Paper 5 Flashcards
1
Q
Common LogMar to Snellen conversions
A
1.00- 6/60
0.60- 6/24
0.50- 6/19
0.40- 6/15
0.30- 6/12
0.20- 6/9.5
0.10- 6/7.5
0.0- 6/6
-0.10- 6/4.8
-0.30- 6/3
2
Q
Which stereo tests need polarising spectacles
A
Titmus
Wirt Fly test
3
Q
Which stereo tests needs red-green glasses
A
TNO test
4
Q
Which focal length is vergence power dependent upon
A
2nd focal length
5
Q
Properties of Purkinje images 1,2,3
A
Virtual
erect
6
Q
Property of Purkinje image 4
A
real
inverted
7
Q
What is an example of refractive or index myopia
A
In nuclear sclerosis, the refractive power of the lens increases as the nucleus becomes more dense
8
Q
In presbyopia how much available accommodation must be kept in reserve
A
1/3rd
9
Q
What are some beneficial uses of contact lenses
A
reduce the aniseikonia associated with high degrees of astigmatism and anisometropia
Contact lenses can also eliminate or reduce the aberrations associated with spectacles for high refractive errors
10
Q
What are the properties of the image produced by an indirect ophthalmoscope
A
real,
horizontally and vertically inverted.
11
Q
In a Placido disk, how do the rings appear if the radius of corneal curvature is short
A
The shorter the radius of curvature of the anterior corneal surface, the closer together the rings of the Placido disc appear because the reflected image is smaller
12
Q
What is diffuse illumination
A
involves throwing the slit beam slightly out of focus across the structure to be inspected.
13
Q
What is specular reflection
A
arise from light reflected by structures of different refractive indices; the greater the differences in refractive indices, the more pronounced the effect.
14
Q
Where is the widest part of the SOF
A
At its medial end
15
Q
What hypothetical line is the visual axis connecting
A
a hypothetical line connecting the fovea centralis and the nodal point.
16
Q
What hypothetical line is the optical axis connecting
A
connects the posterior pole and anterior pole
17
Q
What percentage of the eye is formed by the sclera vs cornea
A
5/6 sclera
1/6 cornea
18
Q
Where are the RPE cells flattened
A
In the ora serratta
19
Q
What is the appearance of the RPE cells at the posterior pole
A
tall and narrow in the posterior pole
20
Q
What is dextroversion
A
both eyes turning to the right
21
Q
What is laevoversion
A
both eyes turning to the left
22
Q
What is supraversion
A
upward gaze,
23
Q
What is infraversion
A
downward gaze
24
Q
What is dextrocycloversion
A
rightward rotation of the eyes
25
What is laevocycloversion
leftward rotation of the eyes.
26
Which cranial nerve has the longest intracranial course
abducens nerve
27
Which cranial nerve is the only one to emerge from the posterior surface of the brain
trochlear nerve
28
What are the dimensions (length and width) of the optic chiasm
12mm wide
8mm long
29
In an average eye how much IOP is generated and how
average intraocular pressure of approximately 15 mmHg is generated by the flow of aqueous humour against resistance.
30
Which antioxidant reduction in the lens can predispose to cataract formation
Glutathione
31
When does the secondary vitreous appear in development
at the end of the sixth week
32
What is the importance of Docosahexaenoic
essential for renewal of the photoreceptor outer segments
33
What accommodative mechanism of the eye did Hemholtz propose
increased anterior surface curvature and anterior movement of the anterior lens surface, but he did not describe posterior movement of the posterior lens surface, which has since been demonstrated
34
What wavelengths of light are short wavelength cones sensitive to
415nm
35
What wavelengths of light are medium wavelength cones sensitive to
530nm
36
What wavelengths of light are long wavelength cones sensitive to
560nm
37
What is sarcoplasm
the intracellular fluid that fills the spaces between myofibrils
38
When an action potential reaches the neuromuscular junction, which voltage gated channels are opened
Calcium NOT sodium
39
Where do the pancreatic acini secrete their digestive juices into
The duodenum
40
What do the pancreatic delta cells secrete
somatostatin
41
What do the pancreatic Epsilon cells secrete
Ghrelin
42
What do the pancreatic PP cells secrete
pancreatic polypeptide
43
What does Vitamin B1 (thiamine) deficiency cause
gastrointestinal tract disturbances,
weakens the heart,
causes peripheral vasodilation
44
What does Vitamin B12 deficiency cause
pernicious anaemia
demyelination of the large nerve fibres of the spinal cord
45
How much of the overall stromal collagen percentage does type 1 collagen contribute
55%
46
How is stromal type 1 collagen arranged
orthogonal (i.e. at right angles) lamellar fashion
47
What is apoptosis
active process involving cleavage of proteins by caspase enzymes
48
What are anterior synechiae
adhesions that form between the peripheral iris and trabecular meshwork
49
What is the most common type of secondary angle glaucoma
Pseudoexfoliation syndrome
50
Does lattice corneal dystrophy recur in grafts
YES
51
Prognosis of juvenile forms of optic nerve gliomas
Good
52
How do dermoid cysts form
Resulting from the incarceration of ectoderm between the frontal and maxillary processes.
They contain pilosebaceous follicles and hair
53
Where do Sudiferous cysts originate from
(hidrocystomas) originate from the glands of Moll.
They are lined by a double layer of epithelium.
54
How do Epidermoid cysts occur
due to epithelial inclusion following surgery or trauma, or following
obstruction of the duct of a pilosebaceous follicle; they are filled with keratin
55
When does Bacillus Ceres cause endophthalmitis
It does not represent normal ocular flora. It can cause endophthalmitis, typically associated with traumatic injury
56
In what type of individuals does Mucormycosis occur
in immunocompromised individuals or those with poorly controlled diabetes mellitus
57
Characteristics of the adaptive immune system
specificity, memory,
specialisation,
tolerance, diversity,
ability to downregulate.
58
What is cytokine pleiotropy
describes the ability to exhibit multiple biological actions
59
What is cytokine redundancy
describes the exhibition of shared biological actions.
60
Examples of microsomal enzyme inhibitors
metronidazole,
chloramphenicol,
isoniazid
warfarin
61
How do topical steroids cause raised IOP
because of reduced aqueous outflow due to the accumulation of glycosaminoglycans and water in the trabecular meshwork
62
Side effects of Azathioprine and mycophenolate
bone marrow suppression and gastrointestinal upset
63
Side effects of ciclosporin and tacrolimus
cause nephrotoxicity, hypertension, hyperlipidaemia, glucose intolerance, gingival hyperplasia, and hirsutism
64
What symptoms does a Horner syndrome with a first order lesion cause
Anhidrosis (loss of sweating) with first-order lesions affects the ipsilateral side of the
body
65
What symptoms does a Horner syndrome with a second order lesion cause
anhidrosis affects the ipsilateral face
66
What symptoms does a Horner syndrome with a third order lesion cause
anhidrosis only affects a small amount of the face adjacent to the ipsilateral brow
67
Why do Apraclonidine and phenylephrine dilate postganglionic Horner’s
syndrome
Due to denervation hypersensitivity
68
What does Hydroxyamphetamine 1% do in Horner's syndrome
causes the release of neurotransmitter from postganglionic fibres (third-order neurons), hence if affecting preganglionic fibres there is normal pupil dilation, whereas if affecting postganglionic fibres there is no dilation as no noradrenaline to release
69
How does cocaine work in Horner syndrome
prevents the reuptake of noradrenaline, causing pupil dilation
70
In mRNA which bases are replaced
uracil (U) replaces thymine (T).
71
What is the p site on the ribosome
peptidyl-tRNA-binding site (P site) holds the tRNA and polypeptide chain
72
What is the a site on the ribosome
The aminoacyl-tRNA-binding site (A site) holds the incoming tRNA molecule
73
What is variable expressivity
Autosomal dominant and X linked recessive inheritance is associated with variable expressivity.
refers to the range of signs and symptoms that can occur in different people with the same genetic condition
74
What is an epigenetic trait
a stably heritable phenotype caused by changes in a chromosome without alteration in the DNA sequence
75
What is the mutation in Stickler syndrome
COL2A1
76
What creates a false positive on the HFA
indicate that the patient responds to the sound of the machine even when it does not present a light stimulus, and/or simply presses the response button too often
77
What creates false negatives on the HFA
occur when the patient fails to respond to a brighter light stimulus presented at a location where they previously responded to a dimmer light stimulus
78
What creates fixation losses on the HFA
typically occur when the patient looks away from the fixation target—these can be detected by periodically presenting the light stimulus in the physiological blind spot
79
What do the Roman numerals mean in the visual field analyzer
The Roman numerals (0, I, II, III, IV, and V) represent the target size in mm2
Each successive Roman numeral represents a fourfold increase in area
80
What do the arabic numerals 1-4 represent on the visual field analyzer
represent the light intensity in apostilbs (asb), whereby each successive number is 3.15
times brighter (0.5 log unit steps).
81
What do the lowercase letters represent on the visual field analyzer
additional minor filters where ‘a’ is the darkest and ‘e’ the brightest— each successive letter represents an increase of 0.1 log unit
82
What percentage is fluorescein bound to albumin
70-85%
83
What causes leakage of dye at the optic disc
papilloedema, inflammation, and ischaemic optic neuropathy
84
What axial resolution can spectral domain OCT's achieve
resolution of 3-8 micrometres
85
Where does the a wave arise from in the ERG
primarily arises from photoreceptors hyperpolarising to light
86
Where does the B wave arise from in the ERG
primarily arises from depolarising bipolar cells.
87
What cells create oscillatory potentials on the ERG
arise from amacrine cells
88
In the EOG what is the normal LP:DT ratio
typically 1.7–4.3
89
What is the normal light peak time range in the EOG
7-12 minutes
90
What does the pattern ERG provide
an objective assessment of retinal macular function and distinguishes maculopathy from retinal ganglion cell/optic nerve disease.
91
In pERG, which photoreceptor cells does p50 originate from
cone driven
92
in pERG which cells does N95 originate from
macula ganglion cells
93
Normal N95/P50 ratio of pERG
typically greater than 1:1
94
Grading of order of SIGN classification
Systematic review and meta-analysis, or randomised controlled trials.
Case–control or cohort studies.
Non-analytical studies (case reports/series).
Expert opinion.
95
Another name for forest plot
blobbogram
96
What is preclinical trial phase
Drug testing in non-human subjects (in vivo and/or in vitro) to explore efficacy, toxicity, and pharmacokinetics with no dose restriction
97
What is phase 0 of a trial
Pharmacokinetics in ~10 humans using small, subtherapeutic doses
98
What is phase 1 of a trial
Dose-ranging in ~20–100 healthy human volunteers for safety
99
What is phase 2 of a trial
Drug testing at therapeutic dose in ~100–300 human patients with specific disease, to assess efficacy and side effects
100
What is phase 3 of a trial
Drug testing at therapeutic dose in ~300–3000 human patients with specific disease, to assess efficacy, effectiveness, and safety
101
What is phase 4 of a trial
Post-marketing surveillance in public to monitor long-term effects (at therapeutic dose)
