11 end me

Question 1

Types of electroretinograms:

Answer 1

Full field erg (ERG)
Pattern erg (PRG)
Multifocal erg (mfERG)
Electrooculogram (ROG)
Cortical visual evoked potential (VEP)

Question 2

General function of DA-ERG

Answer 2

Recording of electric potentials from visual stimuli via electrodes on eye/orbit skin/scalp
Record following 20min dark adaptation, and given light strength (cd sm-2)

Question 3

DA-ERG Flash strength and related retina cells:

Answer 3

0.01 cd sm-2 > Rod bipolar
(standard) 3.0 cd sm-2 > rod ON bipolar
10.0 cd sm-2 > rod ON bipolar

Question 4

Expected wave showing in DA-ERG (full field ERG):

Answer 4

DA 0.01 > flat line > increase to 400uV > slow decrease
DA 3 > decrease to -350uV > increase to 350uv > decrease
DA 10 > decrease to -350uV > increase to 400uV > decrease
Oscillatory potentials > wibbles from amacrine signalling on rising limb of b-waves

Question 5

DA 3 and 10 comparison:

Answer 5

DA 10 > larger A wave peak, shorter wavelength

Question 6

General function of LA-ERG

Answer 6

Recording of electric potentials following 10min with 30 cd ms-2

Question 7

LA ERG and related retina cells:

Answer 7

A-wave > Cone photoreceptors and OFF-bipolar cells
B-wave > Cone ON/OFF-bipolar cells
(Low B/A ratio > dysfunction)

Question 8

VEP vs ERG:

Answer 8

ERG > retina response to stimuli
VEP > Signal transferal from retina

Question 9

Pattern ERG related cells can recording:

Answer 9

Macula ganglion cells / cones
Time Pos 50 of PERG > peak amp.
Time Neg 95 of PVEP > Peak amp.

Question 10

Multifocal ERG:

Answer 10

60-100 separate measurements over 45 degrees of macula

Question 11

Electrooculogram:

Answer 11

RPE assessment via apical/basal potential difference
Provides assessment of RPE/photoreceptor complex

Question 12

DDX via ERG:

Answer 12

Optic neuropathy > abnormal PVEP
Maculopathy > PERG P50 abnormal
Retinopathy > ERG abnormal
RP epitheliopathy (BEST) > ROG abnormal

Question 13

Night blindness testing:

Answer 13

Full field ERG DA 3/10
Retinitis pigmentosa:
a-wave reduction and b-wave reduction > rod dysfunction
B-wave reduction, a-wave sparing > post phototransducion

Question 14

Acquired causes of rapid VA loss

Answer 14

Carcinoma associated retinopathy (CAR)
Autoimmune retinopathy (AIR)
Vit A def.

Question 15

CSNB ERG presentation:

Answer 15

Loss of ON-path, OFF-path preserved
DA ERG will have no increase
Decrease in A-wave (b/a ratio <1)

Question 16

PERG readings:

Answer 16

Reduction of N95, preserved P50 > dysfunction at ganglion cell layer

Question 17

Visual evoked potentials:

Answer 17

Recordings from scalp to measure visual pathway response
P100 component evaluates dysfunction post retina

Question 18

Clinical presentation of melanoma-associated retinopathy:

Answer 18

Normal fundus, DA 0.01 ERG
Abnormal PERG, MfERG, DA 3/10 ERG, LA ERG
Similar response to complete CSNB

Question 19

Retinitis pigmentosa clinical presentation:

Answer 19

Spicule formation, RPE atrophy
All ERG abnormal
Variable rod cone dystrophy

Question 20

Genes in CSNB:

Answer 20

Complete: NYX, GRM, GPR179, TRPM1
Incomplete: CABP4