When is B-scan biometry typically required?

B-scan biometry is particularly valuable when there are media opacities present, such as cataracts or vitreous hemorrhages, that may obstruct clear visualization of the retina and other underlying structures during standard examination techniques. In these instances, traditional imaging methods such as direct examination or conventional optical methods are hindered by the opacities. B-scan biometry utilizes ultrasound to provide detailed images, allowing for assessment of the eye's internal structures and enabling accurate biometric measurements even when typical optical pathways are not clear.

This procedure is not routinely required for standard eye exams, where visual clarity is expected and sufficient. Assessing corneal thickness is generally performed using pachymetry rather than B-scan biometry. Similarly, while acute glaucoma may require specific diagnostic tools, the presence of media opacity directly necessitates B-scan biometry for effective evaluation of the posterior segment and related structures.