Rational management of opticians’ letters

Consultant ophthalmologist Dr Nick Jacobs explains how to translate an optician's recommendation for assessment into an effective referral

GPs often get letters from opticians asking to refer the patient on for specialist assessment. But there are issues over whether the patient really needs referral and, if so, how quickly. This article will advise on how to manage four typical clinical scenarios.

GPs may also not always be sure what information to send with the referral but in my experience there is no need to summarise or try to interpret the optician's findings – but don't forget to include a copy of the optician's report. Medical history is especially useful to the ophthalmologist. You may find it easier to include a printout from the notes even though it is a little less personal than a letter. Cataract referrals should include the optician's referral.

1. Glaucoma

41267801If the pressure is raised but there is no concern about the optic disc or the visual field, the diagnosis being queried is ocular hypertension. To determine whether this is present the corneal thickness or pachymetry must be measured. There is a guideline to show the acceptable combination of pressure and corneal thickness.

Cupped discs are often identified by opticians either unilaterally or bilaterally. Asymmetry in disc cupping is significant.

41267802The hospital standard of visual field test is the Humphrey machine on a full threshold central programme. In the optician community, there is a large range of different types of visual-field machines and types of visual-field assessment programmes that can be used on these machines. Often patients are referred with one or two spots missing or an edge defect, which is often an artefact. An experienced clinician will know from assessing the optic disc that some field tests do not require repeating.

Some visual fields are definitely abnormal in appearance and compatible with a diagnosis of glaucoma. Laser retinal scanning technology is used nowadays to assess and monitor the layer thickness of optic discs and retinal-nerve fibres in glaucoma patients.

Visual fields and driving

There is a certain amount of confusion around this topic. By law, the DVLA must be informed if both eyes have a true defect of the field of vision. Also, if there is a visual-field defect in one eye or both eyes, the car insurer must be informed as the insurance may become invalid if the information is not passed on.

2. Cataract

41267803It is most important that patients being referred for cataract have an optician assessment included. Referral of a cataract patient without such an assessment should be considered as an incomplete referral.

A nuclear cataract, which is a dense brown cataract where the centre of the lens hardens gradually, will cause a change in refraction. The eye will become gradually more myopic.

Following cataract surgery some patients will develop thickening of the posterior capsule, which will then be referred by the optician for possible YAG laser capsulotomy.

3. Retinal abnormalities

Opticians usually carry out a very thorough examination of the patient's retina, particularly the periphery. This leads to the discovery of all sorts of mild abnormalities.

41267804An important finding under retinal abnormalities is retinal pigmented lesions. These range from an insignificant pigment spot to a dark, relatively large area, which is flat and sometimes surrounded by a paler area known as pigment epithelial hypertrophy. These are usually innocent, but a choroidal naevus, which may be raised, has the potential to become malignant and it is therefore recommended that all such conditions are referred.

It is necessary to obtain a reasonable photograph of the lesion via the optician or in the hospital and arrange for the patient to be reviewed on a regular basis, usually annually, with this photograph to hand. It does not matter whether this is done in a hospital setting or by the optician as long as change can be recognised.

41267805Ocular migraine is the experience of visual symptoms caused by underlying migrainous pathology. The episodes are usually typical and not necessarily accompanied by a headache. The history is often an individual having true migraines in earlier life and developing ocular migraine without headaches in midlife. These episodes will normally last 15-30 minutes and consist of zigzag coloured lights or grey and white patches. They are generally incapacitating and make activities such as driving dangerous.

41267806Posterior vitreous detachment is an extremely common condition and usually experienced by patients in late middle age or earlier in myopia. The patient will typically complain of a floater affecting one eye and brief flashes of light in the far periphery of that eye usually occurring in the evening or in darkened conditions. I would dilate the pupil and ensure that apart from the vitreous detachment, the retina shows no evidence of damage. In 98% of cases, this will be the case and the patient will be advised that if there is any change in symptoms, such as persistent flashing lights during the daytime or the appearance of a cloud of spots blurring vision, that this could indicate damage to the retina and a further opinion should be sought soon.

4. Age-related macular degeneration (ARMD)

Just a few years ago, ARMD was essentially an untreatable condition, although focal laser treatment was sometimes used in a bid to ameliorate early wet macular problems.

41267807But things have changed dramatically, first with photodynamic therapy, but particularly more recently with anti-vascular endothelial growth factor intraocular injections. These are able to halt, control, and even reverse wet macular degeneration so it is important that GPs know the type of macular change – in order to refer appropriately.

Dry macular change can take the form of discreet or confluent cream-coloured drusen or little bumps, pigment alteration giving a salt-and-pepper appearance or straightforward thinning and atrophy. These changes can cause gradual reduction and some distortion of central vision.

41267808Wet macular change is characterised by a history of sudden visual change, particularly central distortion with sub- retinal fluid or haemorrhage on the retina.

Dr Nick Jacobs is consultant ophthalmologist and clinical lead for The Practice Ophthalmology Service.

The Practice Ophthalmology Service is an Intermediate care provider of ophthalmology and manages around 20,000 new referrals per year, running approximately 90 community-based clinics a week.

The full version of this article is available by contacting Dr Jacobs at [email protected]