Primary Angle Closure in a 7-Year-Old Child: Evaluation and Findings With Conventional Ultrasound and Ultrasound Biomicroscope.

Primary angle closure (PAC) is rare in pediatric patients, typically associated with persistent hyperplastic vitreous, congenital cataracts, ocular surgery, retinopathy of prematurity, topical or oral medications, and ocular albinism. This case report describes the youngest documented case of unilateral subacute PAC in a seven-year-old female without these underlying conditions. The patient underwent evaluation using A-scan ultrasound and ultrasound biomicroscopy (UBM), revealing a shallow anterior chamber and a short axial length (20.45 ± 0.02 mm in the left eye). The angle closure was caused by a pupillary block associated with anterior displacement of the crystalline lens, unrelated to increased lens thickness or ciliary body abnormalities. A diagnosis was confirmed and laser iridotomy was performed, successfully resolving the condition. Postoperative UBM measurements confirmed the resolution of angle closure. This case highlights the importance of recognizing and promptly treating angle closure in pediatric patients, even in the absence of typical risk factors.