Can Imaging of Temporal Raphe Orientation with fundusphotos or SD-OCT be helpful for the Assessment of Ocular Torsion in Patients with Cranial Nerve Four Paresis?

Strabismic deviations can be horizontal, vertical, cyclorotational, or a combination of all three. Previous literature has established the difference between subjective and traditional objective torsional angles; however, often there is a failure to consider the physiological position of a normal fovea-optic nerve head (ONH) relationship. Using the temporal raphe (TR) orientation has been suggested as a solution for this discrepancy. The current study, approved by IWK Health Center research ethics board was created to assess the viability of using the TR in assessment of ocular torsion as well as investigate the effect of the physiological position of the fundus. Subjective tests were compared to traditional fundus photographs and novel TR scans in patients with long-standing unilateral fourth nerve palsies. Results found no differences between subjective and objective angles when considering the physiological fundus position and that TR angles were not comparable to other torsional testing methods. Therefore, it was concluded that the physiological position should be considered when determining the true amount of abnormal fundus torsion. As well, we found no significant value to using TR imaging by optical coherence tomography compared to the traditional fovea-ONH relationship by fundus photography to assess ocular torsion.