Aniseikonic Lenses and Driving

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Aniseikonic Lenses and Driving

• Hendrik P.Derksen, BSc.Optom.
• Holsboer Optometry, Arnhem, The Netherlands
• Cornelis A. Verezen, BSc.Optom. FAAO
• Ergra Low Vision, The Hague, The Netherlands

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In this retrospective study

• the effect on visual acuity of
• binocular 9 aniseikonic spectacle lenses,
• was investigated in subjects with
• a borderline visual acuity
• aiming to assist in keeping their drivers licence.

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Dutch Requirements for Cardriving

• Binocular BCVA ? 0.5 or Monocular
  vision BCVA ? 0.6
• Unrestricted horizontal visual field ? 140
• Normal dark/light adaptation

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Aniseikonic lenses

• Literature
• First described by Ames, Gliddon Ogle (1932)
• First use for the correction of severe cases of
  clinical Aniseikonia (Lancaster, 1932)
• Aniseikonia
• visual defect in which the shape and size of
  an ocular image differ in the two eyes

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Lens Design (MultiLens Sweden)

• Magnification 9
• Average lens thickness 10 mm
• Curve 9 (inside gt outside)
• Lensmaterial CR39
• Weigth 1 lens 30 gram

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Inclusion criteria

• Possession of valid driving licence
• Binocular BCVA ? 0.3 (18/60) ? 0.5 (30/60)
• Visual status quo gt 6 months
• No other obvious physical or mental disorder
• Strong wish to pass the upcoming drivers test

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Methods

• Best corrected visual acuity (ETDRS)
• Contrast sensitivity function (CSV-1000 LV)
• Stereopsis (Titmus Randot)
• Visual field (Confrontation)
• Quality central field (Amsler)

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Study setup (retrospective)

• 21 Subjects Age69 - 83 (mean 75.5)
• Primary reason for visual acuity loss AMD
  (dry form) in 12 subjects Cataract in 9
  subjects
• Binocular BCVA
  0.33 (20/60) 0.47 (28/60) (mean
  0.39)
• CSF 17.5 - 8.9 (mean 12.9)
• Stereopsis 400 - 100 (mean 178.57)
• No subjective metamorphopsia

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Binocular 9 Magnification
21 Subjects 9 Aniseikonia Binocular BCVA
0.45
(27/60) 0.65 (39/60) (mean 0.51)CSF 8.9 -
6.3 (mean 8.03) Stereopsis 250 - 70 (mean
123.80)
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9 magnification
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Results

• Improvement of VA from below
  to above legal requirement level ( 0.5
  (30/60)) in all 21 subjects
• 12 Subjects succeded to pass the driving test
• 3 Subjects did not execute the medical exam for
  different reasons
  (costs and/or negative advise of family)

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Conclusion

• For individuals with borderline visual acuity,
  fitting 9 aniseikonic lenses is a promising
  option to pass the medical exam for a driving
  licence in the Netherlands
• Aniseikonic lenses should be considered in
  selected patients to enhance visual acuity
• The use of aniseikonic lenses fitted binocular in
  order to enhance visual acuity for driving
  deserves further research

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Thank you for your kind attention