Ophthalmology - age related macular degeneration

Question 1

What is macular degeneration?

Answer 1

Degeneration in the macula that cause a progressive deterioration in vision

Question 2

Types of macular degeneration

Answer 2

Wet (10%) and dry (90%)

Question 3

What is the typical finding on fundoscopy?

Answer 3

Drusen - yellow deposits of proteins and lipids that appear between the retinal pigment epithelium and Bruch’s membrane.

Question 4

Other features of wet and dry macular degeneration

Answer 4

Atrophy of the retinal pigment epithelium

Degeneration of the photoreceptors

WET MD

• New vessel development stimulated by VEGF
• These vessels can leak fluid/blood and cause oedema and more rapid loss of vision

Question 5

Risk factors for AMD

Answer 5

Age
Smoking
White or Chinese ethnicity
Family history 
CV disease

Question 6

Presentation of AMD

Answer 6

Gradual worsening central vision loss

Reduced visual acuity

Crooked or wavy appearance to straight lines

Question 7

Which type of AMD presents more acutely?

Answer 7

Wet age-related macular degeneration

It can present with a loss of vision over days and progress to full loss of vision over 2-3 years. It often progresses to bilateral disease.

Question 8

Examinations and findings

Answer 8

Snellen chart - reduced visual acuity

Visual fields - scotoma

Fundoscopy

Question 9

Diagnosis of AMD is made with

Answer 9

Slit-lamp biomicroscopic fundus examination by a specialist can be used to diagnose AMD.

Optical coherence tomography is a technique used to gain a cross-sectional view of the layers of the retina. It can be used to diagnose wet AMD.

Fluorescein angiography involves giving a fluorescein contrast and photographing the retina to look in detail at the blood supply to the retina. It is useful to show up any oedema and neovascularisation. It is used second line to diagnose wet AMD if optical coherence tomography does not exclude wet AMD.

Question 10

Management of dry AMD

Answer 10

DRY:

• Lifestyle measures that may slow progression
• Avoid smoking
• BP control
• Vitamin supplementation

WET:

• Anti-VEGF medications e.g. ranibizumab, bevacizumab and pegaptanib
• These are injected directly into the vitreous chamber once a month
• They slow the development of new vessels and progression of the disease