Need to know - eye conditions
Ophthalmology consultant Mr Scott Fraser answers GP Dr Pam Brown’s questions on herpes zoster, cataracts, iritis and macular degeneration
Ophthalmology consultant Mr Scott Fraser answers GP Dr Pam Brown's questions on herpes zoster, cataracts, iritis and macular degeneration
1. What red flag symptoms and signs should alert us to serious eye conditions needing specialist assessment or management?
More serious conditions such as keratitis – infection or inflammation of the cornea – and iritis are described by patients as painful and usually cause photophobia. The combination of a red eye and sensitivity to light invariably requires specialist referral.
Acute reduction of vision – whether associated with other symptoms or not – needs investigation. When associated with pain or photophobia this requires same-day referral.
2. What signs and symptoms should make us diagnose blepharitis and what is the evidence that cleansing with baby shampoo will improve the condition long term?
Blepharitis is a chronic inflammatory condition related to dysfunction of the meibomian glands of the eyelid. These produce the oily secretions that stabilise the tear film and keep the eye lubricated. Dysfunction is common and results in alterations to the meibomian secretions that produce inflammation in the eyelid margins and an abnormal tear film causing tears to evaporate more quickly.
The main symptom of blepharitis is chronic irritation often described as a gritty, burning sensation. Symptoms often wax and wane. Examination findings do not always correlate with symptoms but usually a scale can be seen around the lid margins, especially at the base of the lashes – almost as if the lashes were wearing a collar. Closer examination can reveal bubbles in the tear film that are indicative of abnormalities.
Cleaning of the lids – including using baby shampoo – will remove some of the crusted lipid on the lid margins and encourage the glands to work more normally. Many patients get great relief from this and they can do it up to twice a day depending on symptoms.
Artificial tears are often a great help to stabilise the tear film and can be used as often as necessary, when the eye hurts.
Look at the websites listed top right for more information on blepharitis and useful advice on lid hygiene.
3. Should all patients with suspected herpes zoster affecting the eye area be referred for specialist assessment and management?
Herpes zoster ophthalmicus affects the upper trigeminal nerve division and is apparent as the typical vesicles and then crusts around the eye and upper face adhering strictly to the dermatome. The reactivation can affect the eye itself and can be sight-threatening in a number of ways. It is believed that if the vesicles are present down to the tip of the nose on the affected side, ocular complications are more likely – called Hutchinson's sign.
But, as discussed in question one, it's possible to detect ocular problems by taking a simple history. So if the patient has no visual symptoms, no pain and the eye is not red, they do not need to be referred to an eye department. If it is early in the disease course the sufferer should be warned to reattend if they do get symptoms.
Symptoms and signs that do suggest the globe itself has been affected include redness, discharge, reduced vision, double vision and pain. If the eye is only mildly red and the vision is unchanged, ophthalmic referral is not needed. If the patient has pain or reduced vision, refer the same day. If the lids are too swollen or crusted to allow adequate ocular examination, also refer for further assessment.
4. At what stage of cataract development is it most appropriate to refer patients?
Cataracts are almost ubiquitous as one ages and if you examine anyone over the age of 40 you'll see at least the beginnings of a yellowing of their lens. But this usually progresses only very slowly and many are never aware of this subtle change in vision. Often it is their optometrist who first points the cataract out to them.
Modern cataract surgery is very safe and generally leaves patients satisfied. But like any invasive operation, complications can occur – about one patient in 100 needs further surgery and about one in 1,000 can end up with much worse vision than pre-operatively. So deciding to have a cataract removed is not a decision to be taken lightly and simply having an opacity in the lens is not sufficient to warrant surgery.
Surgery is usually indicated if the cataract is reducing the patient's quality of life – this depends of course on the patient's activities. Drivers in their 40s may well be much more affected by the same degree of cataract than housebound people in their 80s.
Like all surgery, the decision on whether to have cataract extraction is a balance between risks and benefits. The question the patient and practitioner need to answer is whether the cataract is having enough of a detrimental effect on quality of life to warrant the – albeit very small – risks of surgery. If the answer is Yes, the patient should be referred for consideration of cataract extraction.
5. In patients who do not have Sjogren's disease, do lubricants significantly improve symptoms, and are some lubricants more effective than others?
Patients with dry eye often get a lot of relief from lubricant eye drops – indeed this can be a useful diagnostic feature. As with any condition, different patients react in different ways. Some may need to use drops prn only whereas others use them a number of times a day.
Some patients find drops such as hypromellose more soothing than the thicker gels such as Viscotears. Some prefer the longer-lasting effect of the gels or ointments, whereas others find the thicker preparations smear their vision too much.
Many patients with dry eyes also have blepharitis and it can be worth asking them to carry out lid hygiene (see question two).
As a rule of thumb, it's worth starting more aqueous drops first and to ask the patient to use them as frequently as they need. If they find they get only temporary relief from the drops but are putting them in frequently, try with some of the gel formulations.
If the patient has weeks or months of relief but then finds the drops begin to irritate, they may be getting an allergy to the preservatives in the drop. It might be worth trying a preservative-free brand.
If the patient is using drops fairly constantly or is not getting enough relief, it's probably worth referring them to an ophthalmologist for consideration of other treatments – for example, blocking of the lacrimal punctum to prevent the tears draining away.
If a patient with known dry eyes develops a red or painful eye, they should be referred to an eye department the same day as they are more susceptible to eye infections.
6. Should we investigate all patients with iritis to exclude underlying causes and if so, which investigations have the highest diagnostic yield?
Treatment and investigation of iritis is best done by those with the appropriate equipment to monitor the patient's eye. Both the iritis and its treatment can have serious detrimental effects on the eye.
The extent of investigation is best decided by an ophthalmologist. The general yield of positive results is very low and investigation is not worth doing routinely. But there are certain features of inflammation that do suggest underlying systemic cause is more likely and it is in these patients that investigation should be concentrated upon.
From the primary care perspective, if a patient has iritis and has had other problems that could be linked – such as chronic back problems, chest problems, skin rashes or gastrointestinal problems – it's worth letting the ophthalmologist know so that investigations can be guided towards those most likely to be positive.
7. How common are systemic side-effects of topical treatments for chronic eye diseases, such as bronchospasm with timolol drops?
Systemic side-effects from eye drops are surprisingly common. The reason for this is that much of the drop is washed by the tears into the nasolacrimal duct. This is a very vascular tissue and absorbs quite a large amount of the drop. The drug then goes directly into the circulation, bypassing the first-pass effect and can result in a significant amount in circulation.
In most cases, this is if no importance – a tiny amount of antibiotic or anti-inflammatory will not have systemic side-effects. But some topical medications can get into the circulation in significant amounts, including ß-blockers.
The most common ß-blocker used to reduce the intraocular pressure is timolol and it has been calculated that one drop of 0.5% is the equivalent of 4mg of oral ß-blocker. Thus these drops can cause bronchospasm and are to be avoided in susceptible patients.
8. Are lutein or other antioxidant supplements – oral or topical – effective in prevention of macular degeneration?
There is some evidence that high-dose vitamins may protect against dry ARMD. But it is, as ever, helpful to consider the simple things first.
Stopping smoking is the one thing that has the greatest benefit in reducing the progression of the disease. A healthy diet, especially including fruit and vegetables rich in lutein and zeaxanthin, is probably as good as taking supplements and can be a useful way of getting patients to improve their lifestyles. See the websites listed above for a full list of foods rich in these.
9. Apart from distortion when looking at straight lines, what other symptoms could alert us to macular degeneration?
‘Wet' macular degeneration is so-called because new vessels grow into the macular area. This causes the macula to be raised – hence the distortion – and vision to be reduced. If these vessels bleed, the vision drops quickly and much more profoundly. Thus, the wet type of ARMD usually causes the patient to seek medical help and the symptoms are usually easy to recognise.
‘Dry' ARMD, which is effectively an atrophy of the photoreceptors at the macula, is more insidious and usually presents as the patient having increasing problems with small print. A common symptom described by sufferers is they see people coming towards them but cannot see their faces when they are close up.
A patient who has these symptoms should initially be asked to see an optometrist who will confirm the diagnosis and ensure the patient has optimal correction in their glasses.
Mr Scott Fraser is a consultant ophthalmologist at Sunderland Eye Infirmary
Competing interests: none declared
Dr Pam Brown responds to the answers to her questions
• I will continue to refer patients who present with new eye pain with or without photophobia or sudden changes in vision
• I wasn't aware of the altered tear film in blepharitis so will examine the film and be more likely to prescribe lubricants
• I will also aim to be more logical in my choice of lubricants and more likely to refer as emergencies patients with dry eyes who present with a red eye
• The information about likelihood of eye involvement in herpes zoster will also help me refer more appropriately
• I will continue to encourage patients with ARMD to eat a diet rich in fruit and vegetables containing lutein and zeaxanthin, and to check for distortion of vision in their unaffected eye
Dr Pam Brown is a GP in Swansea