What causes retinal detachment?

What Causes Retinal Detachment

Retinal detachment is fundamentally caused by retinal breaks (tears or holes) that allow vitreous fluid to enter the subretinal space, with the overwhelming majority being rhegmatogenous in origin. 1

Primary Mechanism

The essential pathophysiology involves full-thickness retinal breaks that permit fluid passage from the vitreous cavity into the subretinal space, separating the neurosensory retina from the underlying retinal pigment epithelium. 2 This process is most commonly triggered by posterior vitreous detachment (PVD), which creates tractional forces on the retina. 1

Major Risk Factors and Causes

Myopia (Most Important Non-Traumatic Factor)

• More than half of all nontraumatic retinal detachments occur in myopic eyes. 1
• Low myopia (1-3 diopters) carries a fourfold increased risk, with proportionately higher risks as axial length increases. 1
• The elongated globe creates increased vitreoretinal traction during PVD. 1

Posterior Vitreous Detachment

• PVD is the primary precipitating event that induces horseshoe tears through vitreoretinal traction. 1
• Typically occurs between ages 45-65 in non-traumatic cases. 3
• After cataract surgery, PVD develops at a median of 7 months postoperatively and represents the major risk factor for subsequent detachment. 1

Lattice Degeneration

• Present in 6-8% of the general population but found in 20-30% of patients with retinal detachment. 1
• Perivascular or radial lattice patterns carry higher risk for tear or detachment formation. 1
• Detachment occurs either from atrophic round holes (rare progression) or more commonly when PVD induces horseshoe tears in lattice areas. 1

Cataract Surgery

• Overall risk of retinal detachment after cataract surgery is approximately 1%. 1
• 34% of all retinal detachments have prior cataract surgery. 1
• Specific risk factors include: axial myopia, pre-existing vitreoretinal disease, male gender, younger age, vitreous prolapse, vitreous loss (ruptured posterior capsule/zonules), and spontaneous capsulotomy extension. 1
• Nd:YAG laser capsulotomy increases risk fourfold, especially in myopic patients. 1
• The critical factor is absence of pre-existing PVD at time of surgery in high-risk eyes (myopic, lattice degeneration), as these eyes subsequently develop PVD postoperatively. 1

Ocular Trauma

• Accounts for 10% of all retinal detachments. 1
• Retinal dialysis (crescentic peripheral break at ora serrata) is pathognomonic for trauma. 2
• Blunt or penetrating injuries that alter vitreous or retinal structure increase risk. 1, 2
• Trauma can induce PVD at younger ages than typical age-related PVD. 2
• Detachment may occur immediately or develop years after initial injury. 2

Genetic and Familial Factors

• Genetic disorders such as Stickler syndrome (characterized by perivascular lattice). 1
• Family history of retinal detachment in first-degree relatives. 1
• History of retinal detachment in the fellow eye (bilateral rate 1.7%). 1

Epidemiology

• Annual incidence: 10-18 per 100,000 persons. 1
• Peak incidence: 53 per 100,000 between ages 55-59 years. 1
• Distribution of causes: 20-40% post-cataract surgery, 10% trauma-related. 1

Clinical Pitfall

The absence of PVD at the time of cataract surgery in high-risk eyes (myopic, lattice degeneration) is the major risk factor for subsequent detachment, not the presence or absence of lattice itself. 1 This explains why detachments typically occur 1-2 years post-cataract surgery when PVD subsequently develops. 1