Retinal detachment

Overview

Retinal detachment occurs when the inner neurosensory retina separates from the retinal pigment epithelium (RPE), depriving photoreceptors of metabolic support - causing irreversible visual loss if not treated promptly.

Risk factors

High myopia

Previous retinal detachment (fellow eye)

Lattice degeneration

Previous intraocular surgery (e.g. cataract)

Trauma

Family history

PVD (age-related)

Presentation

•Photopsia (flashes) - vitreous traction mechanically stimulates photoreceptors; brief, arc-like, peripheral

•Floaters - sudden increase or 'shower of floaters/cobwebs'; dark floaters suggest vitreous haemorrhage from a torn retinal vessel

•Visual field defect - 'curtain' or 'shadow' advancing from periphery; inferior retinal detachment → superior field defect (and vice versa)

•Reduced visual acuity - signifies macular involvement

•RAPD - may be present in extensive detachment

🚨

Macula-on vs macula-off is the key prognostic watershed. Macula-on (acuity preserved) = same-day surgical emergency - every hour risks progression. Macula-off (acuity reduced) = worse prognosis even after successful repair, proportional to duration of macular detachment.

Investigations

🥇 First-line

•dilated fundoscopy - identifies retinal breaks, tears, or frank detachment; peripheral tears can be missed without specialist equipment

•Specialist: slit-lamp examination with indirect ophthalmoscopy - stereoscopic peripheral retinal view

•Gold standard when media opacity present: B-scan ocular ultrasound - confirms detachment when dense cataract or vitreous haemorrhage prevents fundal view

•OCT - assesses macular involvement and subretinal fluid

⚠️

Retinal breaks cannot be reliably excluded on symptoms alone - dilated fundoscopy is required. If in doubt, refer; missed detachment = permanent blindness.

Differential diagnosis

Key differentials for flashes and floaters

Condition	Key distinguishing feature
PVD	Flashes and floaters without tear or detachment; most common cause of new floaters
Vitreous haemorrhage	Sudden painless visual loss; blood prevents fundal view; B-scan required
Retinoschisis	Splitting of retinal layers; benign, does not progress to full detachment
Ocular migraine	Transient scintillating scotoma; resolves completely, no persistent floaters

Management

Step 1 · Retinal tear (no detachment)

1. 1Laser retinopexy or cryotherapy - seals tear, prevents progression to detachment in ~95% of cases
2. 2Same-day urgent ophthalmology referral

↓

Macula-on detachment

Same-day surgical emergency. Options: pneumatic retinopexy, scleral buckling, or vitrectomy with gas tamponade

Macula-off detachment

Urgent surgery still required; prognosis for central vision is proportional to duration of macular detachment before repair

Types

•Rhegmatogenous - most common; vitreous liquefaction → posterior vitreous detachment (PVD) → retinal tear → fluid seeps into subretinal space → retina peels from RPE

•Tractional - fibrovascular membranes pull retina from RPE (e.g. diabetic retinopathy)

•Exudative - fluid accumulates without a tear (e.g. tumour, inflammation)

Complications and prognosis

•Proliferative vitreoretinopathy (PVR) - fibrocellular membrane formation causing redetachment; most common cause of surgical failure

•Permanent visual loss - directly related to macula-off duration before repair

•Raised intraocular pressure - can occur with gas or silicone oil tamponade

•Macula-on repaired promptly → excellent prognosis, near-normal acuity in majority

Follow-up and safety netting

•Assess fellow eye - risk of contralateral detachment is elevated

•Gas bubble tamponade = absolute contraindication to air travel - altitude-related gas expansion can cause catastrophic intraocular pressure rise; patients must carry a warning card

•DVLA must be notified of significant visual field loss; patients must not drive while vision is significantly impaired

•Counsel all patients to return immediately if new flashes, floaters, or visual field defect develop in either eye