Date of Award

January 2024

Document Type

Open Access Thesis

Degree Name

Medical Doctor (MD)



First Advisor

Kristen Nwanyanwu



Thomas L. Chang, Akua Frimpong, Kristen Nwanyanwu. Department of Ophthalmology and Visual Science, Yale University School of Medicine, New Haven, CT.

Diabetic retinopathy is the leading cause of blindness in working-age adults in the United States. More than a quarter of patients are lost to follow-up (LTFU) after they receive anti-vascular endothelial growth factor (anti-VEGF) injections as treatment. This study utilized a mixed-methods approach with both a quantitative and qualitative analysis. The specific aims of the quantitative analysis were to identify any potential factors or socioeconomic indices that may be associated with being lost to follow-up. The subsequent qualitative interviews aimed to elucidate specific barriers and challenges that may prevent patients from returning to the clinic. We first conducted a retrospective chart review looking at individuals who received anti-VEGF injections and subsequently did not return to clinic for more than 6 months following their last appointment. We looked at 66 participants who were lost to follow-up and 269 participants who adhered to care. Factors abstracted and analyzed from the electronic medical record (EMR) include age, sex, race, ethnicity, preferred language, insurance status, smoking status, and alcohol use. Patient addresses were also used to calculate distances from the clinic as well as to retrieve Area Deprivation Index and Distressed Communities Index values. We then utilized a univariate followed by multivariate logistic regression for analysis. We proceeded to conduct semi-structured interviews with seven of the participants who were lost to follow-up. We analyzed those transcripts through the lens of a previously proposed framework and identified themes of potential barriers and challenges that participants faced with diabetic retinopathy and anti-VEGF injections. On univariate and multivariate analysis, the only significant factor associated with being to lost to follow-up was English preference for language (OR= 2.604, p=0.033). Some themes identified through qualitative analysis of the interview transcripts include resource availability (insurance/financial and transportation), knowledge and education (disease knowledge, quality of physician information), Clinic experiences (appointment scheduling, procedure experience), personal context (post-treatment experience, alternatives), vision status (visual symptoms, visual burden), and competing concerns (family, employment, and other health issues). Our study investigates the high rate of patients lost to follow-up after anti-VEGF injections for diabetic retinopathy. With a mixed-methods approach, our quantitative analysis identified English preference as significantly associated with being lost to follow-up. Our qualitative interviews uncovered diverse issues that affect patients’ ability to return to the clinic for monitoring and treatment. These findings provide potential targets for interventions to improve follow-up, and illustrate the complexity of factors that influence patient engagement with ophthalmic care.


This is an Open Access Thesis.

Open Access

This Article is Open Access