This is a sub-trial nested within a larger randomized trial called GSEARCH. The parent trial evaluates whether telemedicine glaucoma screening is more effective for detecting undiagnosed glaucoma cases compared with education alone or delayed intervention, with the final outcomes assessed via a follow-up telephone surveys at 3 months and 12 months. In this sub-study, we will assess whether adding an incentive improves the survey response completion rate. Participants enrolled in the parent GSEARCH trial will be eligible. Participants will be randomized to one of three incentive approaches, offered by telephone at the time of the follow-up survey ($5 gift card, entry into a monthly $100 drawing, or no incentive). The primary outcome will be completion of the telephone survey.
