Ophthalmology - Orthoptics, optometry, other Flashcards
(25 cards)
presentation
3rd nerve palsy
- eye depressed and abducted (down and out)
- ptosis
- pupil dilated and unreactive - if compression
- diplopia -> diagonal
causes
3rd nerve palsy
- microvascular - diabetes, hypertension
- PCA aneurism
- space occupying lesion
- trauma
- demyelinating disease (MS)
- infection
- GCA
- congenital
presentation
4th nerve palsy
- hypertropia, slight esodeviation (eye up and in)
- CHP head tilt to unaffected side, chin depression
- vertical diplopia
causes
4th nerve palsy
- trauma: back of head (e.g. RTC, horse riding, fall from height
- congenital
- microvascular
- demyelinating disease (MS)
- tumour
- aneurysm
features
6th nerve palsy
- esodeviation (eye points in)
- CHP - face turn towards affected side
- horizontal diplopia
- limited abduction
causes
6th nerve palsy
- microvascular
- raised ICP -> BILATERAL
- space occupying lesions
- trauma
- demyelinating disease
- infection
features
thyroid eye disease
- exopthalmos
- conjunctival oedema
- optic disc swelling
- ophthalmoplegia -> diplopia
- lid lag
- lid retraction
- inability to close the eyelids may lead to sore, dry eyes
Mx
thyroid eye disease
- avoid smoking
- topical lubricants
- steroids
- radiotherapy
- surgery
cause
thyroid eye disease
- autoimmune response against TSH receptor autoantibodies
- causes retro-orbital inflammation
complication
thyroid eye disease
- exposure keratopathy
- optic neuritis
- strabismus and diplopia
definition, 2 types
strabismus
Squint (strabismus) is characterised by misalignment of the visual axes
- Concomitant - Due to imbalance in extraocular muscles - common
- Paralytic - Due to paralysis of extraocular muscles
causes
concomitant strabismus
- refractive error
- family history
- prematurity
- developmental delay
- idiopathic
Ix
strabismus
- orthoptic assessment
- VA, CT, OM, classification of squint if possible
- cycloplegic refraction
- drugs used to induce relaxation of the accommodation system and pupil dilation to allow objective measurement of refractive errors
- fundus and media examination
- ensure no cataract or retinal tumour (secondary strabismus)
Mx
strabismus
- referral to secondary care
- start treatment before age 8 - visual fields still developing
- eye patches
- correct refractive errors
definition
ambylopia
“lazy eye,” is a neurodevelopment disorder characterised by reduced vision in one eye due to abnormal visual development.
causes
Amblyopia
- strabismus
- anisometropia - interocular difference in refractive error
- high bilateral refractive error - ammetropia
- stimulus deprivation e.g. ptosis, congenital cataract
- high astigmatisim
Mx
Amblyopia
- correct amblyogenic factor e.g. glasses, remove cataract
- force brain to use weaker eye:
- patching
- atropine
- dichoptic stimulation
UK visual limits for driving
Car:
- VA: 6/12 in one or both eyes
- VF: 120 degrees horizontal vision
Lorry:
- 6/7.5 in bettee eye and 6/60 in bad eye
- VF: 160 degrees horizontal vision
causes of low vision
- UK
- globally
UK:
- ARMD
- glaucoma
- diabetic retinopathy
globally:
- uncorrected refractive errors
- cataracts
- glaucoma
visual impairment register
individuals with sight loss can be certified and then registered as:
- Severely sight impaired (blind)
- Sight impaired (partially sighted)
ophthalmologist completes a Certificate of Vision Impairment (CVI).
- sent to the local authority, which contacts the person to offer registration and support services.
Role of Eye Clinic Liaison Officers
- Providing emotional support and practical advice at the time of diagnosis.
- Helping with the visual impairment registration process.
- Guiding patients to low vision services, social support, and charities.
- Assisting with benefit applications and adaptive aids.
definition
myopia
- refractive error where distant objects appear blurry
- eye is too long or cornea too curved, causing light to focus in front of the retina
Mx and risks
myopia
- corrective lenses, refractive surgery
risk of:
- retinal detachment
- glaucoma
- myopic macuolpathy
- cataracts
definition
Hypermetropia
- a refractive error where near objects appear blurry
- It occurs when the eye is too short or the cornea is too flat, causing light to focus behind the retina.
