Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Year 4: Special Senses > Opthalmology > Flashcards

Opthalmology Flashcards

1
Q

Which walls of the orbit are most likely to fracture as a result of blows and direct trauma?

A

Medial and inferior.

They are particularly thin.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Name the 2 muscles that allow movement of the eyelid and their respective innervation.

A
  1. Orbicularis oculi - facial

2. Levator palpebrae superioris - oculomotor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is a chalazion?

A

Obstruction to the tarsal glands leading to a painless swelling of the eyelid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is a hordeolum?

A

A ‘stye’ or hordeolum can results from acute infection of a gland of Moll, Zeiss or the eyelash follicle.

NOTE: Modified sweat glands (glands of Moll) and sebaceous glands (glands of Zeiss)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Name the 3 components of the lacrimal apparatus.

A
  1. Lacrimal glands
  2. Lacrimal ducts
  3. Lacrimal canaliculi
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Describe the passage of The lacrimal fluid entering the conjunctival sac through the lacrimal ducts until it is swallowed.

A

The lacrimal fluid entering the conjunctival sac through the lacrimal ducts passes into the lacrimal lake at the medial angle of the eye from which it drains to the lacrimal sac.

The fluid passes to the nasal cavity through the nasolacrimalduct, which opens into the nasal cavity (into the inferior meatus) from which it passes into the nasopharynx and swallowed.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Name the 3 components of the tear film.

A
  1. Surface lipid layer: secreted by the meibomian (tarsal) glands
  2. Middle aqueous layer: secreted by the lacrimal gland and accessory lacrimal glands
  3. Inner mucus layer: secreted by goblet cells of the conjunctiva and the epithelial cell surface
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Name some causes of dry eyes.

A
  • Deficiency of the tarsal glands e.g. obstruction to their openings
  • Reduced production of tears e.g. autoimmune disease such as Sjogren’s syndrome, rheumatoid arthritis
  • Medications e.g. antihistamines
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Describe the components of the 3 layers of the eyeball.

A
  1. Outer protective layer: sclera and the cornea
  2. Middle layer: choroid, ciliary body and iris
  3. Inner layer: retina consisting of optic and non-visual parts
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Describe the 2 chambers of the eyeball.

A
  1. Anterior chamber: the space between the cornea and the iris
  2. Posterior chamber: the space between the iris and the ciliary body and the lens
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What does the Hillary body secrete?

A

Aqueous humour

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Name the 2 muscles that control the size of the pupil.

A

Sphincter and dilator pupillae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the cavity behind the lens filled with?

A

Vitreous humour

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are the photoreceptor cells found at the macula lutea specialised for?

A

Visual acuity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the fovea centralis?

A

A depression in the centre of the macula, the area of most acute vision.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Describe the blood supply to the retina.

A

The retina is supplied by the central artery of the retina and drained by the corresponding vein.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Describe the 3 main roles of the cornea.

A
  1. Maintaining transparency (so that we have a clear window through which to see)
  2. Ocular protection (including the corneal reflex)
  3. Refraction of incoming light (along with the overlying tear film)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Name the 5 layers of the cornea.

A
  1. Epithelium
  2. Bowman’s membrane,
  3. Stroma
  4. Descemet’s membrane
  5. Endothelium
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Why do central corneal wounds heal slower than more peripherally located defects?

A

Corneal stem cells are also located at the periphery of

the cornea at the ‘limbus’

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

How long does it take for the corneal epithelium to regenerate.

A

The total time for regeneration of the corneal epithelium is quoted as between 3 to 14 days, being longer for central epithelial defects.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is the significance of recognising Bowman’s layer of the cornea?

A

This is an acellular layer and separates the overlying epithelium from the underlying stroma. It is important to recognise as any trauma extending below this level will result in
corneal scarring as only the epithelium is regenerated.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Why is the cornea transparent?

A

It consists of an arrangment of regularly orientated collagen fibres (type 1 predominantly). The regularity with which these are arranged helps to explain the transparency of the cornea.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Describe the innervation of the cornea.

A

The cornea has a rich nerve supply derived mainly from the ophthalmic branch of the trigeminal nerve (via long ciliary nerves). In some case there is innervation via the maxillary branch which supplies the inferior cornea.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Describe how a patient with infective keratitis would present and why.

A
  • A loss of epithelium exposes free nerve endings causing severe pain.
  • The inflammation also leads to increased peri-corneal vascularity and a red eye.
  • There is an associated watery discharge with epiphora.
  • As the corneal surface and tear film is disrupted along with possible corneal oedema there is a resultant drop in visual acuity.
  • There may also be photophobia and a mucus or mucopurulent discharge.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is a hypopyon?

A

A collection of pus behind the cornea in the anterior chamber

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What are ‘cells’ and ‘flare’ in relation to infective keratitis?

A

‘Cells’ and ‘flare’ are leucocytes and protein respectively derived from the leaky iris blood vessels responding to the infection.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is responsible for maintaining an adequate pressure in the eye?

A

Aqueous humour.

IOP is a balance between the rate of production of aqueous and the rate of drainage.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Describe the passage of the aqueous humour from the ciliary process of the ciliary body to the system venous circulation.

A

Aqueous humour is produced by the ciliary processes of the ciliary body. It then flows up
between the iris and anterior surface of the lens and through the pupil.

After passing through the drainage angle of the eye which consists of the trabecular meshwork followed by the Canal of Schlemm.

Aqueous then drains into the episcleral vessels and finally into the systemic venous circulation.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

How is IOP measured?

A

IOP is measured by measuring the force needed to flatten the corneal surface using a tonometer.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What is the normal range of IOP?

A

11-21 mmHg. Above 21 is considered to be ocular hypertension.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

TRUE OR FALSE: having high intra-ocular pressure does not equate to a diagnosis of glaucoma.

A

TRUE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Describe the autonomic control of IOP.

A

This is via adrenergic receptors. Cholinergic mechanisms have little direct effect on aqueous production.

  • Alpha 2 receptors: stimulation reduces IOP by reducing aqueous production and may increase uveoscleral outflow
  • Beta 2 receptors: stimulation increases IOP by increasing aqueous production
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Name 5 classes of drugs that can be used to lower IOP.

A
  1. Beta blockers
  2. Alpha agonists
  3. Prostaglandin analogues
  4. Carbonic anhydrase inhibitors
  5. Parasympathomimetics
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What structure in the eye has the greatest refractive power?

A

Cornea

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What is the main function of the lens?

A

Accommodation reflex

36
Q

What is the term given to the physiological process that diminishes the degree to which the lens is able to accommodate with age?

A

Presbyopia

37
Q

Name 3 causes for cataracts in younger patients.

A
  1. Trauma: direct injury to lens (penetrating), electric shock/lightning, blunt trauma
  2. Drugs: steroids (systemic and topical), amiodarone, phenothiazines
  3. Systemic disease - diabetes mellitus, myotonic dystrophy, neurofibromatosis type 2
38
Q

What is the fancy doctor word for cataract surgery?

A

Phacoemulsification

39
Q

Name the 3 components of the uveal tract.

A
  1. Iris
  2. Ciliary body
  3. Choroid
40
Q

Describe the role of the iris.

A

The iris controls the amount of light entering the eye by varying the size of the aperture in the middle of the iris – the pupil.

41
Q

In conditions of low light or sympathetic activation, how does the pupil respond?

A

Dilates - mydriasis

42
Q

What muscle allows the pupil to dilate?

A

Dilator pupillae

43
Q

In conditions of bright light or parasympathetic activation, how does the pupil respond?

A

Constricts - miosis

44
Q

What muscle allows the pupil to constrict?

A

Sphincter pupillae

45
Q

Name 3 main roles of the ciliary body.

A
  1. Accommodation
  2. Aqueous humour production
  3. Providing attachment for the lens zonules
46
Q

Describe the 4 functions of the choroid.

A
  1. Allows nerves and vessels to reach the anterior eye by passing through the
    choroid
  2. Removes waste product from the outer retina (area closest to choroid)
  3. Supplies essential nutrients to the outer half of the retina
  4. Absorbs any light passing through the retina, thus preventing it from reflecting
    back and interfering with vision
47
Q

How does the choroid attach to the retina?

A

By way of a basement membrane known as Bruch’s membrane

48
Q

What is anterior uveitis?

A

Inflammation affecting the iris (iritis) +/- the ciliary body (iridocyclitis)

49
Q

What is intermediate uveitis?

A

Inflammation of the posterior part of the ciliary body and nearby peripheral retina and choroid

50
Q

What is posterior uveitis?

A

Inflammation of the retina and choroid

51
Q

What is Panuveitis?

A

Inflammation of the whole uveal tract

52
Q

Describe how a patient with anterior uveitis would present.

A

The patient complains of phtophobia, pain, reduced vision and a watery eye that may overflow (epiphora).

53
Q

Describe how a patient with anterior uveitis would present on examination.

A

Examination reveals circum-corneal injection, cellular deposits on the corneal endothelium (keratic precipitates).

Examination of the anterior chamber reveals cells and flare (protein), which are derived from leaky iris blood vessels.

In the subacute or recurrent cases there may be posterior synaechiae – adhesions between the inflamed iris and anterior lens capsule.

54
Q

Describe the pathology behind retinal detachment.

A

The retina has two parts derived embryologically from the optic cup.

  1. Inner neural retina
  2. Outer retinal pigment epithelium (RPE).

There is a potential space between these two layers - subretinal space - which ‘fuses’ during early foetal life.

The RPE is firmly attached to Bruch’s membrane whereas the neural retina is only attached firmly at the optic nerve head and anteriorly at its termination, the ora serrata.

Trauma and other mechanisms can lead to this separation reforming – retinal detachment.

55
Q

Describe how a patient with retinal detachment will present.

A

Patients will complain of flashing lights and floaters as well as possible visual field defects due to disruption of afferent nervous pathways.

56
Q

What are rod photoreceptors responsible for?

A

Rods are responsible for sensing contrast and motion.

They also assist seeing in darker environments.

57
Q

What are cone photoreceptors responsible for?

A

Cones sense fine detail and colour vision.

58
Q

Describe the blood supply to the retina.

A

The inner 2/3 of the retina are supplied by the central retinal artery whilst the outer 1/3 is supplied by the choroidal blood supply.

59
Q

Name the structure that can be described as a ‘capillary free zone’.

A

Fovea

60
Q

How does the fovea survive without a blood supply?

A

This region is dependant on the underlying choriocapillaris.

61
Q

Describe why, during retinal artery occlusion, the retina becomes pale and oedematous, however, the fovea retains a red colour.

A

The fovea retains a red colour due to being supplied by the choriocapilaris.

62
Q

Describe how a patient with retinal artery occlusion would present.

A

Patients will complain of painless and sudden loss of vision.

63
Q

Name the common causes of red eye.

A
  • Conjunctivitis
  • Corneal ulcer
  • Dry eye syndrome
  • Subconjunctival hemorrhage
  • Inflammation of the cornea, - Glaucoma
  • Sun exposure
    dust or other particles in the eye
  • Injury
  • Swimming
  • Smoking or drinking
  • Environmental irritants or pollutants
64
Q

Describe how a patient with conjunctivitis would present.

A

Eye red and sticky, often bilateral

65
Q

Describe how a patient with a corneal abrasion would present.

A

Something went into the eye, very sore, watering++

66
Q

Describe how a patient with a corneal foreign body would present.

A

Pain, tearing, and a feeling that there is something in the eye

67
Q

Describe how a patient with keratitis would present.

A

Sore red eye, may be sticky, may or may not have blurry vision.

Signs include white areas on periphery of cornea which may be thinner than normal usually associated with blepharitis

68
Q

Describe how a patient with iritis would present.

A

Varying degrees of redness of the affected eye, often with significant pain, sensitivity to light, tearing, and blurred vision

69
Q

Describe how a patient with orbital cellulitis would present.

A

Swelling and redness of the eyelid and surrounding soft tissues, conjunctival hyperemia and chemosis, decreased ocular motility, pain with eye movements, decreased visual acuity, and proptosis caused by orbital swelling.

70
Q

Describe the characteristic visual disabilities in a patient with glaucoma.

A
  • Generally, high levels of illumination are needed with control of glare
  • Difficulty in adapting to various changes of light may be present.
  • Peripheral field loss may restrict mobility and sports activities.
71
Q

Describe the characteristic visual disabilities in a patient with cataracts.

A

It is characterized by opacity or cloudiness of the crystalline lens, which may prevent a clear image from forming on the retina.

72
Q

Describe the characteristic visual disabilities in a patient with ARMD.

A

Early on there are often no symptoms.

Over time, however, some people experience a gradual worsening of vision that may affect one or both eyes.

While it does not result in complete blindness, loss of central vision can make it hard to recognize faces, drive, read, or perform other activities of daily life.

73
Q

Describe the characteristic visual disabilities in a patient with retinitis pigmentosa.

A

When RP first starts to appear, the light-sensing cells that are responsible for vision in dim light (rods) gradually deteriorate and seeing at night becomes more difficult. During later stages of retinitis pigmentosa, only a small area of central vision remains, along with slight peripheral vision.

74
Q

Describe the characteristic visual disabilities in a patient with cerebrovascular vascular disease.

A

Hemianopia.

75
Q

Describe the distinction between painful acute angle closure glaucoma and chronic simple glaucoma.

A

In open-angle glaucoma, the trabecular meshwork offers increased resistance to fluid outflow. This causes the pressure to build up inside your eye.

In closed-angle glaucoma, both the uveoscleral drain and the trabecular meshwork become blocked. Typically, this is caused by a damaged iris (colored part of the eye) blocking the outlet.

76
Q

Describe the systemic side effects of some eye drops for the treatment of chronic simple glaucoma.

A
  • Prostaglandin Analogs: eye color change, darkening of eyelid skin, eyelash growth, droopy eyelids, sunken eyes, stinging, eye redness, and itching
  • Beta Blockers: low blood pressure, reduced pulse rate, fatigue, shortness of breath; rarely: reduced libido, depression.
  • Alpha Agonists: burning or stinging, fatigue, headache, drowsiness, dry mouth and nose, relatively higher likelihood of allergic reaction.
  • Carbonic Anhydrase Inhibitors: in eye drop form: stinging, burning, eye discomfort; in pill form: tingling hands and feet, fatigue, stomach upset, memory problems, frequent urination.
  • Rho Kinase Inhibitors: eye redness, corneal deposits, stinging, and small bleeds on the white of the eye
77
Q

Describe how a patient with diabetic retinopathy would present.

A 
Spots or dark strings floating in your vision (floaters)
Blurred vision.
Fluctuating vision.
Impaired color vision.
Dark or empty areas in your vision.
Vision loss.
78
Q

Describe factors that may contribute to the development of diabetic retinopathy.

A

Diabetic retinopathy is caused by prolonged high blood glucose levels Over time, high sugar glucose levels can weaken and damage the small blood vessels within the retina. This may cause haemorrhages, exudates and even swelling of the retina. This then starves the retina of oxygen, and abnormal vessels may grow.

79
Q

Name some treatments for diabetic retinopathy.

A
  • Photocoagulation
  • Panretinal photocoagulation
  • Vitrectomy
  • Injecting vascular endothelial growth factor (VEGF) inhibitors
80
Q

Describe how a patient with ARMD would present.

A
  • Reduction in visual acuity, noticed particularly for near vision.
  • Loss of (or decreased) contrast sensitivity (the ability to discern between different shades).
  • Size or colour of objects appearing different with each eye.
  • Abnormal dark adaptation (difficulty adjusting from bright to dim lighting). There may be a central dark patch in the visual field noticed at night, which clears within a few minutes as the eyes adapt.
  • Photopsia (a perception of flickering or flashing lights).
  • Light glare.
81
Q

In which ARMD patients may there be scope for treatment?

A

There is no treatment which prevents progression of dry AMD, although lifestyle adjustments may slow progression. Management consists mainly of counselling, smoking cessation, visual rehabilitation and nutritional supplements in those expected to benefit.

82
Q

Name the three causes of amblyopia.

A
  1. Strabismic: by strabismus (misaligned eyes)
  2. Refractive: by anisometropia (difference of a certain degree of nearsightedness, farsightedness, or astigmatism), or by significant amount of equal refractive error in both eyes
  3. Deprivational: by deprivation of vision early in life by vision-obstructing disorders such as congenital cataract[16]
83
Q

Describe how amblyopia is treated.

A
  • Correcting the optical deficit (wearing the necessary spectacle prescription)
  • Forcing use of the amblyopic eye, by patching the good eye
  • Instilling topical atropine in the good eye
84
Q

Describe the importance of red reflex testing in infancy.

A

Red reflex testing is vital for early detection of vision- and potentially life-threatening abnormalities.

85
Q

Name some causes of an abnormal red reflex in infancy.

A
  • Cataracts
  • Glaucoma
  • Retinoblastoma
  • Retinal abnormalities
  • Systemic diseases with ocular manifestations
  • High refractive errors.
86
Q

Describe the genetic significance of retinoblastoma.

A

In hereditary retinoblastoma, mutations in the RB1 gene appear to be inherited in an autosomal dominant pattern.

87
Q

Describe the genetic significance of retinitis pigmentosa.

A

In most cases, the disorder is linked to a recessive gene, a gene that must be inherited from both parents in order to cause the disease. But dominant genes and genes on the X chromosome also have been linked to retinitis pigmentosa.

Year 4: Special Senses (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions