Dengue maculopathy: a case report

Unilateral lateral rectus palsy following dengue: a case report

Introduction and importance

Dengue fever is a mosquito-borne viral infection presenting with high-grade fever and other constitutional symptoms.

Case presentation

This case report details a rare occurrence of lateral rectus palsy in an 18-year-old male subsequent to dengue infection. The patient initially presented with fever, a generalized tonic-clonic seizure (GTCS), and symptomatic hypoglycemia, leading to multiple organ dysfunction syndrome (MODS) necessitating intensive care. Remarkably, no haemorrhagic manifestations were observed. The MODS gradually resolved by the 12th day of admission, coinciding with the emergence of complaints about uniocular diplopia and right esotropia. Systemic examination, including a normal computed tomography (CT) head scan, did not reveal any abnormalities. Additionally, potential causes contributing to esotropia and diplopia were ruled out. The patient was subsequently managed expectantly for lateral rectus palsy following severe dengue. Follow-up assessments indicated a gradual improvement in esotropia and diplopia, and the patient was advised to continue the prescribed medications.

Conclusion

This is the first documented case report of paralytic squint post-severe dengue in Nepal, emphasizing the importance of considering it as a differential diagnosis in tropical regions with endemic dengue infections. The case report advocates early identification and treatment of ophthalmic issues, notably with prednisolone, to achieve favourable outcomes, as evidenced by improvements in visual acuity, esotropia, and diplopia during follow-ups. Further research is essential to determine optimal treatment strategies for such neurological complications associated with dengue fever.

Dengue Virus Infection of Human Retinal Müller Glial Cells

Retinopathy is a recently recognized complication of dengue, affecting up to 10% of hospitalized patients. Research on the pathogenesis has focused largely on effects of dengue virus (DENV) at the blood-retinal barrier. Involvement of retinal Müller glial cells has received little attention, although this cell population contributes to the pathology of other intraocular infections. The goal of our work was to establish the susceptibility of Müller cells to infection with DENV and to identify characteristics of the cellular antiviral, inflammatory, and immunomodulatory responses to DENV infection in vitro. Primary human Müller cell isolates and the MIO-M1 human Müller cell line were infected with the laboratory-adapted Mon601 strain and DENV serotype 1 and 2 field isolates, and cell-DENV interactions were investigated by immunolabelling and quantitative real-time polymerase chain reaction. Müller cells were susceptible to DENV infection, but experiments involving primary cell isolates indicated inter-individual variation. Viral infection induced an inflammatory response (including tumour necrosis factor-α, interleukin [IL]-1β, and IL-6) and an immunomodulatory response (including programmed death-ligand [PD-L]1 and PD-L2). The type I interferon response was muted in the Müller cell line compared to primary cell isolates. The highest infectivity and cell responses were observed in the laboratory-adapted strain, and overall, infectivity and cell responses were stronger in DENV2 strains. This work demonstrates that Müller cells mount an antiviral and immune response to DENV infection, and that this response varies across cell isolates and DENV strain. The research provides a direction for future efforts to understand the role of human retinal Müller glial cells in dengue retinopathy.

Changes in parafoveal retinal thickness and subfoveal choroidal thickness in a patient with dengue fever-associated maculopathy

Background

The time courses of retinal and choroidal thickness changes in dengue fever-associated maculopathy are not known. We measured central macular thickness (CMT), parafoveal retinal thickness (PRT), and subfoveal choroidal thickness (SCT), in one case, employing optical coherence tomography.

Findings

The patient was a 43-year-old man diagnosed with dengue fever in Sri Lanka. He became aware of blurred vision bilaterally and visited our department 2 weeks after the onset. He showed reduced visual acuity. The Amsler test revealed a doughnut-shaped relative scotoma. Based on the course of this condition, dengue fever-associated maculopathy was diagnosed. One month later, 20 mg triamcinolone was injected into sub-Tenon space of the left eye. Both eyes showed subsequent improvement. PRT of both eyes increased 1 week after the first visit and decreased thereafter, reaching a plateau 1 month after the first visit. The change in CMT was minimal. SCT changed markedly, with the similar pattern in both eyes, though no particular tendency was noted during the observation period.

Conclusions

Dengue fever-associated maculopathy appears to be closely associated with thickening of the inner layer of the retina, but not with changes in choroidal thickness.

Ophthalmic complications of dengue Fever: a systematic review

Introduction

In recent years there has been a spurt of peer-reviewed publications on the ophthalmic complications of dengue fever. The authors aim to review the ocular manifestations, utility of relevant diagnostic tests, management, prognosis, and sequelae of dengue-related ocular complications.

Methods

A comprehensive literature search was conducted on Medline, PubMed, and Google Scholar databases. Only articles published or translated into the English language were considered, and key data from the full article of each paper was extracted and evaluated.

Results

The authors’ search yielded 29 articles. A total of 686 patients with a mean age of 33.4 years (range 14–73 years) were included. Blurring of vision was the most common presenting symptom followed by scotoma. Ocular findings were mostly seen in the posterior pole of the fundus, manifesting as retinal hemorrhages, macular edema, foveolitis, vasculitis, and optic neuropathy. Most patients with dengue-related ophthalmic complications recover spontaneously without any treatment. Patients with severe visual loss or bilateral involvement were treated with systemic steroids and occasionally immunoglobulins. Prognosis of dengue-related ophthalmic complications is favorable; almost all patients had normal or showed improvement in visual acuity and complete resolution of dengue ophthalmic complications was noted in almost all cases.

Conclusion

The pathological process of dengue ophthalmic complications is complex and clinical manifestations varied. Ophthalmic complications are usually seen in young adults who often present at the nadir of thrombocytopenia. Despite good recovery of vision and resolution of clinical signs in most patients, ophthalmologists and physicians should be aware and vigilant as isolated reports of cases of dengue ophthalmic complications with poor visual acuity refractory to treatment have been reported.