Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Opthalmology > Gradual loss of vision > Flashcards

Gradual loss of vision Flashcards

1
Q
  • define cataract
  • what are the different aetiologies of cataracts (6)
A
  • cataract=opacificaiton of lens. term “cataract” should only be used when this causes visual impairment.
  • age related
  • diabetes related
  • seondary - eye disease or disease elsewhere
  • trauma - contusion. perforation. radiation
  • congential
  • toxicity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

age related cataracts

  • majority of cataracts are age related. a degree of opacification of lens common in elderly. genetic aspect.
  • where is the opacification (2) .possible morphologies (3)
A
  • opacification is can be limited to periphery of lens typical. only in certain instances does this progree to the point of requiring surgery. or can be nuclear
  • -*morphology typically cortical / wedge shaped pointing toward centre of pupil.
  • may have vesicles under ant lens capsule
  • if nuclear the lens nucleus can take on a yellow-brown colour . aka nuclear sclerosis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q
  • diabetes related cataracts
  • diabetes increases with age therefore age realated cataracts will be seen in diabetes however these are just age related cataracts. nb diabetic pts do tend to present with age related cataracts at an earlier age.
  • special type seen in young diabetes. usuallt T1DM. timing (1) nature (1) mx(1)
A

-over two months lens becomes rapidly opaque. may be reversible . very rare.

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

cataract secondary to eye disease

  • many eye diseases can be associated w cataracts eg (3)
  • specific diseases accompanied by cataract (2) where
A
  • glaucoma, chornic iridocyclitis, intraocular tumours, uveitis this may appear in post subcapsular region
  • inherited retinal degeneration, retinitis pigmentosa. in these opacity is in post part of lens
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q
  • lens has same derivation as skin
  • what conditions may be assx with cataracts (4)
A

-atopy - pts with eczema or asthma more liekly to get cataracts in 50s

-downs

-parathroid function more rarely

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q
  • contusion. caused by blow to eye. eg ball. timing (1)
  • perforation. higher risk of cataract than contusion. caused by perforating object eg broken glass. if there is splitting of lens capsule what occurs (4). nb if object passes through cornea and does not touch lens it is usually spared Mx
A
  • contusion cataract. can occur a year or several years after trauma. onset of unilateral cataracts you can suspect previous trauma.
  • -*perforation. if there is splitting of lens capsule

>lens fibres spill into AC

>vigorous inflammatory reaction ensues in AC

>lens matter gradually absorbed w/o Mx will occur over 1 month

  • >*leaves behind lens capsule in children may leave a clear pupil. in adults tends to leave white fibrous tissue obstructing pupil
  • -*Mx is replacement with artificial intraocular lens
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

cataracts - radiation

  • does visible light cause cataracts
  • what kind of rays can cause cataracts (3)
A
  • visible light does not cause cataracts
  • prolonged exposure to infrared can cause cataracts eg glassblowers, steel workers . however they should wear goggles
  • x rays eg bomb victims, high dose of whole body radiation used to treat leukaemia
  • gamma rays eg bomb victims
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

cataracts - congenital

-causes of congenital cataracts (2)

A
  • inherited eg dominant FH, may be as part of a syndrome
  • acquired by maternal rubella infection during first trimester cataracts may progress . assx with deafness and congenital heart lesions
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q
  • cataracts - toxicity
  • what drugs can cause cataracts
A

-chlorpromazine antipsychotic in high doses, systemic steroids, pilocarpine rare

these cateracts usually present as posterior subcapsular

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

-cataracts - main symptom (1)

A

-reduced visual acuity

nb testing using a snellen chart can be invalidated by the location of the opacities

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

-cataract findings on opthalmoscopy. how to examine (3). findings (1)

A
  • view red reflex from 50cm. best when pupil dilated and in a dark room.
  • cataract will show against red reflex at black spokes against red reflex.
  • after this move closer and attempt to see the fundus. if you can see in pt should be able to see out. if VA is reduced but you can see in suspect other pathology.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

some distincive signs can be seen under the slit lamp

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

what is management of cataracts, what can be performed at same time

A

-surgical removal of lens is management

at same time a new lens can be inserted to correct for refractive errors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q
  • age related macular degeneration
  • commonest cause of severe visual impairment / blindness in elderly*
  • pathology - two types (2) which more commonly causes severe visual impairment
A
  • wet/neovascular AMD. - usually associated with severe visual impairment ie both eyes severely affected
  • dry / atrophic AMD
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Background - age of onset (1)

PC (1)

HPC - nature - unilateral or bilateral (1) what might pts notice (5)

PMH (2)

FH (1)

SH (3)

A
  • age of onset usually around 65
  • PC - loss visual acuity
  • bilateral however usually one eye is considerably more affected. pts might notice straight lines appear kinked. inability to read clearly, blurred vision, inability to recognise faces, seeing bus numbers.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

amd o/e

  • fundus signs early dry AMD (2) at this stage vision is maintained
  • in late dry AMD what is the pathology (2) that is assx with photoreceptor loss
A
  • early dry amd - spots of pigment on macular regeon. and drusen often scattered over poterior pole these are small round yellow spots these are colloid bodies in bruch’s membrane of retina.
  • -*late dry AMD - drusen develop into progressive atrophy of the retinal pigment epithelium (RPE) and choriocapillaris. this atrophy is assx with photoreceptor loss. nb it is called dry as there is no leaking of fluid or bleeding into the retina or subretina space
17
Q

wet amd - o/e

-fundus o/e (4)

A

-in wet AMD a fan of new vessels arise from the choroid - choroidal neovascularisation and these break bruchs membrane of the retina. there can be exudates and haemorraghes as a result. can present as sudden loss of central vision. subsequent healing by scarring can occur leaving permenant loss of vision

18
Q

amd - mx

  • Mx dry amd (1)
  • Mx wet amd (2)
A
  • no treatment for dry amd
  • for wet amd there are two options
  • laser photocoagulation of the choroidal neovascularization /cnv

>only works when leakage is not subfoveal. nb this is only in a fraction of cases and there is high recurrance of cnv following this mx

-photodynamic therapy / pdt

>specifically targets the cnv with low energy laser, avoiding photoreceptor cells

Opthalmology (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions