What is detachment of the retina?
The term is actually a misnomer. It is really a split or a separation between the layers of the retina. The rod-and-cone layer is lifted off the deeper pigment retinal layer. Since the usual term used is detachment, it will be kept as such.
A detachment occurs: either because the retina is pulled off by contractile bands or shrinkage of the liquid in the eye; or because it is pushed off by blood or liquid.
A detachment can also occur if tears or holes appear in the retina and the liquid in the eye leaks behind the retina, separating it off. This is the commonest cause of detachments.
What causes these holes or tears to appear in the retina?
The commonest causes are:
(A) Injury to the eyeball
(B) A degenerated retina, as in old age, or a pathological myopic eye
(C) Sudden jerky movements or excess strain in an eye in which the cataract has been removed (aphakic eye). This acquires more importance if the eye was, in addition, myopic before the cataract
(D) A diseased eye with a past history of blood pressure or diabetes and other constitutional changes.
What does the doctor see in an eye which has a detachment retina? Can there be a doubt about his diagnosis?
Unless the detachment is in the very early stage, its clinical picture is characteristic. The detachment retina (in the opposite pole or segment to which the patient sees the loss of vision, as the retinal image is inverted) is clearly visualised as a grey curtain with wrinkles and folds bulging its surface in which the retinal vessels meander up and down. It is usually an unmistakable diagnosis and there is seldom any doubt.