Lecture 9: Cataract management Flashcards
What are the types of age-related cataract?
*NS: yellowing of lens, centre
*Cortical: spokes start in periphery and gradually approach centre of lens
*Posterior subcapsular: posterior part of lens
*Can get a mixture of these. Not always distinct.
How can yuo detect cataract using a slit lamp?
Slit lamp
*Narrow beam with very bright beam
*Reduce heigh of beam to fill pupil
*Narrow angle (pupil not as wide)
*Very high mag
*Dilation if you can’t view the fundus
Retro-illumination
*Retinoscopy
*Direct Ophthalmoscope
What are the visial symptoms of nuclear sclerosis?
-general reduction in vision
-coluor changes (whites look cremaier due to yellowing)- coluors not as bright
-glare
What are the visual symptoms of cortical cataract?
glare in low lgiht
opacities encorach on centre at a latter stage so VA reduction later on
What are the visual symptoms of posteriro subcapsular cataract?
VA effected more in earlier stages
glare with small opacities
What types of glare can you get?
Discomfort Glare
*High brightness within the field of view which does not impair vision e.g., lights on the ceiling
Disability Glare
*Brightness in the field of view that causes an impairment of vision e.g., sun when driving
Light Scatter
*Clinical measurement involves recording the VA or CS
*Under normal conditions and when hindered by a nearby bright light source
What signs of cataract can yuo see on retinoscopy?
How can yuo change your method to get better results?
*Duller and slow reflex
*Change WD (get closer, may get brighter reflex)
*Off axis (can give you a cyl that isn’t there)
What are the signs of cataract during your subjective routine?
*Yellowing of lens will effect duochrome result (less reliable)
*Pinhole (if VA improves, prescription problem). Location of cataract affects this, may not give accepted result if they have posterior subcapsular cataract.
*Pinhole can get better if you have NS (stops peripheral scatter)
*NEAR ADD: cataract causes reduction in contrast, px might accept more plus.
What visual field results can you expect in someone with cataract?
- General reduction in sensitivity
- High MD
- Low PSD
- Large number of significant points on total deviation map (below age related normal values). Diffuse loss across whole visual field, especially NS cats.
What are the guidelines for cataract referral?
*Cataract surgery SHOULD NOT be restricted based on visual acuity.
*cataract starts to have an impact, the decision to refer a patient for surgery or not, should be based on a discussion with them.
*Balance between clinical measures (VA, indicators of visual function, fundus view) and patient’s personal circumstances (e.g., driving)
*Majority of patients with symptomatic cataract would benefit from surgery
*Not cost effective to delay until a VA threshold is met
What are the considerations for cataract referral?
*How the cataract affects the person’s vision and quality of life?
*Whether one or both eyes are affected?
*What cataract surgery involves, including possible risks and benefits
*How the person’s quality of life may be affected if they choose not to have cataract surgery
*And whether the person wants to have cataract surgery
What are good questions to ask to asses how much cataracts is effecting the px QoL?
Do you have any problems with glare or in bright sunlight ?
Do you have any problems drivnig at night or on sunny days?
What is the effect of vision on your job, interests or hobbies?
What should yuo suggest if px doesnt want to be referred?
*Address glare: AR coat, sunglasses (polarised), hat, increase lighting at home
*Progression: UV block, smoking
