CATARACT Flashcards
Cataract
Loss of lens transparency due to opacification of the lens
Types of cataracts
Age-related cataracts
Paediatric cataracts
Cataracts due to other causes
Most prevalent type of cataract in adults
Age-related cataracts
Most prevalent cataracts in children
Hereditary
Metabolic
Onset of cataracts in adults
40 to 50 years
Which cells does the lens develop from
Surface ectoderm
Shape of the lens
Biconvex
Site of the lens
Patellar fossa
Functions of the lens
Causes refraction and focuses light onto the retina
Parts of the lens
Lens capsule
Lens epithelium
Lens fibres
Lens zonules
Two main parts of the lens
Nucleus (older fibers)
Cortex (younger fibers)
Leading cause of blindness in Ghana and
Cataract
Leading cause of reversible blindness in the world
Cataract
Causes or aetiology of cataract
Age
Endocrine diseases
Systemic diseases
Ocular diseases
Exposure to ionizing radiation
Genetic
Drugs
Endocrine diseases that cause cataracts
Diabetes
Galactosemia
Homocystinuria
Hydpoparathyroidism
Hypocalcemia
Wilson’s disease
Malnutrition
Systemic diseases that cause cataract
Atopic dermatitis
Myotonic dystrophy
Neurofibromatosis type 2
HIV/AIDS
Ocular diseases that cause cataract
Retinitis pigmentosa
Chronic anterioir uveitis
Stickler syndrome
High myopia
most common cause of cataracts
Age
Medications that cause cataracts
Acetylcholinesterase inhibitors
Corticosteroids
Mechanisms of age related cataracts
Congenital cataract
Subcapsular cataract
Cortical cataract
Nuclear cataract
Congenital cataract
Disturbances occurring at any level of lens growth
Subcapsular cataract
Fibrous metaplasia of lens epithelium
Cortical catarct
Cortical hydration between lens fibres
Nuclear cataract
Deposition of certain pigments i.E. Urochrome
Pathophysiology of cataract
Denaturation and coagulatation of lens proteins present in the lens fibres which results in loss of transparency and ultimately cataract formation.
Causes of non-age related cataracts
Photo-oxidation
Trauma
Chemical insults
Risk factors for cataracts
Age
Socioeconomic status
Race
Genetic factors
Cigarette smokin
Alcohol
Hypertension
Hypocalcemia
Diet
UV-B exposure
Type 2 DM
Renal impairment
Which race has the highest prevalence of cataracts
Caucasians
Types of cataracts based on location
Nuclear cataracts
Cortical cataract
Posterior subcapsular cataracts
Congenital cataracts
Classification of cataracts based on maturity
Mature
Immature
Hypermature
Mature cataract
Lens is completely opaque
Immature cataract
Lens is partially opaque
Hypermature (Morganian) cataract
Cataract is shrunken and wrinkled anterior capsule due to leakage of water out of the lens
Type of cataract associated with myopia
Nuclear cataract
This type of cataract causes difficulty distinguishing between shades of color and clouds your vision.
Nuclear cataract
Cataract caused by central opacity in the lens
Nuclear cataract
Cataract that occurs in the equator or periphery of the cortex
Cortical cataract
This type of cataract has little effect on vision
Cortical cataract
In cortical cataracts vision is worse in…….
Very bright light
People with high levels of sunlight exposure have twice the risk of developing…….. cataracts
Cortical
This type of cataract starts as a small opaque area usually near the back of the lens, right in the path of light
Posterior subcapsular cataract
Effects of posterior subcapsular cataract
Interferes with reading vision
Reduces your vision in bright light
Causes glare or halos around lights at night.
Role of B-Scan in cataract investigations
to see retinal detachment or any vitreous pathology
Role of biometry in cataract investigatiosn
for intraocular lens placement during surgery
Tonometry
To rule out glaucoma
Fundoscopy
to rule out any vitreous or retinal pathology
Investigations in cataract
Visual acuity tests
Slit-lamp examinations
Ophthalmoscopy
Peripheral retinal assessment
B-Scan
Biometry
Fundoscopy
Tonometry
Signs and symptoms of cataract
Blurred or hazy vision
Increases sensitivity to glare
Reduced color perception
Double vision in one eye
Need for brighter light
Increased frequency to change refractive glasses
Lifestyle modifications
Quitting smoking
Wearing sunglasses with UV protection
Healthy diet
Surgical techniques for cataracts
Extracapsular cataract extraction
Intracapsular cataract extraction
Phacoemulsification
Intracapsular cataract extraction
opacified lens and capsule are removed in one piece
Extracapsular cataract extraction
Hard central nucleus is removed in one piece and then the soft cortex is removed in multiple small pieces
Phacoemulsification
The hard central nucleus is dissolved by ultrasound and then the soft cortex is removed in multiple small pieces
Drugs use pre-operatively in cataract surgery
Povidone-Iodine
Cefuroxime
Tropicamide with Phenyephrine and Lidocaine
Povidone-Iodine
Cutaneous peri-ocular and conjunctival antisepsis before ocular surgery
Cefuroxim
Prophylaxis of endophthalmitis after catarct surgery
APROKAM
Cefuroxime
Tropicamide with Phenylephrine and Lidocaine
Mydriasis and intraocular anaesthesia during cataract surgery by intracameral injection
Complications of cataract surgery
Choroidal hemorrhage
Endophthalmitis
Cystoid macular oedema
Retinal detachment
Nepafenac
Prophylaxis and treatment of postoperative pain and inflammation associated with cataract surgery
NSAIDS used in cataracts
Nepafenac
Dicofenac
Bromfenac
Diclofenac sodium
Inhibition of intra-operative miosis during cataract surgery Postoperative inflammation in cataract surgery.
NEVANAC
Nepafenac
Bromfenac
Postoperative inflammation following cataract surgery
VOLTAROL
Diclofenac sodium
YELLOX
Bromfenac
Antibiotics used for cataracts
Fluoroquinolones
Gatifloxacin
Moxifloxacin
Ciprofloxacin
Ofloxacin
ZYMAXID
Gatifloxacin
MOXIVIG
Moxifloxacin
EXOCIN
Ofloxacin
ZYMAR
Gatifloxacin
BETNESOL
Betamethasone
MAXIDEX
Dexamethasone
Steroids used in cataracts
Betamethasone
Dexamethasone
Prednisolone
Fluorometholone
PRED FORTE
Prednislone 1%
Nutrients which prevent against development of cataracts
Vitamin A
Carotenoids
Vitamin C
