Does inferior oblique recession cause overcorrections in laterally incomitant small hypertropias due to superior oblique palsy?

Abstract

Aim: To evaluate the effects of inferior oblique muscle recession (IOR) in cases of laterally incomitant hypertropia <10 prism dioptres (PD) in central gaze thact 2t are clinically consistent with superior oblique palsy (SOP).

Methods: We retrospectively reviewed patients with SOP and hypertropias <10 PD in central gaze who underwent graded IOR. Primary outcomes were reduction of lateral incomitance and number of overcorrections in central gaze.

Results: Twenty-five patients were included. Mean follow-up was 13.8 months (range 1.4-66). Mean central gaze hypertropia decreased from 5.6±2.1 to 0.2±1.6 PD (p<0.001). Contralateral gaze hypertropia decreased from 15.9±7.6 to 2.3±3.3 PD (p<0.001). Lateral incomitance (central vs contralateral gaze) was 10.3±6.9 PD preoperatively and 2.0±3.0 PD postoperatively (p<0.001). There were two patients overcorrected in central gaze, and one patient overcorrected in downgaze. One patient necessitated further surgery for overcorrection.

Conclusions: Although small hypertropias can be treated with prisms or small, adjustable inferior rectus recessions, IOR collapses incomitance without causing much overcorrection. IOR is a reasonable treatment for small, laterally incomitant hypertropia due to SOP.

Conflict of interest statement

Competing interests None

Figures

Figure 1

Graded inferior oblique recession. Grading of inferior oblique recession by 1 mm increments from a 14 mm recession which is at the temporal inferior rectus (IR) border 5 mm posterior to the IR insertion. This figure is only reproduced in colour in the online version.

Figure 2

Dose-response relationship for inferior oblique recession (IOR) in (A) central and (B) contralateral gaze. Correlation of amount of IOR (mm) with correction of deviation (prism diopters (PD)) in (A) central gaze and (B) contralateral gaze. Regression lines were forced through zero. Every circle represents an operated eye. Correction of 0.5 PD per mm recession in central gaze (r2=0.04), and 1.2 PD per mm in contralateral gaze (r2=0.28). This figure is only reproduced in colour in the online version.