurate than manual delineation of NPAs and subsequent estimation. This combined with the wide field of view can have a great prognostic and diagnostic clinical impact for future applications in DR and other ischemic retinal pathologies.

Subthreshold Exudative Choroidal Neovascularization (CNV): Presentation of This Uncommon Subtype and Other CNVs in Age-Related Macular Degeneration (AMD).

Age-related macular degeneration (AMD) is a leading cause of irreversible vision loss in people over the age of 50 worldwide. Exudative or neovascular AMD is a more severe subset of AMD which is characterized by the presence of choroidal neovascularization (CNV). Recent advancements in multimodal ophthalmic imaging, including optical coherence tomography (OCT) and OCT-angiography (OCT-A), have facilitated the detection and characterization of previously undetectable neovascular lesions and have enabled a more refined classification of CNV in exudative as well as nonexudative AMD patients. Subthreshold exudative CNV is a novel subtype of exudative AMD that typically presents asymptomatically with good visual acuity and is characterized by stable persistent or intermittent subretinal fluid (SRF). This review aims to provide an overview of the clinical as well as multimodal imaging characteristics of CNV in AMD, including this new clinical phenotype, and propose effective approaches for management.

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.

The Impact of the COVID-19 Pandemic on Ophthalmic Care at an Eye-Specific Emergency Department in an Outbreak Hotspot.

PURPOSE: During the COVID-19 pandemic, there is growing concern that patients are forgoing necessary care. Emergency departments (ED) represent an important site of eye care. We analyzed patterns of ED visits at an eye-specific ED since the declaration of the public health crisis. MATERIALS AND METHODS: In this retrospective, cross-sectional single center study, medical records of 6744 patients who presented to the Massachusetts Eye and Ear ED between March 1st and April 30th in 2018, 2019, and 2020 were studied. The primary outcome measures were total volume of ED visits, proportion of urgent ED visits, and proportion of surgical visits. RESULTS: Overall, the median number of daily visits to the ED decreased by 18 visits per day since the declaration of public health guidelines (interquartile range, 9-24, p < 0.001). This accounted for a 32% decrease in the total volume of ED visits in 2020 compared to prior years during the study period (p < 0.001). There was a 9% increase in the proportion of primary diagnoses considered urgent (p = 0.002). The proportion of visits requiring urgent surgery increased by 39% (p = 0.004). CONCLUSION: The total number of eye-specific ED visits dropped compared to prior years while the proportion of urgent visits increased. Patients were likely more reluctant to seek eye care, deferring less urgent evaluation.

An update on autoimmune retinopathy.

Autoimmune retinopathy (AIR) refers to a group of rare autoimmune retinal degenerative diseases presumably caused by cross-reactivity of serum autoantibodies against retinal antigens. The pathogenesis of AIR remains largely presumptive and there are a significant number of antiretinal antibodies that have been detected in association with AIR. The diagnosis of AIR is largely based on the demonstration of antiretinal antibodies in the serum along with suggestive clinical features and ancillary investigations. A high index of suspicion along with early diagnosis and treatment may play a critical role to lower the risk of irreversible immunological damage to the retinal cells in these patients. A multi-disciplinary approach for complete management and evaluation is helpful in such conditions. Various therapeutic options have been described for the treatment of AIR, though there is no consensus on standard treatment protocol.

Component corneal surgery: An update.

Several decades ago, penetrating keratoplasty was a challenge to corneal surgeons. Constant effort by the corneal surgeon to improve the outcomes as well as utilization of the available resources has led to a revolutionary change in the field of keratoplasty. All these efforts have led to the evolution of techniques that allow a corneal surgeon to disease-specific transplant of individual layers of corneal "so-called component corneal surgery" depending on the layer of cornea affected. This has led to an improvement in corneal graft survival as well as a better utilization of corneal tissues. This article reviews the currently available literature on component corneal surgeries and provides an update on the available techniques.