Date of Award

January 2013

Document Type

Open Access Thesis

Degree Name

Medical Doctor (MD)



First Advisor

Jimmy Zhou

Subject Area(s)

Ophthalmology, Public health


Purpose: To investigate whether pre-scheduled appointments increase follow-up rates among participants identified as at-risk for glaucoma during a community-based glaucoma screening.

Design: Randomized controlled trial.

Methods: Between May 2010 and October 2012 we screened 362 underserved individuals age 40 years or older for glaucoma within the Greater New Haven Area. Screening modalities included visual acuity, automated perimetry, portable tonometry and ophthalmoscopy. Participants with abnormal screening results were randomized to receive either a pre-scheduled appointment for a low-cost complete eye exam within 7-10 days of the date of screening (intervention), or standard counseling (control). Follow-up rates were determined via clinical records and phone surveys and analyzed using Chi-square test with significance set at p<0.05.

Results: The overall follow-up rate among positively screened participants was 30% (n=63). Forty-one percent in the intervention group (n=22) successfully followed up compared to 24% of controls (n=41, p=0.173). Ethnicity (p=0.584), gender (p=0.681), age (p=0.792), access to car (p=0.425), living situation (p=0.893), health insurance status (p=565), or tobacco use (p=0.486) did not independently affect follow-up rates, nor did having an established eye care provider (p=0.118) or diabetes (p=0.334). Among participants lacking access to a car, the follow-up rate among those with prescheduled appointments was 66.7%, compared to 5.3% among controls (OR 36.0; 95% CI 3.1-414.9). Among participants lacking health insurance, the follow-up rate was 46.7% in the intervention group compared to 7.0% among controls (OR 12.3; 95% CI 1.3-118.4). Among those who lived alone or used tobacco, follow-up rates were higher in the intervention group (OR 1.8, 95% CI 0.29-11.2; OR 2.3 95% CI 0.23-22.1, respectively).

Conclusion: Provision of pre-scheduled follow-up appointments to glaucoma suspects at the time of screening does not lead to a significant increase in overall follow-up rates. This intervention may, however, prove both clinically valuable and cost-effective when offered specifically to individuals lacking access to a car and/or health insurance.


This is an Open Access Thesis.

Open Access

This Article is Open Access