A 58-year-old man presents to the ophthalmology clinic with sudden onset of floaters and flashing lights in his right eye for the past 3 days. He has a history of high myopia (−8 D) and had cataract surgery in the same eye 2 years ago. On examination, visual acuity is 6/36 in the right eye. Fundoscopy reveals a superior temporal retinal fold with retinal vessels crossing the fold, and the macula appears elevated. What is the most likely diagnosis?

Explanation

## Diagnosis: Rhegmatogenous Retinal Detachment ### Clinical Presentation Analysis **Key Point:** The triad of floaters, photopsia (flashing lights), and visual field defect in a myopic patient with prior ocular surgery is pathognomonic for rhegmatogenous retinal detachment (RRD). ### Distinguishing Features in This Case | Feature | RRD | TRD | Exudative RD | PVD | |---------|-----|-----|--------------|-----| | **Onset** | Acute (hours–days) | Gradual (weeks–months) | Gradual | Acute but benign | | **Floaters/Photopsia** | Yes, prominent | No | No | Yes, but transient | | **Retinal folds** | Present (elevation) | Present (contraction) | Absent | Absent | | **Vessels crossing fold** | Yes (diagnostic) | No (traction lines) | N/A | N/A | | **Risk factors** | Myopia, trauma, PVD, prior surgery | Diabetes, PDR, ROP | Inflammation, tumor | Normal variant | **High-Yield:** Vessels crossing a retinal fold = retinal elevation = RRD. In tractional detachment, retinal vessels are pulled inward without crossing a fold. ### Pathophysiology 1. **Predisposing factors in this patient:** - High myopia (−8 D) → elongated globe → vitreous liquefaction → increased PVD risk - Post-cataract surgery → vitreous manipulation → accelerated PVD - Vitreous traction → retinal break formation 2. **Mechanism:** - Vitreous traction on degenerative retina → full-thickness retinal break - Liquefied vitreous seeps through break → subretinal space accumulation - Photoreceptor separation from RPE → loss of function **Clinical Pearl:** The superior temporal location is the most common site for RRD because gravity and eye movements favor vitreous traction in this quadrant. ### Why Macula Is Involved Here The elevated macula indicates **macula-on** status (still attached but threatened). This is a surgical emergency—if left untreated, the macula will detach within days, causing permanent central vision loss. **Warning:** Do NOT confuse the retinal fold (elevation) with tractional lines (inward contraction). In RRD, the fold is smooth and elevated; in TRD, the retina is pulled inward with visible traction lines. ### Management Implications ```mermaid flowchart TD A[Rhegmatogenous RD diagnosed]:::outcome --> B{Macula status?}:::decision B -->|Macula-on| C[Urgent vitrectomy/pneumatic retinopexy]:::action B -->|Macula-off| D[Urgent vitrectomy + scleral buckle]:::action C --> E[Aim: reattach within 24-48 hrs]:::action D --> F[Aim: reattach within 7-10 days]:::action ``` **Key Point:** Macula-on RRD requires same-day or next-day surgery to prevent irreversible photoreceptor loss. [cite:Kanski 10e Ch 13]