Measurement of Accommodative Amplitude in Amblyopia

Abstract

Monocular accommodative amplitudes were measured in amblyopic individuals by the subjective minus lens and push-up techniques and by objective dynamic retinoscopy. Accommodative amplitudes were always reduced in amblyopic eyes using the minus lens and retinoscopy techniques, but not with the push-up technique which inflated this measure. Owing to difficulty in detecting defocused stimuli with the amblyopic eye, it is suggested that the objective retinoscopic technique be used by clinicians for accurate assessment of accommodative amplitude in these patients.

Accommodative Performance of Children With Unilateral Amblyopia

“…22,24,38 The motor hypothesis, which predicts an inefficient efferent pathway and output of the accommodative system, is not supported by studies of amblyopic adults who show normal consensual accommodative responses in amblyopic eyes during binocular viewing. 39 In this study, we also observed normal consensual accommodative responses in amblyopic eyes, as evidenced by the absence of IOD in accommodative error in amblyopic subjects viewing binocularly. There is greater support in the literature for the sensory DOF hypothesis: internal and external factors related to the stimulus and optics of the eye have been found to increase the sensory DOF in adult amblyopes, 40 which can result in an increased accommodative error.…”

Static and Dynamic Measurements of Accommodation in Individuals with Down Syndrome

“…3,34 As shown in amblyopes, even a visual acuity reduction to 20/25 (comparable to the best acuity in these subjects with DS) may be enough to impact accommodative performance. 32 For subjects with DS, there was not a significant relationship between level of acuity and accommodative measures. However, a limitation of this analysis is that visual acuity measures were obtained using a variety of tests (dependent on the cognitive ability of the subject), and thus analysis combining these different measures cannot be used to determine definitely if acuity impacted accommodation in the present study.…”

“…Accommodative responses were reduced by Ͼ2 D in the amblyopic eye (VA range of 20/25 to 20/137), with improvement when response was measured consensually while stimulating the nonamblyopic eye. 32 In addition, increased depth of field secondary to decreased visual acuity has been proposed to result in increased accommodative lags in amblyopes. 33 Measurements of accommodation and subjective depth of field in individual amblyopic subjects support this model.…”

A comparison of the reliability of dynamic retinoscopy and subjective measurements of amplitude of accommodation

“…Table 4. Mean and standard deviation of the differences, coefficient of reproducibility (COR) and intraclass correlation coefficient (ICC) for the three methods (DR, Dynamic Retinoscopy; MPD, Modified push down; ML, Minus lens) of determining the AA in the WSR (a) and ISR (b) trials to determine the reproducibility either between examiners (WSR) or between sessions (ISR between the subjective and objective techniques can vary by as much as 1.50-2.00 D. 10 It is important to note that the DR and MPD procedures were made with lenses mounted in a trial frame whereas the ML technique was carried out using a phoropter. This was done because of the ease of changing lenses rapidly in the phoropter.…”