Evaluating ocular torsion following inferior oblique weakening in superior oblique palsy: a pilot study using color fundus photography and spectral domain optical coherence tomography.

PURPOSE

To compare spectral domain optical coherence tomography (OCT) and color fundus photography (CFP) for assessing ocular cyclotorsion in unilateral congenital superior oblique palsy (SOP) before and after inferior oblique disinsertion.

METHODS

This prospective pilot study evaluated 18 patients (36 eyes) with unilateral congenital SOP. Disc-foveal angle (DFA) was measured preoperatively and 3 months postoperatively using CFP (analyzed with ImageJ) and Spectralis OCT (with FoDi software). Contralateral nonparetic eyes served as controls.

RESULTS

Preoperative hypertropia (14.31 ± 4.15 prism diopter, PD) significantly improved postoperatively (1.46 ± 1.98 PD, P < 0.001). CFP measurements showed significantly greater cyclotorsion in paretic versus nonparetic eyes preoperatively (P = 0.001), while OCT revealed no inter-eye difference (P = 0.295). In paretic eyes, CFP-derived DFAs were significantly higher than OCT values both preoperatively (12.26 ± 4.72° vs. 8.87 ± 4.56°, P = 0.002) and postoperatively (7.25 ± 5.18° vs. 4.33 ± 3.98°, P = 0.005). Nonparetic eyes showed no significant inter-method differences at either timepoint (all P > 0.05). Inter-method reliability was moderate preoperatively (ICC = 0.693 paretic, 0.657 nonparetic) and improved postoperatively (ICC = 0.718 and 0.921, respectively). Bland-Altman analysis demonstrated narrowing limits of agreement postoperatively (nonparetic: 8.48° to 4.40°; paretic: 7.97° to 7.50°), with no systematic bias.

CONCLUSION

Spectralis OCT with FoDi software provides a clinically useful alternative to CFP for cyclotorsion assessment in congenital SOP, though it may systematically underestimate DFA values in paretic eyes.