Periphery of retina is best visualised with:
**Core Concept**
The periphery of the retina refers to the area extending from the ora serrata to the equator, which is crucial for peripheral vision. To visualize this area, a diagnostic tool that provides a detailed, magnified view of the peripheral retina is necessary.
**Why the Correct Answer is Right**
The correct answer is the **B-scan ultrasonography**. This diagnostic modality uses high-frequency sound waves to create detailed images of the posterior segment, including the peripheral retina. It is particularly useful in cases where the media is opaque, preventing direct visualization of the retina with other methods such as ophthalmoscopy. The B-scan ultrasonography can help identify retinal detachment, tumors, and other peripheral retinal lesions.
**Why Each Wrong Option is Incorrect**
**Option A:** Fluorescein angiography is a technique used to visualize the retinal and choroidal vasculature, but it is not ideal for visualizing the periphery of the retina. It is more useful for detecting vascular abnormalities and leakage.
**Option B:** Optical coherence tomography (OCT) is a non-invasive imaging technique that provides high-resolution cross-sectional images of the retina. While it is useful for detecting retinal thickness and structural abnormalities, it may not provide a detailed view of the peripheral retina.
**Option C:** Indocyanine green (ICG) angiography is a technique used to visualize the choroidal vasculature, which is not directly related to visualizing the peripheral retina.
**Clinical Pearl / High-Yield Fact**
When evaluating a patient with suspected peripheral retinal pathology, it is essential to consider the use of B-scan ultrasonography as a diagnostic tool to provide a detailed view of the peripheral retina.
**Correct Answer:** B. B-scan ultrasonography.