Gradual Loss of Vision

Name: Gradual Loss of Vision - Pulse Reference
Published: 2022-08-02T05:14:11+00:00

Differential Diagnosis

Key distinguishing features of the most common diagnoses

	Cataract	Glaucoma	Retinopathy	Macular Degeneration	Retinal Detachment
Unilateral Visual Loss	Possible	Possible	Possible	Possible	Yes
Pigment at Macula	No	No	No	Yes	No
Exudate + Haemorrhage	No	No	Yes	Yes	No
Fundus Obscured	Yes	No	Possible	No	No
Disc Cupped >50%	No	Yes	No	No	No

The only investigation the GP is likely to perform is a urinalysis and/or blood sugar or HbA1c for suspected diabetes. If glaucoma is a possibility, and the patient has not already seen the optician, then optician referral will provide information about fields and pressures. More obscure tests – such as posterior pole ultrasound and CT scan for retinal, or other, tumours; syphilis serology; skull X-ray for Paget’s disease; and neurological investigations for MS – are rarely required and are inevitably arranged in secondary care.

Opticians will tend to report cataracts in the elderly routinely. Referral for surgery is only required if the problem is significantly impairing the individual’s normal activities.
The presence of a cataract in relatively young patients is unusual and should prompt referral regardless of visual impairment – there may be a rare underlying metabolic cause.
Remember that significant glaucoma or other causes of visual loss may render the individual unfit to drive.
The elderly patient with a cataract whose vision is not improved considerably with the pinhole test probably has macular degeneration too, and so is unlikely to benefit much from cataract extraction.

It can be very difficult to establish in an elderly person whether the problem really has been gradual in onset or whether the history is more sudden; if in doubt, refer urgently as the cause may be acute and remediable.
Progressive early morning headache or proptosis with gradual loss of vision suggests a tumour. Refer urgently.
Gradual or recurrent visual loss or blurring with other intermittent neurological symptoms, especially in younger patients, suggests the possibility of MS.