bioptics the south african way

BIOPTICSTHE SOUTH AFRICAN WAY

ALLAN KAYE

RODNEY STEDALL

Assisted by Hazel Sacher

SOUTH AFRICA2010

PROBLEMS PRESCRIBINGBIOPTICS Driving decisions are based on vision Standard tests in current use are unreliable in

predicting unsafe driving A driving license is a privilege and not a right A heavy onus is placed on the optometrist to

make a decision on whether the client will be a safe driver

Paucity of training facilities Cost / medical aid

THE BIOPTIC STUDY

ABK RS BHTotal prescribed 30 30 21Age range 12 - 71 17 – 75 14 - 74Mean age 41.5 46 44Sex Males 19 22 14 Females 11 8 7Total number of people in the study 81Published data indicates a higher crash rate in the under 18 and over

75Legal age to obtain a driving license in SA is 18

RANGE OF REFRACTIVE ERROR

ABK RS BH

Range -0.50 - 23.00 -0.25 - 14.75 0 – 19.00

0.50 to 8.00 0.25 to 8.50 0.75 to 3.00 > Cyl -6.00x88 -7.00x60 -4.25X9

VISUAL ACUITY WITH BEST SPECTACLE CORRECTION

Best Eye 20/40 - 20/50

Weaker Eye 20/200 - NLP

Pathology of clients

TOTAL

ALBINISM 15 STARGARDTS 14 MACULAR 13 CONG CATARACTS 3 DIABETES 3 NYSTAGMUS 9 OPTIC ATROPHY 10 OTHER 13 Total 81

TOTAL

pathology

pathology of patients

02468

10121416

albini

sm

starga

rdts

macula

r

cong

cats

diabe

tes

nysta

gmus

optic

atro

phy

other

pathology

num

ber

Series1

Primary uses of Bioptic

ABK RS BH DRIVING 26 28 18 OTHER 4 2 3

WHY THE NEED FOR BIOPTICS The ability to drive contributes strongly to

one’s quality of life To meet the criteria of legally obtaining a

driving license

Technical details of Bioptics prescribed Magnification ABK RS BH

2.2 x - 2 2

3.00 x 8 14 2 4.00 x 22 14 17 Monocular 5 27 20

Binocular 25 3 1 Type of Bioptic Designs for Vision 27 30 21 Occutech 3 - -

VISUAL ACUITY WITH BIOPTIC

V A with Bioptic SA 20/15 - 20/50 V A with Bioptic USA 20/40 - 20/50

Bioptic population USA 20/50 – 20/200 Bioptic population SA 20/15 - 20/400 What is important is that quantitative measures

should give way to qualitative measures

DRIVING STANDARDS SA USA Visual acuity 20/40 20/40 Visual field 140 total 140 total Visual acuity if 20/30 one eye blind Field with one 115 total eye blind Facts from the USA re driving with a Bioptic Unrestricted license ---- 20/30 - 20/70 With road evaluation ---- 20/100 - 20/200 Restricted license ----- 20/100 e.g. time of day; area

Documentation required by authorities in granting a licence to Bioptic clients

SA USA Uncorrected VA Y Y Corrected VA Y Y Peripheral fields Y Y Stability of pathology N Y Depth Perception N Y Color Vision N Y Ability to co-ordinate head N Y neck and eye movement Contrast sensitivity glare - N Y recovery luminance

THE BASIC GUIDELINES ADOPTED IN PRESCRIBING BIOPTICS

A driving licence is a privelege and not an automatic right Visual acuity and Visual fields The will to drive Age; Health Must master the dynamic skills essential for driving with a bioptic

eg cognitive sensory motor and scanning skills; good eye – hand co-ordination

Binocular if possible Stability of pathology

THE WAY FORWARD UFOV computer testing for the LV client Reduce reliance on the present acuity for legal

driving The clients visual & functional performance with

the bioptic should be the main factor in granting a licence

Standardised tests for cognitive motor and sensory functioning

Driving instructors who are educated in the problems associated with disabilities

2 – 3 yr follow up

IS SOUTH AFRICA DIFFERENT ?

Visual acuity with the bioptic is similar Legal driving standards re vision and fields are

similar The onus for prescribing a bioptic for driving in SA

rests on the optometrist The USA optometrist has more guidelines in

reaching a decision Training in the use of a bioptic rests heavily on the

optometrist