If you are diabetic who must take insulin, you take it. But self administration is a huge impediment to market penetration even in this market, and it’s one of the reasons patients defer going on insulin as long as they do (often too long).
(There is a reason why so many drug companies are pursuing a non-injectable formulation of insulin despite the difficulty of making it work.)
From an economic standpoint, your argument may be moot. Even if the FDA were inclined to approve a subcutaneously-administered drug for AMD, would such a drug be likely to be a big seller?
I rather doubt it. The fact that a caregiver would be needed to assure proper usage would probably dissuade many ophthalmologists. And those docs inclined to go along with the idea would probably need to buy extra malpractice insurance.
“The efficient-market hypothesis may be
the foremost piece of B.S. ever promulgated
in any area of human knowledge!”