You should treat the hospital offer as a line of credit with which you will draw on to pay the current expenses of your practice, including your rent, utilities, insurance, staff salaries, monthly payments on equipment loans and EMR vendor fees and your personal draw for living expenses. In a bank-financed startup, the need is the same. Consider that you will have loan payments for capital equipment that will go at least five years, so that won't be wrapped entirely in the startup package, only the months during which you will be drawing. If the area you are looking at can really support a new ophthalmologist, figure you might only be drawing for ten months, and then probably not the full monthly allowance as your collections start coming in and you get busier. Once you hit the break point for taking a draw, say $20K per month for at least three months running, then the amount in excess of $20K collected (again, example, you actually negotiate this figure) is paid back against the principal. So if you hit the $20K x 3 months at one year, and averaged $27K/mo collection over the second year, you would have paid back $84K by the end of your income support period. So if you drew out $150K and paid back $84K, you would have $66K subject to earn-off forgiveness, usually on terms of 1/24th of the principal per month for two years or 1/36th over three years (again negotiable.) You have to decide whether the restrictions imposed on you in exchange for the agreement are worthwhile to you.
You might also consider a stipulation in your agreement that the hospital will not recruit or sponsor another ophthalmologist practice in the area without your permission for a reasonable period of time, say five years. This would protect your practice during the most vulnerable period of your startup.