Evaluation of the Aniseikonia Inspector Version 3 in School-Aged Children

Kehler, Lori Ann; Fraine, Lisa; Lu, Pengcheng

doi:10.1097/opx.0000000000000245

Cited by 11 publications

(10 citation statements)

References 14 publications

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“…This is the first study demonstrating that aniseikonia tests can be reliably performed in adults with anisometropic amblyopia. Previous studies have excluded participants who did not demonstrate simultaneous perception or stereopsis (Antona et al 2007;Awaya S 1982;Kehler et al 2014;Lubkin et al 1999) as aniseikonia was assumed to be difficult to measure in amblyopia due to suppression. While Lubkin et al (1999) investigated the relationships between aniseikonia, anisometropia, strabismus, and amblyopia, their participants had very low levels of suppression as they were required to have stereopsis of 100 secs of arc or better to perform Space Eikonometry.…”

Section: Discussionmentioning

confidence: 99%

“…Internationally there does not appear to be a 'gold standard' test used for the measurement of aniseikonia. The Aniseikonia Inspector version 3 (AI3) (Optical Diagnostics, Culemborg, The Netherlands) (Kehler et al 2014) and the New Aniseikonia Test (NAT) (Good-Lite Company, Tokyo, Japan) (McCormack et al 1992) are two of the more routinely used clinical tests, but there is a lack of evidence around test comparisons and reliability between tests. In this study we investigated the use of 4 different subjective aniseikonia tests on three groups of participants: those with anisometropic amblyopia, anisometropia and no amblyopia, and isometropic controls.…”

Section: Introductionmentioning

confidence: 99%

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Clinical Aniseikonia in Anisometropia and Amblyopia

South¹,

Gao²,

Collins³

et al. 2020

British and Irish Orthoptic Journal

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Purpose: Clinically, aniseikonia (a perceived difference in shape and image size between the eyes) is often neglected in anisometropic amblyopia due to assumed measurement difficulties. Therefore, we currently lack evidence on whether correction of aniseikonia is beneficial. This study aimed to determine whether subjective aniseikonia is measurable in anisometropia with or without amblyopia. Methods: Participants (15-52 years) with Anisometropic Amblyopia (n = 7), Anisometropia without amblyopia (n = 6) and Isometropic Controls (n = 6) were recruited. Subjective aniseikonia was measured using three clinical techniques: Robertson Technique (RT) (penlight and Maddox rod), Aniseikonia Inspector Version 3 (AI3), and the New Aniseikonia Test booklet (NAT), and a psychophysical adaptive method, the Contrast-balanced Aniseikonia Test (CAT), where dichoptic contrast adjustments compensate for any suppression. Results: Eighteen participants completed all tests, one Anisometropic Amblyopia participant could only complete the CAT and NAT due to fusion loss. The Anisometropic Amblyopia group exhibited the most aniseikonia (range-1.50-+10.50%) followed by Anisometropic Controls (range-3.30-+4.50%) and Isometropic Controls (range-1.50-+3.28%). There was a significant trend of more subjective aniseikonia with increasing amounts of anisometropia across all four tests (AI3 r = 0.630, p = 0.005; NAT r = 0.542, p = 0.017; RT r = 0.499, p = 0.035; CAT r = 0.440, p = 0.059. Bland Altman analysis demonstrated clinically significant levels of variability between the tests. Conclusions: Subjective aniseikonia can be reliably measured in patients with anisometropia and suppression. Subjective aniseikonia measurement is recommended as four of the most commonly used clinical tests did not support the 1% per dioptre rule of thumb.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Clinical Aniseikonia in Anisometropia and Amblyopia

South¹,

Gao²,

Collins³

et al. 2020

British and Irish Orthoptic Journal

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“…This computer‐based test requires patients to directly compare two rectangles viewed through red‐green anaglyphic glasses, thus simultaneous perception with minimal suppression is required. The forced‐choice method and the short testing time (approximately four minutes) makes this a simple and quick test to be performed in all age groups, including children aged as young as five years …”

Section: Testing For Aniseikoniamentioning

confidence: 99%

Aniseikonia and anisometropia: implications for suppression and amblyopia

South

Gao

Collins

et al. 2019

Clinical and Experimental Optometry

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Aniseikonia is a difference in the perceived size or shape of images between eyes, and can arise from a variety of physiological, neurological, retinal, and optical causes. Aniseikonia is associated with anisometropia, as both anisometropia itself and the optical correction for anisometropia can cause aniseikonia. Image size differences above one to three per cent can be clinically symptomatic. Common symptoms include asthenopia, headache and diplopia in vertical gaze. Size differences of three and more impair binocular visual functions such as binocular summation and stereopsis. Above five per cent of aniseikonia, binocular inhibition or suppression tend to occur to prevent diplopia and confusion. Aniseikonia can be measured using a range of techniques and can be corrected or reduced by prescribing contact lenses or specially designed spectacle lenses. Subjective testing of aniseikonia is the only way to accurately measure the overall perceived amount of aniseikonia. However, currently it is not routinely assessed in most clinical settings. At least two-thirds of patients with amblyopia have anisometropia, thus we may expect aniseikonia to be common in patients with anisometropic amblyopia. However, aniseikonia may not be experienced by the patient under normal binocular viewing conditions if the image from the amblyopic eye is of poor quality or is too strongly suppressed for image size differences to be recognised. This lack of binocular simultaneous perception in amblyopia may also prevent the measurement of aniseikonia, as most common techniques require direct comparisons of images seen by each eye. Current guidelines for the treatment of amblyopia advocate full correction of anisometropia to equalise image clarity, but do not address aniseikonia. Significant image size differences between eyes may lead to suppression and abnormal binocular adaptations. It is possible that correcting anisometropia and aniseikonia simultaneously, particularly at the initial diagnosis of anisometropia, would reduce the need to develop suppression and improve treatment outcomes for anisometropic amblyopia.

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“…18 Finally, the only published study employing Version 3 has reported acceptably accurate measurements of lens-induced aniseikonia in the short presentation mode with central fixation. 20 Misestimation of aniseikonia has been claimed to be clinically irrelevant [21][22][23] because further checks can be conducted before or after prescribing iseikonic spectacle lenses, although the process is lengthy and may be expensive. Yet, identifying the cause of the underestimation in the NAT and the AI Version 1 as well as the cause of the conflicting patterns of misestimation across versions of the AI is a problem whose solution could render improved tests that save time and costs to patients in clinical practice, also helping to prevent analogous problems that might arise in the use of psychophysical methods for the assessment of other visual functions.…”

Section: Introductionmentioning

confidence: 99%