Cataracts
Extra-Oscular Muscles
- Medial Rectus - Lateral Rectus - Superior Rectus - Inferior Rectus - Superior Oblique - Inferior Oblique
Mature Cataracts
All fibers of lens opacified Lens swells due to osmosis Can leak lens material, causing uveitis or glaucoma Not common Usually due to a secondary etiology
Subscapular
Anterior or posterior Posterior effects vision more due to relation to visual axis Opacity occurs a "smudge" on lens Opacity more central, so vision worse during day Can occur at a younger age (45-60) than commonly found with other types
Evaluation Cataracts
Best detection with slit lamp and dilation Can be viewed as a diminished red reflex with ophthalmoscope If you have a poor view in the eye, the patient has a poor view out
Cortical Cataracts
Cause of light scatter creating glare Very little effect on vision White opacities, appear as spokes of a wheel, or piece of pie Tend to occur more peripheral than central Worse at night due to pupil dilation Night driving very difficult
Cataract Treatment
Current technique is extracapsular extraction with phacoemulsification Outpatient procedure Local anesthetic with mild sedative Patient will take eye drops 2-4 weeks afterward (antibiotic, anti-inflammatory)
Signs and Symptoms of Cataracts
Decreased acuity Gradual, not sudden decrease of vision Increased glare, which can be disabling - Most bothersome during night driving Monocular diplopia Change in color perception No pain No redness
Anterior Segment con't
Iris and Pupil - Dilator and Sphincter Muscle Lens - Capsule - Epithelium - Cortex - Nucleus - Zonules Ciliary Body
Adnexa
Lids and Lashes Nasal Lacrimal System - Lacrimal Gland - Puncta - Canaliculus - Lacrimal Sac - Nasal Lacrimal Duct
Nuclear Cataracts
Most common Appear yellow or brown Distorts colors Can create shift in myopia (nearsightedness) Can be very slow to progress
Types of Cataracts
Nuclear Cortical Subcapsular Mature cataract
Aphakia
Once cataract is removed the eye is aphakic Aphakia is corrected with: lens implant (pseudophakia), most common today - Posterior chamber (mostcommon) - Anteriorchamber contact lens glasses
When to refer?
Once decreased acuity affects daily activities (usually worse than 20/40) Increased glare is disabling Inhibits viewing of other ocular disease (Diabetic Ret.) Cataract causes other eye diseases (uveitis or glaucoma) Rule out change in refractive error Prompt referral in an infant, can lead to amblyopia
Cataracts Etiology
Opacity of lens leading to a generalized decrease in vision Most common cause of decreased vision in adults not correctable by glasses 90% over 65 have some degree of cataracts Despite usually occurring later in life, can develop at any age
Who to refer to
Optician- work with materials Optometrist- eye exam, prescribe glasses, monitor for eye disease, treat with drops Ophthalmologist - surgeon
Complications of Cataracts
Retinal detachment Macular edema Chronic uveitis Endophthalmitis Malposition of IOL
Posterior Segment
Sclera Choroid Retina - Retinal Pigmented Epithelium - Rods and Cones - Macula Vitreous Optic Nerve
Anterior Segment
Tear Film - Mucus - Aqueous - Oil Cornea - Epithelium - Stroma - Endothelium Anterior Chamber - Aqueousfluid - Trabecular Meshwork
Results of Cataract Surgery
Visual acuity restored to pre-cataract level in 95% of uncomplicated cases Visual prognosis is good
Causes of Cataracts
aging - most common, - usually develop in the 65-80 age range trauma - Blunt trauma - Radiation - UV - electrocution medications - steroids metabolic - Eczema endocrine - Diabetes - Parathyroidism Congenital abnormalities
Laser Cataract Surgery
laser assisted surgery still need incision some incisions made by laser, some made by hand
opacification of posterior capsule
very common occurs in over 50% within months to years treatment is a YAG capsulotomy