Ohio Rev. Code Ann. § 5505.53

For each member who elects to participate in the deferred retirement option plan, the state highway patrol retirement system shall determine the member's pension amount under section 5505.17 of the Revised Code. In determining the pension amount, the retirement system shall use the member's total service credit and final average salary as of the last day of the employer's payroll period immediately prior to the effective date of the member's election to participate in the plan. The pension amount shall be calculated using the election made by the member under section 5505.162 of the Revised Code.