Diagnostic dilemmas of mechanical restriction of the medial rectus: A case report

BACKGROUND: Due to the proximity of the maxillary sinus and ethmoid sinuses to the orbit, inflammatory processes that originate in the sinonasal region have the potential to extend into the orbit. OBJECTIVE: We presented a case of ptosis and restrictive strabismus of the medial rectus muscle. METHODS: A case report with a literature review of possible diagnoses. RESULTS: Biopsy, imaging, and laboratory evaluation by otolaryngology, ophthalmology, and rheumatology services were unable to identify the cause of the fibrosis after 22 months of follow-up. A response to oral steroids indicated an inflammatory process. CONCLUSION: Unilateral mechanical restriction of the medial rectus muscle is a rare complication of nasal disease. Inflammatory processes and iatrogenic injury are known to cause fibrosis of surrounding tissue. We presented a unique case of medial rectus fibrosis that did not meet the diagnostic criteria of recognized etiologies.