Optical Coherence Tomography Angiography Findings in Dengue-Related Maculopathy: A Case Report

Optical Coherence Tomography and Optical Coherence Tomography Angiography in Neglected Diseases

A group of self-limiting and frequently neglected diseases exist in the literature like Rickettsial disease, Malaria, Dengue fever, Chikungunya, West Nile virus infection, Rift Valley fever, Bartonellosis, or Lyme disease which are poorly understood due to lack of proper diagnostic testing. Currently, multimodal imaging has become a critical modality in the diagnosis and management of ocular diseases. Optical coherence tomography (OCT) is one such remarkable imaging modality in the field of ophthalmology providing high-resolution, cross-sectional images of the retina and choroid with the recent advances such as enhanced depth imaging and swept source OCT. Additionally, OCT angiography (OCTA) has further revolutionised dynamic imaging of retinal and choroidal vasculature non-invasively. This review article highlights the OCT and OCTA biomarkers in the diagnosis and prognosis of the aforementioned neglected diseases.

Ocular Autoimmune Systemic Inflammatory Infectious Study (OASIS) - Report 6: Dengue Uveitis at a Tertiary Eye Institution in Singapore

OBJECTIVES

To identify the characteristics, treatment, and visual outcomes of dengue uveitis at a tertiary eye care centre in Singapore.

METHODS

Retrospective case record review of all consecutive dengue uveitis patients (2004 to 2015) from the Ocular Autoimmune Systemic Inflammatory and Infectious Study (OASIS) database.

RESULTS

Fifty-four patients were identified from the OASIS database. The most common ocular symptom was blurring of vision (n = 41, 75.9%), followed by floaters (n = 9, 17.0%), scotoma (n = 5, 9.3%), and metamorphopsia (n = 3, 5.7%). Scotoma based on history, Amsler grid, and perimetry accounted for 27 (50%) patients. Majority presented with either a posterior uveitis or retinal vasculitis (n = 51, 94.4%). Treatments ranged from close observation for spontaneous improvement, to the use of high-dose corticosteroids.

CONCLUSIONS

Dengue uveitis may present with a spectrum of disease manifestations including posterior uveitis, vasculitis, and macula edema. Scotoma is significant and may be found on history taking, Amsler charting, and perimetry.

Stepwise approach for fundus imaging in the diagnosis and management of posterior uveitis

An array of retinochoroid imaging modalities aid in comprehensive evaluation of the immunopathological changes in the retina and choroid, forming the core component for the diagnosis and management of inflammatory disorders such as uveitis. The recent technological breakthroughs have led to the development of imaging platforms that can evaluate the layers of retina and choroid and the structural and functional alteration in these tissues. Ophthalmologists heavily rely on imaging modalities such as dye-based angiographies (fluorescein angiography and indocyanine green angiography), optical coherence tomography, fundus autofluorescence, as well as dye-less angiography such as optical coherence tomography angiograph,y for establishing a precise diagnosis and understanding the pathophysiology of the diseases. Furthermore, these tools are now being deployed with a 'multimodal' approach for swift and accurate diagnosis. In this comprehensive review, we outline the imaging platforms used for evaluation of posterior uveitis and discuss the organized, algorithmic approach for the assessment of the disorders. Additionally, we provide an insight into disease-specific characteristic pathological changes and the established strategies to rule out disorders with overlapping features on imaging.

Ocular manifestations of emerging viral diseases

Emerging infectious diseases (EIDs) are an increasing threat to public health on a global scale. In recent times, the most prominent outbreaks have constituted RNA viruses, spreading via droplets (COVID-19 and Influenza A H1N1), directly between humans (Ebola and Marburg), via arthropod vectors (Dengue, Zika, West Nile, Chikungunya, Crimean Congo) and zoonotically (Lassa fever, Nipah, Rift Valley fever, Hantaviruses). However, specific approved antiviral therapies and vaccine availability are scarce, and public health measures remain critical. Patients can present with a spectrum of ocular manifestations. Emerging infectious diseases should therefore be considered in the differential diagnosis of ocular inflammatory conditions in patients inhabiting or returning from endemic territories, and more general vigilance is advisable in the context of a global pandemic. Eye specialists are in a position to facilitate swift diagnosis, improve clinical outcomes, and contribute to wider public health efforts during outbreaks. This article reviews those emerging viral diseases associated with reports of ocular manifestations and summarizes details pertinent to practicing eye specialists.

Retinal Vasculitis with Macular Infarction: A Dengue-related Ophthalmic Complication

Introduction

Dengue-associated ocular complications are increasing owing to the rising global burden of dengue fever. We intend to highlight a rare and sight-threatening complication of this disease.

Case Details

A 44-year-old male, with prior history of dengue fever, presented with diminution of vision in both eyes for 10 days. At presentation, his best-corrected visual acuity was 1/60 in the right eye and 6/18 in the left eye. Anterior segment findings were unremarkable. Fundus examination revealed vitritis, perivascular exudates, intraretinal hemorrhages, macular edema, peripapillary retinal whitening and cotton wool spots in both eyes suggestive of vasculitis, with additional retinal whitening affecting the right macula. Fundus fluorescein angiography revealed disc and perivascular leakage limited to posterior pole along with patches of blocked fluorescence. In addition, there was capillary nonperfusion due to occlusion of multiple small arterioles supplying the macula of right eye confirming macular ischemia. Macular edema with subretinal fluid in both eyes was evident on optical coherence tomography. Treatment was attempted with intravenous methylprednisolone which was futile even after three days of administration.

Conclusion

We report a case of retinal vasculitis with macular infarction attributed to dengue fever. Although uncommon, dengue-associated ocular complications can lead to irreversible visual loss. Therefore, clinicians should keep this disease entity in mind while evaluating febrile patients with visual complaints in dengue endemic regions.

Standardisation of optical coherence tomography angiography nomenclature in uveitis: first survey results

Aim

To standardise the nomenclature for reporting optical coherence angiography (OCT-A) findings in the field of uveitis.

Methods

Members of the International Uveitis Study Group, of the American Uveitis Society and of the Sociedad Panamericana de Infermedades Oculares that choose to participate responded to an online questionnaire about their preferred terminology when reporting on OCT-A findings in uveitis. The response of individuals with several publications on OCT-A (experts) was compared with uveitis specialists (users) who have less than five publications on the field of uveitis and OCT-A.

Results

A total of 108 uveitis specialists who participated in the survey were included in the analysis. Of those, 23 were considered OCT-A ‘experts’. There was an agreement in both groups for the definition of wide-field (WF)-OCT-A, and definition of neovascularisation in uveitis. Moreover, there was a difference in the responses in other areas, such as quantification of ischaemia, definition of ‘large’ areas of ischaemia or terms to describe decreased OCT-A signal from different causes. There was an unanimous need of ‘users’ and ‘experts’ to distinguish size of decreased OCT-A signal in uveitis, to implement a quantitative measurement of decreased flow specifically for WF-OCT-A and to use different terms for different causes of decreased OCT-A signal.

Conclusions

While there was considerable agreement in the terminology used by all uveitis experts, significant differences in terminology were noted between ‘users’ and ‘experts’. These differences indicate the need for standardisation of nomenclature among all uveitis specialists both for the purpose of reporting and in clinical use.

Ocular manifestations of dengue

PURPOSE OF REVIEW

There are an increasing number of publications related to dengue ophthalmic manifestations and multimodality imaging related to dengue. This review summarizes the current literature, describe ocular manifestations, current using of ocular imaging/investigations, and management of ocular dengue.

RECENT FINDINGS

Ocular manifestations of dengue can be present in many stages of dengue fever including after the resolution of systemic disease. Most cases of ocular dengue will exhibit an improvement in vision spontaneously over time. Multimodal imaging such as optical coherence tomography, optical coherence tomography angiography, near-infrared imaging, and microperimetry plays an important role in the diagnosis, follow-up, quantitative measure, and help to understand the disease progression.

SUMMARY

Dengue fever can lead to a variety of ocular manifestations. The mechanisms underlying dengue-related ocular complications remain unclear. Immune-mediated mechanisms and direct viral invasion are thought to play an important role. Ophthalmologists should carefully assess patients with dengue-related ophthalmic disease because some patients may have poor visual acuity and exhibit refractoriness to treatment. Treatment with systemic corticosteroids may benefit those patients with poor presenting visual acuity, progressive ocular symptoms, and lesions involving the optic nerve and/or threatening the macula.

Optical coherence tomography angiography (OCTA) as a new diagnostic tool in uveitis

Background

The broad spectrum of uveitis disorders requires a multimodal imaging approach in the daily practice of an ophthalmologist. As inflammatory conditions, they have in common an alteration in leukocyte migration. In this context, optical coherence tomography angiography (OCTA) might be of great value for diagnosing or following up patients with these disorders. To date, OCTA has rather been used as an additional tool besides the well-established diagnostic imaging tools, but its complementary diagnostic features become increasingly relevant, to follow disease activity and treatment response and for the understanding of pathomechanisms of various uveitis types.

This review summarizes the possible applications of OCTA and its advantages and disadvantages as opposed to dye-based angiographies in uveitic diseases.

Main body

Hitherto gold standards in the diagnostic workup of posterior or intermediate uveitis have been angiography on a dye-based method, which is fluorescein or indocyanine green. It gives information about the status of the blood-retinal barrier and the retinal and choroidal vasculature by visualizing diffuse leakage as a state of inflammation or complications as an ischemia or choroidal neovascularization. As noninvasive methods, fundus autofluorescence depicts the status of metabolic activity of the retinal pigment epithelium and OCT or enhanced depth imaging OCT, respectively, as a depth-resolving imaging method can supply additional information.

OCTA as a non-invasive, depth-resolution imaging tool of retinal and choroidal vessels adds detailed qualitative and quantitative information of the status of retinal and choroidal vessels and bridges the gap between the mentioned conventional diagnostic tools used in uveitis.

It is important, though, to be aware of its limitations, such as its susceptibility to motion artifacts, limited comparability among different devices, and restricted contribution of information regarding the grade of disease activity.

Conclusion

OCTA as a non-invasive, depth-resolution imaging tool can give qualitative and quantitative information about the status of retinal and choroidal vessels, but also has certain limitations. Employing OCTA as a complementary rather than exclusive tool, it can give important additional information about the macro- and microvasculature under inflammatory circumstances. Thereby, it also contributes to the understanding of the pathophysiology of various uveitis entities.

Dengue-Induced Inflammatory, Ischemic Foveolitis and Outer Maculopathy: A Swept-Source Imaging Evaluation

PURPOSE

Dengue maculopathy can present with a unique constellation of features resulting in significant central visual morbidity. We aim to describe various findings of dengue-induced inflammatory, ischemic foveolitis, and outer maculopathy (DIII-FOM) and assess the serial changes in vitreous inflammation, retinal structure, and vascularity using swept-source OCT (SS-OCT) and OCT angiography (OCTA).

DESIGN

Retrospective case series.

PARTICIPANTS

A total of 32 eyes (16 patients; 7 male) with dengue fever (positive serology for NS1 antigen) were enrolled in the study.

METHODS

In this study, serial assessments of ocular findings and imaging using fundus photography, SS-OCT, and SS-OCTA were performed. All the patients received 0.5 to 1 mg/kg/day oral prednisolone that was tapered over 4 to 6 weeks.

MAIN OUTCOME MEASURES

Outcome measures included functional change, that is, improvement in best-corrected visual acuity (BCVA), structural changes in the vitreous and retinal layers on SS-OCT, and retinal perfusion on OCTA.

RESULTS

The mean age of the patients was 29.17±10.91 years. Swept-source OCT showed vitreous cells (32 eyes; 100%), disruption of outer retinal layers (foveolitis) (24 eyes; 75%), and conical foveal elevation (22 eyes; 68.75%). After initiation of systemic corticosteroids, all the eyes showed resolution of vitreous cells and improvement in the integrity of retinal layers. Mean BCVA improved from an initial 0.80±0.33 logarithm of the minimum angle of resolution (logMAR) to 0.23±0.36 logMAR. Retinal plexus flow deficit (superficial plexus: 0.10±0.12 mm²; deep plexus: 0.29±0.13 mm²) persisted in all eyes and correlated well with initial BCVA (P < 0.05).

CONCLUSIONS

The pathophysiology of dengue maculopathy involves both ischemic and inflammatory components. Early institution of corticosteroid therapy may help in resolution of the inflammation-driven vitreoretinal alterations, but ischemia of the deep retinal plexuses may persist and may be the cause of permanent structural and functional changes.

Optical coherence tomography angiography features of acute macular neuroretinopathy in dengue fever

A 39-year-old female with dengue fever presented with decreased vision in both eyes. Visual acuity was 20/200 and 20/80 in the right eye (OD) and left eye (OS), respectively. Fundus showed granular, grayish-white lesions in the parafoveal region in OD. Multimodal imaging including optical coherence tomography angiography (OCTA), optical coherence tomography (OCT), and fluorescein angiography (FA) was performed. FA showed late hyperfluorescence with few microaneurysms in OS. OCT showed hyperreflectivity in various layers, suggestive of acute macular neuroretinopathy (AMN). OCTA showed disruption of retinal capillary plexuses. This case shows how OCTA provides newer insights into the pathogenesis of AMN lesions in dengue fever.

Multimodal Imaging in Dengue-Fever-Associated Maculopathy

Dengue fever can cause ocular complications that may not be easily identified during a regular eye examination. A high degree of suspicion and multimodal imaging will help characterize the lesions during acute stages of the infection.