If the corneal reflex is displaced nasally in one eye during a Krimsky test, which prism should be added to neutralize the finding?

If the corneal reflex is displaced nasally in one eye during a Krimsky test, which prism should be added to neutralize the finding?

• A. BI prism
• B. BO prism
• C. None
• D. Both

Answer: (A)

In Krimsky testing, the direction of the corneal light reflex tells you the type of misalignment and guides which prism to use to neutralize it. If the reflex in the eye sits nasal to the center, that indicates the eye is drifting outward (exotropia). To neutralize this outward deviation, you place a prism with the base toward the nose (base-in) in that eye. The base-in prism shifts the image in a way that brings the reflex back toward the center, harmonizing the two eyes. A base-out prism would be used for inward turning (esotropia), not for this finding. If there were no deviation, no prism would be needed.

In Krimsky testing, the direction of the corneal light reflex tells you the type of misalignment and guides which prism to use to neutralize it. If the reflex in the eye sits nasal to the center, that indicates the eye is drifting outward (exotropia). To neutralize this outward deviation, you place a prism with the base toward the nose (base-in) in that eye. The base-in prism shifts the image in a way that brings the reflex back toward the center, harmonizing the two eyes. A base-out prism would be used for inward turning (esotropia), not for this finding. If there were no deviation, no prism would be needed.