Gradual Loss of Vision Flashcards
Questions
Same as sudden
What are common causes of loss of vision gradual
Macular degeneration Diabetic retinopathy Hypertensive retinopathy Cataract Open angle galucoa Optic atrophy
What are less common causes
Coloboma
Retinal dystrophy
Drug induced
Retinitis pigments
What causes hypertensive retinopathy
Chronic hypertension
Malignant hypertension.
What does it lead too
Ischaemia
No risk of new vessel formation
What are 4 stages
1 = arteriolar narrow 2 = AV nipping 3 = cotton wool exudate + blot haemorrhage 4 = papilloedema
What is most common cause of blindness in 30-60
Diabetic retinopathy
How does DM lead to retinopathy
High BG causes endothelial dysfunction Increased vascular permeability - Exudates released - Blot haemorrhage Cotton wool spots due to ischaemia Micro-aneurysm of capillary Intra-retinal microvascular abnormality = dilated and torturous vessel Neovascularisation due to release of VEGF in response to ischaemia
What is mild non-proliferative
1+ microaneurysm
What is moderate
Microaneurysm Blot haemorrhage Hard exudate Cotton wool spot venous bleed IRMA less severe
What is severe
Blot haemorrhage
Aneurysm all 4 quadrant
Venous bleed 2+
IRMA 1+
What is proliferative
Retinal neovascularisation
What can it lead to
Vitreous haemorrhage + retinal detachment
What is maculopathy
Hard exudate causing changes to macula affecting visual acuity
When is it more common
Type II
How do you visualise changes
Fundoscopy
How do you Rx
DM Control
Regular screening
Lower BP
How do you treat proliferative
Laser photocoagulation
Anti-VEGF (Raibizumab)
What is most common cause of blindness worldwide
Macular degeneration
- Degeneration of photoreceptors in macula
What causes
Dry due to atrophy (Early age related)
Wet due to blood / fluid (Late age related)
What causes dry
Non-exudative
Alterations to retinal pigment epithelium
Atrophy of macula as photoreceptors die
Linked to oxidative stress / inflammation
What causes wet
Secondary to dry
Neovascularisation causes leakage of serous fluid into eye or bleeding
If bleed = catastrophic and leads to scarring
Often stimulated by VEGF
Cause scarring of macula = central visual loss
Sub-retinal haemorrhage
Can cause sensory detachment
What are symptoms
Progressive loss central vision Particular near objects Difficulty in dark adaption Photopsia - flashing Crooked or wavy appearance to straight lines
What may be present
Area of central field visual loss with normal surrounding Patient aware = +Ve scrotoma
What does distortion of vision / crooked lines suggest
Problem with macula
Known as metamorphosia
If patient complains of this = refer urgently
What is it till proven otherwise
Wet related macular degeneration
What are other causes
Macular hole if older
Myoptic degeneration / central serous retinopathy if younger
How does macular hole present
Central loss of vision
Distortion
What are RF for macular degeneration
Age
Smoking
CVS RF
FH - some form of genetics
What are ocular RF
Hypermetropia
Light iris
What is seen on slit lamp / fundoscopy
Drusen - yellow deposition in macula - 1st signs Can scar later Loss of retinal pigment epithelium Areas of hypo and hyperpigmentation
If wet what also may be seen
Red patches suggesting haemorrhage
What is 1st line investigation
Slit lamp
What other tests are used to confirm Dx
OCT = 1st line to Dx wet
- Also used to monitor
- Will see oedema separating but should reduce with Rx
Fluroscein angio used in wet to guide whether VEGF useful
- Sees if there is leaky vessels
How do you Rx dry type
Vitamins slow progression
Stop smoking
Control BP
How do you Rx wet
Anti-VEGF 4 weekly injection into vitreous chamber
Laser photocoagulation
Regular follow up with OCT and visual assessment
What does anti-VEGF do
Limits progression and staibilies loss
What are retinal dystrophies
Inherited disorders affecting photoreceptors
Causes loss of vision
How do you Dx
EOG
What is a coloboma
Hole in structure of the ey e
If in iris
Key shaped hole in pupil
Can’t control how much eye enters eye
If in retina
Strange white space where degeneration occured
Poor central vision
If in optic disc
Wont develop and will be blind
What is CHARGE
Coloboma Heart defect Atresia choanae Retarded growth Genital hypoplasia Ear abnormalities
What is the leading cause of curable blindness
Cataract
What are types of cataract
Immature
Mature
Secondary
What are immature cataracts
Fine in the day as pupil constricted so light doesn’t touch opaque lens
In dark pupil dilates and vision = hazy
What is mature
Hazy all the time
Need surgery
What is secondary
Due to nuclear sclerosis
Sutual and zonular common in childhood
What causes cataract
Normal part of ageing process
Lens gradually opacifies as avascular and can’t shed
Harder for light to reach retina
How does patient present
Reduced vision
Faded colour vision
Glare / halo
Loss of red reflex
What are RF
Age Smoking Alcohol DM Long term steroid Radiation Myotonic dystrophy Metabolic
What shows cataract
Slit lamp
What must be done prior to surgery
Ocular biometry
Opthamolscopy after pupil dilation shows normal funds and optic nerve
How do you treat non-surgical
Stronger glasses
Brighter lightening
What is surgery
Only effective Rx
Replace with artificial lens
What do you need post surgery
Steroid + Ax eye drop 4 weeks
Eyewear
Post op optician at 6 weeks
Stop smoking
if cataract present at birth
REFER urgent to exclude retinoblastoma + surgical correction
What are complication of surgery
Posterior capsule opacification / rupture Retinal detachment Endophthalmitis Wound leak Astigmastic may become noticeable after
What is retinitis pigmentosa
Inherited condition causing inflammation of retina and rod and cone cells
What does it cause
Tunnel vision
- Tends to affect predominantly rods which is more peripheral vision
- Cones preserved till late which is for central and colour
Night blindness = first sign
Can cause earlier cataract formation
How do you Dx
Fundoscopy
What are other causes of tunnel vision
Papilloedema Glaucoma Choroidretintiis Optic atrophy Hysteria
