Most accurate test for classifying red-green deficiency
Best test to determine if a color defect is acquired or inherited
What is achromatopsia
total absence of color discrimination
What is the visual acuity of achromatopsia?
What are the 2 types of achromatopsia and their specific inheritance pattern?
Rod Monochormatism (AR)
Blue-cone monochromatism (X-linked recessive)
What is affected in Rod Monochromatism? How does the child present? What other disorder do you differentiate this disorder from? How do you differentiate this from other disorders with similar presentation
No cone function; thus, true color blindness and see world as gray
Nystagmus, poor vision, photoaversion light fundus (same presentation in both disorders)
ERG to differentiate from congential nystagmus and ocular albinism
Blue cone monochromatism affects which cones?
RED and GREEN cones dont work
How do children with congential stationary night blindness (CSBN) present?
nystagmus, decreased vision, myopia
How does the fundus of congenital stationary night blindness (CSBN) appear.
Depends...there is a variant with a NORMAL and abnormal fundus
What is the inheritance pattern of congenital stationary night blindness (CSBN)
X-linked (most common)
What is the ERG finding in congenital stationary night blindness (CSBN)?
Negative ERG with large a wave and absent or reduced b wave
Normally the b wave is larger than the a wave
What is the problem in congential stationary night blindness (CSBN)?
"ON" photoreceptors dont work
there is a problem with rhodopsin
thus rods dont work=no night vision
What is the vision in congential stationary night blindness (CSBN)?
normal to 20/200
Name the variants of Congential Stationary Night Blindness (CSBN) with abnormal fundus.
Describe Fundus Albipunctatus
disorder of visual pigment regeneration--
abnormal recovery of rhodopsin
after intense light exposure pt are night blind until several hours in a dark environment with abnormal ERG until resolution
What disease must Fundus Albipunctatus be differentiated from? What is the difference between the 2 dieases?
both have small yellow white dots but the latter has narrowed vessels and depressed ERG that doesn't improve after dark adaptation.
What is the problem in Oguchi diease?
problem with retinal circuity and not rhodopsin and adapt to dark slowly
What happens after light exposure in Oguchi disease? What is this called?
Yellow iridescent sheen after light exposure that disappears after dark adaptation
Name the above disorder?
Describe the disorder.
What other disorder is this associated?
Enhanced S cone Syndrome
Rare recessive form of CSNB where photopic and scotopic responses resemble