low vision evaluation and intervention

low vision evals are administered in

a well-lit clinic or home environment with no glare on the test material

clients self report and goals

OT should collab with the person to establish goals focused on improving functional use of remaining visual abilities and learning compensatory strategies

low vision assessment components

• eye dominance

• visual acuity (near and intermediate)

• visual fields (central and peripheral)

• contrast sensitivity

flower card design

used to determine person’s dominant eye

low vision LEA numbers chart with notations at 1 meter

• determines intermediate visual acuity

• assesses acuity in the dominant eye, non-dominant eye, then both

• head tilting is allowed

  • cannot move head closer to target tho

warren text card

• suggests level of magnification person will need

• both eyes tested together

american academy for ophthalmology red dot confrontation test

• tests central visual field

• glasses should not be worn

• 4 testing positions to assess superior and inferior visual fields

two-person kinetic confrontation test

• used to assess peripheral visual field

• 2 examiners needed

• examined in a dimly lit room so person can see when penlight goes into visual field

low contrast flip chart: 10M optotypes

• used to assess contrast sensitivity function

• administered at 3 different distances

• contrast sensitivity tends to be affected first before changes in visual acuity are apparent

clock assessment of sentence assessment (non standardized)

• assess the presence and/or location of a scotoma (macular degeneration)

• missing numbers on the clock (when looking at center) or part of the sentence that are missing are where scotomas are located

revised self report assessment of functional visual performance profile (R-SRAFVP)

• clients rate their ability to perform 33 vision dependent basic ADL and IADL tasks

brain injury visual assessment battery for adults (biVABA)

• evaluate clients with both brain injury and low vision

• standardized assessments for

  • visual acuity, contrast sensitivity, visual field, pupil response, binocular eye movements, diplopia testing, near space search strategies, extra personal search strategies, visual attention, eye dominance

• help practitioner plan intervention by including treatment recommendations on test performance in the evaluation manual

client centered low vision interventions

• training and compensatory techniques

• training in care and use of adaptive devices

• training in effective use of visual skills

• education

environment centered low vision interventions

• educate in home modifications

• educate in effective use of lighting

  • standard lamps should have adjustable necks/hoods

  • standing lamps should be placed over shoulder of dominant eye

preferred retinal locus (PRL) training

• important aspect of low vision rehab for clients with scotomas

• teaches clients how to effectively use intact vision by looking around the scotoma

magnification

• indicated for many clients with low vision

• OTs can provide training but cannot prescribe magnification

convex vs concave lenses

• convex make objects appear larger

• concave makes objects appear smaller

prisms

• often mounted to eyeglasses

• shift images by moving the non viewing area into viewing area

  • ex) person can read book laying down

adaptive equipment focused on compensating with tactile senses

• check writing guides (tyroscopes)

• bump dots as positional markers

• folding different monetary denominations in different ways for organization

adaptive equipment focused on auditory senses

• talking phones

• talking alarm and medication clocks

• liquid level indicators

• audio books

• CCTVs with audio features

trailing

using tactile sense

squaring off

counting steps, turning 90 degrees around corners