"An" versus "a" before a bracketed word that starts with a vowel followed by a non-bracketed word that doesn't start with a vowel

Question

Possible Duplicate:
“A/An” preceding a parenthetical statement

Which of the following is right/preferred:

The request is fulfilled by an (ideally) close by node.

or

The request is fulfilled by a (ideally) close by node.

I'm not sure, as if you skip over the bracketed word when reading, then "a close" would be correct, but if you read the bracketed word, then "an ideally" would be correct.