## Pathophysiology of Rhegmatogenous Retinal Detachment **Key Point:** Rhegmatogenous retinal detachment (RRD) occurs when a break in the neurosensory retina allows vitreous fluid to seep between the retina and retinal pigment epithelium (RPE), separating them. ### Mechanism of PVD-Related RRD Posterior vitreous detachment (PVD) is the most common predisposing event in rhegmatogenous RD. The sequence is: 1. Vitreous liquefaction and collapse (especially in myopes and elderly patients) 2. Vitreous separates from internal limiting membrane 3. Vitreous traction on areas of vitreous base adhesion creates tangential stress 4. Retinal break forms (atrophic hole or tractional tear) 5. Vitreous fluid enters subretinal space via the break 6. Gravity and vitreous contraction cause progressive detachment **High-Yield:** The most common sites of breaks are the equatorial and pre-equatorial regions, particularly in the superior temporal quadrant (as in this case) — this is because PVD traction is greatest at the vitreous base. ### Risk Factors for RRD | Risk Factor | Mechanism | |---|---| | High myopia | Elongated globe, thin retina, vitreous liquefaction | | PVD | Traction on vitreous base and retinal adhesions | | Lattice degeneration | Thinned retina, prone to breaks | | Previous RD in fellow eye | Genetic predisposition | | Trauma | Direct retinal break | | Aphakia/pseudophakia | Loss of lens support, vitreous prolapse | **Clinical Pearl:** In myopic patients, the risk of RD is 5–10 times higher than in emmetropic eyes, and PVD-related traction is the dominant mechanism. **Mnemonic:** **PVD-RRD** — Posterior Vitreous Detachment is the Rhegmatogenous Retinal Detachment initiator. The vitreous "pulls away" and in doing so, pulls the retina with it at adhesion sites. [cite:Yanoff & Duker Ophthalmology 5e Ch 6.14]
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