Welcome to HEL,
Extract from our "OM A" with the requirements for a CAT1 ILS approach, in terms of visual references required at MDA:
Visual reference
No pilot may continue a precision approach below the CAT-I decision height as
determined above, unless at least one of the following visual references for the
intended runway is distinctly visible to and identifiable to the pilot.
Elements of the approach light system;
The threshold;
The threshold markings;
The threshold lights;
The threshold identification lights;
The visual glide slope indicator;
The touchdown zone or touchdown zone markings;
The touchdown zone lights;
The runway edge lights.
That should make things clear for everyone. I hope.