6.1.1 Understands the risk factors for common ocular conditions

Question 1

Glaucoma Risk Factors

Answer 1

• IOP – higher pressure = more likely & disease is usually more aggressive/rapid
  Asymmetry of 4mmHg or more is significant
• Age – older
• Family history – 6-fold increase if 1st degree relative

Question 2

POAG

Answer 2

Race – 4x more common in individuals of African descent

Myopia >4D

Large optic disc

Thin cornea
Diabetes

High blood pressure

Peripheral vascular disease

Contraceptive pill

Ocular hypertension – 10% over 5 years / asymmetry >4mmHg

Question 3

NTG

Answer 3

Ethnicity – Japanese 4-12x more likely
Myopia >4D
Raynaud’s Phenomenon
Migraine
CCT tends to be lower than in POAG
Gender – females
Systemic hypotension
Myopia
Thyroid disease

Question 4

PACG

Answer 4

Race – far eastern and Indian Asians
Refraction – hypermetropic
Short axial length – narrow AC
Age >40 – AC becomes narrow as lens becomes thicker
Gender – females
Family history – genetic factors are important but poorly defined

Question 5

Secondary glaucoma’s

Answer 5

Pseudoexfoliation (open angle)
PXF = grey-white fibrillary amyloid-material
Symptoms worsen following exercise

Pigment dispersion (open angle)
Young, white, myopic males
Pigment is deposited on corneal endothelium Krukenberg spindle

Hyphaemia (open angle)
Blood in AC caused by trauma

Phacomorphic (closed angle)
Lens size increases and blocks drainage

Rubeosis iridis may lead to neovascular glaucoma
Pxs with ischaemic CRVO / DR are at risk of developing this
Iris forms membrane onto TM and new vessels grow within the angle

Question 6

Cataract: Risks

Answer 6

Age
- Older people more likely because the nucleus of the lens gets denser, fibres get packed more together & UV light over many years

• Lens fibre proteins denatured due to oxidative damage which is usually causes by age
• Protein denaturation results in lens opacification

Family history - slightly increased risk if first degree relative with cataract, more relevant if development at young age

Question 7

Nuclear Sclerotic: Risks

Answer 7

Poor diet
Smoking
Larger lens
Diabetes
Higher ambient temperature

Question 8

Cortical: Risks

Answer 8

Sunlight - UVB
Smoking
Larger lens
Diabetes
Female
Non-Caucasian

Question 9

PSC: Risks

Answer 9

High myopia
Steroids
Thyroid hormone use
Diabetes
Male

Question 10

Diabetic retinopathy: Risks

Answer 10

Hyperglycaemia i.e. poor control of diabetes
Duration of diabetes (after 30 years incidence is 90%)
Hypertension, hyperlipidaemia
Pregnancy
Smoking
Ethnicity – African, Hispanic, south asian

Question 11

AMD

Answer 11

Age – increased

Race - late AMD more common in Caucasians

Gender – females > males

Drusen at macula

Heredity – risk of AMD is up to 3 times as high if first-degree relative has the disease

Smoking - doubles risk of AMD
- Tar in cigarettes causes oxidative stress
- Nicotine causes VEGF

Hypertension & other cardio-vascular risk factors (vascular disease > ischaemia/accumulation of waste products > degeneration of RPE)

Dietary factors – high fat intake, obesity, excessive alcohol consumption, low in antioxidants

Other – cataract surgery (can accelerate dry > wet)