In rhegmatogenous retinal detachment, which of the following is the MOST common predisposing factor in a non-myopic, non-traumatized eye?

Explanation

## Predisposing Factors in Rhegmatogenous Retinal Detachment (Non-Myopic, Non-Traumatized Eye) **Key Point:** In a non-myopic, non-traumatized eye, **lattice degeneration** is the single most common predisposing structural lesion leading to rhegmatogenous retinal detachment (RRD). ### Why Lattice Degeneration is the Answer Lattice degeneration is a peripheral retinal degenerative condition characterized by: 1. **Retinal thinning and atrophy** — creates zones of weakness prone to full-thickness holes or tears 2. **Vitreoretinal adhesion at lattice margins** — when PVD occurs, traction is concentrated at these edges, producing horseshoe tears 3. **Prevalence:** Found in ~6–8% of the general population, but present in **30–40% of eyes with RRD** (Yanoff & Duker, Ophthalmology) 4. **Occurs in emmetropic eyes** — unlike high myopia, lattice degeneration is a significant risk factor independent of refractive error ### Why Option A (PVD with Vitreous Base Traction) is Incorrect Here While PVD is the **triggering mechanism** in the majority of RRDs, it is a physiological event (not a predisposing structural lesion). The question specifically asks for the most common **predisposing factor** in a non-myopic, non-traumatized eye. PVD alone rarely causes detachment without a pre-existing retinal weakness such as lattice degeneration. "Vitreous base traction" as a standalone entity is also less common than lattice degeneration as a predisposing lesion. ### Comparison of Predisposing Factors | Factor | Prevalence in RRD | Notes | |--------|-------------------|-------| | **Lattice degeneration** | 30–40% of RRD cases | Most common structural predisposing lesion | | High myopia | 40–55% of RRD (myopic eyes) | Not applicable here (non-myopic) | | Trauma | Variable | Excluded by stem | | Retinitis pigmentosa | Rare cause of RRD | Primarily causes tractional/exudative changes | ### Clinical Pearl Patients with lattice degeneration should undergo regular dilated fundus examination. Prophylactic laser photocoagulation or cryotherapy around lattice lesions is considered in high-risk cases (fellow eye RRD, strong family history, planned cataract surgery). **High-Yield:** Lattice degeneration → retinal thinning + vitreoretinal traction at margins → most common predisposing structural factor for RRD in non-myopic, non-traumatized eyes. (Reference: Kanski's Clinical Ophthalmology, 9th ed.; Yanoff & Duker, Ophthalmology, 5th ed.)