from Ophtho Flashcards
Sherrington’s law violated in
Duane’s syndrome
Duane’s syndrome - which law violated
Sherrington’s law
Hering’s law violated in
dissociated vertical deviation
dissociated vertical deviation - which law violated
Hering’s law
left jerk nystagmus - what compensatory head posture
left head turn (right gaze)
microcornea - definition
10 mm horizontal. 9 mm at birth. 10 mm at 2 years
microcornea - % of POAG
20%
angle can be seen without gonio
megalocornea
management of A and V patterns
MALE Medial to Apex, Lateral to Empty. when oblique dysfunction –> weakening
child - hyperopia increases till
6-8 years (peak)
Hirschberg estimation
1 mm = 7 degrees = 15 PD
Hirschberg - corneal reflex at pupillary margin
2 mm = 15 degrees = 30 PD
Hirschberg - corneal reflex at mid-iris
4 mm = 30 degrees = 60 PD
Hirschberg - corneal reflex at limbus
6 mm = 45 degrees = 90 PD
CMS stands for
C - central (corneal light reflex), S - steady (monocular fixation), M - maintained (binocular)
superior segmental optic nerve hypoplasia
diabetic mother, dense inferior defects, central artery appears to arise from the superior part of the disc
Downbeat - where pathology
cervicomedullary junction (Chiari type 1), cerebellar flocculus
See-saw
parasellar area (craniopharyngioma), midbrain
Opsoclonus
neuroblastoma (usually from adrenals)
Periodic alternating nystagmus
cervicomedullary junction, cerebellar nodulus
Upbeat
cerebellum, medulla, midbrain
IV palsy - if vertical deviation is 15 prism diopters or less - procedure
ipsi inferior oblique weakening
IV palsy - if vertical deviation is more than 15 prism diopters - procedure
recession of the contra inferior rectus + ipsi inferior oblique weakening (tucking of superior oblique tendon is alternative)
types of inferior oblique weakening
IO recession, IO myectomy, IO anterior transposition
Botox to rectus - when start, effect, lasting
start 2-4 days, lengthening, effect lasting 5-8 weeks
Botox to orbicularis - lasting
3 or more months
carry the bulk of the blood supply to the anterior segment
inferior and superior recti
which vessel has each rectus
1-3 anterior ciliary arteries which are branches of the muscular arteries which themselves are branches of the opththalmic artery
lateral muscular branch supplies
the lateral rectus, superior rectus, super oblique, and levator palpebrae
medial muscular branch supplies
the interior rectus, medial rectus, inferior oblique
infraorbital artery supplies
partially inferior oblique and inferior rectus muscles
central fusion
the area near the fovea has small receptive fields; therefore, objects need to be very similar in terms of size and shape to be fused properly
peripheral fusion
peripheral retina has a large receptive points; thus objects can be more dissimilar in size and shape and still be fused
diopters of horizontal deviation and mm of correction
for any 15 diopter horizontal strabismus, the correction will be 4 mm on the lateral rectus and 3 mm on the medial rectus
Kestenbaum-Anderson procedure
for correcting head turns associated with nystagmus. rotates the eye toward the head turn or away from the null zone
Duane I - treatment
medial rectus recession on the involved side
monocular elevation deficiency
(double-elevator palsy) 1) tight inferior rectus 2) weak elevators of the eye
monocular elevation deficiency - treatment
if restriction on forced duction - inferior rectus recession. No restriction - Knapp procedure - transpose the medial and lateral recti to the superior rectus
Knapp procedure
monocular elevation deficiency, if No restriction. transpose the medial and lateral recti to the superior rectus
Hummelshein procedure
VI palsy. portions of the vertical recti are transposed to the lateral rectus to aid in abduction
VI palsy - treatment
Hummelshein procedure. portions of the vertical recti are transposed to the lateral rectus to aid in abduction
time of follow up after patching
1-week per year of age
