C as e rep or t Paediatric optic neuritis
Autumn 2021 • Vol 16 | No 2 SA Ophthalmology Journal
33
Neuromyelitis optica and other causes of demyelinating optic neuritis in children DD Shastry MBChB, FC Ophth(SA); Registrar ORCID: https://orcid.org/0000-0002-2727-172X J Olivier MRCOphth, MMed(Ophth); Head of Department of Ophthalmology C Cullen MBBCh, FC Ophth(SA), Fellowship (Paediatric Ophthalmology and Adult Strabismus); Sessional Consultant Dr George Mukhari Academic Hospital, Department of Ophthalmology, Sefako Makgatho Health Sciences University, South Africa Corresponding author: Dr DD Shastry, Department of Ophthalmology, PO Box 66, Medunsa, GaRankuwa 0204; email: dimple_deepa@hotmail.com; cell: 0724322398
Abstract Optic neuritis in childhood is one of the most frequent presentations of an acquired demyelinating syndrome. Paediatric optic neuritis is, however, an infrequent clinical presentation. We present an interesting case of an 8-year-old female with optic atrophy in the left eye accompanied by a right optic neuritis who subsequently developed a lower limb paralysis and right-sided blindness within a few weeks of discharge. Radiological imaging revealed demyelinating lesions of the transverse spinal cord. A diagnosis of neuromyelitis optica (NMO) was made and the patient was treated with immunosuppressive therapy. This article describes the presentation of paediatric optic neuritis as well as the differences between three common aetiologies thereof, namely neuromyelitis optica (NMO), acute
Introduction
Paediatric optic neuritis (PON) is an uncommon clinical presentation and may be challenging to manage. There are few published case series in the literature, mainly from Europe and North America, with limited data from Asia and subSaharan Africa. The incidence in Canada is approximately 0.2 per 100 000.1 From the majority of these case series, <10% of children with ON are documented to develop a demyelinating condition.2 ON in children presents differently from adults; children are more likely to have more severe visual deficit, a preceding viral illness or vaccination and bilateral optic nerve swelling. The Optic Neuritis Treatment Trial (ONTT) conducted on an adult population provided invaluable long-term data on visual outcomes in patients with ON as well as their risk of developing multiple sclerosis (MS). The treatment guidelines provided
disseminated encephalomyelitis (ADEM) and paediatric multiple sclerosis (MS). Management of paediatric optic neuritis is largely based on adult trials. It is necessary for the clinician to bear the diagnosis in mind if young patients present with similar clinical features. Ruling out such conditions is important to prevent permanent vision loss or other neurologic impairment. Keywords: neuromyelitis optica, acute disseminated encephalomyelitis, multiple sclerosis, paediatric, optic neuritis Funding: No funding was received for this study. Conflict of interest: The authors declare they have no conflicts of interest with regard to this study.
by the study are currently the standard of care for adult ON. It was demonstrated that at 15 years, the visual outcomes were good with 72% of patients enrolled to the study having a visual acuity better than or equal to 20/20 in the eye which had ON, and 66% of patients having better than or equal to 20/20 visual acuity in both eyes.3 MS developed in only a small subgroup of patients.3 In contrast, far less is known about the spectrum and outcomes of ON in children. Parainfectious causes are the most common aetiology of ON in children, while the most common aetiology in adults is MS. When PON occurs as a self-limiting isolated event it carries no prognostic implication with regard to the rest of the nervous system. Most children recover visual acuity spontaneously; however, in the cases that fail to recover, the impact on vision is lasting and may take the form of prominent lowcontrast vision, colour perception and visual
field deficits. Current management of PON is mainly based on adult trials and the results of the ONTT where IV methylprednisolone, if given within the first 15 days after onset, may accelerate visual recovery compared to placebo or oral steroids. 3 For most children with ON the recommended firstline treatment is IV methylprednisolone (20–30 mg/kg/d; maximum dose of 1 g/d) for 3–5 days; thereafter tapering prednisone over two weeks (1 mg/kg/d orally). Additional therapies (IV immunoglobulin G and plasma exchange) may be considered in children with diffuse central nervous system involvement who do not show response to IV methylprednisolone. Acquired demyelinating syndromes in childhood commonly present with unilateral ON, followed by rapid bilateral involvement. Frequent relapses have a cumulative effect on visual loss. Herein lies the importance of PON to
