Surgery for nystagmus related head turn: Kestenbaum procedure and artificial divergence

[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.

[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°.

[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.

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

PURPOSE

To evaluate the effectiveness of a high-dose Anderson procedure (AP) to correct infantile nystagmus-related anomalous head turn (HT).

METHODS

Twenty-nine consecutive orthotropes with infantile nystagmus with and without associated sensory defect received high-dose AP. HT was measured while the patient tried to read letters at best-corrected visual acuity (BCVA) level at 5 m and 0.3 m. BCVA, binocular vision (BV), and alignment (prism and cover test) were measured. High-dose AP with recessions of 9-16 mm was performed. All measures were taken before and 3-6 and ≥ 8 months post surgery. Success was defined by postoperative HT ≤ 10°/HT ≤ 15°.

RESULTS

Medians and ranges (minimum-maximum) were:. Age at surgery was 7 years (4-44). HT at 5 m and HT at 0.3 m were 35° (20-40) and 20° (0-35), respectively. After 4 months (3-6), HT was 10° (- 3-20) and 5° (- 5-20); success rates were 74%/96% and 83%/96%. After 15 months (8-45), HT was 12° (0-20) and 6° (0-15); success rates were 46%/75% and 92%/100%; residual HT > 15° occurred in 5/9 cases with recessions < 13 mm and 1/15 cases with recessions ≥ 13 mm. With recessions ≥ 13 mm, 60% (95% confidence intervals (C.I.), 33-83%) achieved HT ≤ 10° and 93% (95% C.I. 66-99%) achieved HT ≤ 15°. Overcorrection did not occur. Anomalous head posture components in vertical and frontal planes did not improve. Residual motility was 30° (10-45). The mean BCVA improved by only 0.037 logMAR (p = 0.06). BV and ocular alignment were constant, except in 2 patients whose exophoria decompensated.

CONCLUSIONS

Kestenbaum surgery is a common procedure to correct infantile nystagmus-related HT. Anderson surgery is confined to bilateral yoke muscle recession; hence, less invasive but nevertheless comparably effective, high dosage is provided.

Dealing with Nystagmus

Nystagmus has a profound impact on patients visual function and social life. Infantile nystagmus (IN) is much more common than neurological nystagmus, and establishing the correct diagnosis is key in guiding the appropriate treatment paradigm. This paper attempts to demonstrate a stepwise approach in investigation and clinical evaluation, that is (often) sufficient in differentiating IN from nystagmus of neurological origin, and to uncover underlying sensory etiologies of IN. Targeted and rational uses of paraclinical exams are emphasized when they deemed necessary to complement the clinical assessment. The author's preferred surgical and non-surgical strategies to optimize vision, and improve the head posture and strabismus that can accompany nystagmus, are discussed (although without the goal of writing a complete revision on the topic).

Evaluation of the Role of Displacement Surgery in the Management of Congenital Nystagmus

Introduction

The aim of this study was to assess the effectiveness of displacement surgery in damping of ocular oscillation and management of compensatory head posture in patients of congenital nystagmus.

Methods

This study was carried out in 2014. The participants were 50 patients with congenital nystagmus that dampens in a certain direction of gaze with or without abnormal head posture and with or without strabismus. Patients underwent the augmented modified Kestenbaum (augmented parks) procedure. Data were analyzed by SPSS version 15, using Chi-square text, exact test, and Mann Whitney U test.

Results

In this study, 12 patients (80%) were noticed clinically to have damping of nystagmus while 3 patients (20%) had no damping of nystagmus. Twelve patients (80.0%) had no post-operative abnormal head position, while 3 patients (20.0%) had residual abnormal head position. There was a statistically significant difference between the pre-operative BCVA in primary position and post-operative BCVA in primary position (p = 0.001 for both right and left eyes).

Conclusion

The displacement surgeries (e.g. Kestenbaum procedure) for the treatment of patients with congenital nystagmus is an effective procedure for correction of abnormal head posture, improving the visual acuity in the primary position and damping of nystagmus in patients with congenital nystagmus who have null points away from the primary position.

Infantile nystagmus syndrome: clinical characteristics, current theories of pathogenesis, diagnosis, and management

Infantile nystagmus syndrome (INS) is an important clinical diagnosis because it is a common presenting sign of many ocular, neurologic, and systemic diseases. Although INS has been studied for more than a century, its diagnosis and treatment remains a challenge to clinicians because of its varied manifestations and multiple associations, and its pathogenesis continues to rouse considerable scientific debate. Fueled by these challenges, recent basic research and clinical investigations have provided new insights into INS. New genetic discoveries and technological advances in ocular imaging have refined our understanding of INS subtypes and offer new diagnostic possibilities. Unexpected surgical outcomes have led to new understanding of its pathogenesis based on novel hypothesized pathways of ocular motor control. Comparative studies on nonhuman visual systems have also informed models of the neural substrate of INS in humans. This review brings together the classic profile of this disorder with recent research to provide an update on the clinical features of INS, an overview of the current theories on how and why INS develops, and a practical approach to the diagnosis and management of INS.

Kestenbaum procedure with combined muscle resection and tucking for nystagmus-related head turn

BACKGROUND

Literature has dealt extensively with dose-effect relations for recess-resect procedures for correction of horizontal nystagmus-related head turn. However, muscle tucking procedures have some advantages compared to resection procedures. Aim of this study was to evaluate dose-effect relations of Kestenbaum surgery with symmetrical combined recession and tucking (instead of resection) of the horizontal rectus muscles for the reduction of a nystagmus-related head turn.

METHODS

In a retrospective study, clinical findings of 42 patients who consecutively underwent treatment in our institution between 2000 and 2011 were investigated. The patients were aged 4-57 years (median age 6 years). For all patients, surgery aimed to correct a horizontal head turn (to the right: 18 patients) due to infantile nystagmus. The head turn was measured with a goniometer with the patient fixing the smallest age-appropriate target distinguishable for the patient.

RESULTS

The median absolute head turn before surgery was 30° (min. 15°, max. 45°). The four horizontal rectus muscles were recessed or tucked between 5.5 and 10 mm, median 9 mm. All four muscles were recessed or tucked for the same amount. At the first postoperative day, the median dose-effect relation was 1.88° reduction of head turn per millimeter surgery on one eye (min. 0.5°/mm, max. 3.2°/mm). The median head turn was 0° (min. -20°, max. 15°). Surgery was considered successful in 88% of the patients with a reduction of the head turn to max. 10°. Data of 36 patients were available for the long-term postoperative period (median 1.5 years; min. 6 weeks, max. 11 years). The median head turn was 10° (min. -16°, max. 30°). The median dose-effect relation was reduced to 1.35°/mm per eye (min. 0°/mm, max. 2.9°/mm). Surgery was considered successful in 72 % of the patients with a reduction of the head turn to max. 10°. Three patients showed an overcorrection with a head turn of 8°, 15° and 16° to the other side. A squint has not been induced.

CONCLUSIONS

The dose-effect relation for Kestenbaum surgery with symmetrical combined recession and tucking of the horizontal rectus muscles is comparable to the dose-effect relation reported by other authors for symmetrical combined recession and resection.

What we know about the generation of nystagmus and other ocular oscillations: are we closer to identifying therapeutic targets?

Mechanisms underlying acquired nystagmus are better understood than those leading to infantile nystagmus. Accordingly, further progress has been made in the development of effective therapies for acquired nystagmus, mainly through pharmacological interventions. Some of these therapies have been developed under the guidance of findings from experimental animal models. Although mechanisms behind infantile nystagmus are less understood, progress has been made in determining the genetic basis of nystagmus and characterizing associated sensory deficits. Pharmacological, surgical, and other treatments options for infantile nystagmus are now emerging. Further investigations are required for all forms of nystagmus to produce high-quality evidence, such as randomized controlled trials, upon which clinicians can make appropriate treatment decisions.

Kestenbaum procedure on the vertical rectus muscles with simultaneous compensation of the induced cyclodeviation for nystagmus patients with chin-up or chin-down head posture

BACKGROUND

Kestenbaum surgery is performed for nystagmus-related abnormal head posture, and symmetrically changes the position of both eyes to shift the null point to the primary position. Most patients with infantile nystagmus have their null point zone in a lateral gaze position. Less frequently, surgery can be performed to reduce chin-up or chin-down head posture. We report indications for, and the results of eight consecutive interventions performed according to the Kestenbaum principle for the reduction of a chin-up or chin-down head posture.

METHODS

In a retrospective study, the clinical findings for eight patients who consecutively underwent treatment in the University Eye Hospital of Cologne between 2001 and 2007 were investigated. The patients were aged 6 to 16 years; median age was 6.5 years. For all patients, surgery was to correct a chin-up or chin-down head posture due to infantile nystagmus. Preoperatively, five patients showed a chin-down, three a chin-up head posture. All vertical rectus muscles were recessed or tucked between 6 and 7 mm; the resulting cyclodeviation was reduced by an intervention on the superior oblique muscles (6 to 8 mm tucking, in the case of chin-down, or recession in the case of chin-up head posture).

RESULTS

Surgery was successful in seven of the eight patients, with a reduction of the vertical head posture to less than 10 degrees. In the cases of chin-down posture, head posture was reduced to between 0 degrees and a maximum of 20 degrees in one case postoperatively (before the operation 20 degrees to 35 degrees ); in the cases of chin-up posture, to less than 8 degrees (before the operation 25 degrees to 35 degrees). One case showed no postoperative improvement in chin-down posture but a head turn to the left of up to 20 degrees; another case had a remaining chin-up posture of 8 degrees with a right turn of 15 degrees . Binocular vision was better or the same in all cases after surgery.

CONCLUSION

For nystagmus patients with chin-up or chin-down head posture, surgery for bilateral parallel shifting of the eyes can considerably improve the head posture. It is possible to compensate the induced cyclodeviation at the same time by bilateral surgery on the superior oblique muscles.

Kestenbaum procedure with posterior fixation suture for anomalous head posture in infantile nystagmus

BACKGROUND

The purpose of this study was to report the effect of combining the Kestenbaum procedure with posterior fixation suture for infantile horizontal nystagmus with anomalous head posture (AHP) in children.

METHODS

Nine consecutive patients who underwent combined Kestenbaum procedure plus posterior fixation suture to the recessed muscles at the same time were retrospectively studied. All patients were orthotropic before surgery and were followed for at least 6 months. Pre- and postoperative AHP and binocular corrected visual acuity (BCVA), and ocular alignment were assessed.

RESULTS

Mean age at surgery was 4.8 +/- 1.5 years. The average follow-up was 29.7 months. The average head turn preoperatively was 27.4 degrees and postoperatively 7.2 degrees . The average net change in AHP was 24.8 degrees (P = 0.008). Seven of 9 patients (78%) achieved a residual head turn of 10 degrees or less. The average Log Mar BCVA was 0.33 preoperatively and 0.31 postoperatively (P = 0.68). Only 1 patient needed additional surgery for residual horizontal AHP. No patient developed strabismus.

CONCLUSION

Combined Kestenbaum procedure with posterior fixation suture was an effective and stable procedure in reducing AHP of the range of 20 degrees to 35 degrees in children with infantile nystagmus.

Distance and Near Visual Acuity in Infantile Nystagmus

PURPOSE

Infantile nystagmus (IN) has been reported to decrease with convergence. However, previous studies reported equivocal results regarding a corresponding improvement in acuity with near viewing. The aim of this study was to determine whether visual acuity improves with near viewing in patients with IN.

METHODS

In the first experiment, visual acuities were measured using clinical test charts at standard test distances of 3 or 6 m and 40 cm and using S Charts at 3.75 m and 40 cm. In the second experiment, visual acuities were measured using a Bailey-Lovie chart at distance and a Lighthouse modified ETDRS near card held by each subject at his or her preferred working distance. S-chart acuities were obtained again at 3.75 m and 40 cm for comparison. Horizontal eye movements were recorded using infrared limbal reflection for 20 of the 34 subjects in the first experiment and for all 20 subjects in the second experiment.

RESULTS

The S-chart acuities measured at distance and near were almost all within 0.1 logMAR (logarithm of the minimum angle of resolution) in experiments 1 and 2. Clinically measured acuity averaged nearly one line better at 40 cm than at distance in experiment 1, but the mean difference between near acuity using the ETDRS card and distance acuity using the Bailey-Lovie chart was less than one letter in experiment 2. No consistent relationship existed between the changes in visual acuity with viewing distance and the subject's eye movements.

CONCLUSION

Despite a reduction of nystagmus at near distances in many patients with IN, the visual acuity at near does not improve significantly. These results imply that visual acuity in patients with IN is determined primarily by sensory limitations rather than by the moment-by-moment characteristics of these patients' eye movements.

A prospective clinical evaluation of augmented Anderson procedure for idiopathic infantile nystagmus

PURPOSE

To evaluate the efficacy of the augmented Anderson procedure in idiopathic infantile nystagmus (IIN).

METHODS

Twelve consecutive patients older than 5 years having IIN with eccentric null position and anomalous head position were enrolled in an institution-based study. Best-corrected visual acuity (uniocular and binocular and in both null position and primary position), slit-lamp examination, fundus examination, ocular motility examination, and stereopsis using TNO were recorded. In all cases the augmented Anderson procedure, that is, recession of the yoke muscles (9-mm medial rectus and 12-mm lateral rectus), was performed. Eye movements were recorded before and 3 months after surgery in the primary position, right gaze 15 and 30 degrees, and left gaze 15 and 30 degrees.

RESULTS

All patients had improvement in their anomalous head posture after surgery (p = 0.0001). The nystagmus intensity in the primary position decreased from 22.0 +/- 15.9 degrees cycles/s preoperatively to 10.6 +/- 10.2 degrees cycles/s at 3 months postoperatively. The change was statistically significant (p = 0.006). After surgery, binocular visual acuity using the Early Treatment Diabetic Retinopathy Study chart improved in primary position (p = 0.007). No patient developed more than mild limitation of horizontal movements after surgery.

CONCLUSION

The augmented Anderson procedure is successful in correcting face turn in patients having IIN with eccentric null position, resulting in an increase in visual acuity and a decrease in nystagmus intensity in primary position. Further studies with a longer follow-up are required to assess the long-term efficacy of this procedure.