Investigations

Question 1

Excitation and emission peak for fluorescein dye?

Answer 1

490 and 530nm

Question 2

Excitation and emission peak for ICG?

Answer 2

805 and 835nm

Question 3

Contraindications to ICG

Answer 3

Pregnancy
Seafood allergy
Iodine allergy
Kidney,Liver disease

Question 4

Contraindications to FFA

Answer 4

Pregnancy and breastfeeding( secreted in breast milk)
Kidney,liver disease
Previous allergy to fluorescein

Question 5

Image formed by compound microscope

Answer 5

Virtual,inverted,magnified

Question 6

Image formed by Keplerian telescope?

Question 7

Preferred imaging modality for TED

Answer 7

T2 weighted Short tau inversion recovery (STIR) sequence MRI has been reported to strongly correlate with active orbital inflammation and clinical activity scores of thyroid orbitopathy severity

Question 8

ERG parameter to differentiate focal, non progressive vs diffuse progressive disease?

Answer 8

b wave implicit time

Question 9

Laser used for PRP

Answer 9

Argon blue-green laser consists on 70% blue(488nm) and 30% green(514nm) light

Question 10

ERG finding in Leber’s congenital amaurosis?

Answer 10

Severely attenuated/Extinguished ERG

Question 11

Number of clearly defined A scan peaks in a phakic eye?

Answer 11

There are five A-scan peaks in a phakic eye:

corneal surface
lens anterior surface
lens posterior surface
ILM of the retina
sclera

Question 12

Which laser is best for retinal photocoagulation in the setting of dense cataract or vitreous haemorrhage?

Answer 12

Krypton red-646nm
Least absorbed by Hb/RBCs
Poorly absorbed by xanthophyll therefore can be used for macular laser as well

Question 13

True autofluorescence (without FS dye) demonstrated by?

Answer 13

Optic disc and macular drusen- absorb light in the blue spectrum and emit light in the yellow spectrum

Question 14

IOP measurement in erect and supine positions?

Answer 14

Perkins tonometer /Tonopen

Question 15

How many degrees is the size of blind spot?

Answer 15

5-7 degrees
Area of visual field where light cannot be perceived due to ONH lacking retinal receptors
17 degrees from fovea (fovea is 4mm away and 0.8mm below ONH)

Question 16

Principle of confocal microscopy?

Answer 16

Single point of tissue illuminated by point source light -simultaneously imaged by camera in the same plane

Question 17

How much of visual field does amsler grid test?

Answer 17

Central 20 degrees
Pupil not to be dilated, wear presbyopic correction, well illuminated, view at 33 cms

Question 18

Conditions causing inverted/negative ERG?

Answer 18

Occurs with a wave intact,b wave attenuated
Disruption of communication b/w photoreceptors and bipolar cells
-X linked retinoschisis
-CRAO
-Congenital stationary night blindness