Definition: is a disorder of the eye in which the retina peels away from its underlying layer of support tissue. Initial detachment may be localized, but without rapid treatment the entire retina may detach, leading to vision loss and blindness. It is a medical emergency.
Classification / type of disease:
- Rhegmatogenous retinal detachment – A rhegmatogenous retinal detachment occurs due to a break in the retina that allows fluid to pass from the vitreous space into the subretinal space between the sensory retina and the retinal pigment epithelium.
- Retinal breaks are divided into three types – holes, tears and dialyses.
- Holes form due to retinal atrophy especially within an area of lattice degeneration. Tears are due to vitreoretinal traction.
- Dialyses which are very peripheral and circumferential may be either tractional or atrophic, the atrophic form most often occurring as idiopathic dialysis of the young.
- Exudative, serous, or secondary retinal detachment – An exudative retinal detachment occurs due to inflammation, injury or vascular abnormalities that results in fluid accumulating underneath the retina without the presence of a hole, tear, or break.
- In evaluation of retinal detachment it is critical to exclude exudative detachment as surgery will make the situation worse not better.
- Although rare, exudative retinal detachment can be caused by the growth of a tumor on the layers of tissue beneath the retina, namely the choroid. This cancer is called a choroidal melanoma.
- Tractional retinal detachment – A tractional retinal detachment occurs when fibrous or fibrovascular tissue, caused by an injury, inflammation or neovascularization, pulls the sensory retina from the retinal pigment epithelium.
A minority of retinal detachments result from trauma, including blunt blows to the orbit, penetrating trauma, and concussions to the head.
Epidemiology:The risk of retinal detachment in otherwise normal eyes is around 5 in 100,000 per year. Detachment is more frequent in the middle-aged or elderly population with rates of around 20 in 100,000 per year. The lifetime risk in normal eyes is about 1 in 300
Presenting symptoms / signs:
A retinal detachment is commonly preceded by a posterior vitreous detachment which gives rise to these symptoms:
- flashes of light (photopsia) – very brief in the extreme peripheral part of vision
- a sudden dramatic increase in the number of floaters
- a ring of floaters or hairs just to the temporal side of the central vision
- a slight feeling of heaviness in the eye
Symptoms of retinal detachment include:
- a dense shadow that starts in the peripheral vision and slowly progresses towards the central vision
- the impression that a veil or curtain was drawn over the field of vision
- straight lines (scale, edge of the wall, road, etc.) that suddenly appear curved (positive Amsler grid test)
- central visual loss
Treatment / management:
Treatment of Rhegmatogenous retinal detachment
- Cryopexy and Laser Photocoagulation
- Scleral buckle surgery
- Pneumatic retinopexy
Prognosis:85 percent of cases will be successfully treated with one operation with the remaining 15 percent requiring 2 or more operations. After treatment patients gradually regain their vision over a period of a few weeks, although the visual acuity may not be as good as it was prior to the detachment, particularly if the macula was involved in the area of the detachment