What measurement indicates the difference in power between horizontal and vertical k-readings?

What measurement indicates the difference in power between horizontal and vertical k-readings?

• A. Vertical astigmatism
• B. Corneal astigmatism
• C. Lenticular astigmatism
• D. Oblique astigmatism

Answer: (B)

The measurement that indicates the difference in power between horizontal and vertical measurements of the cornea is referred to as corneal astigmatism. This condition arises when the curvature of the cornea is uneven, causing light to focus at different points on the retina. In a situation where horizontal and vertical k-readings (keratometry readings) differ, it suggests that the cornea is more curved in one direction than the other. Corneal astigmatism can be quantified by examining these two readings, where the difference in their values represents the degree of astigmatism present in the cornea. Focusing on other forms of astigmatism, vertical and oblique astigmatism pertain to the orientation of the astigmatic meridians rather than the direct measurement difference of the cornea's surface curvature. Lenticular astigmatism involves the lens of the eye and is not measured through k-readings of the cornea. Understanding these distinctions highlights why corneal astigmatism is the correct focus for this specific measurement comparison.

The measurement that indicates the difference in power between horizontal and vertical measurements of the cornea is referred to as corneal astigmatism. This condition arises when the curvature of the cornea is uneven, causing light to focus at different points on the retina.

In a situation where horizontal and vertical k-readings (keratometry readings) differ, it suggests that the cornea is more curved in one direction than the other. Corneal astigmatism can be quantified by examining these two readings, where the difference in their values represents the degree of astigmatism present in the cornea.

Focusing on other forms of astigmatism, vertical and oblique astigmatism pertain to the orientation of the astigmatic meridians rather than the direct measurement difference of the cornea's surface curvature. Lenticular astigmatism involves the lens of the eye and is not measured through k-readings of the cornea. Understanding these distinctions highlights why corneal astigmatism is the correct focus for this specific measurement comparison.