Medical Library

 History
As in all clinical medicine, an accurate history and examination
are essential for correct diagnosis and treatment. Most ocular
conditions can be diagnosed with a good history and simple
examination techniques. Conversely, the failure to take a history
and perform a simple examination can lead to conditions being
missed that pose a threat to sight, or even to life.
The history may give many clues to the diagnosis. Visual
symptoms are particularly important.
The rate of onset of visual symptoms gives an indication of
the cause. A sudden deterioration in vision tends to be vascular
in origin, whereas a gradual onset suggests a cause such as
cataract. The loss of visual field may be characteristic, such as
the central field loss of macular degeneration. Symptoms such
as flashing lights may indicate traction on the retina and
impending retinal detachment. Difficulties with work, reading,
watching television, and managing in the house should be
identified. It is particularly important to assess the effect of the
visual disability on the patient’s lifestyle, especially as conditions
such as cataracts can, with modern techniques, be operated on
at an early stage.
The patient should also be asked exactly what is worrying
them, as visual symptoms often cause great anxiety. Appropriate
reassurance then can be given.