How detailed was your OQ? If your OQ(s) is(are) rigorous and challenges specific Customer requirements & specifications, fitness for intended use, PQ may not be necessary. This was found approvable by multiple medical device OEMS/ divisions, but we used this approach primarily for manufacturing equipment.
To be more specific to measurement equipment, we did decide to do PQ. My OQs for our MicroVu & similar optical-based vision system included start-up/ shut-down, access, focus & measurement execution, program loading and report retrieval instructions, plus calibration verification procedures, initial execution and scheduling. Be sure to consider ambient temperature and lighting control (equipment & ambient) if not addressed in your IQ!
Our PQ was Gage R&R, bias and linearity, plus paired t-testing against measuring equipment (caliper, micrometer) used in Production, for specific Customer specifications. Also, we challenged said process instructions by trying to induce variation or faults per a short PFMEA developed for the equipment.
Sorry to jump in a little off topic. How do you like the Micro-Vu? We have a couple comparators and a couple Zeiss CMMs and I've been keeping an eye on vision tech along the way. I came across Micro-Vu last year and was intrigued.