[1] Univ Calif San Francisco, Dept Med, San Francisco, CA 94143 USA
[2] Univ Calif San Francisco, Dept Ophthalmol, San Francisco, CA 94143 USA
[3] Univ Calif San Francisco, Francis I Proctor Fdn, San Francisco, CA 94143 USA
[4] San Francisco Gen Hosp, Posit Hlth Program, San Francisco, CA 94110 USA