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

BACKGROUND: The correction of anomalous head posture associated with infantile nystagmus syndrome (INS) is carried out by the Kestenbaum procedure (KP) combining bilateral horizontal yoke muscle recession with resection of their antagonists or by the Anderson procedure (AP) which is confined to yoke muscle recession alone.

AIM OF THE STUDY: To compare the results of highly dosed AP and KP for anomalous head turn (HT).

PATIENTS AND METHODS: The AP (2013-2019) and KP (2003-2013) were used as the exclusive procedures during the respective time periods. A highly dosed AP was performed in a case series of 33 consecutive orthotropic patients with INS and KP in 19 orthotropic patients with INS. Medians and ranges (min-max) in groups AP/KP were: age at surgery 7 years (4-44 years)/6 years (4-27 years), HT 32.5° (20-45°)/30° (17-40°) and surgery on each eye AP 13 mm (10-16 mm) (standard dose), KP 10 mm (6-12 mm) + 10 mm (6-12 mm) (mean 0.6 mm/°HT).

RESULTS: The HT was diminished to 10° (-3-20°)/10° (-7-20°) ca. 3 months after surgery. At the late visit (8-153 months), the residual HT was 10° (0-20°)/10° (-27-30°). The HT was reduced by 67% (20-100%)/64% (14-100%) at the last control. A residual HT ≤15° was present in 79%/81% of cases (91% after AP ≥13 mm; n = 23) and HT ≤10° in 55%/57%, (65% after AP ≥13 mm). The maximum adduction/abduction towards the recessed muscles was 30°/30° (10-37°/15-45°) after AP and 32°/30° (10-40°/12-45°) after KP. An associated head tilt was not improved by the intervention. Mean binocular visual acuity increased by <1 line in both procedures. After AP the mean increase was 1 line in children ≤6 years old and there was no increase in patients >6 years of age.

CONCLUSION: The effectiveness and success rates of AP and KP were similar with the dosing used. Less invasive surgery is an advantage in favor of AP as the primary procedure.