Concurrent vascular flow defects at the deep capillary plexus and choriocapillaris layers in acute macular neuroretinopathy on multimodal imaging: A case series

Optical coherence tomography angiography suggests choriocapillaris perfusion deficit as etiology of acute macular neuroretinopathy

PURPOSE

Acute macular neuroretinopathy (AMN) can cause sudden-onset and permanent scotoma in healthy young patients. Analysis of optical coherence tomography (OCT) and OCT angiography (OCTA) of AMN patients may provide insights into disease mechanism.

METHODS

We conducted a retrospective study of consecutive SARS-Cov-2-related AMN patients that presented in our clinic between Jan 1st, 2022, and April 30th, 2023, within 30 days of symptom onset. Retinal vessel area density (VAD) of AMN lesions in OCTA was quantified and compared to an adjacent tissue control (ATC). This quantification was performed for the superficial vascular plexus (SVP), the intermediate capillary plexus (ICP), the deep capillary plexus (DCP), the choriocapillaris (CC), and choroid. Furthermore, en face OCT images were analyzed.

RESULTS

Nine AMN patients were identified, 6 of these (4 female, 2 male, average age 25 years) fulfilled the inclusion criteria and were included into this study. Average time from symptom onset to OCTA was 14.3 days. No VAD differences between AMN and adjacent tissue were found in either retinal layer (SVP, ICP, DCP). In contrast, VAD in CC was reduced by 27% against the ATC (p = 0.007) and choroidal VAD was reduced by 41% (p = 0.017). Further analysis of en face OCT could show that the pathognomonic infrared hyporeflectivity in AMN is caused by photoreceptor alterations rather than changes in the inner retinal layers.

CONCLUSIONS

Our data suggests that a perfusion deficit in the choroidal layers is responsible for AMN rather than in the DCP, which is the predominant hypothesis in current literature.

Bilateral Acute Macular Neuroretinopathy after COVID-19 Vaccination and Infection

PURPOSE

To describe a case of acute macular neuroretinopathy (AMN) in a patient with recent COVID-19 vaccination and infection who demonstrated atypical features on presentation.

OBSERVATIONS

A 64-year-old woman presented with central vision loss in both eyes (OU). She had recently received the Moderna COVID-19 vaccine and rapidly developed systemic symptoms. Testing revealed COVID-19 infection. Visual acuities were 20/200 OU and near-infrared reflectance revealed hypo-reflective lesions in the maculae OU, optical coherence tomography (OCT) showed outer nuclear layer thinning and ellipsoid zone disruption OU, and OCT-angiography showed flow voids in the deep capillary plexus and choriocapillaris OU, all consistent with AMN. She was treated with oral prednisone with subsequent mild vision improvement and persistent scotomas.

DISCUSSION

COVID-19 associated AMN can present with a more severe clinical presentation than classically seen in AMN. Ischemic and inflammatory changes due to COVID-19 infection may contribute to this more advanced presentation.

COVID Vaccine-Associated Uveitis

PURPOSE

Following the pandemic of coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2, different vaccines were developed and approved by the main medical authorities under emergency protocol regulations. Although highly effective and well-tolerated in most patients, vaccines can uncommonly cause ocular adverse effects. In this article, the current evidence related to vaccine-associated uveitis is reviewed.

METHODS

A literature review of uveitis post various SARS-CoV-2 vaccinations.

RESULTS

Uveitis was reported following various forms of vaccinations but was more commonly seen following the Pfizer mRNA vaccine which is the most used vaccination worldwide. In western countries, the most common uveitis is mild anterior uveitis, developing within a week of first or subsequent vaccination with good resolution following appropriate topical steroid therapy in most cases. Posterior uveitis and particularly Vogt-Koyanagi-Harada disease was more prevalent in Asia. Uveitis may develop among known uveitis patients and those with other autoimmune diseases.

CONCLUSION

Uveitis following Covid vaccinations is uncommon and has a good prognosis.

A Case Report of Dengue-Associated Maculopathy With Literature Review

We report a case of dengue-associated maculopathy in a healthy adult. A 31-year-old lady with dengue fever presented with both eye sudden, painless blurry vision in the left eye. On examination, the best-corrected visual acuity was 6/18 in her right eye and 2/60 in her left eye. Anterior segment examination was unremarkable. Fundi showed bilateral macula edema with cotton wool spots. Optical coherence tomography (OCT) macula scan was suggestive of bilateral macula edema, with higher severity in the left eye. She was started on intravenous methylprednisolone 500mg once daily for three days. Upon completion of steroids, her right eye visual acuity improved to 6/6 however her left eye vision worsened to 3/60 after six months. Her OCT six months later showed resolved macula edema on both eyes. Ocular manifestation associated with dengue fever is rare but may result in permanent visual impairment. The use of high-dose steroids helps in improving visual acuity.

Case Report: Recurrent Acute Macular Neuroretinopathy-Monitoring Recovery with Multimodal Imaging

SIGNIFICANCE

Acute macular neuroretinopathy (AMN) is a rare, nonprogressive condition affecting the outer retina that can be diagnosed clinically using widely available multimodal imaging techniques. This case report presents an exceedingly rare same-eye recurrence of AMN and describes the characteristic imaging findings of this unique, not fully understood clinical entity.

PURPOSE

The following report provides a detailed account of recurrent AMN from 4 hours of symptom onset to 4 months with repeat multimodal imaging captured at different visits. This report also devotes some discussion to the current understanding of its pathophysiology, associations, management, and imaging characteristics.

CASE REPORT

A 32-year-old woman with unilateral recurrent AMN was monitored frequently with various multimodal imaging from 4 hours after onset of new scotoma to 4 months. The primary finding in the acute stage was a hyperreflective lesion of the outer nuclear and outer plexiform layers followed by disruption of underlying external limiting membrane, ellipsoid zone, and photoreceptors. This resolved into stable outer nuclear layer thinning and subtle disruption of the deeper layers after 1 week. Fundus photography revealed a red-brown petaloid lesion adjacent to the fovea, and optical coherence tomography angiography revealed subtle decreased perfusion of the choriocapillaris layer throughout follow-up.

CONCLUSIONS

Acute macular neuroretinopathy is a rare nonprogressive condition of the outer retina most often affecting otherwise healthy young female individuals and is most associated with recent flu-like illness and oral contraceptives. The underlying mechanism of AMN remains unknown, but modern imaging techniques have elucidated the disease locus to be choroidal and/or deep capillary plexus. It is important for eye care providers to recognize AMN as a clinical entity distinct from other retinal conditions that require different management.

Deep Capillary Plexus Features in Acute Macular Neuroretinopathy: Novel Insights Based on the Anatomy of Henle Fiber Layer

PURPOSE

The purpose of this study was to identify a precise location of deep capillary plexus (DCP) injury in acute macular neuroretinopathy (AMN) lesions using multimodal imaging.

METHODS

En face structural optical coherence tomography (OCT) images were manually segmented to delineate outer retinal AMN lesions involving the ellipsoid zone and interdigitation zone. AMN lesion centroid was calculated, and image distortion was applied to correct for Henle fiber layer (HFL) length and orientation. The resulting image was registered with the corresponding en face OCT angiography (OCTA) image segmented at the DCP and structural OCT volume before grading for vascular and structural features, respectively.

RESULTS

Thirty-nine AMN lesions from 16 eyes (11 female patients, mean age 34 ± 4 years) were analyzed. After correcting for HFL anatomy, in 62% of AMN lesions, the centroid co-localized with a capillary vortex (pattern 1); flow defects were detected in 33% of lesions (pattern 2); and in 5% of lesions no specific pattern could be identified (pattern 3). The detection of a specific pattern increased after correcting the projection of AMN lesion for HFL anatomy (28% vs. 5%, P = 0.04). Outer nuclear layer thickness was lower in the centroid area in 10 (29%) AMN lesions from 6 patients, all corresponding to lesions fitting pattern 2 (r = 0.78, P < 0.001).

CONCLUSIONS

AMN lesions might be a result of DCP impairment at the level of the capillary vortex or draining venule. In eyes with AMN, the location of outer retinal changes associated with DCP ischemia appears to be influenced by the length and orientation of HFL.

Ocular effects caused by viral infections and corresponding vaccines: An overview of varicella zoster virus, measles virus, influenza viruses, hepatitis B virus, and SARS-CoV-2

Many viral infections can affect vision and the visual system. Vaccination to prevent diseases is commonplace today, acting by stimulating an immune response without developing the pathology. It involves the production of persisting antibodies against the pathogen and the activation of T cells. Certain diseases have already been eradicated by rigorous vaccination campaigns, while others are hoped to be eliminated soon. Vaccines currently available on the market are largely safe, even if they can rarely cause some adverse effects, such as ocular complications. Analyzing existing literature, we aimed to compare the pathological effects on the eye due to the most common viral infections [in particular varicella zoster virus (VZV), measles virus, influenza viruses, hepatitis B virus, and SARS-CoV-2] with the possible ocular adverse effects of their relative vaccines, in order to establish a risk-benefit relationship from an ophthalmological point of view.

Nahinfrarot-Autofluoreszenz: klinische Anwendung und diagnostische Relevanz

Die Nahinfrarot-Autofluoreszenz (NIA) ist ein nicht-invasives Verfahren zur Untersuchung des retinalen Pigmentepithels (RPE) basierend auf der Darstellung des antioxidativen Schutzfaktors Melanin in den RPE-Zellen. Die NIA verbessert die Früherkennung chorioretinaler Erkrankungen, da bei vielen dieser Erkrankungen mit der NIA Strukturveränderungen des RPE nachweisbar sind, bevor sich in anderen Untersuchungen Krankheitszeichen erkennen lassen.

[Near-infrared Fundus Autofluorescence: Clinical Application and Diagnostic Relevance]

Near-infrared autofluorescence (NIA) is a non-invasive retinal imaging technique for examination of the retinal pigment epithelium (RPE) based on the autofluorescence of melanin. Melanin has several functions within the RPE cells, in one of them it serves as a protective antioxidative factor within the RPE cells and is involved in the phagocytosis of photoreceptor outer segments. Disorders that affect the photoreceptor-RPE complex result in alterations of RPE cells which are detectable by alterations of NIA. Therefore, NIA allows to detect early alterations in inherited and acquired chorioretinal disorders, frequently prior to ophthalmoscopical visualisation and often prior to alterations in lipofuscin associated fundus autofluorescence (FAF) or optical coherence tomography (OCT). Although NIA and FAF relate to disorders affecting the RPE, findings between both imaging methods differ and the area involved has been demonstrated to be larger in NIA compared to FAF in several disorders (e.g., age-related macular degeneration, retinitis pigmentosa, ABCA4-gene associated Stargardt disease and cone-rod dystrophy, light damage), indicating that NIA detects earlier alterations compared to FAF. In addition, due to the absence of blue-light filtering which limits foveal visualisation in FAF, foveal alterations can be much better detected using NIA. A reduced subfoveal NIA intensity is the earliest sign of autosomal dominant BEST1-associated disease, when FAF and OCT are still normal. In other disorders, a normal subfoveal NIA intensity is associated with good visual acuity. This review summarizes the present knowledge on NIA and demonstrates biomarkers for various chorioretinal disorders.

Acute macular neuroretinopathy in dengue virus serotype 1

Purpose

To report a case of acute macular neuroretinopathy (AMN) associated with dengue virus serotype 1 infection.

Observation

An 18-year-old Puerto Rican female was evaluated due to painless paracentral scotomas in each eye that developed after being hospitalized for dengue fever a week before. Clinical examination and multimodal imaging revealed bilateral hypopigmented macular lesions, hyperreflectivity at the outer nuclear and photoreceptor layer, and reduced flow signal in the deep capillary plexus. Additionally, hypoautofluorescent parafoveal lesions were found in the left eye. AMN was diagnosed. Two-month follow-up after the initial evaluation showed resolution of symptoms but persistence of some findings on optical coherence tomography.

Conclusions and importance

Patients with dengue virus serotype 1 may develop paracentral scotomas with classic AMN findings and obtain complete symptomatic recovery without treatment.

[Acute macular neuroretinopathy: En face OCT description, case series]

Acute macular neuroretinopathy (AMN) is a rare disease characterized by involvement of the outer retinal layers of the macula. The diagnosis of AMN is based on multimodal imaging, combining infrared reflectance (IR) imaging and optical coherence tomography with B-scan analysis (OCT-B). The en face OCT is a tomographic image processing technique, integrating data from entire A-scans to create a frontal retinal image of the desired area. Structural en face OCT imaging appears to be effective in delineating AMN lesions, using segmentation between the outer plexiform line and the ellipsoid line. In the future, analysis of the various modalities of a single OCT acquisition may be sufficient to diagnose AMN.

Ocular Adverse Events After COVID-19 Vaccination

PURPOSE

The COVID-19 pandemic has galvanized the development of new vaccines at an unprecedented pace. Since the widespread implementation of vaccination campaigns, reports of ocular adverse effects after COVID-19 vaccinations have emerged. This review summarizes ocular adverse effects possibly associated with COVID-19 vaccination, and discusses their clinical characteristics and management.

METHODS

Narrative Literature Review.

RESULTS

Ocular adverse effects of COVID-19 vaccinations include facial nerve palsy, abducens nerve palsy, acute macular neuroretinopathy, central serous retinopathy, thrombosis, uveitis, multiple evanescent white dot syndrome, Vogt-Koyanagi-Harada disease reactivation, and new-onset Graves' Disease. Studies in current literature are primarily retrospective case series or isolated case reports - these are inherently weak in establishing association or causality. Nevertheless, the described presentations resemble the reported ocular manifestations of the COVID-19 disease itself. Hence, we hypothesize that the human body's immune response to COVID-19 vaccinations may be involved in the pathogenesis of the ocular adverse effects post-COVID-19 vaccination.

CONCLUSION

Ophthalmologists and generalists should be aware of the possible, albeit rare, ocular adverse effects after COVID-19 vaccination.