Retinal Detachment

🔍 When to Suspect

A patient with a sudden onset of a shadow or curtain coming across their vision, often preceded by new, persistent flashes of light (photopsia) and a shower of floaters

From the full topic in The Ocean Library: Retinal Detachment

🧭 When to suspect

A retinal detachment (RD) is separation of the neurosensory retina from the underlying retinal pigment epithelium (RPE). It is a sight-threatening emergency. The classic triad is new flashes of light (photopsia), a sudden shower of floaters, and progressive visual field loss – the "curtain" or "shadow" spreading across the vision. It is characteristically painless and the field defect typically begins in the periphery and advances towards the centre. The annual incidence is roughly 10–15 per 100,000, peaking between 40 and 70 years; it is rare in children.

There are three types. Rhegmatogenous RD (much the commonest) follows a retinal break, usually precipitated by an acute posterior vitreous detachment (PVD). Tractional RD results from contracting fibrovascular membranes, classically in proliferative diabetic retinopathy. Exudative (serous) RD occurs when subretinal fluid accumulates with no break, for example in posterior inflammation or a choroidal tumour.

Type	Mechanism	Typical context
Rhegmatogenous (commonest)	A retinal break (tear or hole) lets liquefied vitreous track under the retina	Acute PVD; myopia; previous cataract surgery; trauma; lattice degeneration
Tractional	Contracting fibrovascular membranes pull the retina off the RPE	Proliferative diabetic retinopathy; retinal vein occlusion; sickle-cell disease
Exudative (serous)	Subretinal fluid accumulates with no retinal break	Posterior uveitis or scleritis; choroidal tumour; malignant hypertension; pre-eclampsia

The two primary-care skills are to recognise the symptomatic patient and to refer at the right tempo, and never to be reassured by a normal bedside examination. Raise suspicion particularly in those with myopia (the more myopic, the greater the risk), previous cataract surgery (pseudophakia or aphakia), a previous detachment in either eye (the fellow eye carries a risk of around 1 in 8), ocular or head trauma, lattice degeneration, a family history of RD, or connective-tissue disease such as Marfan or Stickler syndrome.

🧠 Clinical pearl Flashes and floaters are common and usually benign acute PVD – but you cannot tell from the history alone which conceal a tear. The single most useful pointer is a subjective loss of vision (a true field defect or curtain), which sharply raises the probability of a retinal tear or detachment; vitreous haemorrhage and vitreous pigment ("tobacco dust", Shafer's sign) are further warning signs. This is exactly why every symptomatic patient needs a dilated specialist examination, not reassurance.

Source: Royal College of Ophthalmologists

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