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

Spectrum of retinal microvascular ischemia in patients with COVID-19 based on multimodal imaging

Purpose

To describe and evaluate the multimodal imaging findings in retinal microvascular ischemia associated with COVID-19 infection.

Methods

Patients with COVID-19 associated retinal microvascular ischemia and visiting the outpatient Department of Ophthalmology, Shanghai General Hospital from December 2022, to February 2023, were documented and their multimodal images were retrospectively reviewed. Retinal microvascular ischemia was defined as the presence of isolated or multiple focal retinal whitening(s) on color fundus images. Patients with retinal vessel occlusion or retinopathies secondary to systematic disorders diagnosed before infection were excluded.

Results

A total of 32 eyes from 21 patients were included, 24 (75.00 %) eyes with multiple retinal whitenings, while 8 (25.00 %) eyes with isolated lesions. When divided by the types of ischemia, 9 (28.13 %) eyes had only inner retinal involvement (known as cotton wool spot, CWS), 4 (12.50 %) eyes had only middle retinal involvement (known as paracentral acute middle maculopathy, PAMM), and 19 (59.38 %) eyes had both. In addition, 4 (12.50 %) eyes had coincident angular sign of Henle fiber layer hyperreflectivity (ASHH). Patients with hypertension tended to have multiple lesions rather than isolated lesion of retinal microvascular ischemia (P = 0.008). Transient uncontrolled high blood pressure or acute kidney injury was simultaneously detected in some cases.

Conclusions

Ocular manifestation of COVID-19 associated microvascular ischemia can be variable, including CWS, PAMM and ASHH. Multimodal fundus imaging technologies are useful tools to reveal involved retinal layers, extent, and severity. Moreover, ocular manifestations may serve as a window of COVID-19 related microcirculation in other systems throughout the body.

THE PROGNOSTIC SIGNIFICANCE OF ACUTE HENLE FIBER LAYER HYPERREFLECTIVITY IN PLACOID DISEASES

PURPOSE

To investigate the pathophysiology and prognostic significance of acute Henle fiber layer (HFL) hyperreflectivity in placoid diseases by examining its relationship with impaired choroidal flow and persistent photoreceptor disruption.

METHODS

Retrospective-prospective observational study on patients with placoid diseases. Indocyanine green angiography and optical coherence tomography were performed during the acute phase and follow-up. Impaired choroidal flow, HFL hyperreflectivity, and persistent ellipsoid zone disruption, their colocalization index, and their associations with initial and final visual acuity were explored.

RESULTS

Sixteen eyes from eight patients (mean age, 25.3 ± 6.44 years) were included (median follow-up, 13.5 months). Quantitative analysis revealed significant correlations between areas of impaired choroidal flow, HFL hyperreflectivity, and persistent ellipsoid zone disruption (correlation coefficients of 0.69, 0.63, and 0.46, respectively). Impaired choroidal flow area exceeded HFL hyperreflectivity (P = 0.002) and ellipsoid zone disruption (P = 0.003). A noteworthy 94% nonrandom overlap between HFL hyperreflectivity and ellipsoid zone disruption was observed. Worse initial visual acuity correlated with foveal involvement (P = 0.0002), thicker choroid (P = 0.001), larger impaired choroidal flow areas (P = 0.02), and thinner outer retina post lesion inactivation (P = 0.04).

CONCLUSION

Henle fiber layer hyperreflectivity predicted photoreceptor recovery potential in placoid diseases. If HFL hyperreflectivity corresponds to acute HFL damage, it may suggest more severe involvement of the entire photoreceptor length.

Acute Macular Neuroretinopathy Associated with COVID-19 Pandemic: A Real-world Observation Study

PURPOSE

To evaluate the clinical and retinal imaging features of Chinese patients with acute macular neuroretinopathy (AMN) associated with COVID-19.

DESIGN

A prospective observational study.

METHODS

Retinal imaging, including color fundus photography, near-infrared imaging (NIR), swept-source optical coherence tomography (SS-OCT), optical coherence tomography angiography (OCTA), and Humphrey perimetry, were conducted for each case.

RESULTS

All cases were included within the first three months following the pandemic outbreak. A total of 12 male patients (36.36 %) and 21 female patients (63.64 %) were prospectively recruited, and 29 cases (87.88 %) were bilaterally affected. The median interval between the onset of fever and the appearance of ocular symptoms was two days (range, 0.5-5.0 days). Apart from the outer retinal changes typical of AMN, changes in the inner retinal layers were observed, including intraretinal hemorrhage (8.06 %), cotton wool spots (9.68 %), and paracentral acute middle maculopathy (PAMM) (8.06 %). Smaller retinal inner nuclear layer hyperreflective speckles (RIHS) (41.94 %) were identified as a distinguishing feature from typical PAMM. Voids of vessel signals were found in the superficial (11.54 %), intermediate (82.69 %), and deep capillary plexus (98.08 %), and in the choriocapillaris (19.23 %) on OCTA. Humphrey perimetry illustrated central, paracentral, and peripheral scotomas. The occult lesions associated with AMN, PAMM, and some of the RIHS illustrated by OCT were visualized topographically and further confirmed by OCTA as perfusion defects.

CONCLUSION

An increase in AMN cases correlated with the SARS-CoV-2 outbreak. Additional features, including widespread inner retinal perfusion deficits, were observed and may serve as potential biomarkers for systemic microcirculation dysregulation in COVID-19.

Bilateral acute macular neuroretinopathy associated with COVID-19 infection presenting with central scotoma

Purpose

To report a case of bilateral acute macular neuroretinopathy (AMN) associated with COVID-19 infection presenting with central scotoma.

Observation

A 26-year-old female presented with a chief complaint of bilateral central scotomas for the last seven days. She had a history of fever over the past ten days, and RT-PCR test for COVID-19 was positive on the second day of fever. She had been vaccinated against COVID-19 eight months prior. Her best corrected visual acuity was 6/6 in both eyes on the Snellen chart. Dilated fundus evaluation revealed subtle bilateral perifoveal grey macular lesions. Optical coherence tomography (OCT) demonstrated focal hyperreflectivity at the level of the outer nuclear and plexiform layer consistent with bilateral AMN. Near-infrared reflectance (NIR) and red-free (RF) imaging showed large, confluent hyporeflective lesions in the right eye and discrete petaloid lesions with apices pointing toward the fovea in the left eye. OCT angiography (OCTA) revealed decreased flow signal at the level of the deep capillary plexus (DCP) and choriocapillaris (CC) in both eyes. Automated visual field testing (Humprey Field Analyzer (HFA) 24-2) revealed bilateral central scotoma with depression of adjacent points. After two weeks, the patient had depressed visual fields on HFA 10-2. At two months of final follow-up, OCT macula, NIR and RF images revealed resolving AMN lesions in both eyes. OCTA showed an increase in perfusion at the level of the DCP. There was a decrease in scotoma density on HFA 10-2, suggestive of resolving AMN.

Conclusion and importance

AMN with central scotoma as presenting feature of COVID-19 is rare. Fundus findings may be very subtle in AMN, but NIR and RF imaging delineate the lesions well. OCT, NIR imaging, OCTA and HFA 10-2 can be used to assess the clinical course of AMN.

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.

Unveiling the metabolic and coagulation disruptions in SARS-CoV-2-associated acute macular neuroretinopathy: A case-control study

SARS-CoV-2 infection has been associated with the increased incidence of acute macular neuroretinopathy (AMN), an infrequent ocular disorder. However, the precise mechanisms underpinning AMN in the context of SARS-CoV-2 infection (AMN-SARS-CoV-2) remain elusive. In this case-control study, 14 patients diagnosed with AMN-SARS-CoV-2 between 2022/12 and 2023/3 were enrolled and compared with 14 SARS-CoV-2-infected individuals without AMN, who served as controls (SARS-CoV-2-no AMN). Metabolomic profiling using ultrahigh-performance liquid chromatography-online electrospray mass spectrometry revealed significant alterations in serum metabolites in AMN-SARS-CoV-2 patients. Coagulation abnormalities were observed in AMN-SARS-CoV-2 patients, and their relationship with metabolic disorders was studied. Finally, a predictive model for AMN-SARS-CoV-2 was established. Seventy-six upregulated and 42 downregulated metabolites were identified in AMN-SARS-CoV-2 cases. Notably, arginine metabolism within the urea cycle was significantly altered, evidenced by variations in ornithine, citrulline,  l-proline, and ADAM levels, correlating with abnormal coagulation markers like platelet crit, fibrinogen degradation product, and fibrinogen. Additionally, increased arginase 1 (AGR1) activity within the urea cycle and reduced nitric oxide synthase activity were observed in AMN-SARS-CoV-2. The integration of urea cycle metabolite levels with coagulation parameters yielded a robust discriminatory model for AMN-SARS-CoV-2, as evidenced by an area under the curve of 0.96. The findings of the present study enhance our comprehension of the underlying metabolic mechanisms associated with AMN-SARS-CoV-2 and offer potential diagnostic markers for this uncommon ocular disorder within the context of SARS-CoV-2 infection.

Type II Acute Macular Neuroretinopathy Secondary to Malaria

To the best of our knowledge, we present the first case of type II acute macular neuroretinopathy (AMN) exhibiting in a patient suffering from malarial retinopathy concomitant with cerebral malaria acquired after travelling to West Africa without taking the necessary antimalarial prophylaxis. The patient complained of bilateral blurring of vision after being removed off sedation whilst at the intensive care unit. Subsequent examination revealed bilateral retinal haemorrhages, cotton-wool spots, and foveal pigmentary changes in keeping malarial retinopathy. Macular optical coherence tomography (OCT) revealed patchy hyperreflective changes at the level of the outer plexiform and outer nuclear layers (ONL) in keeping with the areas of deep capillary plexus flow void noted on OCT-angiography (OCT-A). This case report sheds more light on the extent of neurosensory retinal ischaemia in malarial retinopathy and showcases a new imaging biomarker which may be utilized in assessing and quantifying the functional deficit created by this disease.

Acute Macular Neuroretinopathy after SARS-CoV-2 Infection: An Analysis of Clinical and Multimodal Imaging Characteristics

BACKGROUND

This study aimed to analyze clinical and multimodal imaging characteristics of acute macular neuroretinopathy (AMN) post-recent severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection.

METHODS

Retrospective observational study. Medical records and multimodal imaging of 12 AMN eyes of eight patients (six female and two male) with recent SARS-CoV-2 infection were retrospectively analyzed.

RESULTS

Four patients (50%) presented with bilateral AMN. Fundus ophthalmoscopy revealed a reddish-brown lesion around the macula, and two eyes had cotton-wool spots at the posterior pole. Three eyes showed mild hypo-autofluorescence. All FFA images (7 eyes) showed no abnormal signs. On OCT scans, all eyes showed outer nuclear layer (ONL) thinning, 8 eyes (66.7%) showed ONL hyperreflectivity, 5 eyes (41.7%) showed outer plexiform layer (OPL) hyperreflectivity, 8 eyes (66.7%) showed interdigitation zone (IZ) disruption, 11 eyes (91.6%) showed ellipsoid zone (EZ) disruption, 2 eyes (16.7%) showed cotton-wool spots and inner plexiform layer (IPL) hyperreflectivity, 1 eye (8.3%) had intraretinal cyst and 1 eye (8.3%) had inner nuclear layer (INL) thinning. Persistent scotoma, ONL hyperreflectivity and IZ/EZ disruption as well as recovery of OPL hyperreflectivity were reported after follow-up in three cases.

CONCLUSIONS

AMN post-SARS-CoV-2 mostly affected young females and could present unilaterally or bilaterally. Dark lesions on IR reflectance and outer retinal hyperreflectivity on OCT are useful in diagnosing AMN. OPL/ONL hyperreflectivity on OCT could disappear after follow-up, but ONL thinning and IZ/EZ could persist.

Latest advances in white spot syndromes: New findings and interpretations

White spot syndromes (WSS) pose challenges in the field of ophthalmology, particularly in terms of accurate diagnosis and effective management. However, recent advancements in multimodal imaging (MMI) have significantly contributed to our understanding of WSS, allowing for improved characterization of these inflammatory chorioretinopathies. By employing various imaging modalities, including fundus fluorescein angiography, indocyanine green angiography, fundus autofluorescence, optical coherence tomography (OCT), ultra-widefield imaging, and OCT angiography, researchers and clinicians have gained valuable insights into the underlying pathophysiological changes and clinical progression of WSS. Furthermore, MMI has unveiled novel and atypical variants within the spectrum of WSS, expanding our knowledge in this field. Notably, the identification of secondary forms of WSS occurring concurrently with unrelated chorioretinal disorders has suggested a potential autoimmune mechanism underlying these conditions. The introduction of MMI has also facilitated a more comprehensive evaluation of previously ill-defined entities, such as acute zonal occult outer retinopathy, leading to improved diagnostic criteria and enhanced recognition of distinct features. This review paper provides a comprehensive overview of the latest advances and interpretations in WSS. By integrating MMI into the diagnosis and management of these conditions, this review aims to enhance patient outcomes and provide valuable insights into the complexities surrounding WSS.

Acute Macular Neuroretinopathy after COVID-19 Infection: Clinical Characteristics and Associated Factors

OBJECTIVE OR PURPOSE

Acute macular neuroretinopathy (AMN) is a rare, poorly understood retinal disease that affects the outer retina. Recent studies reported the onset of AMN is associated with COVID-19 infection. However, it still lacks thorough evaluation regarding the clinical features of AMN after COVID-19 infection.

DESIGN

Retrospective cohort study.

PARTICIPANTS

This study involved online registration of patients who were diagnosed with AMN after rapid antigen or PCR tests confirmed COVID-19 infections from December 2022 to March 2023.

METHODS

We interviewed all patients and completed an evaluation survey that recorded age, sex, menstruation pattern, medical history, doses of COVID-19 vaccination, symptom onset (days after fever onset), symptoms, and treatment measures. The association between clinical characteristics and baseline visual acuity was investigated.

MAIN OUTCOME MEASURES

Demographic and clinical characteristics of AMN after COVID-19 infection.

RESULTS

A total of 116 eyes from 66 patients were included in the present study. The average age was 30.4 ± 6.7, and 81.8% of patients were female. The average time of ocular symptom onset was 2.62 ± 1.88 days after fever onset. Scotomas (87.9%) were the most common symptoms reported by patients, whereas 25.9% and 1.7% of eyes had blurry vision and photopsia. 80.2%, 60.3%, 26.7%, 10.3%, and 3.4% of eyes showed ellipsoid zone (EZ) disruption, hyper-reflectivity of outer nuclear layer (ONL), hyper-reflectivity of Henle layer, hyper-reflectivity of outer plexiform layer (OPL), and macular edema, respectively. A history of smoking (Coef. =0.12, 95%CI: [0.00, 0.24]), macular edema (Coef. =0.14, 95%CI: [0.00, 0.88]), hyper-reflectivity of OPL (Coef. =0.16, 95%CI: [0.08, 0.24]), hyper-reflectivity of Henle layer (Coef. =0.08, 95%CI: [0.03, 0.14]), and EZ disruption (Coef. =0.07, 95%CI: [0.00, 0.13]) were associated with worse LogMAR visual acuity at baseline.

CONCLUSIONS AND RELEVANCE

AMN after COVID-19 infection is more common in young females. Hyper-reflectivity of ONL and EZ disruption are the most common OCT features of AMN. Macular edema, hyper-reflectivity of OPL, hyper-reflectivity of the Henle layer, EZ disruption, and a history of smoking are associated with worse visual acuity at baseline.

Clinical and Diagnostic Findings of Acute Macular Neuroretinopathy and Paracentral Acute Middle Maculopathy in the COVID-19 Era

BACKGROUND

Growing evidence suggests an association between the infection from the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) and eye disorders. The aim of this review was to analyze the clinical presentation and diagnostic features of acute macular neuroretinopathy (AMN) and paracentral acute middle maculopathy (PAMM) associated with COVID-19 infection. The features are then compared with previous reports regarding these retinal disorders, to recognize possible specific characteristics and to assess the role of multimodal ophthalmic imaging.

SUMMARY

A literature search was performed by consulting PubMed, Scopus, and Embase. The following terms were searched: "(COVID-19 OR SARS-CoV-2 OR coronavirus) AND ([acute macular neuroretinopathy] OR [paracentral acute middle maculopathy])." Inclusion criteria were as follows: (1) publication date from January 31, 2020 to January 31, 2022; (2) English language; (3) original research or case report; (4) free full-text availability.Optical coherence tomography (OCT) findings in AMN patients were hyper-reflectivity (HR) of the outer plexiform layer, of the outer nuclear layer, and ellipsoid or interdigitation zones (EZ and IZ, respectively) disruption. In most cases, the presence of HR and EZ/IZ abnormalities resulted combined. When performed, OCT angiography (OCTA) identified attenuation of signal of the deep capillary plexus (DCP). The most common OCT finding in PAMM was an alteration of the inner nuclear layer, associated with other areas of HR, while no signs of EZ/IZ disruption were detected. When performed, OCTA showed the attenuation of signal of both the DCP and the superficial capillary plexus.

KEY MESSAGES

In this review, we reported a case series of AMN and PAMM in patients with a previous or concomitant infection from SARS-CoV-2. The microvascular changes in these cases are highlighted by the OCTA scans. Even if we are far from the determination of a direct link between COVID-19 and these retinal disorders, we could hypothesize that the vascular alterations associated with SARS-CoV-2 infection could be a possible risk factor for both AMN and PAMM.