Calming the Visual Storm: Management of Childhood Nystagmus

Childhood nystagmus creates a visual storm both for the affected child and the treating doctor. This problem occurring in the development phase of the child affects not only the vision but also the general development, if not diagnosed and managed in time. Moreover, some forms may even harbor a neurological tumor needing timely management. First, a brief introduction of nystagmus classification, a simplified approach to diagnose the common childhood nystagmus, and the value of electrophysiology will be presented. Next, the approach to treatment, using a thorough clinical examination, illustrated by patient examples of different types of nystagmus will be presented. The different forms of childhood nystagmus are described: idiopathic infantile nystagmus syndrome (IINS), sensory nystagmus (SN), fusion maldevelopment nystagmus (FMDN), spasmus nutans syndrome (SNS), nystagmus blockage syndrome, periodic alternating nystagmus, and others as well as their specific management. The role of electronystagmography and that of neuroimaging in specific conditions is life saving and is described. The role of auditory biofeedback, acupuncture, medical treatment, and surgical procedures like Augmented Anderson procedure, Hertle-Dell'Osso procedure, supra maximal retro-equatorial recession, and posterior fixation have been elucidated. Newer techniques have simplified the management options and improved the functional outcomes in childhood nystagmus. To conclude, children with nystagmus of types IINS, FMDN, SNS, or SN need to be managed differently. It is thus possible to timely manage these children, not only to save their life and improve their vision but also to improve their living quotient.

Progress of research on infantile nystagmus syndrome / 国际眼科杂志(Guoji Yanke Zazhi)

@#Infantile nystagmus syndrome(INS)is a congenital pathological nystagmus characterized by binocular involuntary conjugative oscillation and reverse optokinetic nystagmus. This condition is often accompanied by amblyopia, strabismus, and torticollis, affecting the visual function of INS patients. As the cause of the disease is unclear and cannot be completely cured, early detection and appropriate intervention of INS should be carried out. Based on domestic and foreign researches of INS, in this paper, we summarize INS etiology and occurrence mechanism. Furthermore, to provide a reference for clinical application and future research directions of INS, we have systematically introduced the most recent INS examination and treatment methods, and highlight the problems in relevant clinical practice.

Nistagmo secundario a albinismo con compromiso ocular en paciente femenina: un desafío diagnóstico / Nystagmus secondary to albinism with ocular involvement in a female: a diagnostic challenge

INTRODUCCIÓN: El nistagmo infantil es infrecuente y representa un desafío diagnóstico para el pediatra. El albinismo es una de sus principales causas, siendo difícil de sospechar en ausencia de compromiso cutáneo evidente, especialmente en pacientes femeninas, debido a que tipo de herencia del albinismo ocular. OBJETIVO: Describir un caso de nistagmo secundario a albinismo con compromiso ocular aislado en paciente femenina, para discutir el enfoque diagnóstico pediátrico. CASO CLÍNICO: Paciente fe menino de 3 semanas de vida, sin antecedentes mórbidos, derivada a neuropediatra y oftalmólogo por movimientos oculares paroxísticos desde las 2 semanas, con estudio con electroencefalograma e imágenes cerebrales normales. A los 3 meses se confirmó translucencia iridiana, nistagmo y astigmatismo hipermetrópico. La valuación dermatológica descartó compromiso cutáneo. Evolucionó con inclinación cefálica hacia abajo y retraso del desarrollo de la coordinación, fue manejada con lentes de corrección y kinesioterapia. A los 3 años, destacaba mejoría de la agudeza visual, disminución del nistagmo y neurodesarrollo normal. La evaluación oftalmológica de ambos padres fue normal y no había antecedentes de nistagmo o albinismo en la familia. Por decisión de los padres no se realizó estudio genético. CONCLUSIÓN: El diagnóstico de nistagmo secundario a compromiso ocular del albinismo, aún en ausencia de afección cutánea, es clínico; el estudio genético permite confirmar la etiología, sin ser un examen imprescindible, a menos que se considere la planificación familiar. La pesquisa oportuna e intervención multidisciplinaria determinan un mejor pronóstico.

INTRODUCTION: Infantile nystagmus is an infrequent condition that represents a diagnostic challenge for the pediatri cian. Albinism is one of its main causes, being difficult to suspect in the absence of evident cutaneous involvement, especially in female patients, due to the inheritance type of ocular albinism. OBJECTIVE: To describe a case of nystagmus secondary to albinism with isolated ocular involvement in a female patient, in order to provide tools for pediatric approach and diagnosis. CLINICAL CASE: Three- weeks-old female patient, without morbid history, referred to a pediatric neurosurgeon and ophthal mologist due to paroxysmal eye movements since 2 weeks of age. The electroencephalogram and brain images were normal. In follow-up monitoring at 3 months, iris translucency, nystagmus, and hypermetropic astigmatism were confirmed. Dermatologic evaluation ruled out cutaneous invol vement. The patient developed cephalic downward inclination and coordination development de lay was confirmed, the patient was handled with corrective lenses and kinesiotherapy. In follow-up monitoring at 3 years, there was an improvement in visual acuity, decreased nystagmus and normal neurodevelopment. The ophthalmological evaluation of both parents was normal and there was no history of nystagmus or albinism in the family. Upon her parents' decision, no genetic study was ca rried out. CONCLUSION: The diagnosis of nystagmus secondary to ocular albinism, even in the absence of cutaneous involvement, is clinical. The genetic study allows confirming the etiology, without being an essential examination, unless family planning is considered. Timely research and multidisciplinary intervention determine a better prognosis.

Surgical Management of Concurrent Strabismus and Face Turn in Patients with Infantile Nystagmus

PURPOSE: To investigate the effect of adjusted Kestenbaum surgery in patients with idiopathic infantile nystagmus who were affected by both strabismus and face turn. METHODS: This retrospective consecutive case series included 12 patients with infantile nystagmus who had face turn and strabismus. All patients underwent adjusted Kestenbaum surgery between 1996 and 2014, and primary outcome measures were the postoperative degree of face turn and strabismus. RESULTS: All patients had jerky nystagmus with compensatory face turn and strabismus. Of the 12 patients, eight patients were exotropes and four patients were esotropes. The mean age at surgery was 12.5 ± 10.7 years (range, 2–36 years). The mean postoperative follow-up was 17.8 ± 12.0 months (range, 7–43 months). Surgery was successful in eight (66.7%) out of 12 patients. Improvement of anomalous head posture was satisfactory in all patients, but an angle of deviation within 10 prism diopters was not achieved in four patients. CONCLUSIONS: Adjusted Kestenbaum surgery simultaneously improved both ocular misalignment and face turn with one-stage surgery. Two or three rectus muscles surgery can be considered in these patients because it is not only simpler than four muscles surgery but also can preserve one or two rectus muscles.

Clinical characteristics of X-linked infantile nystagmus in a Chinese family / 上海交通大学学报（医学版）

Objective • To identify the clinical features of a Chinese Han family with X-linked infantile nystagmus. Methods • A Chinese family with X-linked infantile nystagmus was recruited from Department of Ophthalmology in Xinhua Hospital, Shanghai Jiao Tong University School of Medicine. Peripheral blood from the members of the family was collected and molecular genetic analysis was done. The 5 patients in the family received comprehensive ocular examinations including measurement of visual acuity, degree of anomalous head posture, stereoscopic vision, binocular function, electroretinogram, visual evoked potential, optical coherence tomography, eye movement recording and cycloplegic refraction. Results • A frame-shift mutation (c.823-829delACCCTAC, p.Thr275fs) in the 9th exon of FERM domain containing protein 7 (FRMD7) in the family was found. The similar clinical features of the family included moderate impairment of visual acuity, mild astigmatism, reduced stereoscopic vision, no fusion function, and bidirectional jerk wave form. Their electroretinograms were normal, but there was a peak latency and decreased amplitudes in visual evoked potential. And the structures of maculae had no obvious abnormality. The performance of the anomalous head posture was varied. Conclusion • Thr275fs in FRMD7 protein is identified as the main factor in the Chinese family with X-linked infantile nystagmus. The clinical features of the family show a certain degree of consistency.

Caracterización medicoquirúrgica en el síndrome de nistagmos infantil / Medical and surgical characterization of infantile nystagmus syndrome

Introducción: las oscilaciones oculares involuntarias en la infancia pueden comprometer la agudeza visual del niño; de ahí la importancia de manejarlas adecuadamente. Objetivo: describir el tipo de nistagmos y el tratamiento indicado en cada paciente con síndrome de nistagmos infantil. Métodos: se realizó un estudio observacional, descriptivo, de corte transversal, de una serie de 60 pacientes con diagnóstico síndrome de nistagmos infantil. Se analizaron la edad, los tipos de nistagmos, los defectos refractivos asociados y los tratamientos indicados en cada caso. Se procesaron con el programa informático para análisis estadístico SPSS para Window, versión 2.1, y se utilizó la media y la mediana como medidas de tendencia central, y la desviación estándar y el rango intercuartílico como medidas de dispersión. Resultados: la edad promedio de los pacientes estudiados fue de 5,8 años. Predominaron los pacientes del sexo masculino (56,7 por ciento vs. 43,3 por ciento). El nistagmos sensorial fue el encontrado con mayor frecuencia (80,0 por ciento) y la mediana fue de 4 años 6 meses. La causa más frecuente de este tipo de nistagmos fue la hipoplasia papilar (20,8 por ciento), en uno y otro sexos. El astigmatismo hipermetrópico fue el defecto refractivo hallado con mayor frecuencia en estos pacientes. El tratamiento farmacológico fue el más utilizado (65,0 por ciento), en particular con dorzolamida 2 por ciento colirio (94,9 por ciento). El tratamiento quirúrgico se empleó en el 20,0 por ciento de los pacientes y la técnica más empleada fue la recesión de los 4 rectos horizontales. Conclusiones: los nistagmos sensoriales son los más frecuentes y se manejan fundamentalmente con tratamiento farmacológico(AU)

Introduction: the involuntary eye movements in childhood may compromise the child´s visual acuity; hence it is important to properly manage them. Objectives: to describe the type of nystagmus and the prescribed treatment for each patient suffering the infantile nystagmus syndrome. Methods: observational, descriptive and cross-sectional study conducted in 60 patients with diagnosis of infantile nystagmus syndrome. Age, types of nystagmus, associated refractive defects and prescribed treatments in each case were analyzed and processed with statistical analysis software SPSS for Windows, version 2.1. Mean and median; and standard deviation and interquartile range were used as central tendency and as dispersion measures, respectively. Results: the average age of the studied patients was 5,8 years. Men predominated (56,7 percent vs. 43,3 percent). The sensorial nystagmus was the most frequent (80 percent) and the median was 4 years and 6 months. The most common cause in this nystagmus type was papillary hypoplasia (20,8 percent) in both sexes. The hypermetropic astigmatism was the most found refractive defect in these patients. The drug treatment was the most used (65 percent), particularly 2 percent dorzolamide eyedrop (94,9 percent). The surgical treatment was used in 20 percent of the patients and the most used technique was recession of the 4 horizontal rectus muscle. Conclusions: sensorial nystagmus is the most frequent and they are fundamentally managed with drug treatment(AU)

Two Cases of Mirror-Image Eye Anomalies in Monozygotic Twins

We report two cases of mirror image anomalies in two different pairs of monozygotic twins. In case 1, the twins exhibited mirroring of strabismus and refractive errors. Twin 1 had 35 prism diopters (PD) right intermittent exotropia at distant fixation and myopic anisometropia that was spherical 2.00 diopters more myopic in the right eye. Twin 2 had 35 PD left intermittent exotropia at distant fixation and her left eye was more myopic by - spherical 1.00 diopters. In case 2, the twins were diagnosed with infantile nystagmus with upbeat jerk. Twin 1 exhibited a habitual head turn of 30degrees to the left with dampening of her nystagmus in dextroversion. Twin 2 also exhibited abnormal head position, but in his case the habitual turn was 30degrees to the right. We believe that this is the first report describing mirror imaged intermittent exotropia with anisometropia and infantile nystagmus with opposite abnormal head positions in pairs of monozygotic twins.

Relationship Between Visual Acuity and Foveation Window in Infantile Nystagmus by Analyzing Nystagmus Waveforms

PURPOSE: To report herein on Nystagmus Acuity Estimator Function (NAEF) based on the foveation time, obtained by analyzing waveforms of infantile nystagmus patients and comparing the results with the patients' actual visual acuity. METHODS: Electro-oculographic data of 27 patients with infantile nystagmus were reviewed. Data of patients only with jerk type nystagmus and reliable visual acuity were analyzed. The foveation time was measured, and NAEF was calculated and compared with the patients' actual best corrected visual acuity. RESULTS: A correlation analysis of the patients' best corrected visual acuity with NAEF was performed, and the retrieved coefficient was 0.4266. The p-value calculated using the Pearson correlation coefficient was 0.0282, implying that high NAEF correlates positively with visual acuity. CONCLUSIONS: Estimated visual acuity, calculated based on the waveforms, positively correlates with the patients' actual visual acuity with statistical significance. However, since the foveation time can be measured only in the patients with jerk-type nystagmus waveforms, further study should be performed on the measurement of the foveation time with other waveforms. Furthermore, the present study shows that such analysis is possible with electrooculogram settings in most general hospitals.

Surgery for Vertical Abnormal Head Posture in Infantile Nystagmus

PURPOSE: The purpose of this study is to assess the effect of surgical management for infantile nystagmus with vertical abnormal head posture. METHODS: We performed surgical procedures to correct the vertical abnormal head posture of more than 10degrees in 6 patients with infantile nystagmus. One patient with the chin-up head posture was treated with recession of bilateral inferior rectus muscles and resection of bilateral superior rectus muscles, and 5 patients with the chin-down head posture were treated with recession of bilateral superior rectus muscles and resection of bilateral inferior rectus muscles. The pre- and post-operative measurements of the head posture were evaluated and compared with each other. RESULTS: Preoperatively, the degree of vertical head posture ranged from 10 to 30degrees, and 4 patients were with the 20~30degrees abnormal head posture. In the average follow-up period of 35.8 months, 5 patients (83.3%) showed less than 5degrees of chin-up or chin-down head posture. In one case, 20degrees left face turn was noted postoperatively. However, duction was full in all cases. CONCLUSIONS: These results suggest that the surgical management with bilateral vertical rectus muscles was effective for the correction of vertical abnormal head posture in infantile nystagmus.

The Effect of Wearing Prism in Infantile Nystagmus

In infantile nystagmus, we evaluated the changes in visual acuity, nystagmus intensity and face turning between with prism and without prism. 4 patients chosen in our study had a fusional ability examined by Worth-4Dot test and were not accompanied with strabismus. It was confirmed by the inspection of eyes and electro-oculogram that visual acuity at near fixation was better than that at distant fixation and the nystagmus intensity was decreased by convergence. The age distribution of the patients was between 6 and 20 years old. The period of wearing prism ranged from 2.5 to 8.5 months. Improvement in binocular visual acuity at distant fixation with prism was noted relatively from 4 lines to 1 line, the nystagmus intensity (Amplitude x Frequency) calculated by analyzing eletro-oculogram records resulted in the decrease with prism in comparison with that without prism (p<0.05). And the main cause of decrease in nystagmus intensity was determined by that in amplitude rather than frequency. The ranges of correction of face turning at distant fixation wer between 10 degrees and 20 degrees. As the result of this study, in case that nystagmus intensity can be decreaed by convergence and prism is worn succeedingly without any trouble, we assume that the use of bilateral base-out prism will be one of the effective methods for decrease in nystagmus intensity, improvement in visual acuity and face turning.

The Effect of Modified Kestenbum Procedure (6-7-6-7mm) for Abonormal Heal Position in Infantile Nystagmus

We assessed the efficacy of modified Kestenbaum procedure for the correction of abnormal head position in 16 patients with the diagnosis of in fantile nystagmus. Instead of Parks 5-6-7-8mm modified Kestenbaum procedure, we performed 6-7-6-7mm modified Kestenbaum on 11 patients with head turn of 20-30, 20% augmented procedure(7.2-8.4-7.2-8.4mm) on 4 patients with head turn of 30 or more, and-1mm procedure(5-6-5-6mm) on 1 patent with head turn of less than 20. In the average follow-up of 7 months, 10 patients(62.5%) showed head turn of less than 5, in which 14 of 16 patients had less than10 .87.5% of the patients showed satisfactory correction of abnormal head position., 12 prism diopter of exotropia was noted postoperatively in 1 case but the duction was not limited in any case. From the above results, we conclude that 6-7-6-7mm modified Kestenbaum nystagmus.

Clinical Characteristics of Infantile Nystagmus

The authors analyzed clinical characteristics of 33 patients who were diagnosed as infantile nystagmus from August, 1994 to January, 1995 at St. Pauls Hospital Catholic University Medical College. The 26 patients were men and the seven patients were women. Onset or detected age of nystagmus was 1.68 year old in average(at birth-10 year old) and inheritances were presented in 8 case. Visual acuity were better at near than at far and at head tilting position than at straight position(p<.01). Abnormal head postures were presented in 31 cases. In waveform analysis at primary position, horizontal waveform were 30 cases, vertical waveform were 2 cases, vertical and rotational waveform was 1 cases, and then pendular type were 17 cases, jerk type were 10 cases, and combined type were 6 cases. Patients of 28 cases were orthotropia, 5 cases were accompanied by various type of strabismus, 23 cases were accompanied by fusional capacity, and 3 cases were showed head nodding.

Electrooculographic Study of Latent Nystagmus

The authors analysed eleven patients with latent nystagmus who were diagnosed by clinical manifestation and electrooculography during six months. Among them, six patients had monocular amblyopia, four had binocular amblyopia and only one had normal visual acuity. All of them had manifest latent nystagmus which had a small amplitude of nystagmus in binocular fixation. Two of them showed typical latent nystagmus, jerky wave form characterized by decreasing velocity in slow phase and directing to fixing eye. Seven patients showed typical latent nystagmus wave form associated with pendular wave form and two patients showed jerky wave form with increasing velocity in slow phase. Therefore nine patients had componant of infantile nystagmus wave form. Ten of them had strabismus. Among them, five patients had hyper tropia. Three of the hypertropic patients showed dissociated vertical deviation. The authors suggest that the latent nystagmus is a kind of infantile nystagmus, and abnormal ocular conditions such as strabismus and amblyopia affects the infantile motor nystagmus.

Analysis of Inheritance in Infantile Nystagmus

Infantile nystagmus is characterized by involuntary oscillations of one or both eyes being present at birth or shortly thereafter without systemic or ophthalmologic lesions. Its inheritance pattern is not known exactly, but three types have been distinguished; irregular dominant, sex linked recessive, and simple recessive patterns. We observed 15 patients with family history and analyzed the characteristics of their inheritance patterns. We concluded the patterns of inheritance are irregular X-linked or autosomal dominant inheritance with incomplete penetrance in 7 families(47%), X-linked recessive or autosomal dominant inheritance in 5 families(33%), and autosomal dominant inheritance in 3 families(20%), respectively.

The Effect of Kestenbaum Procedure for Abnormal Head Position in Infantile Nystagmus

We performed modified Kestenbaum procedures for correction of abnormal head position in 24 patients with infantile nystagmus. Preoperatively, the degree of head turn ranged from 15 degrees to 45 degrees. For 12 patients with head turn of 15 degrees ~ 30 degrees, 5-6-7-8 modified Kestenbaum procedures were performed. For 9 patients with head turn of 30-40, 20% augmented Kestenbaum procedures were performed and one patient with a 45degree head turn underwent a 30% augmented Kestenbaum procedure. Two patients with vertical chin down underwent 6-7mm recessions of both superior rectus muscles and 5mm resections of both inferior rectus muscles. In the follow-up of an average 12 months, 20 out of 24 patients showed no residual head turn or head turn less than 10 degrees. The modified Kestenbaum procedure could correct the abnormal head position successfully in 83% of infantile nystagmus with one operation. From the above results, we found that the proper amounts of Kestenbaum surgery were 5-6-7-8mm for 25 degrees or less than 25 degrees head turn, 20% augmentation for 30 degrees head turn and 30% or more augmentation for 40 degrees or more head turn.

A Case of Atypical Latent Nystagmus Associated with Infantile Nystagmus

The latent nystagmus seems to be absent when both eyes are open, but on covering one eye, bilateral jerky nystagmus is evoked with the fast phase toward the uncovered eye. The confirmed diagnosis of latent nystagmus can be made with the aid of the Electro-oculography (EOG). On EOG recording, we experienced a case of latent nystagmus in light, which showed the characteristics of infantile nystagmus in darkness.

Absence of visual sampling in infantile nystagmus

The possibility that patients with infantile nystagmus achieve spatial constancy by sampling the visual scene only during certain range of velocities or certain phases of their nystagmus cycle was investigated by asking patients to detect a flashed test target that was presented repeatedly during all phases of the nystagmus cycle. After observing a 543 nm fixation spot projected on a diffusely illuminated tangent screen 1 m in front of the eye, patients were asked to detect a 2 msec test flash of the spot, now locked to the retina, that occurred 200 msec after the fixation spot was extinguished. The test target appeared randomly at 3,6,9, or 12 o'clock at, in separate trials, 0.8 deg or 10.0 deg from central vision. To avoid forcing patients from guessing a direction cued by the disappearance of the fixation spot, sometimes the flash did not occur at all. To avoid dark adaptation in our patients, the diffuse background illumination was adjusted to the brightest level allowing easy detection of the test flash. In every condition, all patients reported the fixation spot stationary. The probability of detection was the same across all velocity ranges. Remarkably, patients were just as likely to detect the test flash when the eye was nearly stationary even when it was moving more than 100 deg/sec. In one patient, the background illumination was raised so that he began missing the test flash more often. Here too, the probability of detection, now reduced to about 50%, was the same across velocity ranges. In some patients we tried to backward mask the test flash by having the fixation spot reappear at various time after the test flash (40-2000 msec). Detection probability was unaffected by the reappearance of the fixation spot with the time interval tested. We conclude that the absence of oscillopsia in our patients was not accomplished by a sampling or masking process.