Ophthalmology

Medical conditions presenting as eye disease.

Ophthalmologists and physicians have different perceptions of what is common. Many referrals have to do with diabetes, hypertension and thyrotoxicosis – see the relevant section. Also consider:

• Stroke related cortical blindness or visual field defect.
• Uveitis – the two types are anterior uveitis (acute iritis) and posterior uveitis (chorioretinitis). Acute iritis – painful red eye with blurred vision, circumcorneal injection and small pupil. Think of syphilis, sarcoidosis, tuberculosis and toxoplasmosis. (CMV too, if HIV positive.) Do serology for all (except TB and sarcoidosis). An elevated SACE (serum angiotensin converting enzyme) result should be treated with caution as many granulomatous diseases can cause mild elevation. In adolescents also think of juvenile chronic arthritis (Still’s.)
• Optic atrophy or papilloedema. Both may signify a space-occupying lesion in the head, and warrant serious consideration of the need for a CT scan.
• Cataracts and calcium disorders – easily resolved by checking the serum calcium..

Eye medications and their systemic effects

Beta-blocker eye drops are listed as potentially causing systemic effects, and indeed they can cause asthma and bradyarrhythmias. The reason this is often overlooked is that doctors and patients often do not consider topical eye preparations to be medicines – ‘because they aren’t swallowed they can’t have systemic effects…’ Stopping the timolol may well cure a wheezy chest.

Eye medications with adrenalin-like activity may cause a transient increase in blood pressure. The true size and significance of this effects is not particularly well characterised, but in the case of an equivocal BP it may be worth repeating the reading a few hours later without the benefit of the sympathomimetic.