Rare Case of Subacute Vision Loss following development of Rash reported by JAMA

CASE REPORT:

A 37-year-old man with no history of vision problems presented with subacute loss of vision in his right eye for 1 week. The patient described a paracentral scotoma that progressed to involve central fixation over the course of 3 days. Two weeks earlier, the patient and his children had developed malaise, low-grade fever, and a rash. He worked in the armed services and denied foreign travel, tick bites, or recent immunization.

The patient had been evaluated by his primary care clinician and was referred to an ophthalmologist for further evaluation. On examination, his best-corrected visual acuity was 20/70 OD and 20/20 OS.

Test results of intraocular pressures, ocular motility, and pupillary reactions were normal. Confrontation visual fields showed inferonasal and central defects in the right eye.

External examination revealed a macular rash of the scalp and all 4 extremities, including the soles and palms.

Anterior segment examination was normal. Posterior segment examination revealed irregular, gray-white pigmentation of the temporal macula of the right eye without vitritis, optic nerve edema, or vasculitis.

Ocular coherence tomography (OCT) revealed focal, heterogenous disruption of the inner segment ellipsoid zone without neurosensory detachment.

Fluorescein angiography showed late staining at the level of the retinal pigment epithelium (RPE) superotemporal to the fovea. Findings from a dilated fundus examination were normal in the left eye.

Diagnosis revealed Unilateral acute idiopathic maculopathy.

The subacute development of unilateral vision loss in an otherwise healthy young patient with recent viral illness initially led to a referral for possible optic neuritis. However, the lack of pain or relative afferent pupillary defect and irregular macular pigmentation raised concern for an inflammatory maculopathy, such as acute macular neuroretinopathy or unilateral acute idiopathic maculopathy (UAIM).

Although these 2 entities both present with inflammatory changes of the RPE, the unilateral nature and more substantial acuity decline favored UAIM. Furthermore, characteristic unilateral gray-white retinal pigment changes with heterogeneous disruption of the photoreceptor layer and hyper reflective thickening of the apical RPE in the foveal region on OCT confirmed the diagnosis of UAIM.

Despite similarities in temporal profile of vision loss with optic neuritis, UAIM does not involve the retrobulbar optic nerve or intracranial structures, so neuroimaging is not indicated. Herpes virus infection may cause focal retinal whitening secondary to acute retinal necrosis but has not been implicated in UAIM. Although hydroxychloroquine and other potential retinal toxins can present with similar patterns of maculopathy with ellipsoid zone disruption, they are typically insidious and bilateral.

Unilateral acute idiopathic maculopathy is a rare maculopathy. Characteristic findings were inflammatory RPE changes with exudative macular detachment and spontaneous near-complete resolution of vision loss over weeks to months following viral illness. Clinical spectrum of the disease described cases with papillitis, bilateral involvement, and fewer retinal hemorrhages. These first series postulated that UAIM is an inflammatory process and noted potential associations with pregnancy, HIV, and coxsackievirus.

Coxsackievirus is a well-known cause of the highly contagious hand-foot-and-mouth disease (HFMD) that is characterized by its namesake viral exanthem. In 2004, Beck et al presented 2 cases of adult-onset HFMD associated with UAIM. The author group posited that coxsackie virus may have been the cause. Subsequently, numerous case reports have been published of patients with UAIM and concomitant adult-onset HFMD, supporting the potential association. Among these reports, there is no consensus regarding treatment, with many clinicians choosing to observe the often selflimited disease. The potential unproven benefit of using systemic corticosteroids that others elected to provide should be balanced with the potential harm for patients at high risk for systemic complications of treatment. Regardless of treatment, the prognosis is generally good, with most patients recovering near-normal vision.

The patient was diagnosed with adult-onset HFMD. He elected to receive 60 mg of oral prednisone daily with planned taper over 6 weeks for presumed coxsackievirus-related UAIM. Two weeks later, his uncorrected distance visual acuity improved to 20/20 OD, with subjective reduction in scotoma size. There was substantial reduction of the ellipsoid zone disruption on OCT. After 2 months, the patient's visual acuity improved to 20/15 OD with near complete resolution of visual field defect and minimal persistent outer retinal changes on OCT.

Source: doi:10.1001/jamaophthalmol.2020.6586