Retinal detachment

• 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 - more common in diabetic retinopathy
  • Exudative - underlying retinal disease leads to the build up of exudative fluid
• 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.
• 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
  • 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.