Cataract

Question 1

What are cataracts?

Answer 1

Any opacity of the lens, regardless of aetiology.

Question 2

What are the types of cataract?

Answer 2

• Nuclear sclerosis
• Cortical
• Posterior subcapsular

Question 3

What are cortical cataracts?

Answer 3

Radial or spoke-like opacification in the cortex of the lens, either anteriorly or posteriorly.
-A/w ageing and diabetes

Question 4

What are nuclear sclerosis cataracts?

Answer 4

Yellow to brown discolouration of the central part of the lens. Due to new cortical fibres produced concentrically leading to thickening and hardening of the lens.
Age related.

Question 5

What are posterior sub capsular cataracts?

Answer 5

Usually in posterior of the lens; adjacent to capsule. Due to migration and enlargement of lens epithelial cells (Wedl cells) posteriorly.
A/w steroid use, intraocular inflammation, diabetes, trauma, radiation, ageing.

Question 6

Aetiology of acquired cataracts?

Answer 6

• Age-related
• Systemic disease (DM, metabolic disorders, hypocalcemia)
• Traumatic
• Intraocular inflammation (e.g. uveitis)
• Toxic (steroids, phenothiazines)
• Radiation

Question 7

Presentation of congenital cataracts?

Answer 7

• High myopia
• Present with altered red reflex or leukocoria
• Treat promptly to prevent amblyopia.

Question 8

Clinical features of cataracts?

Answer 8

• Gradual painless decrease in VA.
• Glare, dimness, halos around lights at night
• Monocular diplopia
• Second sight phenomenon

Question 9

What is the second sight phenomenon?

Answer 9

Patient more myopic than previously noted due to increased refractive power of the lens (nuclear sclerosis only)

Question 10

Diagnosis of cataracts?

Answer 10

• Slit lamp exam and noting changes in red reflex using ophthalmoscope
• May impair view of retina in fundoscopy

Question 11

Indications for surgical treatment of cataracts?

Answer 11

• VA loss leads to functional impairment
• Aid management of other ocular disease (e.g. cataract preventing adequate retinal exam or laser treatment of DR)
• Congenital or traumatic cataracts

Question 12

Surgical treatment of cataracts?

Answer 12

Phacoemulsification

Question 13

Pathophysiology of cataracts?

Answer 13

Changes in lens proteins (crystallins) affect how the lens refracts light and reduce its clarity, thus decreasing VA.

Question 14

Ix in suspected cataracts?

Answer 14

• Dilated fudoscopy: normal
• Intra ocular pressure: N unless also glaucoma
• Glare vision test: reduced VA under glare stress
• Slit lamp: cataract visible