The retina is the light sensitive membrane that lines the inside of the eye and transforms an image into signals the brain can understand. For the retina to work properly, it needs to be attached to the back of the eye. Sometimes, breaks are formed on the retina which may lead to fluids from inside the eye seeping underneath and lifting it off. This happens to around 1 person in 10 thousand every year. Usually the reason is the breakdown of the vitreous jelly, a normal event that happens to everybody sooner or later. If the vitreous jelly is too strongly attached to the retina, it may pull a break on it. Less commonly, the break is formed in weak areas of the retina, due to rare inherited conditions or as a result of severe blows to the eye.
When the retina detaches, it stops sending a picture to the brain therefore people may notice that a part of the field of vision is suddenly missing. This can progress rapidly over days, and if the detachment is not fixed, the vision will be lost permanently. If the centre of the retina (the macula) becomes involved, the vision drops very significantly. In these cases while the vision can usually be improved by treating the detachment, it often remains below the level it was before.
The treatment of a retinal detachment involves blocking the breaks that caused the retina to be detached, sealing the tissue around it and relieving the pull from the vitreous jelly. This can be done via two approaches: operating from inside the eye, removing the vitreous gel (this is called a vitrectomy), or operating from outside the eye, applying a silicone implant that seals the holes (this is called scleral buckling). The breaks are then closed with either freeze therapy or laser treatment, which will create a welding scar securing the damaged retina. Sometimes it is needed to inject a gas or silicone oil bubble inside the eye to support the retina as it heals. If gases are used, they will dissipate over the course of a few weeks, silicone oil will require another operation to be removed. It depends on the complexity and type of detachment whether one operation is chosen over another.
Most of the times a retinal detachment can be fixed with an operation only.