B-scan ultrasonography is specifically indicated for evaluation of the posterior segment when:

• A The pupil cannot be dilated due to posterior synechiae
• B Intraocular pressure is above 30 mmHg
• C The patient has a history of retinal laser photocoagulation
• D Dense vitreous hemorrhage or mature cataract prevents fundus visualization ✓

Explanation

B-scan ultrasonography provides valuable structural information about the posterior segment when optical media opacities (dense vitreous hemorrhage, hypermature cataract, corneal opacity) prevent direct fundoscopy or indirect ophthalmoscopy. It can detect retinal detachment, vitreous bands, choroidal masses, and foreign bodies through opaque media. Options A, C, and D do not impair fundus visualization in themselves.

Reference: Khurana Comprehensive Ophthalmology, 7th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.