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Leadership Team

Headshot of Acuity Eye Group co-founder Tom Chang MD smiling on a grey background

Tom Chang, MD

Founder & Managing Partner

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Headshot of Acuity Eye Group co-founder Michael Samuel smiling on a grey background

Michael Samuel, MD

Founder & Chief Medical Director

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Education & Innovation

Michael Davis, retina specialist at Acuity Eye Group

Michael Davis, MD

Fellowship Educational Director

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Vy Pham Optometrist Acuity Eye Group

Vy Pham, OD

Director of Optometry Services

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Headshot of Pia Rios

Pia Rios

Executive Director

Clinical Operations

Headshot of Alex Ashwal

Alex Ashwal

Chief Operating Officer & Chief Financial Officer

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Photo of Tom Johnstone from Acuity Eye Group

Tom Johnstone

Senior Director, Contact Center

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Angie Berber Director of Call Center

Angie Berber

Director, Contact Center


Marlana Rivera

Director, Field Operations - Inland Empire

Headshot of Eddy Josh

Josh Eddy

Director, Field Operations - LA County

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William Matthias Director of Field Operations Acuity Eye Group

William Matthies

Director, Field Operations - San Diego

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Robert Miller, Director of Field Operations at Acuity Eye Group

Robert Miller

Director, Strategic Partnerships

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Clinical Engineering, Research & Development

Photo of Joe Viscomi

Joseph Viscomi

Chief Technology Officer

Headshot of Brett Harris

Brett Harris

IT Services Manager

Mher Grigoryan of Acuity Eye Group

Mher Grigoryan

Manager, Special Projects

Stephen Jewell of Acuity Eye Group

Stephen Jewell

Systems Administrator

Nathan Lowry at Acuity Eye Group

Nathan Lowry

Principal Data Scientist


Samantha Hofstad of Acuity Eye Group

Samantha Hofstad Chi


Siyouneh Torousian of Acuity Eye Group

Siyouneh Torousian

Revenue Cycle Manager

Enriqueta Cortes of Acuity Eye Group

Enriqueta Cortes

Revenue Cycle Manager


Terry Marchillo of Acuity Eye Group

Terry Marchillo

Director, Contracts & New Business Development


Stephanie Lamb, Esq.

General Counsel and Chief Compliance Officer

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Marie Sakounphong of Acuity Eye Group

Marie Sakounphong

Compliance Manager

Human Resources

Jessica Carlson of Acuity Eye Group

Jessica Carlson

Vice President, Human Resources

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Celia Leung Director of HR

Celia Leung

Director, Human Resources

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Sheri Alley Credentialing Department of Acuity Eye Group

Sheri Alley

Director, Credentialing

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Arcy Bumgarner Payroll Manager

Arcelia Bumgarner

Payroll Manager

Kathy Peysar of Acuity Eye Group

Kathy Peysar

Corporate Recruiter



Joseph Pineda

Marketing Manager

April Weekley of Acuity Eye Group

April Weekley

Business Development Manager

Ambulatory Surgery Centers

Susi Khan Director of Nursing

Susi Khan

Director of Nursing

Nancy Montigny

Nancy Montigny

Director of Nursing

Kimberly Quaglia Director of Nursing

Kimberly Quaglia

Director of Nursing


Martin Lebedda

Director of Nursing

Our clinical leadership team is made up of 21 physicians who mentor our doctors and drive the clinical culture in our practices.