Final Exam Part 3 Flashcards
Patients with photophobia
Media opascities, retinal dystrophies that affect cones (acromatopsia, C/R dystrophies, some patients with RP), Oculocutatneous albinism, congenital anterior segment disease (aniridia, peter’s anomaly) congenital glaucomas.
Strategies for photophobia
Tinted lenses, polarization, close fitting sunder, brim on hat, use of direct incandescent instead of fluorescent.
Tints that improve VA with cataracts
Yellow to amber that block short wavelengths. May just improve contrast. Does not help reading acuity or performance.
ARMD/DR and tins
Less evidence of improvement with tints. More likely to benefit if cataracts also present. Need to trial and prescribe based on symptoms.
Tints for RP, Chromatopsia, and cone/cone rod dystrophies
Dark amber to Red tints (2-6% transmission)
Albninism Tints
Light amber in room and dark amber in son. Photo chromatic tint with additional 50% amber tint.
Who does driveway work well for
Albinism.
Photosensitivity in RP
May be due to fact cones and rods both affected or that cones become more active once rods die.
Melanopsisn Retinal Ganglion Cells
Respond to light ind. of rod/cone to function on circadian rhythm. Respond to blue light. Slow onset but lasting response.
Noir Medical Technologies
Most comprehensive line of tints.
Cocoons
4 tints but low cost.
Contact Lens optoins
Improve optical correction in nystagmus.
Aniridia tx
opaque soft lenses to create pupil for cosmoses and light attenutation
Achromatopsia/Con dystrophies and cl
Red tint are helpful.
Strategies for Dealing with field loss
Optical (lenses/prisms) or compensatory training (orientation and mobility/ eye movement training for central field loss)
Field loss that can be helped with lenses/prism
General peripheral contraction with near normal VA (RP and late stage glaucoma) and hemianopsia.
Mini faction strategies
Use reverse telescopes. Equal to equivalent power in reverse).
Goal with magnification strategies
Want field of at least 20 degrees and Va no less than 20/100.
Why is bioptic a good option
Since person only needs to access minefield with orienting to a new area.
Why do patients need to adapt to reverse telescopes
Things appear further than they really are.
Ocutech
handheld and bioptic field expansion telescopes
Designs for vision
0.45x bioptics
Conforma
BITA reverse telescope
Cheap reverse telescope
door peep
Optical management of hemianopsia
Sector prisms.
Best hemianopsia candidates of sector prisms
Good central vision, no neglect, good mobility.
Sector prism basics
Need at least 20. Base direction toward field loss. Usually applied to eye with temporal field loss. Can do binocular sector prism if patient has difficult with diplopia. Allows patient to access peripheral field quicker.
Fitting Sector Prism
Begin with fresnel stick on or trial. Place prism edge 2 mm temporal to visual axis. Go on back side if using stick on.
Peli Lens
applied to superior and inferior field. Avoid diplopia and allows view of normal and expanded field. Apply the superior first.
Sector prism training in office
image shift training-have pt. touch images, decreased va (especially fresnel) wayne
sector prism training at home
constant wear, walk in familiar areas first, laser pointing while walking, video games.
Orientation and Mobility training
Help people with severe vision loss to determine where they are (orientation) and how to navigate (mobility). Provided in school up to 21. Provided by commission for the blind for legally blind adults.
When should O&M training occur?
Before the patient with progressive field loss (RP, progressive glaucoma) loses all their vision.
CVA or acquired field loss O&M
Important to put in rehabilitation. Rehab occupation al therapists are skilled in helping patient with acquired field loss lear to scan.
O&M basic instruction
Maximize all senses, self protection, sight guided techniques, cane or other technology, strategies to find direction, Navigate street crossings.
Central Field Loss Help
Patient with new scotooms are generally not aware of the position and size. Awareness of scotoma may aid in establishing a fixation strategy. Your near VF evaluation can be helpful in demonstrating scotomas to the patient.
Training for central field scotoms
Teach them to use PRL (typically inferior or superior to primary scotoma). Do fixations with awareness of stimuli in paracentral field. Saccades with localization (non-reading to reading), pursuit activities.
Services for birth to 18
special education services (21 if developmentally delayed)
Services for 18 and up
Commission for the blind. Other nonprofits.
Commission for the Blind criteria
Must have “legal blindness” criteria.
Birth to age 2 services
Early intervention
Age 3-21
Special education
Commission for the blind services
Independents living services including O & M. Vocational rehabilitation including training on adaptive software and other technology.
Why do early intervention
Allows to level the playing field for kids with VI.
Teachers of the Visually impaired
Training to assist in all aspects of education for children with visual impairment. Usually have 20-30 students and work with IEP. May have specific training for early intervention, Orientation and mobility, deaf blind, brail instruction.
Identification of children who need IEP in Oregon
Must be documented by ophthamoligst or optometrist. Acuity is 20/70 or less in better eye with correction, VF is restricted to 20 degrees in better eye, student has progressive visual condition to reduce either acuity or field to the above criteria. Student is unable to be tested but demonstrates inadequate visual function (use with very young children)
Optometrist’s role for qualifying Children
May not be able to get VA (have lots of tests), In borderline cases or when no VA measurements must see if VI is impacting development or education. Look at other visual dysfunctions like ocular motor control and adaptive skills
Are visual adaptations necessary for the child
Ultimately this is not our call. The special education team determine eligibility. Your information and opinion go into the decision.
How optometrists help education plan
Get them the best LV device, educate those making the decision. Make sure you educate and counsel.
What special ed folks need to know
acuity, which eye dominant, binocular field, is refractive correction helpful, ocular motor restrictions, nystagmus, color vision, contrast sensitivity. Recommendation for education materials, recommendations for LV technology or aids.
Restricted driving
20/50-20/70
Minimum binocular horizontal field
100-140 degrees.
Disability Evaluation
based on VA and field. Report.
Mandatory reporting
Some states have laws you must report someone driving with 20/70 or worse. Not required to inform patient.
Video Magnification systems: desktop units (standard CCTVs)
Provides adjustable magnification up to 50x (best device if acuity worse than 20/200). Comforatable working distance. Can adjust print and background contrast. Can perform other near tasks that require detail vision.
Portable desktops
Work well for students or people on the go (moderate vision impairment.
Disadvantages of CCTV
Expensive, not as portable, Magnification may be effective for patients with central scoots or limited central viewing area.
Portable video magnifers
Moderate magnification. Must consider patients fine motor control. Same contrast as CCTV.
Computer based accessiblity
patient with mild-moderate VI can use built in accessibility options on Windows or Mac OS.
Text to speech options
Almost all printed material is now available in digital formation and reliable software can convert text to speech.
Apple features
Screen magnifiers, text to speech, speakable commands.
IPAD and Iphone
Ultimate technology for mild to moderate impaired. Tactile interface. MAC accessibility plus APPS. Those with vision worse than 20/400 can’t really use.
Bookstore and Read2Go
Gives people with print disability free access to many books. Must verify liability by doctor.
Typoscope
Reading slit to isolate print, reduce reflective glare
Tactile aids
Press on dots. Raised keyboards.
Equivalent power of an focal telescope
zero
Magnification of focal telsecopes
on LIM helps.
Mts
Measured far VA/Demand at far or -fobj/feyepeice
Objective lens
Gathers light from some object. Always a positive lens.
Faster lens
An objective lens that is better at gathering light
Galilean max magnification
4x.
Keplerian max magnification
8x is practical but are available up to 12.
Eyepiece ocular lens
Positive in kleperian and negative in gallean.
Tube length
fobj+Feyepeince
Keplerian Erecting prism
Most have a roof-pecan prism. Made up of two unique prisms separated by air. Light will refract off the prism and some light is lost.
What will you see when viewing through objective lens of kleperian
A fain line bisecting the image. This is a reflection of the roof edge of the prism