Retinal detachment

    Cards (13)

    • Retinal detachment occurs when the layers of the retina separate – specifically the neurosensory retina from the retinal pigment epithelium
    • This is a sight-threatening condition and considered an ocular emergency warranting an urgent referral to ophthalmology.
    • The retina:
      • 10 separate layers
      • Inner neurosensory retina - photoreceptors (rods and cones)
      • Outer retinal pigment epithelium
    • Causes:
      • Most commonly occurs secondary to a full thickness retinal tear which enables the build up of vitreous fluid behind the neurosensory retina
      • Tractional - scar tissue grows over the retina and tractional forces pull the retina away - associated with diabetic retinopathy
      • Exudative - fluid accumulates beneath the retina, usually due to inflammation such a uveitis
    • posterior vitreous detachment (PVD) often precedes retinal detachment. This is where the vitreous gel separates from the retina and is due to trauma or ageing. A posterior vitreous detachment can lead to a retinal tear. Once a retinal tear has occurred a new potential space allows for the liquefied vitreous to enter the space causing a retinal detachment
    • Risk factors for rhegmatogenous retinal detachment (most common), include:
      • Age >40
      • Male
      • Myopia (near-sightedness)
      • Family history of retinal detachment
      • Previous ocular surgery
      • Trauma
      • Retinal detachment in the contralateral eye
    • Typical symptoms of retinal detachment include:
      • Painless loss of vision
      • Flashing lights and floaters
      • “Cobwebs” in the peripheral vision
      • Shadow or grey curtain moving across the field of vision
    • Clinical findings may include:
      • Poor visual acuity
      • Relative afferent pupillary defect
      • Vitreous harmorrhage
      • Altered red reflex (grey or folded appearance)
      • Reduced visual acuity (if the macula is involved)
      • Visual field defects
      • A sheet of sensory retina billowing towards the centre of the globe
    • Slit lamp examination may reveal a ‘Tobacco dust’ appearance of the anterior vitreous: a result of pigment cells migrating through a tear in the retina (also known as Shafer’s sign)
    • Investigations:
      • Slit lamp with a triple mirror is used to assess for anterior breaks
      • Indirect ophthalmoscopy will reveal the location and number of retinal tears and the amount of underlying fluid
      • Ultrasound can be used if there is a vitreous haemorrhage caused by a tear involving a retinal vessel
    • Preventative management:
      • Patients with symptoms of an acute PVD or a retinal tear should be examined without delay.
      • If a retinal tear is found, this can be treated with laser photocoagulation in the clinic and to reduce the risk of a detachment occurring.
      • The majority of cases are treated at this point and do not progress to a retinal detachment.
    • Surgical management:
      • Vitrectomy (most common) - drain vitreous fluid to allow the retina to lie flat. Cryotherapy or laser therapy is used to deal the retinal tear.
      • Pneumatic retinopexy - expansile gas pushes retina back
      • Scleral buckle - cryotherapy or laser photocoagulation used to create a scar and then a silicone band is then sutured onto the sclera
    • Complications of retinal detachment include:
      • Partial or complete unilateral vision loss
      Retinal detachment involving the macula carries the worst prognosis and results in the poorest visual outcomes.