The challenges faced by clinicians diagnosing and treating infantile nystagmus Part I: diagnosis

ABSTRACT

Introduction

Infantile nystagmus syndrome (INS) consists of involuntary oscillation of the eyes, that usually develop within the first months of life. INS can be idiopathic or associated with albinism, retinal dystrophies, low vision, or it can be part of syndromes and neurological disorders. Due to the variety of etiologies and clinical presentations, clinicians often face challenges in the diagnostic workup of INS, and patients often undergo numerous investigations.

Areas covered

This review will address approaches to improve the diagnosis of children with INS, and provide the best clinical care and future opportunities for affected children. We will discuss updates on clinical assessment, laboratory investigations, and strategies to advance the diagnosis and monitoring of INS using advanced ophthalmic imaging, diagnostic equipment, and genetic testing.

Expert opinion

Recent advances in pediatric retinal imaging, by means of handheld optical coherence tomography, provide detailed assessment of foveal structure in several pediatric eye conditions associated with nystagmus, and it can be used to determine the ocular abnormalities of infantile nystagmus. Additionally, the identification of new genes has greatly enhanced our understanding of INS and facilitate early diagnosis and management.

KEYWORDS:

• Foveal hypoplasia
• idiopathic infantile nystagmus
• fusion maldevelopment nystagmus syndrome
• manifest latent nystagmus
• ocular albinism
• optical coherence tomography
• spasmus nutans
• visual evoked potential

Article highlights

• Infantile nystagmus syndrome is commonly seen in pediatric ophthalmology practice and may pose diagnostic dilemmas due to the variety of aetiologies and clinical presentations.

• The most common forms of INS are idiopathic infantile nystagmus (IIN) and albinism-associated nystagmus.

• The gene FRMD7, which is involved in neurite development, has been identified as the major cause of hereditary X-linked IIN.

• In ocular albinism, there are typical clinical signs, such as iris transillumination, foveal hypoplasia and optic nerve misrouting at chiasma.

• Fusion maldevelopment nystagmus syndrome (FMNS) is almost always associated with the congenital squint syndrome.

• Acquired nystagmus is an alarming sign, that requires immediate neurological and neuroimaging investigation.

• Assessment of the child with nystagmus includes several investigative methods, such as eye movement recordings, optical coherence tomography (OCT), electrodiagnostics, brain neuroimaging and genetic testing.

• Recently, a handheld OCT diagnostic algorithm has been developed for the investigation of children with nystagmus and to focus diagnostic testing.

• Molecular genetic testing plays an increasingly important role in identifying the exact etiology of INS.

Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.