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.

Mutations analysis of FRMD7 gene in idiopathic congenital nystagmus families / 中华实验眼科杂志

Objective@#To reveal the pathogenic mutations in Chinese families with idiopathic congenital nystagmus(ICN)@*Methods@#Six families with ICN were recruited from Subei People's Hospital.DNA was extracted from peripheral blood samples of all participants.All coding and exon-intronic boundary regions of the targeted gene FRMD7 were amplified with PCR and sequenced using Sanger sequencing to detect potential pathogenic mutations.This study followed the Helsinki Declaration and was approved by the Ethics Committee of Subei People's Hospital (NO.2015KY-126). All patients or their guardians signed informed consent.@*Results@#Three mutations (c.902A>G, c.1944T>A and 1945G>T) were screened in two families after co-segregation validation of intrafamilial genotype-phenotype, c.1944T>A and 1945G>T were newly detected mutations which were not detected in 100 normal controls.No significant mutations were found in the FRMD7 coding region and adjacent splicing sites in the probands of the other four families.@*Conclusions@#Two novel pathogenic mutations of FRMD7 are discovered, which expands the pathogenic mutational spectrum of FRMD7 gene causing ICN.

Mutations analysis of FRMD7 gene in idiopathic congenital nystagmus families / 中华实验眼科杂志

Objective To reveal the pathogenic mutations in Chinese families with idiopathic congenital nystagmus(ICN) Methods Six families with ICN were recruited from Subei People's Hospital. DNA was extracted from peripheral blood samples of all participants. All coding and exon-intronic boundary regions of the targeted gene FRMD7 were amplified with PCR and sequenced using Sanger sequencing to detect potential pathogenic mutations. This study followed the Helsinki Declaration and was approved by the Ethics Committee of Subei People's Hospital (NO. 2015KY-126). All patients or their guardians signed informed consent. Results Three mutations (c. 902A>G, c. 1944T>A and 1945G>T) were screened in two families after co-segregation validation of intrafamilial genotype-phenotype,c. 1944T>A and 1945G>T were newly detected mutations which were not detected in 100 normal controls. No significant mutations were found in the FRMD7 coding region and adjacent splicing sites in the probands of the other four families. Conclusions Two novel pathogenic mutations of FRMD7 are discovered,which expands the pathogenic mutational spectrum of FRMD7 gene causing ICN.

Clinical features of fundus diseases of familial congenital nystagmus / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To investigate the clinical features of fundus diseases of familial congenital nystagmus.?METHODS: Totally 40 eyes of 20 nystagmus patients from 3 congenital nystagmus families were enrolled in our study. The eye position, refractive error, anterior segment and fundus, including fundus photograph, optical coherence tomography ( OCT) , and visual evoked potential ( VEP) were performed on them.?RESULTS: There were 8 patients in Family A, all of which were horizontal nystagmus, in that 6 cases of strabismus ( 2 of which combined with compensatory head posture) , 2 cases of nuclear cataract, 2 cases of posterior polar cataract, 1 case of retinopathy of prematurity, 2 cases of severe ametropia. There were 6 patients in Family B, all of which were horizontal nystagmus, in that 3 cases of albinism ( 2 of which combined with macular hypoplasia) , 2 cases of severe ametropia, 1 case of achromatopsia, 1 case of nuclear cataract. There were 6 patients in Family C (5 of which were horizontal nystagmus and 1 rotatory nystagmus) ,2 cases of Leber congenital amaurosis, 1 case of familial exudative vitreoretinopathy, 2 cases of posterior polar cataract, 1 case of iris atrophy, 2 cases of strabismus.?CONCLUSION:We have to do detailed examinations on patients suffered from familial congenital nystagmus to understand its causes and to improve their visual functions as well as possible.

Congenital Nystagmus in Turner Syndrome

No abstract available.

A previously unidentified deletion in G protein‑coupled receptor 143 causing X‑linked congenital nystagmus in a Chinese family.

Background: Congenital nystagmus (CN) is characterized by conjugated, spontaneous, and involuntary ocular oscillations. It is an inherited disease and the most common inheritance pattern is X‑linked CN. In this study, our aim is to identify the disease‑causing mutation in a large sixth‑generation Chinese family with X‑linked CN. Methods: It has been reported that mutations in four‑point‑one, ezrin, radixin, moesin domain‑containing 7 gene (FRMD7) and G protein‑coupled receptor 143 gene (GPR143) account for the majority patients of X‑linked nystagmus. We collected 8 ml blood samples from members of a large sixth‑generation pedigree with X‑linked CN and 100 normal controls. FRMD7 and GPR143 were scanned by polymerase chain reaction (PCR)‑based DNA sequencing assays, and multiplex PCR assays were applied to detect deletions. Results: We identified a previously unreported deletion covering 7 exons in GPR143 in a Chinese family. The heterozygous deletion from exon 3 to exon 9 of GPR143 was detected in all affected males in the family, while it was not detected in other unaffected relatives or 100 normal controls. Conclusions: This is the first report of molecular characterization in GPR143 gene in the CN family. Our results expand the spectrum of GPR143 mutations causing CN and further confirm the role of GPR143 in the pathogenesis of CN.

Nondecussating retinal-fugal fiber syndrome: Clinical and neuroimaging clues to diagnosis.

We report the clinical details and imaging findings for a case of nondecussating retinal‑fugal fiber syndrome or isolated achiasma in a 4‑year‑old female child. Findings included the isolated absence of optic chiasm with unremarkable rest of the optic pathway and midline structures in a child presenting clinically with see‑saw nystagmus. Clinically congenital see‑saw nystagmus, “mirror reversal” of visual field representation and interocular ipsilateral asymmetry on monocular visual evoked potential point toward achiasma and warrant further evaluation with magnetic resonance imaging (MRI). Isolated achiasma is a rare condition that may remain undiagnosed unless MRI is done.

Laser Refractive Surgery Using an Active Eye-Tracking System in Congenital Nystagmus

PURPOSE: Nystagmus is not considered a good indication for laser refractive surgery. However, we report 2 cases with congenital nystagmus that underwent a safe procedure due to improvement of laser firing rate and eye tracker. CASE SUMMARY: Two myopic patients with congenital nystagmus underwent transepithelial photorefractive keratectomy with the Schwind Amaris laser platform using an eye tracker. The laser ablations were performed under topical anesthesia without any mechanical eyeball fixation. A 30-year-old man with a history of muscle surgery at 11 years of age had a conjugate, 4 Hz right beating jerk nystagmus. His preoperative refractive error was -8.50 D sph = -0.50 D cyl x 160degrees x 20/30) in the right eye, and -6.00 D sph = -0.75 D cyl x 30degrees x 20/25) in the left eye. A 19-year-old man had a conjugate, 3 Hz pendular nystagmus. His refractive error was -5.25 D sph = -2.50 cyl x 175degrees x 20/30) in the right eye, and -4.25 D sph = -2.50 D cyl x 180degrees x 20/30) in the left eye. Both patients underwent a well-centered laser ablation without any problems. Six months after surgery, uncorrected visual acuity was 20/25 or better, and refractive error was within +/-0.50 D in all 4 eyes. In addition, the 19-year-old man showed decreased nystagmus amplitude. CONCLUSIONS: In some patients with congenital nystagmus, laser refractive surgery may be safely and accurately performed under topical anesthesia using an active tracking system. The best uncorrected visual acuity may improve in certain patients postoperatively.

Changes of palisade ending of extraocular muscle in patients with congenital nystagmus / 中华实验眼科杂志

Background The afferent signals of proprioceptor in extraocular muscles play an important role in controlling eye position and conjugate movement. Palisade ending in the extraocular muscles is the main source of proprioceptive information, and its abnormalities in structure and function may be associated with the occurrence of nystagmus. Objective This study was to observe the changes of palisade ending in the extraocular muscles of patients with congenital nystagmus ( CN) and discuss the probable mechanism. Methods Modified Kestenbaum procedure was performed on 10 patients with CN, and the extraocular muscle samples were collected during the operation. Normal extraocular muscle samples were obtained from the enucleated eyeballs after ocular wound. The ultrathin sections of extraocular muscles were prepared and double-staining by uranyl acetate and lead citrate. The morphological changes of the palisade ending of extraocular muscles were examined under the transmission electron microscopy. Written informed consent was obtained from each subject before surgery. Results The ultrastructure of palisade ending in the extraocular muscle of CN subjects showed the different degrees of alterations. The mild changes included the collapse and disconnection of external capsules and the nonhomogeneous electron-dense substracts. The degeneration and dissociation of myelin in nerve endings, swelling and vacuolation of mitochondria were also exhibited. Myeloid body was found in axon. In the severe patients,the necrosis of Schwann' s cells,dissolve of axon and disappear of capsules were seen. Conclusion The palisade ending of extraocular muscle in the patients with CN are obviously abnormal in comparison with normal one. These alterations are probably associated with the etiology and pathogenesis of CN.

Surgical treatment for correcting abnormal mixed head position in nystagmus with a predominant head turn / 眼科

Objective To evaluate the surgical effect for congenital nystagmus (CN) with an abnormal head position in all three axes of a predominant head turn. Design Retrospective case series. Participants 11 patients with horizontal nystagmus and abnormal head position treated in Xingtai Eye Hospital during 2003-2008. All had an abnormal head position in all three axes with a predomi-nant head turn. Methods Recession of the yoke muscles responsible for the slow phase of nystagmus (one medial rectus of 6mm, and one lateral rectus 8 mm), and simultaneously resection of the yoke muscles responsible for the fast phase of nystagmus (the other lateral rectus 9 mm, and medial rectus 7 mm) were performed. The follow-up was from 6 to 20 months. Main Outcome Measures The visual acuity of both eyes in primary position, the degree of head turn, chin elevation or depression, head tilt. Results At the last follow-up, the all 11 patients undergoing the operation for CN gained two or more lines of Snellen acuity with both eyes in primary position for be-ing corrected best. The postoperative mixed head position of 9 cases got disappear or ≤ 10°. Of 1 case developed overcorrection of the head turn. 1 case has the head turn of ≤15°, and 1 case remained the head turn of 25°. Conclusion Recessions and resections of the horizontal yoke rectus muscles in nystagmus with blockage position, when the head turn predominates over the vertical and torsional components, are effective in diminishing the abnormal head position on all three axes, and improve the visual acuity with both eyes in primary position. (Ophthalmol CHN, 2009, 18: 275-278)

Resultados de la cirugía del tortícolis horizontal por nistagmus ocular congénito / Surgical results of horizontal ocular torticollis present in congenital nistagmus

Objetivo: Conocer los resultados de nuestra cirugía correctora del tortícolis (T) horizontal por nistagmus ocular congénito sin estrabismo. Material y Métodos: Estudio retrospectivo de 31 casos operados con diferentes procedimientos según las características del bloqueo y magnitud del T. Según esto último, los casos se clasificaron en 5 grupos. Resultados: La corrección del T fue exitosa (T residual del 12° o menos) en 80.7 por ciento del total de casos. En dos grupos obtuvimos curación del 100 por ciento de los casos, en otros 2,77 por ciento y 75 por ciento, respectivamente. En el 5° grupo la cirugía no fue uniforme y no es posible extraer normas de sus resultados. Como complicaciones tuvimos la aparición de un pequeño estrabismo en 3 casos y 4 pacientes debieron ser reintervenidos por tortícolis residual. Conclusiones: Las publicaciones con procedimientos comparables a los nuestros son escasas o con resultados vagos. Este estudio permite sacar guías quirúrgicas cuantitativas recomendables para 4 de los 5 grupos.

Purpose: To evaluate our surgical results in horizontal ocular torticollis present in congenital nystagmus without strabismus. Methods: A retrospective review was made in 31 consecutive patients, undergoing different surgical procedures considering the so called null zone and quantity of torticollis. Cases were classified in five groups. Results: In 80.7 percent of cases a successful result was obtained, defined as a residual torticollis not greater than 12°. Two groups obtained 100 percent correction. Two other groups obtained 77 and 75 percent correction respectively. The surgery indicated in group five was too heterogeneous and therefore non conclusive. After surgery a small strabismus presented in 3 cases. Four other patients were reoperated due to remaining torticollis. Conclusions: Papers with comparable procedures are few and don't show exact or detailed results. Our review allows us to obtain guide lines at least in 4 of the 5 groups.

Novel Mutation in FRMD7 Gene in X-linked Congenital Nystagmus

BACKGROUND AND OBJECTIVES: Congenital nystagmus (CN) is an ocular oscillation that usually manifests during early infancy. To report a novel mutation in FERM domain containing 7 (FRMD7) gene in a Korean family with CN. MATERIALS AND METHODS:Genomic DNA was prepared from peripheral blood leukocytes and direct sequencing of the entire coding and adjacent intronic regions was performed to detect sequence variation of FRMD7 gene, where mutations were found recently in patients with familial CN. The family showed an X-linked pattern of inheritance without father-to-son transmission. RESULTS: Three family members with CN exhibited two sequence variations which were a novel mutation (c. 875T>C; Leu292Pro) and a polymorphism (c. 1403G>A; Arg468His, dbSNP rs#6637934). The proband was hemizygous for both variations and his mother and maternal grandmother were heterozygous carriers. CONCLUSION: This study provides an additional evidence for mutations in FRMD7 as a common cause of X-linked CN and expands its mutation spectrum.

Clinical and Oculographic Findings of X-linked Congenital Nystagmus in Three Korean Families

BACKGROUND AND PURPOSE: Congenital nystagmus (CN) is an ocular oscillation that usually manifests during early infancy. Typical features of CN include bilateral, conjugate, uniplanar, and usually horizontal eye movements, a null position, increased oscillation during fixation, and decreased amplitude during convergence. Our purposes were description and analysis of clinical and oculomotor findings of patients with X-linked familial CN. METHODS: We describe the clinical and oculographic features of five patients from three families with X-linked CN. Three-dimensional video-oculography disclosed various patterns of CN and variable degrees of gaze-holding deficits and visual impairments. RESULTS: The features of CN varied even in patients from the same family. Head tilt, strabismus, reversal of optokinetic nystagmus, and impairments of the vestibulo-ocular reflex, smooth pursuits, and saccades were frequent findings. CONCLUSIONS: The intra- and interfamilial diversities imply that heredity plays a secondary role in determining the clinical phenotypes and waveforms of CN.

Clinical and Oculographic Findings of X-linked Congenital Nystagmus in Three Korean Families

BACKGROUND AND PURPOSE: Congenital nystagmus (CN) is an ocular oscillation that usually manifests during early infancy. Typical features of CN include bilateral, conjugate, uniplanar, and usually horizontal eye movements, a null position, increased oscillation during fixation, and decreased amplitude during convergence. Our purposes were description and analysis of clinical and oculomotor findings of patients with X-linked familial CN. METHODS: We describe the clinical and oculographic features of five patients from three families with X-linked CN. Three-dimensional video-oculography disclosed various patterns of CN and variable degrees of gaze-holding deficits and visual impairments. RESULTS: The features of CN varied even in patients from the same family. Head tilt, strabismus, reversal of optokinetic nystagmus, and impairments of the vestibulo-ocular reflex, smooth pursuits, and saccades were frequent findings. CONCLUSIONS: The intra- and interfamilial diversities imply that heredity plays a secondary role in determining the clinical phenotypes and waveforms of CN.

A Case of Infantile Nystagmus in a Child with Schizencephaly

PURPOSE: Nystagmus is a rare involuntary eye movement which has no known, specific, underlying diseases. Schizencephaly is also a rare disease. A child with generalized developmental delay came to the pediatric clinic. He showed schizencephaly on MRI, and was referred to department of rehabilitation. During rehabilitative evaluation, the patient was referred to the department of ophthalmology due to esotropia. We found that the patient had little esotropia, but did have nystagmus. Therefore, we report a case of congenital nystagmus associated with schizencephaly. METHODS: A one-year-old boy showing schizencephaly on MRI and esotropia underwent examination. RESULTS: The patient did not have a remarkable past or familial history, and didn't show any other anomaly. There were no abnormal findings on slit lamp examination, and according to strabismus studies, he showed very little esotropia. He did show nystagmus. We couldn't find any significant refractive error or ocular dysfunction on cycloplegic refraction and fundus examination, respectively. Visual evoked potential showed normal findings. On MRI, ordered by the pediatrician, open-lip type schizencephaly on the right frontal lobe and absence of septum pellucidum were seen. There was no endocrinologic abnormality. CONCLUSIONS: We report the case of a child with congenital nystagmus accompanied by schizencephaly, and present a literature review.

Two Cases of Oculocutaneous Albinism with Congenital Nystagmus / 대한이비인후과학회지

Albinism is a hereditary disease caused by the defect of tyrosinase that converts tyrosine to dihydroxyphenylalanine (DOPA). `Oculocutaneous albinism' is classified as hypopigmentation of skin, hair and eyes, but incidences of `ocular albinism' where hypopigmentation is limited to eyes are found rarely. Biochemically, albinism is caused by the tyrosinase activity. Typical findings in oculocutaneous albinism include not only ophthalmologic problems such as hypopigmentation of skin, foveal hypoplasia, photophobia and decreased visual acuity but also congenital nystagmus. We cannot determine distinctive characteristics of nystagmus of albinism because domestically, there are only a few reports that have been recorded correctly about nystagmus of albinism. Merely, we present our experience of two cases of albinism with congenital nystagmus because we think that these two cases, showing different types of nystagmus and electronystagmography, stand for the two representative types of nystagmus found in the literature up to date.

Two Cases of Bilateral Reversed Optokinetic Nystagmus / 대한이비인후과학회지

Normally, the fast phase of optokinetic nystagmus (OKN) beats on the opposite direction to the movement of an optokinetic stimulus. The fast component of OKN beating in the same direction are called "reversed OKN". Eventhough the mechanism of reversed OKN is still disputed, it is well known that reversed OKN occurs exclusively in patients with congenital nystagmus, or in some cases, with acquired neurologic disease. It is easy to diagnose the congenital nystagmus when the spontaneous nystagmus can be seen at birth. But when the congenital nystagmus can be seen only on eccentric gaze or when the patient has a wide neutral region around the primary position, the abnormal eye movement can not be detected until a medical examination is performed. It is thought that causes of reversed OKN may be the abnormal neural decussation of the visual system or spontaneous nystagmus. Recently, we experienced two cases of bidirectional reversed OKN as a congenital nystagmus. One patient had bilateral reversed optokinetic nystagmus and gaze evoked nystagmus, whereas the other patient had periodic alternative nystagmus and bilateral reversed OKN. Bilateral reversed OKN may be one of the pathognomic signs of congenital nystagmus.

Congenital Nystagmus

Twenty patients were operated on under the diagnosis of congenital nystagmus(CN). Of these, nineteen were motor CN and one was sensory CN. Head turning was toward the leftside in 13 patients(65.0%) and the rightside in 7(35.0%). Preoperatively, the degree of head turn ranged from 20 degrees to 45 degrees with a mean of 34.5 degrees. Primarily, modified Kestenbaum procedures were performed and, if necessary, 2nd and/or 3rd operations(Anderson's procedure, Goto's procedure) were performed additionally. The degrees of head turn after the 1st operation ranged from -5 degrees to 30 degrees with a mean of 11.5 degrees. On an average, 23.5 degrees was corrected by 14.8mm of operation on muscles(resection plus recession) for each eye. By these procedures, seventeen patients(85.0%) showed improvement or cure(75% after 1st operation and 10% after 2nd and/or 3rd operation).

Surgical Effect of Augmented Modified Kestenbaum Procedure Combined with Conjunctival Recession for the Abnormal Head Position in Congenital Nystagmus

We performed surgery for correction of abnormal head turn in 10 patients with congenital nystagmus. For 3 patients with a head turn of 30 degrees, a 40% augmented modified kestenbaum operation was performed. For 4 patients with a head turn of 45 degrees, a 40% augmented modified kestenbaum operation combined with a 3 - 4 mm recession of conjunctival and subconjunctival tissues was performed. Finally, for 3 patients with a head turn of 60 degrees, a 60% augmented modified kestenbaum procedure combined with a 3 - 4 mm recession of conjunctival and subconjunctival tissues was performed. At the final follow-up visit(averaging 5.9 months), 7 patients showed complete corrections of previous head turn and 3 patients showed a small residual head turn of less than 10 degrees to the same side of the preoperative head turn. The average amount of correction we obtained from the surgery described above were 26.7, 42.5 and 56.7 degrees for the patients who had had a preoperative head turn of 30, 45 and 60 degrees respectively. Among the 10 patients, 4 showed no change in corrected visual acuity, but 6 showed increased corrected visual acuity by over 1 Snellen line. From the above results, we concluded that if recession procedure of the conjunctival and subconjunctival tissues was combined with augmented modified Kestenbaum procedure, its effect for correction of abnormal head turn in a patient with congenital nystagmus could be enhanced.