A 58-year-old man presents to the ophthalmology clinic with sudden onset of floaters and flashing lights in his right eye for 2 days. He is a high myope (−12 D) with a history of lattice degeneration. On examination, visual acuity is 6/36 in the right eye. Fundoscopy reveals a grey, elevated retinal fold extending from the optic disc towards the macula, with multiple retinal breaks at the edge of the detachment. The vitreous shows mild inflammation. What is the most likely diagnosis?

Explanation

## Diagnosis: Rhegmatogenous Retinal Detachment ### Clinical Presentation This patient presents with the classic triad of rhegmatogenous retinal detachment (RRD): 1. **Sudden floaters** — vitreous haemorrhage or pigment from the break 2. **Photopsia (flashing lights)** — vitreous traction on the retina 3. **Visual field defect** — the grey, elevated retinal fold extending from the optic disc ### Key Risk Factors Present - **High myopia (−12 D)** — causes posterior staphyloma and retinal thinning - **Lattice degeneration** — area of retinal thinning predisposed to breaks - **Acute symptom onset** — typical of RRD, not gradual as in tractional or exudative forms ### Fundoscopic Findings **Key Point:** The presence of **retinal breaks at the edge of the detachment** is pathognomonic for rhegmatogenous detachment. The grey, elevated appearance is due to the detached neurosensory retina separating from the retinal pigment epithelium (RPE). ### Pathophysiology ```mermaid flowchart TD A[Retinal break in high myope]:::outcome --> B[Vitreous fluid seeps through break]:::action B --> C[Fluid accumulates subretinally]:::action C --> D[Separation of neurosensory retina from RPE]:::outcome D --> E[Loss of photoreceptor function]:::urgent E --> F[Vision loss if macula involved]:::urgent ``` ### Differential Distinction | Feature | RRD | Tractional | Exudative | | --- | --- | --- | --- | | **Retinal breaks** | Present | Absent | Absent | | **Onset** | Sudden | Gradual | Gradual | | **Vitreous inflammation** | Mild/none | None | Moderate/severe | | **Causes** | Myopia, lattice, PVD | Proliferative DR, PVR | Uveal melanoma, inflammation | | **Detachment edge** | Irregular | Regular, smooth | Smooth, gentle slope | **High-Yield:** In a myopic patient with acute floaters, photopsia, and a retinal break visible on fundoscopy, RRD is the diagnosis until proven otherwise. ### Management Implications **Clinical Pearl:** Macula-on RRD (visual acuity 6/36 suggests macula-off) requires **urgent surgical intervention** — either pneumatic retinopexy, scleral buckle, or pars plana vitrectomy depending on break location and extent.