An optical trocar assembly includes an obturator assembly and a cannula assembly configured for receipt of the obturator assembly. The obturator assembly has a retention member disposed within a cavity defined in an obturator housing of the obturator assembly. The retention member has a main body defining an opening dimensioned for receipt of a surgical instrument. The retention member has a plurality of first sections formed in the main body and circumferentially disposed about the opening. The sections have a reduced thickness relative to the main body to facilitate flexing of the retention member during insertion of a surgical instrument into the opening.
