A 22-year-old male patient visited our clinic complaining of diplopia after a traffic accident 1 year prior. There was no abnormal eye position noted before his accident. The trauma caused encephalomalacia and fracture of the frontal bone and orbital bone. His best-corrected visual acuity (BCVA) was 1.0 in both eyes. Fundus examination revealed bilateral bow-tie shaped optic atrophy. His VF examination showed complete bitemporal hemianopia []. Traumatic optic chiasmopathy was then diagnosed. Ocular motility testing revealed no ophthalmoplegia, and the prism-cover test demonstrated 16 prism-diopter (PD) exotropia (XT) and 7 PD right hypertropia (RH). To eliminate this diplopia, we performed lateral rectus muscle (LRM) recession of 6.5 mm and superior rectus muscle (SRM) recession of 3 mm in the right eye. Three months after strabismus surgery, the prism-cover test revealed 0.5 PD XT and 4 PD RH at the primary position. Eye-alignment examination with the Hess chart also showed improvement over the preoperative findings. However, the patient complained that his diplopia persisted and failed to fuse with any prism.
A 29-year-old man presented with diplopia after a traumatic skull base and orbital bone fracture 4 years prior. He was an architect and the diplopia considerably hindered his work. Ocular examination revealed the BCVA to be 1.0 in both eyes. Fundus examination revealed bilateral optic atrophy, and VF examination showed bitemporal hemianopia []. The prism-cover testing revealed 18 PD XT and 6 PD RH at the primary position. Ocular-motility testing demonstrated normal eye movement bilaterally. The Bagolini striated glasses test demonstrated right-eye suppression. To eliminate the diplopia, we performed LRM recession of 9 mm and SRM recession of 2 mm in the right eye. One month after surgery, prism-cover testing revealed 10 PD XT and 5 PD RH. Three months later, synoptophore testing demonstrated an unstable subjective angle from 1 to 3 PD XT and from 3 to 6 PD RH. The patient still experienced diplopia and could not tolerate prism glasses.