ophtha - optical defects, optical motility, Neuro-ophtha Flashcards
0
Q
Process by which the media alters the course of light
A
Refraction
1
Q
2 ocular media
A
Cornea and lens
2
Q
Refractive power of cornea
A
43 D (38-47)
3
Q
Refractive power of lens
A
17 D (12-22)
4
Q
Total refractive power
A
60 D
5
Q
Measurement of refraction
A
Diopter
6
Q
Total amt of disparity between the length of eye and RO of eye if accom is suspended
A
Total ametropia
7
Q
Amt that accom can help
A
Latent ametropia
8
Q
Amt that the lenses can help correct When accom is active, it is the diff between latent and total ametropia
A
Manifest ametropia
9
Q
Light rays are not focused at a pt but at 2 planes. One or both if which are not at same level as plane of retina.
A
Astigmatism
10
Q
Ametropia is hereditary
A
True
11
Q
Refractive error of ___ are physiologic variation
A
<5 D
12
Q
Indiv with ametropia complain of blurred vision which is improved with
A
Pinhole
13
Q
Most common symptom of ametropia which is bilateral situated in frontal or temporal area, and most common in people with small RE.
A
Headache
14
Q
Due to too short or too weak RP
A
Hyperopia
15
Q
Convergent squint
Ant chamber is shallow
Pupil is smaller
Disc is smaller
A
Hyperopia
16
Q
Management for hyperopia
A
Convex
17
Q
Decreased or loss of power of accom
A
Presbyopia
18
Q
Too long eyeball or too strong RP
A
Myopia
19
Q
Also caused by centicular sclerosis as in incipient cataract.
A
Myopia
20
Q
Divergent squint
Ant chamber is deep
Wider pupil
Bigger optic disc
A
Myopia
21
Q
An extreme condi of myopia with hyper pigmentation
A
Myopic crescent
22
Q
Management for myopia
A
Concave lens
23
Q
Regular/irreg astigmatism: most common, there are only 2 focal lines produced
A
Regular
24
Astigmatism is hereditary
True
25
Astigmatism due to corneal scar or faulty surgical incision
Irreg astigmatism
26
Management for astigmatism
Cylindrical lense
27
Astigmatism with no accompanying spherical correction
Simple astigmatism
28
Objective method if refraction that catches the rays of light reflected at the pt's retina whose source comes from a mirror near the examiner's eye
Retinoscope
29
Method of refraction that administers drugs that paralyze accom
Cycloplegic refraction
30
Drugs to be uses for cycloplegic refraction for children <6 y/o
Atropine
31
Drugs to be uses for cycloplegic refraction for persons >38 y/o
Holm atropine
Cyclopenyolate
Topicamide
32
Measurement for corneal astigmatism
Keratometry
33
Shatter proof lenses. Ordinary lenses given to patient are made of
Crown glass
34
Additional protection can be given by ___ them which is made possible thru additional heating if ordinary lens ff by cooling
Hardening
35
Another way is to use ___ which do not break and are of light weight but appears thicker and scratch easily
Plastic lens
36
It is due to optical fatigue rather than excessive lighting
Glare
37
Used by persons exposed to excessive UV or infra-red rays
Colored lens
38
Useful in decreasing illum becoz half of light rays are diverted under wards. Consists of 2 laminated lenses.
Polarizing lenses (Polaroid)
39
Corneal lens becoz it is smaller than the diameter of cornea.
Corrects corneal astigmatism.
Cheaper and easier to clean
Needs build up period for tolerance
Hard lens
40
Hard lens is worn only for
8-12hrs with comfort
41
Scleral lens whose edges arrest beyond the cornea.
Corrects cornea not higher than 1D
More comfortable to wear and tolerable longer
Hard to sterilize becoz of too many pores
Soft lens
42
Intraocular lens is removed after ___ to avoid complication
15 yrs
43
2 images coming from each eye are perceived by brain as one
Fusion
44
Corresponds to plane of pull of that particular ms
Primary action
45
Concomitant pulling effect that may happen becoz of change of position of eyeball from primary position
Secondary action
46
Primary position
Straight forward
47
One eye can not move in any direction without concomitant movement if the other. In order for both eyes to move in same direction, it will involve the action of at least one ms in each eye.
Yoke ms
48
Binocular vision is not present at birth
True
49
Mos that follow large obj
2 mos
50
Mos that hold obj
3 mos
51
Mos that fix at an obj for 1-2min
6 mos
52
Visual acuity at birth
6/180
53
Visual acuity at 1year
6/30
54
Visual acuity at 3 yr
6/6
55
Convergence present at what month
6 mos
56
Develops due to any interruption of development of binocular vision
Strabismus
57
Measures angle do deviation in strabismus, 2 dissimilar targets are placed at end of 2 tubes and can be observed separately by 2eyes thru corresponding eyepiece
Amblyoscope
58
Normal ms balance, when either eye show no deviation when fusion is partly or completely suspended.
Orthophoria
59
Deviation that can be corrected by fusion mechanism. Elicited when fusion is partly interrupted.
Heterochromia
60
Deviation manifested where in the fusion mechanism can not keep the eyes in parallel alignment.
Heterotropia
61
Deviation due to excessive ms tone or excessive accom
Comitant heterotropia
62
Deviation due to paresis or paralysis of one or more EOM
Non-Comitant or paralytic heterotropia
63
Deviation of eye in presence of epicanthis or presence of drooping upper eyelid laterally
Pseudo-strabismus or false squint
64
Most common strabismus
Comitant esotropia
65
Esotropia that occurs in 1 y/o, MR is recessed (weakened) or LR is Resected (strengthened)
Non-accommodative esotropia
66
Esotropia with high hyperopia (great degree of convergence) and deviation greater when fixing at near than far.
Accommodative esotropia
67
Exotropia due to excessive ms tones of LR.
| Either recessed LR or Resected MR
Non accommodative exotropia
68
Exotropia with high myopia (minimal degree of convergence) and deviation greater when fixing at far than near.
Accommodative exotropia
69
Where optic nerve fuse
Optic chiasm
70
Visual cortex
Bowmann's area 17
71
Optic nerves don't have neurolemal sheath (Schwann)
True
72
Inflammation of optic nerve (optic neuritis) localized in optic disc ( sudden blurring if 1 eye)
Pappilitis
73
Inflammation of optic nerve (optic neuritis) localized beyond the globe (no ophthalmoscopic finding)
Retrobulbar neuritis
74
Hyperemic disc with blurred margin
Dilated blood vessels
Elevated disc
Macular star
Optic neuritis
75
Swollen disc due to some interference of optic nerve circulation
Papilledema or choked disc
76
In papilledema, there is visual disturbance and visual field is abnormal
False
77
In optic atrophy, when nerve fibers are destroyed , they are replaced by ___ and the finer blood vessels ___
Neuro glial tissue and blood vessels closes
78
Chiasmal lesions are commonly caused by
Pituitary tumors ans craniopharyngioma
79
Lower/Upper portion of optic radiation is involved in CV accident
Upper
80
Lower/Upper portion of optic radiation is involved in temporal lobe tumors and otitis abscess
Lower
81
Cn that Elevates upper lid, constricts pupil and incites accommodation
CN3
82
CN that do not decussate
CN 6
83
Various nuclei are connected cn 6 to higher center responsible for various eye movements thru medial longitudinal fasciculus:
For invol conjugate movement
Vestibular nucleus
84
Various nuclei are connected cn 6 to higher center responsible for various eye movements thru medial longitudinal fasciculus:
For vol conjugate movement
2nd frontal gurus
85
Various nuclei are connected cn 6 to higher center responsible for various eye movements thru medial longitudinal fasciculus:
For lateral gaze
Pons
86
Various nuclei are connected cn 6 to higher center responsible for various eye movements thru medial longitudinal fasciculus:
For ff movement of eye
Occipital lobe
87
Test for cn 3,4,6
```
Levator function test
Duction test
Vergence test
Pupillary reaction
Accom test
Diplopia test
```
88
Pis lateral oculomotor paralysis
| Contralat intention tremors
Benedik's syndrome
89
Oculomotor paralysis
Contralat hemiplegia
Paralysis of tongue and lower part of face
Weber's syndrome
90
Cn3&4 paralysis
Contralat hemianesthesia
Hemiataxia
Claude's syndrome
91
Cn3 palsy
| Cerebellar ataxia
Nothnagel's syndrome
92
Cn6&7 palsied
| Contralat hemiplegia
Muller-gambler syndrome
93
Cn6 palsy
| Contralat hemiplegia
Raymond's syndrome
94
Cn5 receives fibers from ___ located outside brain
Gasserian ganglion
95
Semilunar ganglion of cn5 receives 3 main branches
Ophthalmic branch
Maxillary branch - infra orbital n
Mandible branch
96
Ophthalmic branch
Frontal branch - supra orbital, supratrochlear n
Lacrimal branch
Nasociliary branch - infra torchbearer
97
Branch ophthalmic common in lesion
Frontal branch
98
Tests for cn 5
Corneal reflex
Blinking reflected
Sensation of touch, pain and temp in lids
99
Branch of cn7 that supplies the upper potion of OO
Frontal branch
100
Branch of cn7 that supplies the lower portion of OO
Zygomatic branch
101
Cn that closes the lids
Cn7
102
Lesion that involves corticobulbar pathways and upper facial ms is spared
UMN lesion
103
Lesion that involves the nucleus or facial nerve and the entire half of face is paralyzed.
LMN lesion
104
It's vestibular division has connection to medial longitudinal fasciculus for control of conjugate eye movement in relation to movement of head
Cn8
105
Stimulation of nuclei turns the eye to opposite direction (slow component of nystagmus). But cortex sensing this abnormal condi rights them by making he eyes move back to other direction (quick)
Cn8
106
Para/sympa system: affects the pupil and iop
Sympathetic system
107
Stimulation of sympathetic system induces pupillary dilation/constriction
Pupillary dilation
