The eye as a mirror of systemic disease.

Whilst full ophthalmological examination is timeconsuming, a rapid examination can pick up many significant abnormalities. The bulbar and tarsal conjunctival surfaces should be inspected for signs of inflammation, haemorrhage, anaemia and jaundice. Using a small hat-pin, visual fields can be assessed surprisingly accurately by confrontation, a relative field loss being detected if the head of a red pin loses colour at any point. Using this technique, even an enlarged blind spot can be found, but field defects will need to be confirmed with formal perimetry. Examination of the pupils will reveal asymmetry or irregularity; generally speaking, the older the patient the smaller are the pupils. Light reflexes, both direct and consensual, should be tested as well as pupil constriction with convergence. It is usually possible to examine the optic discs through an undilated pupil, but if a full fundus examination is necessary the pupils may be dilated with a short-acting mydriatic such as cyclopentolate. This is contraindicated in patients with glaucoma and those whose consciousness is fluctuating or who need neurological observation following a head injury or surgery. The optic discs are examined first and then the retinal arteries and veins are followed out to the four quadrants of the retina. Particular attention should be paid to the area of the macula \\ disc diameters on the temporal side of the optic disc, since even minor abnormalities in this region produce a profound decrease in visual acuity.