High-dose Anderson operation for nystagmus-related anomalous head turn

[High-dose medialis recession in latent nystagmus]

BACKGROUND

Large muscle recessions reduce anomalous head turn (AHT) in infantile nystagmus syndrome (INS). Their quantitative effect to reduce AHT in fusion maldevelopment nystagmus syndrome (FMNS) is unknown.

AIM OF THE STUDY

To evaluate the reduction of AHT by large medial rectus muscle recession in patients with FMNS.

METHODS

We analyzed data of 12 patients with pure FMNS who received large medial rectus muscle recessions on the sound eye or only eye between 2014 and 2019. Medians and ranges (min-max) were: age at surgery 14 years (3-43 years); decimal BCVA sound eye/fellow eye 0.56 (0.4-1.0)/0.01 (0-0.4); AHT at 5 m/0.3 m fixation distance 35° (15-45°)/20° (0-45°); amount of recession 13 mm (11.5-15 mm); follow-up 13 (4-39) months.

RESULTS

At the final visit, AHT at 5 m/0.3 m was 10° (0-20°/0-15°). The individual reduction of AHT at 5 m amounted to 25° (8-35°) without any overcorrection. The available visual field of functionally monocular patients increased correspondingly. Slight overcorrection at 0.3 m occurred in 2 cases. Adduction of the sound eye was limited to 25e-40°). BCVA and anomalous head posture in vertical and frontal planes did not improve.

CONCLUSION

Large medial rectus muscle recession on the sound eye improves AHT in FMNS by a similar amount compared to INS and the available visual field of functionally monocular patients.

Surgical Treatments to Improve Visual Acuity in Infantile Nystagmus Syndrome: A Report by the American Academy of Ophthalmology

PURPOSE

To review the literature on the efficacy of surgical procedures to improve visual acuity (VA) in patients with infantile nystagmus syndrome (INS).

METHODS

Literature searches were last conducted in January 2022 in the PubMed database for English-language studies with no date restrictions. The combined searches yielded 354 abstracts, of which 46 were reviewed in full text. Twenty-three of these were considered appropriate for inclusion in this assessment and were assigned a level of evidence rating by the panel methodologist.

RESULTS

One included study was a randomized trial; the remaining 22 were case series. The 23 studies included children and adults with INS and a variable proportion with anomalous head position (AHP), strabismus, and sensory diagnoses. The surgical interventions evaluated included large recessions, tenotomy and reattachment (TAR), myectomy with or without pulley fixation, and anterior extirpation of the 4 horizontal rectus muscles, as well as various procedures to correct an AHP in which VA was reported as a secondary outcome. The data were mixed, with improvements in binocular best-corrected visual acuity (BCVA) ranging from no improvement to 0.3 logarithm of the minimum angle of resolution (logMAR), or 3 lines. (Most studies were in the range of 0.05-0.2 logMAR.) Statistically significant improvement in VA was noted in 12 of 16 studies (75%) that performed statistical analyses, with no clear advantage of any single procedure. Complications and reoperations were lowest in patients who underwent TAR and highest in those who underwent myectomy or anterior extirpation.

CONCLUSIONS

The best available evidence suggests that eye muscle surgery in patients with INS results in a modest improvement in VA.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found after the references.

[Nystagmus in Children - a Survey]

Nystagmus describes an involuntary, periodic movement of one or both eyes. About 1/600 children and adolescents have nystagmus, most of them idiopathic infantile nystagmus (IIN), also called "congenital nystagmus", which can be caused by mutations in the FRMD7 gene. Other frequent forms of nystagmus are latent nystagmus, which is usually associated with infantile strabismus, and nystagmus associated with albinism. Sometimes difficult to distinguish in young infants is a sensory nystagmus, where a defect in the visual system reduces vision and causes nystagmus. Causes include retinal dystrophies, congenital stationary night blindness and structural ocular defects including optic nerve hypoplasia or dense bilateral congenital cataracts. Unilateral nystagmus can be the sign of an anterior visual pathway lesion. Seesaw nystagmus may be associated with suprasellar and mesodiencephalic lesions and - rarely - with retinal dystrophies.The ophthalmology plays a key role in identifying the form of nystagmus. Children with new onset nystagmus, with spasmus nutans, with vertical or unilateral nystagmus and those with seesaw nystagmus require neurologic evaluation including imaging of the brain.The treatment of nystagmus depends on the underlying cause. Even minor refractive errors should be corrected, contact lenses offer advantages over glasses.Gabapentin and memantine, possibly also carbonic anhydrase inhibitors, are effective in treating IIN, nystagmus in albinism and sensory nystagmus. Nevertheless, pharmacologic treatment of nystagmus is rarely used in children; the reasons are the limited effects on vision, the need for lifelong therapy, and potential side effects. Eye muscle surgery (Anderson procedure, Kestenbaum procedure) can correct a nystagmus-related anomalous head posture. The concept of "artifical divergence" of Cüppers may help to decrease nystagmus intensity in patients whose nystagmus dampens with convergence. The four-muscle-tenotomy, which involves disinsertion and reinsertion of the horizontal muscles at the original insertion of both eyes, has a proven but limited positive effect on visual acuity.

Nystagmus bei Kindern – eine Übersicht

Nystagmus ist definiert als unwillkürliche, periodische Bewegung, bei der eines oder beide Augen vom Fixationspunkt wegdriften (sog. Drift). Auf die Drift, die langsame Phase, folgt entweder eine schnelle, refixierende Bewegung (sog. Refixationssakkade oder schnelle Phase) oder eine langsamere Bewegung zur Wiederaufnahme der Fixation. In dieser Übersichtsarbeit sollen die wichtigsten Formen von Nystagmus bei Kindern erörtert werden, für eine Übersicht bei Erwachsenen sei auf 1 verwiesen.

A Preliminary Study on the Outcome of Plication Augmentation of the Augmented Anderson Procedure for Patients with Infantile Nystagmus Syndrome and a Face Turn

Purpose:

To report the results of plication augmentation of the augmented Anderson procedure in patients with infantile nystagmus syndrome and face turn.

Methods:

In this retrospective study, all patients who underwent plication augmentation of the augmented Anderson procedure between August 2015 and November 2018 were included. Our study included patients older than 6 years with a face turn >25°. We also included patients with residual face turns ≥15° after Anderson-type procedures. The face turn was measured by a goniometer and also quantified with prisms placed with apex in the direction of the face turn. We plicated the medial rectus of one eye by 5.0 mm and lateral rectus of the fellow eye by 7.0 mm based on the direction of the face turn in addition to the augmented Anderson procedure. Patients were reviewed on the 1^st postoperative day, 1^st month, and every 6 months thereafter.

Results:

Eight patients with a mean face turn of 27.5° ± 6.5° underwent plication augmentation of the augmented Anderson procedure. Two patients had residual face turns after a previous Anderson-type procedure. We obtained a mean correction of 25° ± 6.5° with a median prismatic correction of 45 prism diopters (PD) for each eye. The median face turn at the last review was 2.5°, and all patients were corrected to within 10°. Excluding patients operated for residual face turns, we had a mean dose response of 2.7 PD/mm and 1.7°/mm of surgery on each eye. Five patients had an improvement in null zone visual acuity. Two patients had a restriction in ocular motility of −2 in the direction of the recessed extraocular muscle at the last review, and the remaining had a −1 restriction.

Conclusions:

Plication augmentation of the augmentation Anderson procedure appears to be a safe and effective procedure for patients with infantile nystagmus syndrome and a face turn more than 25°. It may also be used for residual face turns more than 15°.

Surgical interventions for infantile nystagmus syndrome

BACKGROUND

Infantile nystagmus syndrome (INS) is a type of eye movement disorder that can negatively impact vision. Currently, INS cannot be cured, but its effects can potentially be treated pharmacologically, optically, or surgically. This review focuses on the surgical interventions for INS. Despite the range of surgical interventions available, and currently applied in practice for the management of INS, there is no clear consensus, and no accepted clinical guidelines regarding the relative efficacy and safety of the various treatment options. A better understanding of these surgical options, along with their associated side effects, will assist clinicians in evidence-based decision-making in relation to the management of INS.

OBJECTIVES

To assess the efficacy and safety of surgical interventions for INS.

SEARCH METHODS

We searched CENTRAL, MEDLINE Ovid, Embase Ovid, ISRCTN registry, ClinicalTrials.gov, and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) to 3 July 2020, with no language restrictions.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) studying the efficacy and safety of surgical options for treating INS.

DATA COLLECTION AND ANALYSIS

Our prespecified outcome measures were the change from baseline in: binocular best-corrected distance visual acuity; head posture; amplitude, frequency, intensity, and foveation period durations of the nystagmus waveform; visual recognition times; quality of life and self-reported outcome measures; incidence of adverse effects with a probable causal link to treatment; and permanent adverse effects after surgery. Two review authors independently screened titles and abstracts and full-text articles, extracted data from eligible RCTs, and judged the risk of bias using the Cochrane tool. We reached consensus on any disagreements by discussion. We summarised the overall certainty of the evidence using the GRADE approach.

MAIN RESULTS

We only identified one eligible RCT (N = 10 participants), undertaken in India. This trial randomised participants to receive either a large retro-equatorial recession of the horizontal rectus muscle of 9 mm on the medial rectus and 12 mm on the lateral rectus, or a simple tenotomy and resuturing of the four horizontal rectus muscles. We did not identify any RCTs comparing a surgical intervention for INS relative to no treatment. In the single eligible RCT, both eyes of each participant received the same intervention. The participants' age and gender were not reported, nor was information on whether participants were idiopathic or had sensory disorders. The study only included participants with null in primary position and did not explicitly exclude those with congenital periodic alternating nystagmus. The study did not report funding source(s) or author declaration of interests. The evaluation period was six months. We judged this study at low risk for sequence generation and other sources of bias, but at high risk of bias for performance and detection bias. The risk of bias was unclear for selection bias, attrition bias, and reporting bias. There is very uncertain evidence about the effect of the interventions on visual acuity and change in amplitude, frequency, and intensity of the nystagmus waveform. We were unable to calculate relative effects due to lack of data. None of the participants in either intervention group reported adverse effects at six-month follow-up (very low-certainty evidence). There was no quantitative data reported for quality of life, although the study reported an improvement in quality of life after surgery in both intervention groups (very low-certainty evidence). Change in head posture, foveation period durations of the nystagmus waveform, visual recognition times, and permanent adverse effects after surgery were not reported in the included study. We judged the certainty of the evidence, for both the primary and secondary efficacy outcomes, to be very low. Due to a lack of comprehensive reporting of adverse events, there was also very low-certainty of the safety profile of the evaluated surgical interventions in this population. As such, we are very uncertain about the relative efficacy and safety of these interventions for the surgical management of INS.

AUTHORS' CONCLUSIONS

This systematic review identified minimal high-quality evidence relating to the efficacy and safety of surgical interventions for INS. The limited availability of evidence must be considered by clinicians when treating INS, particularly given these procedures are irreversible and often performed on children. More high-quality RCTs are needed to better understand the efficacy and safety profile of surgical interventions for INS. This will assist clinicians, people with INS, and their parents or caregivers to make evidence-based treatment decisions.

Congenital Nystagmus and Its Congeners

In recent years, we have made enormous strides in elucidating the phenomenology of congenital nystagmus. The purpose of this review is to briefly summarize our current understanding of congenital nystagmus in terms of its clinical symptomatology, pathophysiology, differential diagnosis, and ancillary testing, and clinical management. Finally, this discussion provides the reader with an armamentarium of clinical pearls to facilitate diagnosis of the numerous sensory visual disorders that can underlie congenital nystagmus.

[Highly dosed Anderson and Kestenbaum operations for anomalous head posture due to nystagmus]

Hintergrund

Die Korrektur einer Kopfzwangshaltung (KZH) bei infantilem Nystagmussyndrom (INS) erfolgt mit der Kestenbaum-Operation (KO) in Form der beidseitigen Rücklagerung der in KZH aktiven Agonisten und Verkürzung ihrer Antagonisten oder mit der Anderson-Operation (AO) durch die alleinige Rücklagerung der Agonisten.

Ziel der Arbeit

Vergleich der Ergebnisse hoch dosierter AO und KO bei ähnlicher KZH.

Patienten und Methoden

In unterschiedlichen Zeiträumen (2013 bis 2019 bzw. 2003 bis 2013) kam ausschließlich die AO bzw. die KO zur Anwendung. Eine hoch dosierte AO erhielten in einer konsekutiven Fallserie 33 Orthotrope mit INS und KZH, eine KO erhielten 19 Patienten. Die Mediane und Streubreiten (min–max) in den Gruppen AO/KO betrugen: Alter bei OP 7 (4–44) Jahre/6 (4–27) Jahre; KZH 32,5°(20–45)/30°(17–40); Operationsstrecke pro Auge AO 13 (10–16) mm (Standarddosis), KO 10 (6–12) mm + 10 (6–12) mm (Mittel 0,60 mm/°KZH).

Ergebnisse

Die KZH betrug nach ca. 3 Monaten 10°(−3–20)/10°(−7–20), bei der Spätkontrolle (8 bis 153 Monate) 10°(0–20)/10°(−27–30). Sie war bei der letzten Kontrolle um 67 % (20–100)/64 % (14–100) verringert. Eine Restdrehung ≤15° fand sich in 79/81 % der Fälle (91 % nach AO ≥13 mm; n = 23), ein Rest ≤10° in 55/57 %, (65 % nach AO ≥13 mm). Die Ad‑/Abduktionsfähigkeit der rückgelagerten Muskeln betrug nach AO 30°/30° (10–37/15–45), nach KO 32°/30° (10–40/12–45). Eine assoziierte Kopfneigung wurde durch den Eingriff nicht verbessert. Der mittlere Anstieg des binokularen Visus betrug jeweils <1 Zeile, in der Gruppe AO 1 Zeile bei Kindern ≤6 Jahre, kein Anstieg in der Altersklasse >6 Jahre.

Schlussfolgerung

AO und KO waren bei der verwendeten Dosierung wirkungsgleich. Die geringere Invasivität der AO spricht für deren Anwendung als Ersteingriff.