A Rare Case of Posterior Scleritis Masquerading as Acute Angle Closure Glaucoma: Highlighting the Diagnostic Value of Multimodal Imaging.

In this article, we present a rare case of posterior scleritis presenting as acute angle-closure glaucoma, highlighting the diagnostic challenges, clinical findings, and therapeutic approach, while emphasizing the importance of imaging modalities and detailed systemic evaluation. A 52-year-old, one-eyed, diabetic patient presented to the emergency department with mild ocular pain, photophobia, elevated intraocular pressure in the right eye, and a somewhat shallow anterior chamber. During examination, papilledema was noted. The patient was admitted for evaluation and management. During hospitalization, the patient's condition deteriorated rapidly, with significant worsening in visual acuity and uncontrolled intraocular pressure elevation. Detailed ophthalmologic and systemic evaluations were performed, which included optical coherence tomography (OCT), B-mode ultrasonography (u/s B-mode), ultrasound biomicroscopy (UBM), fundus fluorescein angiography (FFA), and magnetic resonance imaging (MRI) of the eyes and orbit. Initial findings included optic disc edema, a shallow anterior chamber, and serous retinal detachment extending from the macula to the periphery. U/S B-mode revealed the characteristic "T-sign" indicative of posterior scleritis. MRI of the orbit and UBM revealed inward dislocation of the ciliary body and the presence of fluid in the suprachoroidal space of the right eye. Laboratory tests ruled out infectious and systemic autoimmune causes. Treatment for posterior scleritis led to significant improvement in visual acuity and intraocular pressure (IOP), along with gradual resolution of symptoms. Over nine months of follow-up, the patient remained stable. Posterior scleritis is a rare but important differential diagnosis in cases of acute angle-closure glaucoma with arduous IOP control. In such cases, imaging modalities such as u/s B-mode and UBM are crucial for diagnosis and management. Early recognition and an appropriate therapeutic approach can lead to favorable outcomes even in atypical presentations.