trouble with regular expression

Hi experts,

I have a problem regarding regular expression.

In my database (version 8.0.2 ) I have a value stored as
"([t]{0,1})^(t?)+$\"
(Please note that this value uses many characters which have special
meaning in regular expression)

Earlier I had a query which used to fetch this value
SELECT "Topic" FROM "schema1"."Topics" WHERE "Topic" *similar to*
'\\(\\[t\\]{0,1}\\)\\^\\(t?\\)\\+\\$\\\\' ORDER BY "Topic"
This query worked fine and did return the matching value stored in
database .

Later on to support, case insensitive value search, I modified the query to
SELECT "Topic" FROM "schema1"."Topics" WHERE "Topic" ~** *
'\\(\\[t\\]{0,1}\\)\\^\\(t?\\)\\+\\$\\\\' ORDER BY "Topic"

(Please note that I just replaced similar to with ~*)

The new query does not work. Please let me know where I am making a mistake.
If there are other approaches to go about case insensitive pattern
matching in query, please provide pointers to that.

Thanks in advance.

Regards,
Pushker Chaubey

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