Eye, gradual loss of vision

Question 1

Probability diagnosis

Answer 1

Cataract

Chronic glaucoma

‘Dry’, age-related macular degeneration

Gradual retinal detachment

Diabetic retinopathy

Question 2

Serious disorders not to be missed

Answer 2

Vascular:

• hypertensive retinopathy
• cerebromacular degeneration

Infection:

• syphilis
• onchocerciasis (filariasis)

Cancer/neoplasia:

• intraorbital tumours
• intracranial tumours
• choroid melanoma

Other:

• optic neuritis (multiple sclerosis)
• Paget disease of skull

Question 3

Pitfalls (often missed)

Answer 3

Retinitis pigmentosa

Drug toxicity (e.g. quinine, methanol, arsenic)

Rarities:

choroid retinitis

vitamin A deficiency

Leber hereditary optic atrophy

Question 4

Key history

Answer 4

PMHx including;

• risk factors for CVD
• family history
• drug history
• associated symptoms or problems.

Question 5

Key examination

Answer 5

Visual acuity

ophthalmoscopic examination

tonometry

although early ophthalmological referral is recommended

Question 6

Key investigations

Answer 6

Initial tests are:

FBE

ESR/CRP

blood sugar

syphilis serology (if clinically indicated).

Question 7

Diagnostic tips

Answer 7

Keep the big three causes in mind—

• cataract
• chronic glaucoma an
• age-related macular degeneration

—and refer for shared care.

In the older pt whose cataract is not significantly improved with the pinhole test consider macular degeneration.