topic 1: cataract Flashcards
what are 7 factors that cause earlier onset of cataract?
- Congenital
- Aging>senile
- Inflammation, high myopia, RP, etc>complicated
- Diabetes
- Drugs (steroid)
- Trauma
- Heat / Irradiation>exfoliation
what are some signs and symptoms of cataract?
signs:
Loss of transparency / opacity /cloudy
symptoms: Myopic/hyperopic shift Reduced vision (distance/near) Glare Desaturation of colours
what is congenital cataract? what are some causes?
PX is born with cataract, non-progressive and often does not affect vision
causes: Maternal infection Metabolic Chromosomal Hereditary Birth trauma
what should you do if young px has cataract?
Refer to ophthalmologist for early surgery (6 wks old) to prevent risk of stimulus deprivation amblyopia and nystagmus
Accurate refractive correction pre- and post- surgery (if applicable)
Patient reassurance:
little impact on vision
most cases not dense and rarely progressive
Patient education:
to monitor opacity and visual function
for dense cases, risk of amblyopia/nystagmus
what are the 3 main types of acquired cataract?
- senile
- complicated
- irradation (true exfoliation)
what are the 3 sub types of senile cataract?
Nuclear sclerosis (NS) Cortical (CC) Posterior subcapsular (PSCC)
what are the 4 sub types of complicated cataract?
Systemic disease
Congenital anomalies
Drugs related
Trauma
what are the 7 risk factors of acquired cataract?
- Age-related
- Primary ocular diseases (eg. chronic uveitis)
- Systemic diseases (eg. diabetes mellitus)
- Congenital anomalies (eg. Marfan syndrome)
- Drugs (eg. Corticosteroids)
- Trauma (eg. blunt trauma)
- Others (eg. UV exposure, high myopia)
what are 4 ocular conditions that may cause earlier onset of complicated cataract?
1.high myopia
2. chronic anterior uveitis
3. retinitis pigmentosa (genetic condition
)
4. retinal detachment
what are the pathogenesis, signs, symptoms and VA of nuclear sclerosis?
pathogenesis:
Photo-oxidation of lens protein
signs:
Yellowing of lens nucleus or “lemon drop” appearance
Myopic shift
symptoms:
Reduced distance vision
Glare during bright light
Desaturation of colours
VA:
Affected/reduced
what are the pathogenesis, signs, symptoms and VA of cortical cataract?
pathogenesis:
Imbalance of electrolytes causing over hydration of cortex
signs:
Water vacuoles, clefts, spokes and wedges appearance in lens cortex
Hyperopic shift
symptom:
Reduced near vision
Glare during night time
Affects central vision in later stage
VA:
Normally not affected except in late stage
what are the pathogenesis, signs, symptoms and VA of posterior subcapsular cataract?
pathogenesis:
Due to migration of epithelial cells toward the posterior pole to replace lens fibre nuclei loss
signs:
Granular opacity just in front of posterior lens capsule
no shift
symptoms:
VA drastically affected for both distance and near
glare in bright light
VA:
Severely impairs central vision, especially in bright light.
how does cataract occur in diabetes?
High level of glucose in aqueous humour Sorbitol buildup Osmotic pressure change causing over hydration of lens substance Onset in teens Predispose to senile cataract earlier. PSCC is common
what kind of cataract is seen in diabetes>
snowflake cataract
just behind anterior capsule or in front of posterior capsule
what are the 2 drugs that could cause cataracts? what kind of cataract do they result in?
- corticosteroids
- miotics
Usually bilateral PSCC
what cataract is commonly seen in traumatic cataract?
rosette cataract (secondary to blunt trauma)
what are 2 kinds of cataract commonly seen in irradiation exposure cataract?
1.True exfoliation
Caused by long-term heat exposure (glassblower, welder)
Separation and curling up of anterior lamellae of the capsule
- Pseudoexfoliation (DDx)
Senile lenticular abnormality
White granular material on anterior pole, AC angle, pupil border, iris, ciliary body
Risk of glaucoma
What are the management options for cataract?
- UV protection to reduce rate of progression by sunglasses, visors, wide brimmed hat or umbrella, particularly when driving and outdoors.
- Patient education on progressive normal aging change.
- Avoid driving at night or in dim illumination due to possible glare.
- Self-monitoring of vision / regular eye check.
- Eating foods with Antioxidant
- Referral and surgery to remove cataract if severe
when should we refer px for cataract surgery?
- When corrected VA dropped below 6/12
- when blurring of vision is affecting patient’s daily activities
- Both the above
- f there is a narrow anterior angle and increased risk of angle closure glaucoma.
what does immediate, urgent, early and non urgent referral mean? (in terms of time stamp)
immediate: attend A&E or eye clinic immediately
urgent: same day
early: within 2 weeks
non urgent: > 2 weeks but preferrably within 1 month
what kind of referral if Best corrected VA worse than 6/12 ?
Non urgent referral if patient is keen for surgery
what kind of referral for PSCC? (patient is symptomatic eg poor reading, glare and photophobia even if distant VA is 6/12 or better)
Non urgent referral if patient is keen for surgery
what kind of referral if brunescent cataract?
Non urgent referral
what kind of referral if white cataract in adult?
Early referral if cornea is clear, urgent referral if cornea is hazy
what kind of referral if subluxated cataract?
Early referral
what kind of referral if lens induced glaucoma
Urgent referral
Advice Sheet for all types of cataract
