uwu Flashcards
Stable Myopia management options:
Glasses
Soft CLs > daily/fortnightly, monthly
RGPs
OrthoK
Laser refective correction > LASIK, LASEK, PRK, SMILE
Clear lens extraction
Risk factors for myopia:
Genetic evidence from families show 7/20/40% risk (MYOP1 gene for axial length)
Environmental:
Lack of outdoor activity > poor luminance and increased near work
Evidence shows 30minutes of 1200Lux luminance reduces development, outdoor work 2h/d is reccomended
Detail effect on vision of cataracts:
Nuclear:
brunescence > contrast loss and desaturation of short wavelengths (tritan defect)
Reduced contrast from scattered light > glare in light conditions and blur in dim conditions
Myopic shift from RI increase
Cortical:
Peripheral opacities > veiling glare at night (dilated pupils)
Astigmatic shift from localised RI change
PSC:
Significant VA loss due to postior nodal point opacity
Worse in day with small pupils and near work with rapid/irregular progression
Atropine studies on myopia progression:
Exact mechanism unknown
ATOM1 shows efficacy
ATOM2 shows decreased % needed
LAMP shows 0.05% effective to avoid photophobia, blur, rebound chance
Complications of cataract Sx:
Posterior capsule opacity (50% by 3y) > YAG removal
Usually have mild uveitis (forign material)
1/200 may note loss of VA
Endopthalmitis
Macula oedems from IOP variation > usually resolves
Risk increases with DM
Risk of lens dislocation/rupture increases with Marfans syndrome/high myopia
6 factors for DED:
Contact lenses
Loss of lacrimal production (sjrogrens)
Loss of meibum secretion (MGD)
Poor lid closure / ocular surface exposure (TED)
Loss of lacrimal reflex stimulation (CLs)
Ocular surface infection (blepharitis)
Medication (contraceptives)
Step 1-3 management of DED:
1:
Education > screen use
Environment change > AC/Dust
Medication change > Caffiene/smoking
Lubricants without preservatives
2:
Viscous lubricant/overnight ointment (Lacrilube)
Short term cortico. FML0.1% QID 7d
Punctal occlusion/moisture chamber
3:
Therapeutic CLs (bandage)
Collagen punctal plug
Autologous serum drops
Differentiate SCC from BCC:
BCC:
Reddish, central ulceration, rolled edge
Pearly w/feeder vessel
Waxy, slow growing
SCC:
Keratin horn / scaly
Recurrent ulceration / bleeding
Signs of choroidal naevus becoming a melanoma:
> 5mm diameter, >1mm deep
Lipofuscin deposits
SRD
Symptoms > flash/float
Causes of ptosis:
Aponeurotic ptosis: age/trauma>degeneration>LPS dishisence from tarsal plate
Floppy lid syndrome: elastic lids
Loss of sympathetic innervation: Horners > Mullers loss > partial ptosis
CN3 palsy: DM/lesion > LPS loss > full ptosis
MG: autoantibodies against ACHr > muscle weakness > variable ptosis
Ocular findings with autoimmune diseases:
AAD from loss of self tolerance > B-cell production of autoantibodies or T-cell targeting self antigens
Usually from genetic predisposition, stress, UV, viral infection
Any autoimmune condition is associated with uveitis (50% uveitis from AAD)
TED: autoantibodies against TSHr expressed on orbital fibroblasts > adipogenesis / hyaluronic acid(GAG) synthesis > proptosis/EOM loss/compressive ON/SLK
Sjrogrens: T-cell destruction of mucosal membranes > DED
MS: macrophage against myelin of CNS > internuclear ophthalmoplegia > medial longitudinal fasciculus loss > dissociation between vergence and adductions. Optic neuritis
MG: autoantibodies against ACHr of striated muscle > variable ptosis/loss of EOMs
SL erythematosus: CWS
Patho of CL overwear:
CLs reduce O2 perfusion to cornea > hypoxia > ^anaerobic respiration > ^LA/ROS/cellular stress > osmotic influx > cell swelling > TJ dysfunction > loss of cell adhesion / apoptosis > loss of tear adhesion (glycolax loss) > DED
^water influx > endo. Pump stress / stroma hydration > endo. Blebs / corneal haze
Loss of epith. Barrier protection > infection susceptibility > MK
CLARE/CNPU/Tight lens/GPC/Dot tox/3’9’ stain
DDX bacterial and adenoviral conjuntivitis:
BC:
Rapid onset, crusting/sticking of lids, mucopurulent discharge, fornix hyperemia
AC:
Slow onset, watery discharge, limbal flush, corneal staining if kerato-conjuntivitis, follicles, preauricular adenopathy, upper respiratory infection
