It is the purpose of this article to encourage the employment of persons with disabilities by protecting employers from excess liability for compensation when an injury to a disabled worker merges with a preexisting permanent impairment to cause a greater disability than would have resulted from the subsequent injury alone. It shall not be construed to create, increase, or provide any benefits for injured employees or their dependents not otherwise provided by this chapter. The entitlement of an injured employee or dependents to compensation under this chapter shall be determined without regard to this article, the provisions of which shall be considered only in determining whether the employer or insurer who has paid compensation under this chapter is entitled to reimbursement from the Subsequent Injury Trust Fund.