Retinal detachment (RD) - Separation of the sensory retina from the retinal pigment epithelium (RPE) by subretinal fluid (SRF).
It is one of the most time-critical eye emergencies along with central retinal artery occlusion and chemical burns to the eye.
RD can be broadly classified into 3 categories:
1) Rhegmatogenous RD (most common) - due to a retinal break, hole or tear.
2) Tractional RD - due to pre-retinal membrane formation and scarring that pulls the retina away from its attachment.
3) Exudative/Serous RD - due to abnormalities in the transport of water across the RPE or in its blood supply.
Floaters (moving vitreous opacities casting a shadow on the retina)
Flashes (photopsia - probably caused by traction on the retina at sites of vitreoretinal adhesion)
Field loss (perceived as a dark curtain)
Falling acuity (loss of central vision due to involvement of the fovea)
Marcus Gunn Pupil (Relative afferent pupillary defect) - detected using the swinging light test. As the flashlight is swung from the unaffected eye to the affected eye, the pupils constrict less (therefore appearing to dilate).
Intraocular pressure in affected eye normally lower (5 mmHg) than normal eye
Mild anterior uveitis is very common
Red discontinuities on the retinal surface
Gold standard - Binocular indirect ophthalmoscopy with scleral indentation.
Ultrasound could also be used. RD is seen as a thick, undulating, hyperechoic membrane that appears to have been lifted off the posterior wall of the eye.
Optical Coherence Tomography (OCT) could also be used prior to surgery in order to document the amount of fluid below the retina. OCT would show a break or tear in the retina and any space below the retina, where it has separated from the underlying membrane.
Treatment is via Laser, Cryotherapy or Surgery. Exudative RD is treated by resolving the underlying cause.
The principle of surgery is to close all the breaks to prevent new breaks and complications occurring.
Retinal detachment surgery options:
Post surgery - Corticosteroid drops (to reduce inflammation) and prophylactic antibiotic drops are given. The patient is advised to keep their head in a certain position or not to travel on an aeroplane if a gas was injected into the eye.
Prognosis is inversely related to the degree of macular involvement and the length of time the retina has been off.
Clinical Ophthalmology A Systematic Approach, Fifth Edition, Jack Kanski
Jalali, Retinal Detachment, Journal of Community Eye Health, 2003
Wills Eye Hospital Atlas of Clinical Ophthalmology
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