Unit 1 - diagnostics

Question 1

Over what anterior elevation difference is considered suspicious of keratoconus?

Answer 1

12-15 suspicious,

>15 keratoconic

Question 2

Over what posteror elevation difference is considered suspicious of keratoconus?

Answer 2

17-20 suspicious

>20 keratoconic

Question 3

What disadvantages are there of using ultrasound biomicroscopy?

Answer 3

contact method which requires a water bath, poor resolution compared to OCT and the patient to be supine

Question 4

What is ultrasound biomicroscopy useful for?

Answer 4

Real time image of anterior segment particularly ciliary body, irdocorneal angle,

Question 5

What is anterior segment OCT useful for?

Answer 5

Assessment of corneal lesions/scars
Post DSAEK/DALK/PKP
LASIK flaps
A/C dimensions
Pachymetry
Anterior segment IOLs

Question 6

Does A/C OCR penetrate behind iris?

Answer 6

No that’s when you need ultrasound biomicroscopy

Question 7

What structures does specular microscopy look at?

Answer 7

Imaging endothelium and epithelium

Question 8

What is specular microscopy used for?

Answer 8

Assessment of endothelial cell density and morphology
Eye bank assessment of graft
Diagnosis of inflammation of cornea

Question 9

What is a typical cell density in spec microscopy?

Answer 9

2000-4000cdm

Question 10

What happens to cell density with age?

Answer 10

declines

Question 11

What would an abnormal coefficient of variation be in spec microscopy?

Answer 11

above 0.40

Question 12

How is confocal microscopy used?

Answer 12

Contact method

Question 13

What does confocal microscopy look at?

Answer 13

All coneal layers

Question 14

What does fungal keratitis look like under confocal microscopy?

Answer 14

filaments

Question 15

What does acanthomoeba look like under confocal microscopy?

Answer 15

Bright specks in corneal stroma