I Weeks Ago, I Was Issued A Prescription For An

I Weeks ago, I was issued a prescription for an uncomfortable eye condition. The pharmacist filled that prescription with "Tobramycin Ophthalmic solution." I recently refilled that prescription, and I was issued"Tobradex Opthalmic Ointment." Are the two products the same, interchangeable, or do I need to have the dispensing pharmacist check the original prescription? Thanks.
P. L. Todd