Latanoprost's effect on the pupil in lens instability is to cause which change?

Latanoprost's effect on the pupil in lens instability is to cause which change?

• A. Pupillary atony
• B. No pupil change
• C. Mydriasis
• D. Miosis

Answer: (D)

Latanoprost is a prostaglandin F2α analog used to lower intraocular pressure by increasing uveoscleral outflow, but it can also influence the iris by modestly affecting the tone of iris smooth muscle. In the context of lens instability, a smaller pupil tends to stabilize the iris-lens diaphragm and reduce anterior movement of the lens, which can help minimize lens-capsule movement during accommodation or changes in gaze. Therefore, latanoprost can lead to pupil constriction (miosis), making this the expected effect. Pupillary atony would imply loss of iris sphincter function, which is not how latanoprost acts. No pupil change would ignore the potential influence on iris tone, and mydriasis (pupil dilation) would worsen lens instability by allowing more movement. Hence, the best answer is miosis.

Latanoprost is a prostaglandin F2α analog used to lower intraocular pressure by increasing uveoscleral outflow, but it can also influence the iris by modestly affecting the tone of iris smooth muscle. In the context of lens instability, a smaller pupil tends to stabilize the iris-lens diaphragm and reduce anterior movement of the lens, which can help minimize lens-capsule movement during accommodation or changes in gaze. Therefore, latanoprost can lead to pupil constriction (miosis), making this the expected effect.

Pupillary atony would imply loss of iris sphincter function, which is not how latanoprost acts. No pupil change would ignore the potential influence on iris tone, and mydriasis (pupil dilation) would worsen lens instability by allowing more movement. Hence, the best answer is miosis.