Competency 6.1.6 Flashcards
1
Q
What is Nuclear Sclerotic Cataract?
A
- Is an exaggeration of normal aging changes
- associated with a myopic shift due to an increase in refractive index
- Upon retro-illumination there is not much to see but a subtle distinction between the affected nucleus and the cortex.
2
Q
Nuclear Sclerotic Cataract Symptoms
A
- Slow development of symptoms
- Bilateral but often asymmetrical
- Improvement in near vision
- Blurring of vision
- Colors may appear faded or yellowed
3
Q
Nuclear Sclerotic Cataract Signs
A
- Opacity densest in centre of lens
- Yellow discolouration
- Colour progresses to brown as progresses
- Reduced VA
4
Q
What is a Cortical Cataract?
A
- May involve any part of the lens cortex
- The opacities start as small clefts between lens fibres due to cortical hydration
- These clefts then develop into spoke-like opacities in the lens cortex.
5
Q
Cortical Cataract Symptoms
A
- Slow development of symptoms
- Bilateral but often asymmetrical
- VA may be unaffected
- Glare
- Monocular diplopia
6
Q
Cortical Cataract Signs
A
- Mid-peripheral opacities
- Clear nucleus
- Straight line/wedge shaped cortical opacities
- Black shadows on retro-illumination
7
Q
What is a Posterior Subcapsular Cataract?
A
- Lies just infront of the posterior capsule
- and has grainy appearance on direct viewing
- Retro-illumination reveals a black opacity with vacuoles present
- Is very commonly associated with steroid use.
8
Q
Posterior Subcapsular Cataract Symptoms
A
- Profound effect on vision
o Disproportionate to signs
o Near vision typically more affected
o VA more affected in bright light (miosis)
o Glare
9
Q
Posterior Subcapsular Cataract Signs
A
- White/yellow opacity at centre of pupil
- Rough texture visible on high magnification
10
Q
What is a Morgagnian Cataract?
A
- an advanced stage of a cataract where the cortical lens has become liquified and the dense and hardened lens nucleus has sunk down to the bottom of the lens capsule
- Morgagnian cataracts will typically present with profound visual loss (hand-motions or light-perception)
- Morgagnian cataract may undergo spontaneous rupture into anterior chamber causing inflammatory reaction
11
Q
Morgagnian Cataract Prognosis
A
- Patients should be counseled about the increased risk of complications and the possible need of more than one surgery to achieve the best visual outcome.
- Preoperative assessment for projection of light and relative afferent pupillary defect are important prognostic factors.
- Patients should also be cautioned about possible binocular diplopia post cataract removal if morgagnian cataract was longstanding and may have lead to loss of fusion.
11
Q
Causes of Traumatic Cataract
A
- Penetrating trauma
- Blunt trauma
- Electric shock
- IR/ionising radiation
12
Q
Causes of Cataract in Young Individuals
A
- The majority of bilateral congenital or infantile cataracts not associated with a syndrome have no identifiable cause
- Trauma is a known cause of pediatric cataracts
- If there is no known history of trauma to explain an acquired cataract in this age group, investigation must be considered in children who present with other signs suggestive of child abuse
- In many cases of congenital cataracts, there is a family history.
13
Q
Management of Cataract in Young Individuals
A
- Not all pediatric cataracts require surgery
- small, partial or paracentral cataracts can be managed by observation.
- Management of a cataract in a child is different from adults because of the anatomically younger ocular tissues, continuous ocular growth and other associated structural anomalies
14
Q
Indications for Cataract in Young Individuals
A
- Cataract < 3mm in diameter
- Peripheral or paracentral cataract not obscuring the visual axis
- Blue-dot cataract which is not afftecting the vision
- Presence of good red reflex viewed with direct ophthalmoscope or retinoscope
- Absence of strabismus or nystagmus