25th December 2023

Retinal detachment

Retinal detachment (RD) refers to an abnormal separation of the neurosensory retina from the underlying retinal pigment epithelium (RPE). The photoreceptors are susceptible to ischaemia because of separation from the choroidal blood supply, with potentially irreversible vision loss. Urgent surgery is warranted if the macula remains attached to preserve central vision. In macula-off detachments vision may remain poor despite surgical intervention.

Classification

There are three classifications of retinal detachments: rhegmatogenous retinal detachment (RRD), tractional retinal detachment (TRD), and exudative retinal detachment (ERD).

1. Rhegmatogenous retinal detachment: A tear, break, or hole occurs in the retina. Vitreous enters the space underneath the neurosensory retina, causing a detachment from the RPE. This detachment can occur over hours to days.
2. Tractional retinal detachment: Retinal traction is exerted from the proliferation of fibrotic membranes in the vitreo-retinal interface. When the force is strong enough, the neurosensory retina may be detached from the underlying RPE. Often associated with advanced diabetic eye disease.
3. Serous retinal detachment: This is a result of a local exudative process, such as a tumour or local inflammation.

Risk factors for rhegmetogenous retinal detachment:

• Lattice degeneration
• High/pathological myopia
• Previous intraocular surgery
• Trauma
• Previous retinal detachment in the contralateral eye
• Family history

Clinical presentation

Vision loss is often painless and progressive over hours to days. The main characteristics of a retinal detachment are summarised by the four ‘F’s:

• Floaters
• Flashes
• Field defect
• Fall in acuity

Management

The primary treatment of RRD is surgical. If the macula is detached, surgery may be delayed by a few days. If the macula is preserved, urgent surgery is warranted to preserve this. Surgical options include retinopexy (pneumatic or silicone oil) and scleral buckling. A retinal tear in the absence of an RD may be sealed with laser retinopexy.

Differential diagnoses

The main differential diagnosis for new onset floaters and flashes is a posterior vitreous detachment. Posterior vitreous detachment is the most common cause of primary symptomatic floaters. A rapid increase in the number of floaters with sudden onset of photopsia (flashes) needs urgent ophthalmic assessment.

Summary

Any patient complaining of flashes and floaters should be referred for urgent ophthalmological assessment to exclude a retinal detachment.