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FRCOphth Part 1 Revision > Questions I got wrong > Flashcards

Questions I got wrong Flashcards

1
Q

What is the lens that makes up the 0.50 Jackson cross cylinder?

A

+0.50 DC / -1.00 DS

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2
Q

What percentage of incident light is scattered by the cornea?

A

10%

This increases in corneal oedema and causes reduced visual acuity

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3
Q

Is diffraction greater at shorter or longer wavelengths?

A

Longer wavelengths

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4
Q

Pinhole improves ametropia of up to how many dioptres?

A

4D

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5
Q

What is the power of a concave mirror of radius 10cm?

A

Power = 1/f = 2/r
= 2/0.1
= 20D

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6
Q

What is the angle of minimum deviation of a crown glass prism with apical angle of 4 degrees?

A

Angle of minimum deviation = (RI - 1) x apical angle

= (1.5-1)(4) = 2

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7
Q

Where in the retina are hard exudates located?

A

Outer plexiform layer. Pathophysio = leakage of plasma from the inner blood-retinal layer

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8
Q

When doing keratometry, what does each step on a Javal-Schioltz keratometer correspond to?

A

1 dioptre

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9
Q

When doing keratometry, the power of the cornea is equal to 337.5 / (length of cornea in mm)

A

Yes

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10
Q

What sort of image is produced by a panfundoscope?

A

Real inverted image

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11
Q

What growth factor stimulates the differentiation of lens epithelial cells into secondary lens fibres?

A

Fibroblastic growth factor (FGF)

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12
Q

What is the trigger for shedding of rod photoreceptors?

A

First light

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13
Q

How long does it take for the outer segment of a rod cell to undergo complete turnover?

A

10 days

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14
Q

At what gestational age does myelination of the optic nerve start?

A

7 months (complete at 1-3 months post birth)

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15
Q

What is the principal DNA polymerase used in mitochondrial DNA replication?

A

DNA polymerase gamma (POLG gene)

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16
Q

What is the inheritance of Leber’s hereditary optic neuropathy and Kearns-Sayre syndrome?

A

Mitochondrial inheritance

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17
Q

Is HLA-B27 an MHC I or MHC II molecule?

A

MHC I

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18
Q

What are the roles of MHC I and MHC II molecules?

A

MHC I: expressed on all cells of the body, present intracellular antigen, recognised by CD4 T cells
MHC II: expressed on antigen presenting cells, present soluble antigen, recognised by CD8 T cells

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19
Q

What is the approximate volume of the orbit?

A

30mL

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20
Q

What are the 3 actions of the inferior oblique?

A

Extorsion, abduction and elevation

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21
Q

Does the superior ophthalmic vein pass within the common tendinous ring?

A

No

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22
Q

Which of the EOMs assumes a fusiform shape?

A

Superior oblique

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23
Q

Is the anterior or posterior lens surface more convex?

A

Posterior (6mm radius of curvature compared to 10mm)

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24
Q

What is the diameter of the lens?

A

10mm

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25
Q

Where in the sphenoid is the optic canal located?

A

Lesser wing of the sphenoid

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26
Q

What is the lymphatic drainage for periocular tissue?

A

Lateral: superficial preauricular
Medial: submandibular

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27
Q

Which layers of the lateral geniculate nucleus receive input from the contralateral optic nerve?

A

Layers 1, 4, 6

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28
Q

What is the blood supply to the lateral geniculate?

A

Dual blood supply: anterior choroidal + posterior cerebral arteries

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29
Q

Which laser type is absorbed by both melanin and haemoglobin? What about melanin only?

A

Argon blue-green: Melanin and Hb

Diode: Melanin only

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30
Q

What is Rose Bengal stain used for and what filter on the slit lamp is used to best visualise it?

A

Stains devitalised cells. Used to check for dry eye / KCS.

Red-free filter is used.

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31
Q

What type of image is formed by the compound microscope?

A

Real, inverted and magnified

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32
Q

What is the difference between the Bausch and Lomb vs the Javal-Schiotz/Helmholtz keratometer?

A

Bausch and Lomb: Object size fixed, prism doubling varied. One position instrument (no need to change positions)
Javal-Schiotz: Object size varied, prism doubling fixed with Wollaston prism. Two position instrument

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33
Q

What is a Hruby lens?

A

High negative power lens used to visualise the retina by counteracting the positive refraction of the eye. It is a non-contact lens

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34
Q

What colour light is used in a focimeter and why?

A

Green, to reduce chromatic aberration

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35
Q

In a standard retinoscope, what mode is shaft down and shaft up?

A

Shaft down = diverging
Shaft up = converging

Usually shaft down –> plano effect rather than converging effect which is the stnadard mode used

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36
Q

In OCT, what wavelength class of light is used?

A

Infra-red

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37
Q

In autoregulation of blood flow, which of the following leads to vasoconstriction (excluding in the pulmonary vasculature)?

a. Reduced O2
b. Reduced pH
c. Increased CO2
d. Increased BP

A

d. Increased BP

Increased BP –> reflex vasoconstriction to limit blood flow

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38
Q

Glucose metabolism in the lens typically occurs by which pathway?

A

Anaerobic glycolysis

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39
Q

Which eponymous law is used in the principle of IOP measurement (with a Goldmann applanation tonometer)?

A

Imbert-Fick principle: Pressure in an idealised sphere is equal to that needed to flatten the sphere divided by the area of flattening

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40
Q

Which of the following neuromodulators does not exert an effect on the retina?

a. TRH
b. Taurine
c. Insulin
d. Glucagon

A

c. Insulin

Glucagon: Neuromodulator in amacrine cells
Taurine: Acts on horizontal cells
TRH: Acts on amacrine and ganglion cells

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41
Q

Within the retina, which cell type contains dopamine?

A

Amacrine cells

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42
Q

What is the Bezold-Brücke phenomenon and the Purkinje shift?

A

Refers to the effect of luminosity (intensity of light) on perceived hue (chromaticity)

Bezold-Brücke phenomenon: As luminosity increases, all hues appear yellow-white
Purkinje shift: As luminosity decreases, all hues appear achromatic

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43
Q

Lesions to which location cause motor blindness?

A

Superior temporal sulcus

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44
Q

Lesions to which location cause prosopagnosia?

A

Lingual or fusiform gyrus

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45
Q

What percentage of ganglion cell axons pass within the parvocellular and magnocellular pathways?

A

Parvocellular: 80%
Magnocellular: 10%

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46
Q

What is the minimum threshold of Vernier hyperacuity?

A

10 seconds of arc

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47
Q

Is Adie’s tonic pupil more common in the old or young?

A

Young

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48
Q

In an electroretinogram, above which frequency can only cone cells respond?

A

20Hz

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49
Q

Which of the following has the highest lipid content?

a. Retina
b. Choroid
c. Lens
d. Cornea

A

Retina - contains about 20% lipid, mainly phospholipid - most likely used in retinal / rhodopsin cycle

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50
Q

Which of the following is not a characteristic of trabecular meshwork cells?

a. High levels of microtubules
b. Active phagocytic properties
c. High concentrations of actin
d. Low levels of microtubules

A

d. Low levels of microtubules

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51
Q

How wide are desmosomes?

A

20nm

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52
Q

What is the difference between a desmosome and an adherens junction?

A

Both are cell-cell anchoring junctions. Desmosomes connect intermediate filaments in both cells. Adherens junctions connect actin filaments in both cells.

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53
Q

Which cytokine is involved in eosinophil activation?

A

IL-5

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54
Q

Which vitamins act as free radical scavengers?

A

Vitamins A and E

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55
Q

Which of the following is not mediated by histamine H1 receptors?

  1. CNS depression
  2. Smooth muscle contraction
  3. Increased vascular permeability
  4. Increased pepsin production
A
  1. Increased pepsin production is mediated by H2 receptors.
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56
Q

In the blood-retinal barrier, what size molecules cannot pass through the retinal vessels?

A

> 20 000 Da

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57
Q

What types of retinal emboli are Hollenhorst emboli?

A

Cholesterol

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58
Q

What two dyes would a corneal specimen from someone with Avellino dystrophy stain for?

A

Avellino dystrophy = lattice + granular dystrophy

Hence: amyloid (Congo red) + hyaline (Masson trichome)

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59
Q

Is measles virus an RNA or DNA virus?

What about adenovirus?

A

Measles: RNA virus.
Adenovirus: DNA virus

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60
Q

Are autoclaves effective in destroying bacterial spores?

A

Yes

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61
Q

What hypersensitivity type is ocular circatricial pemphigoid?

A

Type 2

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62
Q

What is the trigger for the classical and alternative complement pathways?

A

Classical: antibody-antigen complexes
Alternative: cell walls of G- bacteria

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63
Q

What cells in the neuroretina are derived from the outer and inner neuroblastic layers? 3 each.

A

Outer neuroblastic layer:
- Photoreceptors, bipolar cells, horizontal cells

Inner neuroblastic layer:

  • Amacrine cells
  • Ganglion cells
  • Müller cells
64
Q

Zonules are derived from which stage of vitreous development?

A

Tertiary

65
Q

At what age are cones fully developed?

A

6 months after birth

66
Q

At what age does the eyeball reach its final size?

A

8 years

67
Q

What is the most common ocular complication of maternal rubella in the first trimester?

A

Cataract (bilateral in 75% of cases)

Congenital rubella syndrome: Eye abnormalities, sensorineural deafness and heart defects (PDA, pulmonary artery stenosis)

68
Q

What is the most common ocular complication of maternal mumps?

A

Dacroadenitis

69
Q

Describe the image formed by a prism.

A

Virtual, erect and displaced towards the apex of the prism.

70
Q

Barrel effect and pincushion effect: Which is caused by which sort of lens?

A

Barrel effect: Caused by convex lenses

Pincushion effect: Caused by concave lenses

71
Q

What is the dioptric power required for contact lenses for a hypermetrope who usually wears glasses of +5.0D power? (Back vertex power = 1.5mm)

A

F2 = F1 / (1 - dF1)
Lens is moving towards the eye so sign of d is positive i.e. 0.015m.

F2 = 5 / (1 - (0.015)(5))
= 5 / 0.975
= 5.4

72
Q

What is the SRK formula and what range of axial lengths is it accurate for?

A

IOL power required for emmetropia = A (constant) - 2.5 (axial length in mm) - 0.9 (keratometry reading in dioptres).

Valid for axial lengths between 22 and 24.5mm, after which SRK2 or other formulae can be used

73
Q

Does keratoconus cause axial or refractive myopia?

A

Refractive myopia (increases the refractive power of the cornea)

74
Q

With a normal distribution, what percentage of data is within 1, 2 and 3 standard deviations of the mean?

A

68.3%, 95.5%, 99.8%

75
Q

How many cranial bones are there? How many facial?

How many of each are paired?

A

Cranial: 8, 2 paired
Facial: 14, only 2 unpaired

76
Q

What compounds were shown to reduce AMD progression in the AREDS trial?

A

Vit C, Vit E
Zinc
Beta-carotene

77
Q

A closed head injury is most likely to damage which nerve?

A

CN4 (longest intracranial course)

78
Q

IS PAX6 linked aniridia AR or AD inheritance?

A

Autosomal dominant

79
Q

Femtosecond laser assisted cataract surgery: what are the advantages over traditional phacoemulsification?

A
  1. Capsulorhexis is more accurate and reproducible with FLACS
  2. Likewise for corneal incisions
  3. Lens fragmentation can be done with reduced instrumentation and power
80
Q

By what means does uveal melanoma spread?

A

Haematogenous (rich blood supply to uvea)

81
Q

Is the Prentice position usually used to specify glass or plastic lenses?

A

Glass

82
Q

A crown glass prism with apex angle of 4 degrees is has what minimum angle of deviation?

A

2 degrees

83
Q

When treating heterotropia with prisms, which direction should the apex of the prism point?

A

Apex should point towards direction of deviation

84
Q

How many prism dioptres can be incorporated into CORNEAL contact lenses?

A

3 dioptres (6 dioptres for scleral contact lenses)

85
Q

Can horizontal strabismus be corrected with corneal contact lenses?

A

No - the prism weights the contact lens so it is always at the bottom. Thus, corneal contact lenses can only be used to correct vertical tropias

86
Q

What sort of lenses are used in:

  • Galilean telescope
  • Compound microscope / astronomical telescope
  • Loupe
A

Galilean: + -
Compound: + +
Loupe: +

87
Q

What is thermokeratoplasty used to treat?

A

Refractive surgery for hyperopia - cornea is burned and scar tissue causes contraction and steepening of cornea

88
Q 
Silicone oil in
(a) phakic
(b) aphakic
Gas fill in
(c) phakic
(d) aphakic
eyes, what is the ametropia caused in each case?
A

(a) Silicone oil in phakic eye: Hypermetropia. High RI of silicone oil means light rays diverge from lens to silicone oil.
(b) Silicone oil in aphakic eye: Myopia. No lens present. Curved surface of silicone oil bubble acts as strong converging lens.
(c) Gas bubble in phakic eye: Myopia. Low RI of gas increases converging power of lens
(d) Gas bubble in aphakic eye: Hypermetropia. No lens present and light is not converged by vitreous as vitreous is removed.

89
Q

If two base out prisms are stacked, will the prism powers summate?

A

No, as the light entering the second prism will be at the wrong angle (not the position of minimum deviation).
However, perpendicular prisms can be stacked.

90
Q

When prescribing prisms, are they usually incorporated into one lens only or split across both?

A

Split across both lenses

91
Q

Is the image formed by a thin concave lens laterally inverted?

A

No. It is virtual, erect, diminished and located between F2 and the lens.

92
Q

A convex lens decentred superiorly results in what sort of prism?

A

Base-up

93
Q

Is the base curve of a cylindrical lens the meridian with minimum or maximum curvature?

A

Minimum curvature

94
Q

When a convex lens is placed over a cross and moved side to side, is the direction of movement with or against?

A

Against (similar to retinoscopy rules)

95
Q

In the Duochrome test, does a myope see the red or green background more clearly?

A

Red background

96
Q

Manifest vs latent hypermetropia?

A

Manifest: Equivalent to the strongest convex lens correction accepted for clear distance vision
Latent: Residual hypermetropia which is involuntarily corrected for by ciliary tone and accommodation

97
Q

If an emmetropic person has 3D of accommodation remaining, what presbyopic correction do they need to read clearly at 20cm?

A

20cm: 5D of accommodation necessary.

1/3 of amplitude of accommodation should be held in reserve for comfortable near vision (1D in this patient).

Therefore, this patient will need 6D of accommodative power in total –> 3D of correction.

98
Q

Does the Stiles-Crawford effect affect rods or cones?

A

Cones only

99
Q

What do the primitive dorsal and ventral ophthalmic arteries become?

A

Dorsal - ophthalmic artery proper

Ventral - nasal long posterior ciliary artery

100
Q

Most common ocular abnormality with maternal rubella in first trimester?

A

Cataract

101
Q

Does CN3 run medially or laterally to the posterior communicating artery?

A

Laterally.

Emerges from ventral midbrain between the posterior communicating artery and the superior cerebellar artery

102
Q

Which nerve is relatively protected with cavernous sinus lesions?

A

CN6 as it is protected by the internal carotid.

103
Q

The SOF lies between the roof and medial wall of the orbit - true or false?

A

False - it lies between the roof and lateral wall

104
Q

Roundworm associated with Chrysops horseflies / deerflies

A

Loa loa (endemic in W Africa)

105
Q

Does the cornea have a subepithelial nerve plexus?

A

Yes, and a sub-basal nerve plexus as well.

Innervation is CN V1 via long ciliary nerves.

106
Q

Does Bowman’s layer contain Type 2 collagen?

A

No. Mainly contains types 1, 3, 5, 6

107
Q

Are corneal endothelial cells highly interdigitated?

A

Yes - many gap junctions and cell-cell transport

108
Q

The sclera is thinnest posteriorly, true or false?

A

False. It is thickest posteriorly (1mm) and thinnest at the insertions of the EOMs

109
Q

Does the sclera contain more or less GAGs than the cornea?

A

Less - almost half the amount and chondroitin sulfate rather than keratan sulfate

110
Q

What gestational age is aqueous produced from?

A

7th month - when angle forms

111
Q

At what gestational age does the ciliary body start to develop?

A

3rd month (week 12)

112
Q

When does the lens placode form?

A

Day 27

113
Q

When do the sphincter and dilator pupillae muscles form? Which one first?

A

Sphincter before dilator (14 weeks and 6 months respectively)

114
Q

Which gene localises to the future ciliary body / iris in the embryo?

A

Hox 7.1

115
Q

What order neurones does the optic nerve contain?

A

Second order neurones (GCs)

First order are bipolar cells

116
Q

When does the choroidal fissure begin to close?

A

Week 6; complete by week 7

117
Q

Malleus, incus, stapes: which pharyngeal arches?

A

Malleus and incus: First pharyngeal arch

Stapes: 2nd pharyngeal arch

118
Q

What is the main collagen in the vitreous?

A

Type 2

119
Q

Which margin of the orbital rim is thickest?

A

Lateral

120
Q

Does the trigeminal nucleus form part of the midbrain?

A

Yes - the mesencephalic nucleus extends into the midbrain

121
Q

Does lipofuscin accumulate intra or extracellularly?

A

Intracellularly in RPE cells

122
Q

Does retinoblastoma metastasise?

A

Yes - mainly via orbital nerve, but also through sclera

123
Q

How much does the LPS raise the lid by?

A

12-13mm

124
Q

How thick is the tear film?

A

10um

125
Q

State the mechanisms of inheritance of oculocutaneous albinism and ocular albinism.

A

Oculocutaneous: Autosomal recessive
Ocular: X-linked recessive

126
Q

Where is the superior salivatory nucleus located?

A

Pons (just above pontomedullary junction)

127
Q

Secretory IgA is highest in concentration in non-stimulated basal tears: true or false?

A

True

128
Q

The majority of retinal ganglion cells encode information via which pathway: magnocellular or parvocellular?

A

Parvocellular (90% of axons!)

129
Q

What are transitions and transversions in DNA mutations?

A

Transitions: purine -> purine or pyrimidine -> pyrimidine
Transversions: one type is replaced by another

130
Q

Can first and second order Horners syndrome be distinguished pharmacologically?

A

No, only third order reacts differently

131
Q

What HLA subtype is associated with MS?

A

HLA-DR2

132
Q

HLA for birdshot chorioretinopathy?

A

A29

133
Q

HLA for Behcet’s

A

B51

134
Q

In X-linked dominant inheritance, what percentage of offspring of an affected mother will be affected?

A

50% (affects boys and girls equally)

135
Q

Which parasympathetic ganglion supplies the conjunctiva?

A

Pterygopalatine

136
Q

Is thioglycollate broth used for only anaerobic bacteria?

A

No, is a general all-purpose medium

137
Q

In ERGs, is the b wave generated by outer or inner retinal element?

A

Inner (bipolar and Muller cells)

138
Q

Which 2 adrenergic receptors are dominant in the ciliary body epithelium?

A

apla-2 and beta-2

139
Q

Patient with:

  • L inferior rectus, inferior oblique and medial rectus weakness
  • R superior rectus weakness
  • Bilateral ptosis

Where is the lesion?

A

Left oculomotor nucleus.

3 groups of subnuclei:

  • Ipsilateral IR, MR, IO innervation
  • Contralateral SR innervation
  • Bilateral LPS innervation from central nucleus
140
Q

What are the 2 most common sites of scleral rupture?

A 
Superonasal limbus (from trauma)
Insertion of the recti
141
Q

What germ layer is the trabecular meshwork derived from?

A

Mesenchyme / NCC

142
Q

Is vancomycin effective against G- bacteria?

A

No (cannot penetrate cell membrane)

143
Q

In surgery, what anatomical position is marked by the grey line?

A

Anterior border of the tarsal plate

144
Q

Rate of CSF production and total CSF volume

A

550ml produced / day

Total vol 150ml

145
Q

Which bones in the orbit do not derive purely from membranous ossification?

A

Sphenoid and ethmoid (skull base) derive from cartilaginous ossification

146
Q

Pelli-Robson and Hardy-Rand-Rittler: which one does not assess colour vision?

A

Pelli-Robson - assesses contrast sensitivity

147
Q

What sort of image is produced by a Hruby lens?

A

Virtual, erect and diminished image is formed within the vitreous.

148
Q

Is HLA-B27 associated uveitis granulomatous or non-granulomatous?

A

Non-granulomatous

149
Q

What is the inheritance pattern of Gorlin-Goltz syndrome?

A

Autosomal dominant

150
Q

Describe the % hydration of the cornea and sclera

A

Cornea: 80% hydrated
Sclera: 70% hydrated

151
Q

What is the effect of mydriasis on depth of field and depth of focus?

A

Decreases both.

152
Q

What stage of trachoma is characterised by contraction of the palpebral conjunctival stroma?

A

Stage 4

153
Q

Effect of acetazolamide on pH and K+

A

Metabolic acidosis (reduced renal reabsorption of bicarb) but hypokalaemia

154
Q

What is the primary route of glucose utilisation by the corneal endothelium?

A

Anaerobic glycolysis. (More aerobic glycolysis than the epithelium, but still mostly anaerobic)

155
Q

The maximal number of axons in the optic nerve is acheived at:

A

15 weeks gestation. (Nearly 4 million, then gets pruned down to the normal 1.2million by 30wks)

156
Q

In what part of the nephron does water absorption not take place?

A

Ascending limb of loop of Henle

157
Q

What is the horizontal corneal diameter at birth

A

10mm (compared to 11.7 in the adult)

FRCOphth Part 1 Revision (13 decks)

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