Role of Muscle Biopsy in the Diagnosis and Management of Extraocular Muscle Pathologies

To evaluate the role of extraocular muscle (EOM) biopsy in diagnosing and managing patients presenting with EOM pathologies.

A retrospective review of patient records for those who underwent EOM biopsy between January 2010 and August 2022 was conducted. Data collected included demographic details, initial diagnosis, radiological findings, response to initial treatment, histopathological reports of the specimen, and any changes in treatment modality following biopsy.

Twenty-three eyes of 18 patients were included. The mean age of the cohort was 42.4 ± 18.04 years, with a male preponderance (n = 10; 55.6%). Unilateral involvement was observed in 13 (72.22%) cases, and bilateral involvement in 5 (27.77%). Proptosis was the most common clinical presentation (n = 12; 66.6%). On imaging, the lateral rectus was the most frequently involved muscle (n = 11; 61%). Muscle biopsy confirmed the diagnosis as Idiopathic orbital inflammatory disease in 10 (55.55%) patients, dermoid in 2 (11.11%), and leiomyoma, amyloidosis, extranodal marginal zone lymphoma, benign reactive lymphoid hyperplasia, sarcoid granuloma, and carcinoid in 1 (5.55%) patient each.

EOMs can be involved in a variety of orbital lesions. Muscle biopsy is indicated in patients with clinicoradiological ambiguity or poor response to initial treatment.