Retinal detachment

Retinal detachment is the separation of the outer retinal pigment epithelium from the inner neurosensory-retina. When the force which holds the retinal attachment fails, fluid accumulates in the subretinal space causing the separation (1).

Separation of the retina can be caused by

• scarring of the vitreous and retina – tractional
• leakage of fluid into the subretinal space – exudative
• tears or breaks in the retina (causing fluid from the vitreous cavity to enter the subretinal space) (1), either from trauma, or when it is unusually thin - as in the elongated myopic eye, or else congenital defects.

Most retinal breaks are caused by Posterior vitreousdetachment (PVD). It is an age dependant process caused by the vitreous partly separating from the retinal surface (2).

• in majority of the patients PVD is benign and may go unnoticed
• symptomatic patients have a 10-15% risk of developing retinal breaks
• rarely seen in patients under 40 years, prevalence increases with age (40% in the seventh decade and up to 86% in the ninth decade) (1)

When the retina detaches it takes its blood supply with it; the exception here is the macula. This means that appropriate treatment may restore the sight. However, prompt surgery is required to arrest progressive detachment and complete loss of sight.

Reference:

• (1) Kang HK, Luff AJ. Management of retinal detachment: a guide for non-ophthalmologists. BMJ. 2008;336(7655):1235-40
• (2) Gariano RF, Kim CH. Evaluation and management of suspected retinal detachment. Am Fam Physician. 2004;69(7):1691-8