AED - Cataracts I - PAP Week 1 Flashcards
Describe the SOAP acronym.
Subjective - symptoms
Objective - signs
Assessment - detecting signs and symptoms
Plan - optometric and medical management
Is the lens vascular or avascular?
Avascular
Is the lens innervated or non-innervated?
Non-innervated
List the three components of the lens.
Capsule
Cortex with endothelium
Nucleus
List the two cell types of the lens.
Cuboidal
Bow
What connects the lens to the ciliary bodies?
Zonules
Which of the three crystallin proteins form foetally? How do the others form (2)?
γ forms foetally. Others form over life or due to the effects of light oxidation.
What is the main means of metabolism in the lens epithelium? Where does this energy go (3)?
Anaerobic glycolysis
Energy needed for ion pumps, protein synthesis, and provide antioxidants
What molecule is used as an antioxidant by the lens?
Glutathione
Describe the fluid flux within the lens, where it enters and exits. Name the protein responsible for pumping water out.
Enters via the thin posterior capsule
Pumped out of the anterior epithelium by Na/K-ATPase
Describe how bow cells contribute to lens growth. Where do lens fibres meet?
Bow cells elongate to form fibres
Lens fibres elongate and meet at suture lines
Describe the shape of suture lines anteriorly and posteriorly
Anterior - Y
Posterior - ⅄
What happens to the number of lens fibres over time and what does this lead to? What is the consequence of this (3)?
Lens fibre numbers increases over time due to continuous addition to outer coats, leading to increased protein density with age
- increased refractive index with age
- compression promotes cataract formation
- chromophores accumulate
What causes the lens to yellow with age?
Accumulation of chromophores
What happens to the capsule (which region specifically) with expansion and ageing of the lens? What is a consequence of this (2)?
Posterior capsule thinning
- increased fluid uptake
- cataract formation
List the four types of cataracts. Note the most common type.
Artefacts
Congenital
Aquired
Senile - most common
List the two types of congenital cataracts. Note which is more common.
Sight debilitating - not common
Non-debilitating - common
List the three types of acquired cataracts.
Induced/toxic
Secondary/metabolic
Trauma/radiation
List the three types of senile cataracts.
Posterior sub-capsular
Cortical
Nuclear
List three anterior cataractous artefacts.
Epicapsular stars
Persistent pupillary membrane
Lenticonus
Describe what lenticonus looks like.
Cone-like bulging of the lens cortex and thinning in the anterior, posterior, or both poles of the lens
With what two conditions is lenticonus associated with?
High myopia
Alports syndrome
Is it possible to have lenticonus concurrently with cataracts?
Yes
List two posterior cataractous artefacts.
Mittendorf dots
Nets/whorls (vitreous condensations)
What may sight debilitating congenital cataract be associated with?
Neural underdevelopment
Tropia