Discerning the optic nerve and retinochoroidal pathology using B-scan ultrasound in cases with anterior segment opacity.

Urkude J, et al. BMJ Case Rep 2017. doi:10.1136/bcr-2017-221549 Description Case 1: A posterior segment B-scan ultrasonography in a patient with typical iris coloboma and total cataract, showed well-defined excavated area in the inferior part just below the optic disc (red arrow) with the absence of retinochoroidal layer, suggestive of fundal coloboma (yellow arrow) (figure 1A). Involvement of macula and types of fundal coloboma can be ascertained quite fairly based on ultrasonography which might provide a clue or prediction about postoperative visual gain or visual prognosis. Case 2: Axial section ultrasonography in a 6-year-old child with total corneal opacity revealed a well-defined area of posterior excavation (yellow arrow) over the optic nerve head (red arrow) along with thinned out inferior neuroretinal rim (purple arrow) suggestive of optic disc coloboma (figure 1B). An entity like glaucomatous optic nerve cupping may be confused with optic disc coloboma but the simple hint of knowing thinned out inferior margin of optic nerve head in later case can give a clue to the diagnosis. Most of the time, these cases have syndromic association because of the same initial ultrasound assessment followed by relevant imaging and genetic evaluation is necessary. Case 3: Similarly, posterior segment scan in a patient with high myopia (axial length=39 mm) Discerning the optic nerve and retinochoroidal pathology using B-scan ultrasound in cases with anterior segment opacity