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.
