PubMed Health⌕ Search
Home/Archive/PubMed

PubMed · 11738434

Dynamic retinoscopy: the missing data.

D G Hunter
View original source ↗Export metadata ↓

Abstract

Dynamic retinoscopy is a well described but often overlooked technique that allows rapid assessment of accommodative ability. The key to the technique is the neutralization of the retinoscopic reflex that occurs when the patient accommodates on a target adjacent to the retinoscope. This clinical tool can provide critical data that can help solve treatment dilemmas, such as when a child presents with high hyperopia or when a patient presents at any age with possible accommodative insufficiency. In this review, performance of dynamic retinoscopy will be detailed, with the applicability of the technique demonstrated with use of case examples.

Explore related subjects

Accommodation, OcularAdultChildChild, PreschoolFemaleHumansHyperopiaInfantMaleRefraction, OcularVision TestsVision, BinocularCase ReportsJournal ArticleResearch Support, Non-U.S. Gov't

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

D G Hunter. Dynamic retinoscopy: the missing data.. https://doi.org/10.1016/s0039-6257(01)00260-0

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2006

Contrast detection in noise with positive and negative defocus in myopes.

PURPOSE: Previous studies have shown that myopes produce an asymmetrical loss in contrast sensitivity with positive and negative defocusing lenses at low-medium spatial frequencies (1-7c/deg) compared to non-myopes. The measurement of contrast detection in noise allows any given loss in visual sensitivity to be attributed to two components namely sampling efficiency and/or equivalent noise. Previous work has also shown that sampling efficiency gives an indication of the neural effects and in the absence of sampling efficiency changes, changes in equivalent noise levels are considered to be due to optical factors. We investigate whether the asymmetrical loss shown by myopes to defocus can be explained by changes in sampling efficiency or equivalent noise, or both. METHODS: Contrast thresholds in four different levels of externally added noise were measured in five myopic and five non-myopic subjects for Gabors of 3c/deg. Measurements were obtained under cycloplegia with 0 D, +/-0.50 D, and +/-1.00 D defocusing lenses. RMS wavefront aberrations were also measured using a Shack-Hartmann aberrometer. RESULTS: In the absence of noise, there was no significant difference in contrast sensitivity without defocus between myopes and emmetropes. When sampling efficiency and equivalent noise were measured from Contrast Detection in Noise functions, analysis of variance showed no significant difference in sampling efficiency between myopes and non-myopes (p=0.145). Myopes showed maximum levels of equivalent noise with +1.00 D defocus, decreasing to a minimum with -1.00 D defocus (p=0.009). Non-myopes showed a symmetrical increase in equivalent noise from zero for both positive and negative defocus. A significant correlation was found between equivalent noise and the total RMS of Wavefront aberrations of the eye (p=0.026). CONCLUSION: Optical factors explain the observed differences in contrast sensitivity with positive and negative defocus between myopes and non-myopes.

Accommodation, Ocular↗
PubMed2006

Visual angle is the critical variable mediating gain-related effects in manual control.

Theoretically visual gain has been identified as a control variable in models of isometric force. However, visual gain is typically confounded with visual angle and distance, and the relative contribution of visual gain, distance, and angle to the control of force remains unclear. This study manipulated visual gain, distance, and angle in three experiments to examine the visual information properties used to regulate the control of a constant level of isometric force. Young adults performed a flexion motion of the index finger of the dominant hand in 20 s trials under a range of parameter values of the three visual variables. The findings demonstrate that the amount and structure of the force fluctuations were organized around the variable of visual angle, rather than gain or distance. Furthermore, the amount and structure of the force fluctuations changed considerably up to 1 degrees , with little change higher than a 1 degrees visual angle. Visual angle is the critical informational variable for the visuomotor system during the control of isometric force.

Accommodation, Ocular↗