A 58-year-old man presents with sudden onset of floaters and flashing lights in his right eye for 2 days, followed by a progressive shadow in the superior temporal visual field. He has high myopia (−8 D) and a history of posterior vitreous detachment noted 1 month ago. On examination, visual acuity is 6/9, and fundoscopy reveals a corrugated, grayish-white membrane that is elevated above the retinal plane and moves with eye movement. The retinal vessels appear stretched and attenuated. What is the most likely diagnosis?

Explanation

## Diagnosis: Rhegmatogenous Retinal Detachment ### Clinical Presentation Analysis **Key Point:** The classic triad of sudden-onset floaters, photopsia (flashing lights), and a progressive visual field defect (shadow) in a highly myopic patient with recent posterior vitreous detachment (PVD) is the hallmark presentation of **rhegmatogenous retinal detachment (RRD)**. ### Why Rhegmatogenous RD is the Correct Diagnosis | Feature | This Case | Rhegmatogenous RD | Tractional RD (PVR) | Exudative RD | |---------|-----------|-------------------|---------------------|--------------| | **Onset** | Sudden (hours–days) | ✅ Sudden | ❌ Gradual (weeks–months) | ❌ Gradual | | **Symptoms** | Floaters + photopsia + shadow | ✅ Classic triad | ❌ No photopsia typically | ❌ No photopsia | | **Fundus appearance** | Corrugated, grayish-white, elevated, mobile | ✅ Bullous, mobile, corrugated | ❌ Concave, immobile, taut | ❌ Smooth, shifting fluid | | **Vessel status** | Stretched, attenuated | ✅ Vessels draped over detachment | ❌ Radially pulled by membranes | ✅ Normal course | | **Risk factors** | High myopia, recent PVD | ✅ Both are major risk factors | ❌ Requires prior surgery/trauma/RD | ❌ Inflammatory/vascular cause | | **Retinal break** | Implied by PVD + myopia | ✅ Required by definition | ❌ Not required | ❌ Not present | ### Pathophysiology of Rhegmatogenous RD 1. **Posterior vitreous detachment (PVD)** — vitreous separates from retina, creating traction at areas of firm vitreoretinal adhesion 2. **Retinal break formation** — traction tears the retina (horseshoe tear most common in high myopia) 3. **Liquefied vitreous ingress** — passes through the break into the subretinal space 4. **Progressive detachment** — retina elevates, producing the corrugated, grayish-white, mobile appearance on fundoscopy 5. **Vessel stretching** — retinal vessels are passively draped over the elevated, undulating retina, appearing stretched and attenuated **High-Yield:** High myopia (>6 D) increases risk of RRD by ~10-fold due to peripheral lattice degeneration and vitreous liquefaction. Recent PVD is the most common precipitating event for RRD. ### Why PVR with Tractional RD (Option B) is Incorrect - **PVR is a complication of RRD**, not a primary diagnosis in a patient presenting acutely with no prior retinal surgery or known retinal break - PVR develops **weeks to months** after an untreated or surgically repaired RRD — a 2-day history is far too acute - In tractional RD, the retina is **concave and immobile** (tethered by fibrovascular membranes), not corrugated and mobile as described - The "corrugated" appearance in this stem reflects the **undulating, bullous nature of rhegmatogenous detachment**, not PVR membranes - PVR requires prior RPE cell proliferation and fibrosis — this does not occur within 2 days ### Why Other Options are Incorrect - **Option C (Exudative RD):** Caused by subretinal fluid accumulation from inflammation, tumors, or vascular disease. The retina is smooth (not corrugated), fluid shifts with position, and there are no floaters/photopsia. No risk factors present here. - **Option D (Anterior PVR):** A subtype of PVR affecting the anterior retina/vitreous base — requires established PVR, not an acute 2-day presentation. **Clinical Pearl:** The corrugated, grayish-white, mobile retina on fundoscopy is the classic appearance of **rhegmatogenous retinal detachment** — the retina billows like a sail in the wind. This is in contrast to tractional RD, where the retina is taut, concave, and immobile. (Kanski's Clinical Ophthalmology, 9th ed., Ch. 12; American Academy of Ophthalmology BCSC Section 12)