@naturalcranberry
My experience with plaquenil is an initial visual field eye exam and then every 6 months thereafter. My Daughter is taking it now for RA which is why I took it. She is also on the every 6 months schedule. We are in the US. Interesting that the schedule for you at Mayo is so different. Both my daughter and I were in mid 50s when we started it.
I did a little research and found this from the American Academy of Ophthalmology . It looks like the protocol is no longer what it used to be and what Mayo is doing is the currant protocol.
https://www.aao.org/education/clinical-statement/revised-recommendations-on-screening-chloroquine-h
I have retinal toxicity from it. I was overdosed from the beginning. in 2000 at 200 mg twice a day. In 2000 there was no protocol to give it according to weight. That came later. I remained on it for 12 years at that overdose. I am a small, thin person. My weight has been stable at approximately 52 Kg.
Perhaps they are doing eye exams on my daughter every 6 months because of my having retinal toxicity. My eyes have not gotten worse since being off of Plaquenil. I stopped it in 2012.

This is the currant protocol for dosing Plaquenil

"Dosage: The recommended daily dosage remains unchanged at ≤5.0 mg/day/kg real weight. Keep under 400 mg/day for severly obese patients."