You can retire with an unreduced pension when your age plus years of service equal 80. Your pension is "maxed-out" at 70 per cent after 35 years of service. ie: You can not increase it.
Reasons to stay on the job after 35 years could include a sense of civic duty, overtime ( which is not included in OMERS ) or a promotion ( which would increase your retirement earnings ).
Without knowing the age or years of service of a member, it is impossible to calculate a pension. But, this explains the formula:
"OMERS Supplemental Pension Plan for Police, Firefighters and Paramedics"
http://www.omers.com/pdf/Supplemental_Plan_handbook.pdf