Related Experiment Video
Updated: Feb 12, 2026
08:17
Chemical Analysis of Water-accommodated Fractions of Crude Oil Spills Using TIMS-FT-ICR MS
Published on: March 3, 2017
11.7K
Accommodative accuracy by retinoscopy versus autorefraction spherical equivalent or horizontal meridian power
Angeline T Nguyen1, Jenna L Wayne1, Ayeswarya Ravikumar1
1Department of Clinical Sciences, University of Houston College of Optometry, Houston, Texas, USA.
Clinical & Experimental Optometry
|March 26, 2018
Summary
This study found good agreement between autorefraction and retinoscopy methods for measuring accommodative lag in children and adults. Using autorefraction power in the 180 meridian provided the narrowest agreement range, even with mild astigmatism.
Area of Science:
- Ophthalmology
- Optometry
- Vision Science
Background:
- Accurate measurement of accommodative lag is crucial for understanding visual function in both pediatric and adult populations.
- Discrepancies between different measurement techniques can impact clinical assessment and research findings.
Purpose of the Study:
- To compare the agreement between monocular estimation method (MEM) retinoscopy and Nott retinoscopy with open-field autorefraction for measuring accommodative lag.
- To evaluate the utility of spherical equivalent versus power in the 180 meridian from autorefraction in assessing accommodative lag across different age groups.
Main Methods:
- The study included 26 children (7-16 years) and 27 adults (22-29 years).
- Accommodative lag was measured using MEM retinoscopy, Nott retinoscopy, and open-field autorefraction at a near target (33 cm).
- Autorefraction data were analyzed for both spherical equivalent and power in the 180 meridian, with statistical analysis including two-factor repeated measures ANOVA.
Main Results:
- No significant difference in mean accommodative lag was found across the techniques (p = 0.48).
- Children exhibited smaller accommodative lags than adults (p < 0.001) and higher amounts of uncorrected astigmatism.
- Mean differences between techniques were small, with the narrowest limits of agreement observed when using autorefraction power in the 180 meridian.
Conclusions:
- Autorefraction and retinoscopic techniques demonstrate good agreement, centered on zero bias, for measuring accommodative lag in both children and adults.
- Calculating autorefraction power in the 180 meridian enhances the agreement range, particularly in individuals with moderate uncorrected astigmatism.
Related Concept Videos
01:28Meridians
941
In surveying, meridians are vital reference lines to measure directions and establish accurate land orientations. Meridians run from the north to the south poles, providing a stable framework for angular measurements and mapping. Meridians are fundamental in survey design, with the primary types being astronomic, magnetic, and assumed meridians. Each type offers distinct benefits and limitations, selected based on the project's scale and precision needs.The astronomic meridian is aligned with...
941
01:23Spherical Coordinates
16.2K
Spherical coordinate systems are preferred over Cartesian, polar, or cylindrical coordinates for systems with spherical symmetry. For example, to describe the surface of a sphere, Cartesian coordinates require all three coordinates. On the other hand, the spherical coordinate system requires only one parameter: the sphere's radius. As a result, the complicated mathematical calculations become simple. Spherical coordinates are used in science and engineering applications like electric and...
16.2K
02:07Improving Translational Accuracy
15.0K
Base complementarity between the three base pairs of mRNA codon and the tRNA anticodon is not a failsafe mechanism. Inaccuracies can range from a single mismatch to no correct base pairing at all. The free energy difference between the correct and nearly correct base pairs can be as small as 3 kcal/ mol. With complementarity being the only proofreading step, the estimated error frequency would be one wrong amino acid in every 100 amino acids incorporated. However, error frequencies observed in...
15.0K
01:26Pharmaceutical Equivalents
208
As defined by regulatory standards, pharmaceutical equivalents require generic drug products to have identical dosage forms and chemically identical active pharmaceutical ingredients (APIs). They must adhere to compendial or applicable standards for potency, content uniformity, disintegration times, and dissolution rates. In the case of modified-release dosage forms, variations in drug content are permissible as long as the delivered amount remains consistent with the innovator drug product.
208
01:19Equivalent Capacitance
2.2K
Multiple capacitors can be connected in a circuit in series or parallel configuration. When the capacitor combination is connected to a battery, the potential drop across each capacitor and the magnitude of charge stored in the individual capacitor depends on the type of the connection. The capacitor combination is replaced by a single equivalent capacitor that stores the same amount of charge as the combination for a given potential difference.
The following strategies are adopted to calculate...
The following strategies are adopted to calculate...
2.2K
03:37Uncertainty in Measurement: Accuracy and Precision
104.7K
Scientists typically make repeated measurements of a quantity to ensure the quality of their findings and to evaluate both the precision and the accuracy of their results. Measurements are said to be precise if they yield very similar results when repeated in the same manner. A measurement is considered accurate if it yields a result that is very close to the true or the accepted value. Precise values agree with each other; accurate values agree with a true value.
104.7K