Date of Award

January 2022

Document Type


Degree Name

Medical Doctor (MD)



First Advisor

Lucian V. Del Priore



Elton K. Zhou, Jessica Chow and Lucian V. Del Priore. Department of Ophthalmology, Yale University School of Medicine, New Haven, CT.

Part I: Tumor size is an important clinical predictor of choroidal melanoma (CM) metastasis; however, the natural history of untreated CM remains unclear. To understand CM growth, we conducted a systematic search and meta-analysis for publications containing longitudinal measurements of untreated CM size prior to 2019. A mathematical model was developed to describe the growth pattern of CM tumor height as a function of inferred tumor age after a temporal translation factor was applied to correct for differences in the time of enrollment of subjects. Forty-four patients were identified from three studies that met our selection criteria. Regression analysis showed that the tumor height could be well-described by an exponential function of the inferred tumor age with an exponential time constant of 49.75 months (R2 = 0.83), or a doubling time of 34.48 months in tumor height. This model provides an estimate of the overall growth rates of untreated CM, which may serve as a convenient reference in accessing CM progression and treatment efficacy.

Part II: In the US, there has been a steady trend from hospital outpatient departments (HOPDs) to ambulatory surgical centers (ASCs) as the location of ophthalmic surgeries. It remains to be understood how this trend impacts patient demographics and social disparities in ophthalmic surgeries. The purpose of this project was to determine the likelihood of ophthalmic surgery at an ASC versus a HOPD based on patient demographics. This cohort study analyzed data from the State Ambulatory Surgery and Service Database. Patients who underwent ambulatory ophthalmic surgeries in Florida between 2012 and 2014 were included in the study. Univariate and multivariate logistic regression were performed to identify characteristics of the ASC and HOPD cohorts. Over 1.1 million patients (71 years mean age, 57.7% female, 76.2% White, 12.8% Hispanic, 6.7% Black) were included in our analysis. After adjusting for other factors, the likelihood of receiving care at an ASC was statistically significantly lower for Black (adjusted odds ratio (aOR): 0.59, 95% CI: 0.58-0.61, p<0.001) and Hispanic patients (aOR: 0.69, 95% CI: 0.67-0.70, p<0.001) compared to White patients. Overall, Black or Hispanic race, public insurance, and large metropolitan location were independent factors that were associated with a lower likelihood of receiving surgical care in an ASC. Because the prevalence of ASCs continues to increase, understanding which patients receive care in ASCs is vital to providing both equal care and improved quality.


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