Visual acuity test for suspected malingerers

• Published in: JAPANESE ORTHOPTIC JOURNAL Vol. 32; pp. 175 - 180
• Main Authors: Noguchi, Masue, Noguchi, Kazumi, Kani, Kazutaka, Miyazaki, Kiyono, Ito, Taku, Ofuchi, Tomoko, Yamade, Shinichi
• Format: Journal Article
• Language: English
• Published: JAPANESE ASSOCIATION OF CERTIFIED ORTHOPTISTS 2003
• Subjects: binocular visual acuity; constant method; malingering; pinhole; plus lens for occlusion
• ISSN: 0387-5172; 1883-9215
• DOI: 10.4263/jorthoptic.32.175

We experienced a patient who was a suspected malingerer with a monocular eye. At first, the visual acuity of the injured eye was measured as 0.05. But re-examination using our stratagem confirmed that it was more than 0.5. This method is a modified version of a binocular visual acuity test, therefore the patient wears a pinhole on the injured eye and a plus lens for occlusion on the other. Using this method, one important problem is which lens power should be selected for the occlusion. To solve this, seven visually normal subjects (fourteen eyes) were tested for visual acuity deterioration while wearing from -1.0D to +5.0D lenses added to their full correction. For this test, we used various-sized single Landolt's rings shown on the display of a lap top computer. The measurement was done using the constant method. There were additional variations in visual acuities for each individual, especially when +1.0D was added. The higher the lens power, the slower their visual acuity decreased. When wearing +3.0D, none could get above 0.15. It is suggested that over +3.0D plus lens was suitable to occlude sufficiently.