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 40-year-old man complained of diplopia 4 days after trabeculectomy of the right eye 4 months before visiting our clinic. His corrected vision was 0.5 with − 5.50-diopter correction in the right eye and 1.0 with − 3.50-diopter correction in the left eye. Fundus examination revealed enlarged disc cupping in the right eye and a normal left eye. His VF examination showed an extremely constricted VF in the right eye, with only 7.5° × 5° remaining in the central island []. Prism-cover testing revealed 20 PD XT at the primary position. Ocular motility testing demonstrated no ophthalmoplegia. To eliminate the diplopia, we performed a right LRM recession of 7.0 mm. One month postoperatively, prism-cover testing revealed 3 PD right hypotropia. The patient described alleviation in diplopia, although it did occur sometimes. He also reported improved stereoacuity.