Review

Authors: Eleni Papageorgiou, Rebecca J McLean, Irene Gottlob...

Nystagmus is an involuntary rhythmic oscillation of the eyes, which leads to reduced visual acuity due to the excessive motion of images on the retina. Nystagmus can be grouped into infantile nystagmus (IN), which usually appears in the first 3-6 months of life, and acquired nystagmus (AN), which appears later. IN can be idiopathic or associated to albinism, retinal disease, low vision, or visual deprivation in early life, for example due to congenital cataracts, optic nerve hypoplasia, and retinal dystrophies, or it can be part of neurological syndromes and neurologic diseases. It is important to differentiate between infantile and acquired nystagmus. This can be achieved by considering not only the time of onset of the nystagmus, but also the waveform characteristics of the nystagmus. Neurological disease should be suspected when the nystagmus is asymmetrical or unilateral. Electrophysiology, laboratory tests, neurological, and imaging work-up may be necessary, in order to exclude any underlying ocular or systemic pathology in a child with nystagmus. Furthermore, the recent introduction of hand-held spectral domain optical coherence tomography (HH SD-OCT) provides detailed assessment of foveal structure in several pediatric eye conditions associated with nystagmus and it can been used to determine the underlying cause of infantile nystagmus. Additionally, the development of novel methods to record eye movements can help to obtain more detailed information and assist the diagnosis. Recent advances in the field of genetics have identified the FRMD7 gene as the major cause of hereditary X-linked nystagmus, which will possibly guide research towards gene therapy in the future. Treatment options for nystagmus involve pharmacological and surgical interventions. Clinically proven pharmacological treatments for nystagmus, such as gabapentin and memantine, are now beginning to emerge. In cases of obvious head posture, eye muscle surgery can be performed to shift the null zone of the nystagmus into the primary position, and also to alleviate neck problems that can arise due to an abnormal head posture.

Topics: Cataract; Child; Eye Movements; Head; Humans; Nystagmus, Pathologic; Posture

PubMed: 25086850
DOI: 10.1016/j.pedneo.2014.02.007

Review

Authors: Karen Grønskov, Jakob Ek, Karen Brondum-Nielsen...

Oculocutaneous albinism (OCA) is a group of inherited disorders of melanin biosynthesis characterized by a generalized reduction in pigmentation of hair, skin and eyes. The prevalence of all forms of albinism varies considerably worldwide and has been estimated at approximately 1/17,000, suggesting that about 1 in 70 people carry a gene for OCA. The clinical spectrum of OCA ranges, with OCA1A being the most severe type with a complete lack of melanin production throughout life, while the milder forms OCA1B, OCA2, OCA3 and OCA4 show some pigment accumulation over time. Clinical manifestations include various degrees of congenital nystagmus, iris hypopigmentation and translucency, reduced pigmentation of the retinal pigment epithelium, foveal hypoplasia, reduced visual acuity usually (20/60 to 20/400) and refractive errors, color vision impairment and prominent photophobia. Misrouting of the optic nerves is a characteristic finding, resulting in strabismus and reduced stereoscopic vision. The degree of skin and hair hypopigmentation varies with the type of OCA. The incidence of skin cancer may be increased. All four types of OCA are inherited as autosomal recessive disorders. At least four genes are responsible for the different types of the disease (TYR, OCA2, TYRP1 and MATP). Diagnosis is based on clinical findings of hypopigmentation of the skin and hair, in addition to the characteristic ocular symptoms. Due to the clinical overlap between the OCA forms, molecular diagnosis is necessary to establish the gene defect and OCA subtype. Molecular genetic testing of TYR and OCA2 is available on a clinical basis, while, at present, analysis of TYRP1 and MATP is on research basis only. Differential diagnosis includes ocular albinism, Hermansky-Pudlak syndrome, Chediak-Higashi syndrome, Griscelli syndrome, and Waardenburg syndrome type II. Carrier detection and prenatal diagnosis are possible when the disease causing mutations have been identified in the family. Glasses (possibly bifocals) and dark glasses or photocromic lenses may offer sufficient help for reduced visual activity and photophobia. Correction of strabismus and nystagmus is necessary and sunscreens are recommended. Regular skin checks for early detection of skin cancer should be offered. Persons with OCA have normal lifespan, development, intelligence and fertility.

Topics: Albinism, Oculocutaneous; Diagnosis, Differential; Humans; Prevalence

PubMed: 17980020
DOI: 10.1186/1750-1172-2-43

Authors: Nele Reynaert, Elke Braat, Francis de Zegher...

We observed a male newborn with bilateral nystagmus and central hypothyroidism without hypoprolactinemia due to a deletion of chromosome band Xq26.1q26.2, containing FRMD7 and IGSF1. These two loss-of function mutations are known to cause, respectively, congenital nystagmus and the ensemble of central hypothyroidism, hypoprolactinemia and testicular enlargement. These latter two features may not yet be present in early life.

PubMed: 25780367
DOI: 10.1186/s13633-015-0003-5

Authors:

Topics: Eye; Humans; Nystagmus, Pathologic

PubMed: 7356925
DOI: 10.1136/bjo.64.1.1

Authors: T S Evans

PubMed: 20771952
DOI: 10.1136/bmj.1.3349.453

Review

Authors: Asma Aa Zahidi, J Margaret Woodhouse, Jonathan T Erichsen...

Infantile nystagmus (IN), previously known as congenital nystagmus, is an involuntary to-and-fro movement of the eyes that persists throughout life. IN is one of three types of early-onset nystagmus that begin in infancy, alongside fusion maldevelopment nystagmus syndrome and spasmus nutans syndrome. Optometrists may also encounter patients with acquired nystagmus. The features of IN overlap largely with those of fusion maldevelopment nystagmus syndrome, spasmus nutans syndrome, and acquired nystagmus, yet the management for each subtype is different. Therefore, the optometrist's role is to accurately discern IN from other forms of nystagmus and to manage accordingly. As IN is a lifelong condition, its presence not only affects the visual function of the individual but also their quality of life, both socially and psychologically. In this report, we focus on the approaches that involve optometrists in the investigation and management of patients with IN. Management includes the prescription of optical treatments, low-vision rehabilitation, and other interventions such as encouraging the use of the null zone and referral to support groups. Other treatments available via ophthalmologists are also briefly discussed in the article.

PubMed: 30214368
DOI: 10.2147/OPTO.S126214

Authors: Sung Soo Hwang, Wan Soo Kim, Soo Jung Lee...

AIM

To evaluate the prevalence, clinical features, and the factors affecting onset of strabismus and nystagmus in patients with bilateral congenital cataracts.

METHODS

This study evaluated 116 eyes of 58 patients who underwent lens removal for the treatment of bilateral congenital cataracts between January 1999 and January 2011. The presence and type of strabismus and nystagmus were determined before and after surgery. Type of strabismus and final visual acuity were compared in patients with and without nystagmus. Patients were divided into three groups (orthotropia/orthotropia, orthotropia/strabismus, and strabismus/strabismus) according to their preoperative and postoperative ocular alignment. Age at cataract surgery and associations of nystagmus and primary intraocular lens (IOL) implantation with strabismus were analyzed.

RESULTS

Six patients (10.3%) had strabismus preoperatively and an additional 11 (19.0%) developed postoperative strabismus. Exotropia was more common than esotropia both preoperatively and postoperatively. Eighteen patients (31.0%) had postoperative nystagmus, with sensory nystagmus being the most common type. Of the 18 patients with nystagmus, 10 had strabismus, with exotropia being more common than esotropia. Postoperative visual acuity was poor in patients with nystagmus. Age at cataract surgery and rate of primary IOL implantation were significantly lower, and postoperative nystagmus was more common, in the orthotropia/strabismus group than in the other two groups.

CONCLUSION

Exotropia and sensory nystagmus are common in patients with bilateral congenital cataracts. Age at cataract surgery and rate of IOL implantation are lower and nystagmus more common in patients with postoperative onset of strabismus. Nystagmus is associated with poor visual prognosis.

PubMed: 29862181
DOI: 10.18240/ijo.2018.05.16