Welcome to the forum Mary
Plaquenil is such an incredibly useful medication with numerous beneficial and not very obvious side effects such as reducing cholesterol and risk of diabetes, that people take it at the maximum recommended dose for decades or forever if a lower dose results in return of symptoms. As some people put it, it will " have to be prised from their cold dead hands"
By the way, that dosage is for ideal body weight and 400mgs is the maximum recommended because above that the risk of it affecting the eyes increases somewhat over the years. It is also greater if the person is obese and elderly and has liver or kidney problems, if I remember rightly.
Dosages are cumulative and risk increases after 10 years.
I have been on Plaquenil for decades and for the past ten+ years on its stronger cousin Aralen without any problems, touch wood.
The lupus doctors I see don't see any reason for eye testing even in my circs, although I said that cost was not a factor, but I do get them done twice a year all the same.
This max recommended dose is reckoned so safe that in the UK eye tests are not even recommended as routine, although there is a cost/benefit consideration to this decision and of course if you are unlucky it is 100% to you.
In the USA my eye tests were covered by my insurance and cost $30 copay with an ophthalmologist
I reckon getting eyes tested is worth every penny for peace of mind but if that is a very real problem either financially or logistically there are things you can look out for that might indicate trouble brewing.
The eye tests should detect signs of damage starting before the person is aware of it.
Some indications of possible trouble are seeing haloes round lights, & difficulty distinguishing certain colours. There's also a device called the Amsler Grid available for print -out on line. You could also do your own field vision test by looking straight ahead stretching out your arm at shoulder height to the side & backward then bringing it round slowly in front of you, noting where the arm is when you can see a finger in your peripheral vision.
I'll see if I can find a list of self checks and symptoms
If there ever is a problem, another antimalarial called Quinacrine in the USA, Mepacrine in the UK, does not affect the eyes. It can also be added to Plaquenil to great effect if there's a need for greater antimalarial pow.
Of course nobody wants to take more medicine than necessary. If things are looking good and you are feeling good, your doctor might be willing to let you try to lower it as trial.
Many doctors keep the patients on it for at least two years before suggesting stopping to make sure its full disease remitting potential has been achieved. Reducing before stopping is a good idea.
Many patients who are in remission of very severe disease stay on Plaquenil even when they have stopped other meds, as an 'insurance', as one renowned lupologist puts it.
It may well avoid the need for more toxic drugs with greater potential for harmful side effects.
All the best
Clare