STRABISMUS MANAGEMENT AFTER ORBITAL BLOWOUT FRACTURE

Abstract

Orbital floor fractures (OBF) account for 40% of mid-facial injuries and are therefore the most common of all trauma injuries in this region. The post-treatment complication that often follows orbital floor repair is residual diplopia or 1 persistent diplopia and is seen in 86% of the OBF cases. The causes for persistent diplopia can be varied and is often related to the degree of inflammation, trauma to 2 musculature, fat or nerves and surgical timing. Some of the common causes of the same are - malpositioning of the globe, fibrosis of the inferior fibro fatty muscular complex following trauma, direct damage to an extraocular muscle (commonly inferior rectus muscle), local injury to a motor nerve, ischemia (or compartment syndrome), iatrogenic damage during reconstructive surgery or entrapment under improperly placed alloplastic material. Our case report mentions a rare case of persistent vertical diplopia even after successful repair of orbital blowout fracture. A 15-year-old male patient following a road traffic accident presented with persistent headache and vertical diplopia. The patient was evaluated by a oral maxillofacial surgeon and a presumptive diagnosis of a case of large orbital floor fracture with entrapment of inferior rectus muscle was made which was confirmed on CT Scan. He was managed surgically by reduction of the fracture and fixation with a titanium mesh. 2 weeks post-surgery he reported to the squint clinic with complaints of persistent double vision. On comprehensive ocular examination, it was found that patient had vertical diplopia with limitation of infraduction in the left eye with negative FDT, on re-evaluation of MRI scans with 1 mm cuts, a partial left inferior rectus tear was seen and documented as the cause of persistent diplopia. Patient was treated conservatively by prescribing prismatic glasses with fusional exercises. After 6 months of follow up, the patient was relieved of diplopia in primary position but there was a residual hypotropia in downgaze for which he was prescribed prisms only for downgaze.