This is a common reason for an urgent surgery appointment. If a visit request is made, try to negotiate consultation in surgery, where optimal examination conditions and equipment are to hand. Carefully examine to assess acuity, state of the cornea and pupillary reflexes.
Diplopia is nearly always binocular, with movement of one eye being limited for a number of possible reasons. Although relatively uncommon as a presenting symptom, the majority of causes are significant and therefore careful assessment is essential.
Because of their close proximity to the eye, and their occasional cosmetic effect, eyelid problems can be disproportionately distressing to the patient. The differential diagnosis is wide – so the temptation to treat this presentation as a ‘quickie’ via a brief examination shouldn’t distract from the need to take a careful history.
This symptom can be very difficult to fathom, not least because patients often find it nigh on impossible to describe exactly what they’ve experienced. Patience and a painstaking approach are essential – most of the clues are likely to be in the history rather than in the examination. This section does not cover double vision, gradual loss of vision or persistent sudden loss of vision, which are dealt with elsewhere.
The four major causes of gradual blindness in the world are: cataract, onchocerciasis, vitamin A deficiency and trachoma. The latter three are very rare in the UK. Cataract occurs in 75% of over-65 s, but only 20% of 45- to 65-year-olds. Most cases of gradual loss of vision encountered in primary care arrive via the optician, often with a letter outlining the problem and suggesting referral to an ophthalmologist.
This is a nuisance symptom which patients present with directly, or via their optician. It can be very difficult to ascertain whether the problem is arising from the eyelid or the eye itself. Often, the symptoms affect both and the causes overlap – which is why they’re considered together here.
Sudden loss of vision is a genuine GP emergency. Most causes require an urgent ophthalmological opinion as there is little that the GP can do. This particular symptom is not often encountered in general practice – a prompt appointment or visit and a careful examination are necessary to assess the situation and exclude the causes not requiring urgent specialist treatment. Blurring, such as that found in some cases of the acute red and painful eye, is not covered here.