2 - Causes And Consequences Flashcards
Cloudy media
-problems (4)
General blur
Glare
Contrast
Severe K problems = diplopia (e.g. keratoconus)
Cloudy media
-causes
—corneal (3)
Dry eye
Keratoconus
Scarring
Cloudy media
-causes
—cataracts (3)
Nuclear - generally just need magnification
Cortical - glare control
PSC - glare control, difficult to provide magnification
Cloudy media
-causes
—vitreous (3)
Hemorrhages and inflammation - depends on severity, can completely block light
Floaters
Cloudy media
-management (4)
Best refraction
Filters - glare, contrast
Good lighting
Magnification
Cloudy media
-management
—filters and uses (2)
Yellow/orange = contrast when reading
Brown/gray = reduce glare
Central VF defect
- what they have
- if one eye is unaffected
- often have
Relative/absolute scotoma in/near central vision
Reduced depth perception
Reduced contrast sensitivity
Central VF defect
-causes
—most common
AMD
Central VF defect -causes: dry AMD —onset —early —may develop —GA
Slow, progressive
Begin as relative scotoma
Ring scotoma - fovea is temporarily preserved while surrounding areas develop atrophy
-typically do well with acuity charts, struggle with reading quickly
GA - almost always absolute scotoma
Central VF defect
-causes: wet AMD
—onset
—issues
Sudden, severe
More difficulty reading than expected from their VA
Central VF defect
-cauesses: AMD
—treatment/intervention for both types (3 things)
Illuminated magnifiers and improving contrast are important
Begin ASAP
May develop eccentric viewing
Central VF defect
-causes
—toxoplasmosis
—myopic degeneration
Both: similar field deficits to mac degen
T: healthy tissue surrounding scars, may have acuities up to 20/20
M: may be able to take off their glasses instead of use magnifiers, be careful to not overminus
Central VF defect
-causes
—optic nerve disorders
Central or cecocentral defects
Perform baseline VF
Central VF defect
-causes: diabetic ret
—complications causing loss (3)
Vitreous hem
Mac edema
PRP
Central VF defect
-management (4)
Careful refraction
Perimetry/Amsler
Filters - esp yellow for reading contrast
Magnification - D and N
Peripheral VF defect -causes: retinitis pigmentosa —onset —first complaint, second —helpful for spot reading —helpful to reduce glare —recommend (2)
Gradual, eventually total blindness
Night blindness -> bumping into things
Mini flashlight
Filters - red
Reading assessment, O and M
Peripheral VF defect
-causes: glaucoma
—onset
—often have __, management (2 each)
Gradual, eventually total blindness
Poor contrast - filters
Field loss - O and M
Peripheral VF defect -causes: neurologic disorders —R vs L hemianopia —aid to maintain same line when reading —other training (2)
R - usually good VA, but trouble reading
L - trouble finding next line
Typoscope
O and M, scanning training
Peripheral VF defect
-management (5)
Refract Glare control Least magnification (maintain FOV) Field expansion - only with good VAs, generally use scanning techniques as first option, prisms/etc. next O and M (orientation and mobility)
