Claudius ignores Ophelia for much of her existence except when he needs to use her in a plan to discover the cause of Hamlet's supposed lunacy. Claudius and Polonius use her as a pawn to decide if Hamlet is is crazy because Ophelia has denied his amorous advances.
Claudius curtly asks, "But how hath she received his love?" (II,ii,137) and has only the mildest interest in Polonius' answer before agreeing to spy on their interactions....
Claudius ignores Ophelia for much of her existence except when he needs to use her in a plan to discover the cause of Hamlet's supposed lunacy. Claudius and Polonius use her as a pawn to decide if Hamlet is is crazy because Ophelia has denied his amorous advances.
Claudius curtly asks, "But how hath she received his love?" (II,ii,137) and has only the mildest interest in Polonius' answer before agreeing to spy on their interactions. He later concludes that that Polonius is incorrect:
Love? His affections do not that way tend;
Nor what he spake, though it lacked form a little,
Was not like madness (III,i,176-178).
His only reaction is to consider his own safety from Hamlet.
Later, when Ophelia has gone crazy herself at the death of her father and the betrayal of Hamlet, Claudius treats her with disdain. His lines in Act IV are short; he interacts with her only briefly, and then demands that a guard "follow her close" (IV, v, 81), primarily for his own benefit, not hers. When Gertrude reports her death, Claudius expresses no sorrow for Ophelia, only fear for himself.
Claudius has no real use for Ophelia or care for her well-being, even after her father dies. He does not care for her mental state, except that he can use it to fuel Laertes' desire for revenge and keep himself safe. A young girl seems to have no place in his kingdom except as collateral.