allergies can happen to them at anytime just like humans if it is an allergy

I certian breeds are prone to hypertrophic cardiomyopathy,  hip dysplasia
polycystic kidney disease and Gum disease

I have had several main coons before  have one right now   none every had
that

You know a second opinion would not hurt

Some cats have very small tear ducts to start with.  My Rosie had one that
was totally blocked.  I washed her face every day.  She didn't know any
better so she didn't mind.

But once something happens to cause it to become inflamed, instead of just
being very small, the inflammation will cause it to block entirely.  Turns
into a vicious circle.

I'd keep using the ointment, it likely has something in it to reduce the
swelling and infection.

BTW it doesn't just happen to cats, but you need to be tactful in making
comparisons.  My four month old granddaughter also has problems with blocked
tear ducts.  She will most likely outgrow it.  For now a cold or allergies
with cause her problems and the warm wash cloth treatment is normally
enough.  But not so sure my daughter appreciated me comparing her with my
cat.

Jo

Crush up 1/2 a 500mg tablet of L-Lysine (OTC in the vitamin section) into
his food twice daily.  It cleared up Da Boyz eyes in about 4 weeks.

Hugs,

CatNipped

So sorry Sharon.  I had this problem with Casey, my Himalayan.  The
vet prescribed a gel to put on the eye lid rim, which I did for
weeks.  He also was given some eye drops.  I forget what the names
were of these prescriptions.  The vet said both his tear ducts were
non-existenet.  None at all!  This was when he was only a kitten
though.  The vet also wanted to perform an operation to open them up.
It was expensive and I didn't go for it.  As Casey got older, the eye
problems lessened and lessened.    Since your cat is already 6 years
old, I would probably go to another vet and get a 2nd opinion or
treatment option.  Good luck!