Clinical Characteristics of Idiopathic Orbital Inflammation Syndrome in Relation to IntraoculaPressure

Purpose: To investigate the clinical characteristics of idiopathic orbital inflammation and changes in intraocular pressure (IOP) before and after its treatment. Patients and Methods: We retrospectively studied 20 eyes from the medical records of 19 patients who were diagnosed with idiopathic orbital inflammation between April 1, 2004, and April 30, 2019, at Toyama University Hospital. The inflammation site (type of disease), treatment provided, IOP before and after treatment, and the symptoms (proptosis, decreased ocular movements or diplopia, periorbital edema, and ocular pain) were analyzed. Results: The types of idiopathic orbital inflammation were dacryoadenitis in 14, myositis in 7, diffuse-type in 3, and posterior periscleritis in 1 case. The mean IOP after treatment was 15.4±3.9 mm Hg, which was significantly lower than the mean pretreatment IOP of 19.0±5.3 mm Hg (p = 0.009). Before treatment, all cases with the diffuse-type had high IOPs of 21 mm Hg or more. Ocular pain and eye movement disorders were present in 86% and 100% of subjects in the group with an IOP of 21 mm Hg or higher, but 38% and 31% in the group with an IOP of 20 mm Hg or lower, respectively. Conclusion: Diffuse-type of idiopathic orbital inflammation is prone to develop high IOP. Patients with idiopathic orbital inflammation and high IOP exhibit many symptoms such as decreased ocular movements, diplopia, and ocular pain.