Related Experiment Video
Updated: Feb 2, 2026
04:48
Establishing a Severe Corneal Inflammation Model in Rats Based on Corneal Epithelium Curettage Combined with Corneal Sutures
Published on: November 22, 2024
856
Age-Related Changes in Corneal Spherical Aberration.
Journal of Refractive Surgery (Thorofare, N.J. : 1995)
|November 15, 2018
Summary
Corneal spherical aberration (CSA) and higher order aberrations (HOAs) increase non-linearly with age, particularly after age 39 and 46, respectively. A new model helps estimate and compensate for these age-related changes in the aging cornea.
Area of Science:
- Ophthalmology
- Optometry
- Corneal Physiology
Background:
- Age-related changes in corneal aberrations are significant.
- Understanding these changes is crucial for refractive surgery and vision correction.
Purpose of the Study:
- To analyze age-related changes in corneal spherical aberration (CSA) and higher order aberrations (HOAs).
- To develop a novel model for estimating CSA changes with age.
Main Methods:
- Cross-sectional study of 3,769 patients' right eyes.
- Measured anterior, posterior, and total corneal spherical aberration (ASA, PSA, TSA) and HOAs using Scheimpflug tomography.
- Plotted smoothed fitting curves against age to determine aberration changes.
Main Results:
- CSA and HOAs increased non-linearly with age, with significant increases after age 39 (TSA) and 46 (4-mm HOAs).
- The average change in TSA was -0.013 µm/10 years (18-39 years) and 0.057 µm/10 years (after 39 years).
- Strong correlation found between ASA and TSA (r=0.976), and PSA and TSA (r=0.192).
Conclusions:
- Corneal spherical aberration and HOAs increase non-linearly with age.
- A novel model is presented to calculate compensation for age-related CSA increases in the aging cornea.
Related Concept Videos
01:23Spherical Coordinates
16.0K
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...
16.0K
01:27Gravity between Spherical Bodies
9.5K
Newton's law of gravitation describes the gravitational force between any two point masses. However, for extended spherical objects like the Earth, the Moon, and other planets, the law holds with an assumption that masses of spherical objects are concentrated at their respective centers.
This assumption can be proved easily by showing that the expression for gravitational potential energy between a hollow sphere of mass (M) and a point mass (m) is the same as it would be for a pair of extended...
This assumption can be proved easily by showing that the expression for gravitational potential energy between a hollow sphere of mass (M) and a point mass (m) is the same as it would be for a pair of extended...
9.5K
01:26Spherical and Cylindrical Capacitor
6.8K
A spherical capacitor consists of two concentric conducting spherical shells of radii R1 (inner shell) and R2 (outer shell). The shells have equal and opposite charges of +Q and −Q, respectively. For an isolated conducting spherical capacitor, the radius of the outer shell can be considered to be infinite.
Conventionally, considering the symmetry, the electric field between the concentric shells of a spherical capacitor is directed radially outward. The magnitude of the field,...
Conventionally, considering the symmetry, the electric field between the concentric shells of a spherical capacitor is directed radially outward. The magnitude of the field,...
6.8K
01:26Aging
703
Aging is a complex biological phenomenon influenced by various processes that affect cellular and systemic functions. Several prominent theories attempt to explain its mechanisms, highlighting cellular limitations, oxidative damage, and hormonal changes as central factors in aging.
Cellular Clock Theory
The cellular clock theory posits that the human lifespan is closely tied to the finite capacity of cells to divide, a phenomenon governed by telomeres, which are protective caps at the ends of...
Cellular Clock Theory
The cellular clock theory posits that the human lifespan is closely tied to the finite capacity of cells to divide, a phenomenon governed by telomeres, which are protective caps at the ends of...
703
01:26Gauss's Law: Spherical Symmetry
9.3K
A charge distribution has spherical symmetry if the density of charge depends only on the distance from a point in space and not on the direction. In other words, if the system is rotated, it doesn't look different. For instance, if a sphere of radius R is uniformly charged with charge density ρ0, then the distribution has spherical symmetry. On the other hand, if a sphere of radius R is charged so that the top half of the sphere has a uniform charge density ρ1 and the bottom half has a...
9.3K
01:14Gravitation Between Spherically Symmetric Masses
1.4K
The gravitational potential energy between two spherically symmetric bodies can be calculated from the masses and the distance between the bodies, assuming that the center of mass is concentrated at the respective centers of the bodies.
1.4K