In a patient with ATR astigmatism, which meridian is steeper?

• A. Vertical
• B. Horizontal
• C. Equal
• D. Not determinable

Answer: (B)

In astigmatism, the eye’s curvature differs between meridians, giving different refractive powers along those directions. ATR (against-the-rule) means the cornea is steeper in the horizontal direction, so the horizontal meridian has greater refractive power and is the steepest. The vertical meridian is flatter, which is why ATR is described as the horizontal meridian being steeper. That’s why the horizontal meridian is the best answer. The other possibilities describe different patterns: vertical would be with-the-rule (steep vertical), equal would indicate no astigmatism, and not determinable isn’t appropriate here.