British Journal ofOphthalmology, 1984, 68, 796-800

Surgical management for abnormal head positionin nystagmus: the augmented modified KestenbaumprocedureLEONARD B. NELSON, LAURI D. ERVIN-MULVEY, JOSEPH H. CALHOUN,ROBISON D. HARLEY, AND MARK S. KEISLER

From the Department of Pediatric Ophthalmology and Strabismus, Wills Eye Hospital,Philadelphia, Pennsylvania, USA

SUMMARY Patients with nystagmus and an eccentric null point in lateral gaze may assume anabnormal head position to maximise visual acuity. Surgical procedures for this condition can resultin significant undercorrection of the head turn. A follow-up of 15 patients for an average of 33months revealed a sustained improvement in head position with the use of the augmented modifiedKestenbaum procedure.

The surgical procedures for the correction of abnormalhead positions in patients with congenital nystagmusbegan with the independent reports of Anderson,Goto, and Kestenbaum in the early 1950s. '-3 In anattempt to explain the abnormal head positionAnderson postulated that the muscles acting in theslow phase of the nystagmus overacted. He advisedas treatment a weakening procedure for the two yokemuscles involved. Goto believed that there was anunderaction of the muscles acting in the fast phase ofthe nystagmus; he advised that bilateral resection ofthese two muscles be performed. Kestenbaumadvocated a combined recession/resection procedurefor all four horizontal rectus muscles. He recessed orresected the two muscles of each eye from 4mm to 10mm. Parks4 subsequently suggested a modifiedKestenbaum procedure. He advocated horizontalrectus muscle surgery of 5 mm, 6 mm, 7 mm, and 8mm, with a total of 13 mm of surgery performed oneach eye. Surgery of 5 mm or 6 mm was alwaysperformed on the medial rectus muscles, the formerwith a recession, the latter with a resection. Surgeryof 7 mm or 8 mm was performed on the lateral rectusmuscles, again the former with a recession and thelatter with a resection. At that time Parks believedthat these amounts of surgery were the maximumamounts which could be performed to preserve fullductions.

Correspondence to Dr Leonard B. Nelson, Department of PediatricOphthalmology, Wills Eye Hospital, 9th and Walnut Streets,Philadelphia, PA 19107, USA.

Because of the high rates of recurrence and under-correction following the modified Kestenbaumprocedure Calhoun and Harley recommendedincreasing the amount of surgery by 40%.1 The Parksmeasurements of 5 mm, 6 mm, 7 mm, and 8 mm wereaugmented by 40%, resulting in surgery of 7 mm, 8-4mm, 9*8 mm, and 11*2 mm on the rectus muscles.This maintained the Parks ratio for the modifiedKestenbaum procedure, which had been shown byCalhoun and Harley to preserve binocular functionpostoperatively.5 From 1973 until the present timewe have used the modified Kestenbaum procedure,augmented by either 40% or 60% (augmentation of60% results in surgery of8 mm, 9.6 mm, 11-2 mm, and12*8 mm) as the procedure of choice for correctingthe abnormal head position in congenital nystagmus.We report here on the long-term surgical results ofthe augmented modified Kestenbaum procedure.

Subjects and methods

The patients in this study were selected from thosebeing treated at the Pediatric OphthalmologyDepartment of Wills Eye Hospital. A total of 17patients underwent the augmented modifiedKestenbaum procedure from 1973 to 1982. Two ofthese cases were excluded from the series becausefollow-up times were less than six months. All of thepatients included had at least an eight-month follow-up. The longest follow-up was 105 months; theaverage was 33 months. Twelve of the patients weremales and three were females.

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Surgical managementfor abnormal headposition in nystagmus

Fig. I Left: Estimated head lurn o1J450. Centre: Estimaled heaid turni of 300. Right: Estimated head turn of 150.

The indication for surgical intervention in patientswith congenital nystagmus was an unacceptable headposition (300 or greater) that was not correctable byglasses. Preoperative head turns were estimated andwere assessed while the patient fixated on a small,distant object (Fig. 1). The head position assumed bythe patient was then estimated by the observer(either Dr Calhoun or Dr Nelson) to the nearest 150preoperatively and 50 postoperatively. Surgicalintervention was designed to correct the maximumestimated distance deviation. Table 1 indicates pre-operative and postoperative head turns for distantfixation only.

All patients who underwent surgery had a completeophthalmological examination. The mean age at thetime of surgery was 9*8 years. The range was from 3½/2to 30 years and the median age was 5 years. In 14 ofthe 15 patients nystagmus was noted shortly afterbirth. Patient 2 developed nystagmus after a roadaccident in which he suffered a brain stem injury.

Patient 5 had tyrosinase-positive oculocutaneousalbinism, while patient 10 had unilateral microph-thalmos with severely compromised vision. Patient15 had anisometropic amblyopia without strabismus.Preoperative visual acuities were measured while thepatients maintained their greatest degree of headturn (Table 1). None of the patients had strabismusbefore operation.The surgical technique was performed in order to

move the eyes in the direction that the face wasturned (toward the direction of the quick phase of thenystagmus). The measurement for the caliper place-ment was rounded off to the nearest half millimeterfor both the 40% and 60% augmented procedures.

Results

The results of the surgery are summarised in Table 2.Of the eight patients who underwent the modifiedKestenbaum procedure with a 40% augmentation

Table 1 Preoperative and postoperative head turns

Patient Age Pre- and postoperative Head turn Procedure % Follow-up(years) visual acuities augumentation (months)

Preoperative PostoperativeOD OS measurement measurement

1 30 20/50 20/50 R 300 00 +40 252 11 20/25 20/25 L 300 00 +40 383 5 20/60 20/60 L 300 00 +40 564 31/2 20/30 20/30 L 300 00 +40 85 5 20/100 20/100 L 450 L 150 +40 386 5 20/40 20/40 R 450 R 50 +40 307 41/2 20/40 20/40 R 450 R 150 +40 88 17 20/80 20/80 R 450 L 150 +40 129 7 20/60 20/70 R 450 R 100 +60 2110 3 20/40 HM R 450 00 +60 4011 14 20/50 20/50 R 450 R 150 +60 3012 3 20/40 20/40 L 450 00 +60 3413 5 20/60 20/60 R 450 00 +60 4014 4 20/60 20/60 L 450 L 150 +60 10515 11 20/400 20/30 L 450 00 +60 33

*HM=Hand motion.

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798 Leonard B. Nelson, Lauri D. Ervin-Mulvey, Joseph H. Calhoun, Robison D. Harley, andMark S. Keisler

Table 2 Results ofthe augmented modifiedKestenbaum procedure

Procedure Number Number Total Percentageofpatients ofpatients number of curedcured improved patients

ModifiedKestenbaum+40% 4 4 8 50%ModifiedKestenbaum+60% 4 3 7 57%

four (50%) were classified as cured of their head turn.'Cured' by our definition meant that there was noresidual head turn at the time of the last ophthalmicevaluation. The remaining four patients (50%) wereclassified as 'improved,' which we defined as having aresidual head turn of 150 or less. Since the indicationfor surgery is largely for cosmesis, the authors con-sidered a residual head turn of 15° cosmeticallyacceptable and not an amount that necessitated aninitial surgical correction.

All four patients who were cured of their headturn with a 40% augmentation had a preoperative

Fig. 2 Above: Preoperative lateralgaze awayfrom theoriginal head turnfollowing a 40% augmentation. Below:Postoperative gaze. Note moderate restriction ofgaze.

head turn estimated at 300. The remaining fourpatients who improved all had a preoperative headturn estimated at 450.Of the seven patients who underwent the modified

Kestenbaum procedure with a 60% augmentationfour (57%) were classified by the same criterion ascured. Three (43%) were classified as improved. Allpatients who underwent the 60% augmentation had apreoperative head turn estimated at 450.Although preoperative and postoperative head

turns were tabulated for distant fixation only, none ofthe patients evidenced an overcorrection for nearfixation after surgery. The distance head turns in ourpatients were greater than those at near both pre- andpostoperatively.When an attempt to measure the angle of head

turning with a perimeter was made, several problemswere encountered. First, unless particular attentionwas paid to maintaining distant fixation by having thepatient look over the perimeter, a false underestimateof the head turning resulted. Secondly, it was tech-nically difficult for a child to look over the perimeter.Finally, as a patient gradually turned his head assmaller optotypes were presented at a distance, headmovement occurred posteriorly from the chin restcausing a false overestimate of the head turning.

Restriction of motility after operation varied in ourseries. In the majority of patients this restriction wasmoderate, with less than 50% reduction in lateralgaze away from the original head turn (Fig. 2).Although the 60% augmentation procedure limitedmotility more than the 40% augmentation procedure,the amount was not significantly greater.Our 'cured' rates of50% to 57% and our 'improved'

rates of 43% to 50% pertain to horizontal headalignment only. Two of the cases (patient 3 andpatient 6) showed a vertical torticollis postoper-atively, and one case (patient 10) had a head tilt.These head positions were not noted prior to surgery,and no A or V pattern was present either preoper-atively or postoperatively in these children.

Discussion

The abnormal head turn adopted by some patientswith congenital nystagmus correlates with the positionof minimum ocular excursion and maximum visualacuity.67 This position may result in a disfiguringtorticollis.With the advent of the Kestenbaum procedure and

the Park modification a surgical correction was madepossible for this abnormal head position. The curerates for this procedure have been modest. In Parks'sinitial report four of these 10 patients with an averagefollow-up of 1-5 years were classified as cured.4 A lowcure rate was also reported with the modified

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Surgical managementfor abnormal headposition in nystagmus

Kestenbaum procedure in the series published byCalhoun and Harley; only two of their 10 patientswere cured by this technique.5More recent experience with the modified

Kestenbaum procedure has come from Flynn andDell'Oso.7 Their one patient with binocular visionhad a heterotropia created after the modifiedKestenbaum procedure accompanied by a recurrenceof a head turn in the immediate postoperative period.These authors suggest that the modified Kestenbaumprocedure is generally inadequate to correct theabnormal head position in congenital nystagmus.To overcome the high rates of recurrence with the

Kestenbaum and modified Kestenbaum proceduresseveral authors have suggested that different amountsof surgery should be performed. Taylor recom-mended that an 8 mm to 9 mm recession of the lateralrectus muscle, and 6 mm recession of the medialrectus muscle, be performed in conjunction with 6mm resections of the respective antagonists.8 Thissmall surgical modification produced encouragingresults in two patients. Kommerell published theresults from a series of 28 patients with congenitalnystagmus who underwent a Kestenbaum type ofoperation .9 Sixteen ofthese patients had an associatedstrabismus. Of the 12 patients without strabismus sixreceived the traditional Kestenbaum procedure (4mm to 5 mm of surgery on each muscle). Becausethree of these patients had significant postoperativehead turns (greater than 250), Kommerell increasedthe amount of surgery to 8 mm for the remaining sixpatients. These patients had less postoperative headturn (0 to 150) after a follow-up period of 4 to 50months.

In the recent European literature some success hasbeen reported with the use of a Faden or posteriorfixation suture, which can be combined with atraditional Kestenbaum procedure. "" The bestresults from this technique occurred when twoseparate surgical procedures were used: the first wasa Kestenbaum operation, the second was a Fadenprocedure performed three months later if residualhead turn was found. Unfortunately there has beenno detailed publication on the long-term surgicalresults for large numbers of these patients.The initial report of the modified Kestenbaum pro-

cedure augmented by 40% demonstrated a high rateof success in a small group of patients.5 Three of fourpatients were classified as cured of their abnormalhead turn, and the fourth was significantly improved.However, follow-up time was short, so the long-termsurgical benefits could not be indicated in this study.Our series of 15 patients affords a more complete

assessment of the augmented modified Kestenbaumprocedure. Follow-up time averaged 33 months. Astandard amount of surgery (involving either a 40%

or 60% augmentation) was performed by two of theauthors (Drs Calhoun and Nelson).Four of eight (50%) patients who underwent the

40% augmentation were cured of their abnormal headturn. All four patients had a preoperative head turnestimated at 300. The remaining four patientswho improved with the 40% augmentation had pre-operative head turns estimated at 45°. All sevenpatients who underwent a 60% augmentation pro-cedure had a preoperative head turn estimated at 45°;four of seven (57%) were cured of the head turnpostoperatively.

Patients with nystagmus and an eccentric null pointin lateral gaze will assume a head position to maximisevisual acuity. These patients essentially have a gazepalsy in the direction of the head turn. Following the40% or 60% augmentation, reduction of lateral gazeaway from the original head turn may be as great as50%. Postoperatively, a gaze palsy is created in theopposite direction. However, in our experienceparents and patients preferred the more normal headposition and did not complain about the decreasedfield of rotation. In addition, no strabismus wasproduced with either the 40% or 60% augmentedprocedure.

Flynn and Dell'Oso (and initially Kestenbaum)reported an increase in visual acuity after aKestenbaum type of procedure.36 We measured ourpatients' preoperative visual acuities while theymaintained their largest degree of head turn.Therefore in our series of 15 patients we couldnot demonstrate any improvement in visual acuitypostoperatively.The augmented modified Kestenbaum procedure

produces a more sustained surgical correction for theabnormal head position in congenital nystagmus thanthe Kestenbaum or modified Kestenbaum procedures.We recommend using a 40% augmentation of themodified Kestenbaum procedure for those patientswith 300 of head turn. For patients with 450 of headturn we recommend a 60% augmentation to achievemaximum correction.

This work was made possible in part by grants from Fight for SightInc., New York, New York to the Fight for Sight Children's EyeCenter of Wills Eye Hospital; it was also supported in part by theWills Eye Hospital Research Division.

References

I Anderson JR. Causes and treatment of congenital eccentricnystagmus. BrJ Ophthalmol 1953; 37: 267-80.

2 Goto N. A study of optic nystagmus by the clectro-oculogram.Nippon Ganka Gakkai Zasshi (Tokyo) 1954; 58: 851-65(abstracted in Ophthalmic Lit 1954; 8: 1493).

3 Kestenbaum A. Nouvelle operation de nystagmus. Bull SocOphtalmol Fr 1954; 2: 1071-8.

4 Parks MM. Congenital nystagmus surgery. Am Orthop J 1973;23: 35-9.

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5 Calhoun JH, Harley RD. Surgery for abnormal head position in 8 Taylor JN. Surgery for horizontal nystagmus: Anderson-congenital nystagmus. Trans Am Ophthalmol Soc 1973; 71: Kestenbaum operation. AustJ Ophthalmol 1973; 1:114-6.70-87. 9 Kommerell G. Nystagmusoperationen zur Korrektur ver-

6 Dell'Oso LF, Flynn JT. Congenital nystagmus surgery: a quan- schiedener Kopfzwagshaltungen. Kin Monatsbl Augenheilkdtitative evaluation of the effects. Arch Ophthalmol 1979- 97 1974; 164:172-91.462-9. 10 Berad PV, Spielmann A, Reydy R. L'operation du fil de Cuppers.Bull Soc Ophtalmol Fr 1977; 76: 1111-6.

7 Flynn JT, Dell'Oso LF. The effects of congenital nystagmus 11 Spielmann A. Le traitement chirurgical du nystagmus. Archsurgery. Ophthalmology 1979; 86: 1414-25. Ophtalmol (Paris) 1977; 37: 751-63.

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