A 65-year-old man with high myopia presents with sudden onset of floaters and photopsia. Fundoscopy reveals a retinal detachment. What is the most common cause of retinal detachment in this patient?

Explanation

## Most Common Cause of Retinal Detachment **Key Point:** Rhegmatogenous retinal detachment (RRD) accounts for approximately 90% of all retinal detachments and is the most common type encountered in clinical practice. ### Pathophysiology of RRD Rhegmatogenous retinal detachment occurs when: 1. A break (hole or tear) forms in the neurosensory retina 2. Vitreous fluid seeps through the break into the subretinal space 3. This separates the retina from the underlying retinal pigment epithelium (RPE) 4. The retina loses its blood supply and begins to degenerate ### Risk Factors for RRD | Risk Factor | Mechanism | Relative Risk | | --- | --- | --- | | High myopia | Posterior staphyloma, vitreous traction | Very high | | Lattice degeneration | Retinal thinning predisposes to breaks | High | | Prior RRD in fellow eye | Bilateral predisposition | High | | Vitreous hemorrhage | Obscures view, increases traction | Moderate | | Posterior vitreous detachment (PVD) | Vitreoretinal traction at break edges | Very high | **High-Yield:** The patient in this case has high myopia, which is the single most important risk factor for RRD. Myopic eyes have elongated axial length and posterior staphyloma, creating chronic vitreous traction and retinal thinning. ### Why RRD is Most Common **Clinical Pearl:** RRD is the most common type because: - It occurs spontaneously in susceptible individuals (myopia, lattice degeneration, prior PVD) - It does not require underlying systemic disease (unlike exudative detachment) - It does not require advanced proliferative disease (unlike tractional detachment) - The incidence increases with age and is exacerbated by myopia ### Comparison with Other Detachment Types | Type | Frequency | Pathophysiology | Common Causes | | --- | --- | --- | --- | | Rhegmatogenous | ~90% | Break in retina + vitreous fluid ingress | Myopia, PVD, lattice degeneration | | Exudative | ~8% | Fluid accumulation beneath intact retina | Choroidal neovascularization, inflammation, Harada disease | | Tractional | ~2% | Scar tissue mechanically pulls retina | Proliferative diabetic retinopathy, advanced PVR | **Mnemonic: RRD Risk Factors — "HELM"** - **H** — High myopia - **E** — Elongated axial length - **L** — Lattice degeneration - **M** — Myopic posterior staphyloma