A 42-year-old woman with high myopia presents with sudden onset of photopsia and multiple floaters. Dilated fundus examination reveals a superior temporal retinal detachment with a horseshoe tear. Which investigation is most appropriate to assess the extent of detachment and rule out additional breaks?

Explanation

## Investigation for Assessing Extent and Identifying Additional Retinal Breaks ### Clinical Context The patient has: - Confirmed retinal detachment with a visible horseshoe tear - High myopia (risk factor for multiple breaks) - Need to assess full extent and identify all breaks before surgery ### Gold Standard for Complete Assessment **Key Point:** Indirect ophthalmoscopy with scleral depression is the investigation of choice to: 1. Confirm the extent of the detachment 2. Identify all retinal breaks (horseshoe tears, atrophic holes, dialyses) 3. Plan the surgical approach ### Why Scleral Depression? **High-Yield:** Scleral depression is a clinical technique (not a separate investigation) performed during indirect ophthalmoscopy that allows visualization of the peripheral retina and equatorial region, which is otherwise difficult to see. It is essential for identifying breaks that may not be visible without depression. | Aspect | Indirect Ophthalmoscopy Alone | With Scleral Depression | |--------|-------------------------------|------------------------| | **Peripheral retina visualization** | Limited to equator | Full visualization to ora serrata | | **Detection of breaks** | May miss peripheral breaks | Identifies all breaks | | **Horseshoe tear assessment** | Partial | Complete | | **Surgical planning** | Incomplete | Comprehensive | | **Dialysis detection** | Poor | Excellent | ### Clinical Pearl **Clinical Pearl:** In myopic patients, multiple retinal breaks are common. Scleral depression is mandatory before any retinal detachment surgery to avoid missing breaks that could lead to recurrent detachment. A missed break is a common cause of re-detachment post-operatively. ### Why Other Investigations Are Inadequate **Fundus fluorescein angiography (FFA):** - Assesses retinal perfusion and vascular integrity - Does NOT identify retinal breaks or assess detachment extent - Used for evaluating retinal vascular diseases, not detachment **Indocyanine green angiography (ICG):** - Visualizes choroidal circulation - Has no role in assessing retinal detachment or identifying breaks - Used for choroidal neovascularization, polypoidal choroidal vasculopathy **Anterior segment OCT:** - Evaluates anterior segment structures (cornea, anterior chamber, lens) - Completely irrelevant to posterior segment retinal detachment ### Mnemonic for Retinal Detachment Investigations **SCAR for Retinal Detachment:** - **S** = Scleral depression (to see all breaks) - **C** = Clear media? Use indirect ophthalmoscopy - **A** = Absent view? Use B-scan - **R** = Retinal breaks identified? Plan surgery ### Workflow After Diagnosis ```mermaid flowchart TD A[Retinal detachment suspected]:::outcome --> B[Dilated fundus exam with indirect ophthalmoscopy]:::action B --> C{Media clear?}:::decision C -->|Yes| D[Perform scleral depression]:::action C -->|No| E[B-scan ultrasonography]:::action D --> F[Identify all breaks and extent]:::outcome E --> G[Assess detachment extent]:::outcome F --> H[Plan surgical approach]:::action G --> H ``` [cite:Khurana Comprehensive Ophthalmology 7e Ch 8]