Difficult vertical diplopia studied by video-oculography in aphakia after contact lens use. A case report.

Purpose: To establish the utility of a video-oculography system (3D-VOG) in the diagnosis of a patient with difficult idiopathic vertical diplopia.

Case report: We present a clinical case of an 87 year old female who was operated for glaucoma and cataract with the intracapsular technique in both eyes. She reported vertical diplopia with the use of contact lenses but not while using her aphakia spectacles. A complete ophthalmological study was carried out with special interest in the ocular motility study with 3D-VOG.

Results: Besides the hypertropia in lateroversion of the non-fixing eye, the video-oculography showed an incyclotorsion of the hypertropic eye, a fundamental factor for the differential diagnosis between bilateral superior oblique overaction and DVD or dissociated vertical divergence. Such a torsional strabismic deviation is very difficult to detail by other methods and is the important clue for diagnosis. The 3D-VOG made this diagnosis possible.

Conclusions: The occurrence of a vertical diplopia with use of contact lenses, and not with spectacles, is explained by the limitation of ocular gaze movements with the aphakia spectacles which limitation is not found with the use of contact lenses, with diplopia appearing in the more extreme lateroversion possible with the contact lenses. The 3D-VOG system enabled us to analyze torsional movements in lateroversion that allowed the diagnosis of bilateral superior oblique overaction to be made.