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 This Is Rhegmatogenous RD The term "rhegmatogenous" derives from the Greek *rhegma* (break). Liquefied vitreous passes through a full-thickness retinal break (tear or hole) and accumulates in the subretinal space, elevating the neurosensory retina from the RPE. **Fundoscopic findings in this case:** - **Corrugated, grayish-white elevated membrane** — the detached neurosensory retina appears corrugated/undulating because it is no longer tethered to the RPE; it billows and moves freely with eye movement - **Moves with eye movement** — classic for RRD (the detached retina undulates); in tractional RD, the retina is tethered by fibrovascular membranes and is relatively immobile - **Stretched, attenuated retinal vessels** — vessels on the detached retina appear stretched as the retina is elevated and pulled away from the choroidal circulation ### Risk Factors Present in This Patient | Risk Factor | Relevance | |-------------|-----------| | **High myopia (−8 D)** | Peripheral lattice degeneration → retinal tears; vitreous liquefaction | | **Recent PVD (1 month ago)** | Dynamic vitreoretinal traction at the time of PVD is the most common cause of retinal tears | | **Age 58** | Increasing incidence of PVD and subsequent RRD | ### Distinguishing RRD from Other Detachments | Feature | Rhegmatogenous RD | Tractional RD (PVR) | Exudative RD | |---------|-------------------|---------------------|--------------| | **Onset** | Sudden (hours–days) | Gradual (weeks–months) | Gradual (weeks) | | **Retinal mobility** | Mobile, billows with eye movement | Immobile, tethered by membranes | Immobile, smooth | | **Appearance** | Corrugated, grayish-white, undulating | Corrugated but fixed, fibrous membranes visible | Smooth, dome-shaped, shifting fluid | | **Retinal break** | Present (required by definition) | Not required | Absent | | **Vitreous** | Liquefied, tobacco-dust (Shafer's sign) | Fibrovascular bands/membranes | Clear | | **Vessels** | May appear stretched on detached retina | Pulled radially by membranes | Normal course | ### Why PVR/Tractional RD Is Incorrect Here Proliferative vitreoretinopathy (PVR) with tractional RD is a **complication** of longstanding or previously treated rhegmatogenous RD. It develops over **weeks to months** after a retinal break, not acutely over 2 days. PVR produces fixed, star-fold membranes that restrict retinal mobility — the retina does NOT move freely with eye movement. This patient's 2-day history and mobile corrugated retina are inconsistent with established PVR. **Clinical Pearl:** The corrugated appearance of the detached retina in RRD is due to loss of the normal taut attachment to the RPE, allowing the retina to fold and undulate. This is distinct from the fixed, contracted star-folds of PVR. The "moves with eye movement" descriptor is the critical differentiator — it confirms RRD, not tractional RD. ### Management Principle Urgent surgical repair is required: scleral buckling, pneumatic retinopexy, or pars plana vitrectomy depending on the break location and extent of detachment. Early repair prevents macular involvement and preserves central vision. [cite: Kanski Clinical Ophthalmology 9e Ch 12; American Academy of Ophthalmology BCSC Section 12]