Practice 10-Minute Consultation

Gradual loss of vision in adults

BMJ 2015; 350 doi: https://doi.org/10.1136/bmj.h2093 (Published 08 June 2015) Cite this as: BMJ 2015;350:h2093
  1. Shyamanga Borooah, clinical research fellow in ophthalmology1,
  2. Arjun Dhillon, general practitioner, clinical lead ophthalmology23,
  3. Baljean Dhillon, professor of ophthalmology1
  1. 1Princess Alexandra Eye Pavilion, University of Edinburgh, Edinburgh EH3 9HA, UK
  2. 2Argyle Surgery, London, UK
  3. 3Ealing Clinical Commissioning Group, South Greenford, UK
  1. Correspondence to: S Borooah shyamanga{at}aol.com
  • Accepted 9 April 2015

The bottom line

  • Although cataract is a common cause of gradual vision loss in older patients, consider other treatable red flag conditions in this age group, such as giant cell arteritis, macular degeneration, retinal detachment, and vitreous haemorrhage, and refer urgently if you suspect these

  • Do not refer patients for cataract surgery if their cataracts do not affect their daily life or if they are not keen to have surgery

How patients were involved in the creation of this article

In the process of writing this article we sought the opinions of patients who had recently undergone cataract surgery. They were asked what they would have liked to have known before the surgery. Their responses were taken into account when writing box 2. They were also asked what symptoms have improved since their surgery. Their input was used to modify the history section.

A 70 year old man presents with gradual blurry vision in both eyes. He has recently noticed increasing glare when looking at lights.

What you should cover

Gradual loss of vision has many causes, and cataract is one of the most common causes in this age group. A logical history and examination can help to exclude sinister causes that require urgent treatment.

History

How quickly has your vision become blurry?Sudden visual loss within weeks is unlikely to be caused by age related cataract. Symptoms of age related cataract usually develop over months to years.

Does the blurring affect only part of your vision?Patients who describe a central dark spot probably have wet age related macular degeneration and require urgent ophthalmic referral. Consider intracerebral or glaucomatous causes of visual loss in patients with bilateral field defects.

Do you have any other changes to your vision?—New floaters or flashing lights (suggesting posterior vitreous detachment, retinal detachment, or a vitreous haemorrhage) or visual changes that cause the patient to note the bending of straight lines (suggesting wet age related macular degeneration) require urgent ophthalmic referral. Other symptoms associated with cataracts include progressive myopia (nuclear cataract, fig 1), glare when looking at lights (cortical), worsening of reading vision out of proportion to distance vision (posterior subcapsular).

Figure1

Fig 1 The lens is normally a clear structure composed of a dense central region, known as the nucleus, surrounded by softer material known as the cortex. These layers are all encased within an elastic capsule. Age related cataract results from a change in the proteins within these structures, which causes haziness in the lens and ultimately reduced vision

Are your eyes affected in any other way?—Pain, photophobia, and redness are not associated with cataract and suggest corneal disease—for example, infective keratitis or inflammatory conditions, such as uveitis.

Do you have any symptoms elsewhere?Ask about systemic symptoms because giant cell arteritis may cause vision loss in this age group. Ask specifically about temporal headache, pain on chewing, new fatigue, fever-like symptoms, and myalgia (especially at the hips and shoulders).1 If there are any doubts, start the patient on glucocorticoids and refer urgently to an ophthalmologist.

How does it affect your daily activities?—Particularly useful activities to ask about are reading, watching television, playing sports (such as golf or bowls), and driving.

Examination

Visual acuityMeasure visual acuity using a Snellen chart. Improvement in the visual acuity when a pin hole is used suggests a refractive cause of visual loss.

Cornea and conjunctivaConjunctival redness is usually caused by conditions such as conjunctivitis and iritis, rather than cataract. A new corneal opacity suggests an infective lesion. If corneal disease is suspected, use fluorescein drops illuminated by the ophthalmoscope’s blue light to highlight corneal epithelial damage. If found, refer urgently to an ophthalmologist.

Red reflexCheck the red reflex at 1 m through the ophthalmoscope. A cataract will obscure this.

PupilsUsing an ophthalmoscope light, first check the direct and consensual pupil responses, then steadily swing the ophthalmoscope beam between the eyes. If a relative afferent pupillary defect is present, the affected pupil will dilate when light is shone on it, suggesting optic nerve disease, rather than cataract alone. This warrants ophthalmologic review. Ideally perform the remainder of the examination with pupil dilatation by instilling tropicamide (1%) into each eye.

LensAdjust the ophthalmoscope lens to +10 dioptres and assess the anterior segment from close up through the ophthalmoscope. In the normal eye the pupil will remain dark when the ophthalmoscope light is shone (fig 2A). A cataract usually appears as whiteness in the pupil (fig 2B).

Figure2

Fig 2 Photographs illustrating the iris and pupil during ophthalmic examination in (A) a normal eye and (B) an eye with a moderate nuclear sclerotic cataract

Retinal examinationSet the ophthalmoscope to zero. While examining the retina, turn the ophthalmoscope lens towards the positive lenses if the patient is long sighted and towards the negative lenses if the patient is short sighted, until the retinal view is clear. If the disc looks pale or cupped, consider glaucoma or optic nerve disease. Haemorrhages in the central retina are associated with wet macular degeneration and warrant urgent ophthalmic referral. Scattered haemorrhages associated with yellow exudates suggest retinal vein occlusion or diabetic retinopathy. Check for diabetic and cardiovascular risk factors and refer to an ophthalmologist.

What you should do

Refer urgently to an ophthalmologist if there is sudden loss of vision (suggesting branch retinal arterial or vein occlusion, or vitreous haemorrhage), a central dark spot affecting vision or new visual distortion (wet macular degeneration), new flashes or floaters (retinal detachment), marked pain or photophobia (iritis, corneal ulcer), or systemic features suggestive of giant cell arteritis associated with visual disturbance, including a temporal headache, jaw claudication, new fatigue, and myalgia.

Refer non-urgently if there is a gradual onset of blurriness of vision associated with glare, progressive short sightedness, or if the patient has developed a gradual onset loss of part of the field of vision.

If cataract is suspected, explain that a cataract is a clouding of the lens near the front of the eye that causes blurred vision and offer possible referral for surgery as appropriate (box 1). Explain that cataract surgery entails the extraction of the old cloudy lens and replacement with a new clear artificial lens. The operation takes about 30 minutes and is usually performed under local anaesthetic (see box 2 for more details).

Box 1: Referral for cataract surgery

Avoid referral if:

  • The patient is not keen to have surgery

  • The symptoms do not impinge on the patients’ activities of daily living

  • The patient’s overall prognosis is poor, owing to other comorbidities

  • There are medical contraindications to surgery, including poorly controlled diabetes, hypertension, or coagulation profile

Driving adviceUK driving standards require patients to have a Snellen chart measurement of at least 6/12 with both eyes open and full spectacle or contact lens correction.2 Ask patients to contact the Driver and Vehicle Licensing Authority if they are driving and do not reach this standard.

Box 2: Information on cataract surgery

Before surgery on the first eye patients undergo an assessment at the eye clinic. The new intraocular lens is usually selected to provide either good near or distance vision without the need for spectacle correction. In some settings it may be possible to have an intraocular multifocal lens that allows the patient to focus over a range of distances. The patient’s refractive requirements are usually discussed with the ophthalmologist during the assessment.

Cataract surgery takes around 30 minutes and is usually performed under local anaesthesia. After surgery, 90% of patients will have a vision of 6/12 or better. Rare complications include: one person in every 1000 going blind in that eye as a direct result of the operation, and one in 10 000 losing the operated eye. There is virtually no risk to the other eye.3

The most common postoperative complications are redness, bruising of the eyelids, pain, and foreign body sensation. The most serious complication is intraocular infection (endophthalmitis), which is seen in 0.1% of operations and is usually accompanied by increasing redness, pain, floaters, or vision loss.

After the operation, patients are asked to avoid strenuous activity for two weeks and heavy lifting for four weeks because the incisions in cataract surgery are self sealing and need time to heal. Patients are usually asked to use antibiotic drops (such as chloramphenicol) four times a day for one week after the operation and corticosteroid drops such as dexamethasone (0.1%) and prednisolone (1%) four times a day for four weeks.

Notes

Cite this as: BMJ 2015;350:h2093

Footnotes

  • This is part of a series of occasional articles on common problems in primary care. The BMJ welcomes contributions from GPs.

  • Contributors: All three authors fulfil the four criteria as authors. SB provided the initial idea for the paper. All authors helped in the design and writing of the paper and its revisions. BD is guarantor. All the authors approved the final version to be published and are accountable for all aspects of the work.

  • Competing interests: We have read and understood BMJ policy on declaration of interests and declare the following interests: none.

  • Provenance and peer review: Not commissioned; externally peer reviewed.

References

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