Key questions – ocular disorders
- Half of cases of infectious conjunctivitis will be viral and the vast majority of bacterial conjunctivitis is self-limiting.
- A Cochrane review examined use of antibiotics versus placebo for acute bacterial conjunctivitis and found symptoms resolved more quickly with antibiotics but the benefits were marginal.
- The typical signs of an acute conjunctivitis are grittiness, redness and discharge without visual disturbance.
- Swabs should be taken for neonatal conjunctivitis, highly purulent, or where there is lack of response to treatment.
- There is very little evidence from clinical trials of antibiotic against placebo for corneal abrasions.
- Serious complications from laser refractive surgery are now extremely rare.
- Smoking is a clear risk factor for both cardiovascular disease and age-related macular degeneration.
- Hyperlipidaemia has been linked to age-related maculopathy
- But a Cochrane review concluded that statins do not have a role in preventing or delaying the onset or progression of ARMD
- Eating oily fish at least twice a week has been associated with a reduced risk of ARMD.
- But there is insufficient evidence to recommend omega 3 fatty acid supplementation for ARMD prevention in the general population.
- Some forms of glaucoma are both more frequent in certain ethnic groups and may take a more aggressive course.
- Phakoemulsification is the most common cataract surgery – where an ultrasonic probe is used to break up or emulsify the cataractous lens.
Rational management of opticians’ letters
- Asymmetry in disc cupping is significant
- The hospital standard of visual field test is the Humphrey machine.
- Often patients are referred with one or two spots missing or an edge defect, which is often an artefact.
- Some visual fields are definitely abnormal in appearance and compatible with a diagnosis of glaucoma
- Include the optician’s assessment with a cataract referral
- Following cataract surgery some patients will develop thickening of the posterior capsule
- Retinal pigmented lesions are important findings – ranging from an insignificant pigment spot to a dark, relatively large area.
- These are usually innocent but a choroidal naevus has the potential to become malignant.
- Ocular migraine episodes are usually typical and not necessarily accompanied by a headache.
- Posterior vitreous detachment is extremely common and usually experienced by patients in late middle age or earlier in myopia.
Age-related macular degeneration
- It’s important to know the type of macular change – in order to refer appropriately
- Dry macular change can cause gradual reduction and some distortion of central vision.
- Wet macular change is characterised by a history of sudden visual change, particularly central distortion.
Lesions of the eyelid
- Meibomian cysts are firm, painless nodules – usually solitary although multiple cysts can be found – small lesions can be left alone
- Hordeolum is an acute focal infection – usually staphylococcal – and are focal abscesses and present with a painful, warm, swollen, red lump on the eyelid.
- Xanthelasma are painless, soft, yellowish lesions in the inner eyelid –and medical care involves dietary advice and lipid-lowering therapy if necessary.
- Anterior blepharitis centres on lashes and follicles while posterior blepharitis involves the meibomian glands – patients usually experience burning, itchy, erythematous lids.
- Entropion is an inversion of the eyelid, usually the lower. It can lead to ocular surface damage if left untreated.
- Ectropion is an eversion of the eyelid, usually the lower -patients may complain of epiphora, recurrent infections, irritation or the sensation of a foreign body.
Ten Top Tips- managing red eye
- Anyone presenting with a red eye needs to be examined and have visual acuity checked.
- If anyone who wears contact lenses develops a red eye – irrespective of whether there is pain, photophobia or visual blurring – they must be referred to eye casualty immediately
- The main causes of photophobia are corneal lesions and anterior chamber inflammation – commonly seen as iritis.
- Viral conjunctivitis is irritating but shouldn’t be painful and doesn’t cause much visual disturbance.
- Allergic conjunctivitis is generally seasonal but can occur with winter allergens and tends to be itchy and less red.
- Chlamydial conjunctivitis tends to have more redness and discharge but less itch.
- Conjunctivitis occurring five to 19 days after birth is a medical emergency and a notifiable disease.
- Some 15% of all shingles cases affect the first division of the trigeminal nerve – herpes zoster ophthalmicus.
Ophthalmology referral dilemmas
- The sixth and third nerve palsies are the most common in clinical practice.
- Most obvious cases will be seen as a convergent squint when looking straight ahead (sixth nerve palsy) and a divergent squint (third nerve palsy).
- There are two main diagnoses to tease out with transient visual loss– amaurosis fugax and ocular migraine
- Both are neurological but routinely dealt with by ophthalmology
- In ocular migraine there is a visual disturbance of spiralling or zigzagging lights culminating in loss of central vision and eventual recovery- the whole process takes 20-30 minutes.
- Amaurosis fugax is a form of TIA and is a potential precursor to stroke.
- Acutely, cases of facial palsy are best referred to ENT but ophthalmology referral is required fairly promptly if there is concern about corneal exposure.
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