Retinal detachment

Definition/diagnostic criteria Retinal detachment is characterised by the separation of the neurosensory retina from the underlying retinal pigment epithelium, disrupting the photoreceptor layer from its blood supply and leading to vision loss if not promptly treated. It is classified into three types: rhegmatogenous, tractional, and exudative.

• Rhegmatogenous retinal detachment: Caused by a tear or break in the retina, is the most common type.
• Tractional retinal detachment: Occurs without a retinal break and is usually secondary to proliferative diabetic retinopathy.
• Exudative, or serous, detachment: Results from fluid accumulation under the retina without a break.

Epidemiology In the UK, retinal detachment affects approximately 1 in 10,000 people per year. It is most prevalent in individuals aged 60–70 years. Risk factors include myopia, previous cataract surgery, trauma and family history.

Diagnosis
Clinical features: Patients with retinal detachment may present with photopsia (flashing lights), floaters, a shadow or curtain effect that progresses across the visual field, and visual loss. Acute symptomatic posterior vitreous detachment (PVD) can indicate a retinal tear that may lead to detachment. It is crucial for GPs to recognise these symptoms as potential retinal detachment and refer urgently to ophthalmology.

Investigations: Examination by an ophthalmologist includes direct and indirect ophthalmoscopy, which can reveal retinal tears, holes, or detachment. Ultrasonography is also employed when the ophthalmoscopy is inconclusive, particularly in the presence of dense cataract or vitreous haemorrhage.

Treatment The treatment for retinal detachment is surgical. The urgency of surgery depends on whether the macula is detached. Macula-on detachments are a surgical emergency to prevent central vision loss. Procedures include pneumatic retinopexy, scleral buckle, vitrectomy, or a combination of these techniques, depending on the type and extent of the detachment. Pre-operative and post-operative care may involve the use of topical and oral corticosteroids to reduce inflammation and antibiotics to prevent infection.

Prognosis The prognosis for retinal detachment is variable and depends on the duration and extent of the detachment, and whether the macula was involved. Timely surgical repair before macular detachment usually results in good visual outcomes. However, the presence of proliferative vitreoretinopathy, a complication of retinal detachment surgery, can adversely affect the prognosis. Anatomical reattachment rates are high with modern surgical techniques, but functional recovery may not always correspond, especially if the macula was detached for an extended period.