Structural Confirmation of Lymphatic Outflow from Subconjunctival Blebs of Live Humans

Jong Yeon Lee, MD; Gad Heilweil, MD; Phuc Le, MD, PhD; Sindhu Saraswathy, PhD; Young-Kwon Hong, PhD; Christopher A. Girkin, MD, PhD; Alex S. Huang, MD, PhD

Ophthalmology Science (Dec 2021)

Structural Confirmation of Lymphatic Outflow from Subconjunctival Blebs of Live Humans

Jong Yeon Lee, MD,
Gad Heilweil, MD,
Phuc Le, MD, PhD,
Sindhu Saraswathy, PhD,
Young-Kwon Hong, PhD,
Christopher A. Girkin, MD, PhD,
Alex S. Huang, MD, PhD

Affiliations

Jong Yeon Lee, MD: Doheny Eye Institute and Stein Eye Institute, Department of Ophthalmology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California; Department of Ophthalmology, Gachon University College of Medicine, Gil Medical Center, Incheon, South Korea
Gad Heilweil, MD: Doheny Eye Institute and Stein Eye Institute, Department of Ophthalmology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California
Phuc Le, MD, PhD: Doheny Eye Institute and Stein Eye Institute, Department of Ophthalmology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California
Sindhu Saraswathy, PhD: Doheny Eye Institute and Stein Eye Institute, Department of Ophthalmology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California
Young-Kwon Hong, PhD: Department of Surgery, Norris Comprehensive Cancer Center Keck School of Medicine, University of Southern California, Los Angeles, California
Christopher A. Girkin, MD, PhD: Department of Ophthalmology, University of Alabama at Birmingham, Birmingham, Alabama
Alex S. Huang, MD, PhD: The Viterbi Family Department of Ophthalmology, Shiley Eye Institute, University of California, San Diego, La Jolla, California; Correspondence: Alex S. Huang, MD, PhD, The Viterbi Family Department of Ophthalmology, Shiley Eye Institute, University of California, San Diego, 9415 Campus Point Drive, La Jolla, CA 92093.

Journal volume & issue: Vol. 1, no. 4
p. 100080

Abstract

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Purpose: To uncover the mechanism of subconjunctival outflow in humans. Design: Cross-sectional study. Participants: Fifteen patients receiving subconjunctival anesthesia before intravitreal injection for routine clinical care. Methods: Anterior segment (AS) OCT was performed in patients with various instances of conjunctival edema or subconjunctival fluid. Other patients received a subconjunctival mixture of 0.005% indocyanine green and 2% lidocaine. After subconjunctival injection of the tracer and anesthetic mixture, blebs and associated outflow pathways were imaged angiographically and the time for appearance was recorded. The pattern and structure of outflow pathways were studied using AS OCT. Angiographic and AS OCT results were compared with trabecular and conventional outflow imaging, which demonstrates veins. Main Outcome Measures: Ocular surface lymphangiography and AS OCT images. Results: Anterior segment OCT of the conjunctiva in a normal eye demonstrated thin nonedematous conjunctiva with absent intraconjunctival lumens or subconjunctival fluid. Patients with a history of trabeculectomy, subconjunctival drug injection, or chemosis demonstrated thickened conjunctiva and intraconjunctival luminal pathways that contained valve-like structures. Tracer-based studies in patients demonstrated blebs with irregular subconjunctival bleb-related outflow patterns that arose in a time-dependent fashion. These angiographic pathways were luminal on OCT, sausage shaped, and contained intraluminal valve-like structures. This was in contrast to trabecular and conventional outflow imaging, where pathways were classically Y-shaped, of even caliber, and lacked valve-like structures. Conclusions: Outflow pathways were seen in patients with conjunctival edema and after subconjunctival tracer injection. These pathways were lymphatic based on pattern and structural study. Better understanding of bleb-related lymphatic outflow may lead to improved bleb-requiring glaucoma surgeries and subconjunctival drug delivery.

Published in Ophthalmology Science

ISSN: 2666-9145 (Online)
Publisher: Elsevier
Country of publisher: United States
LCC subjects: Medicine: Ophthalmology
Website: https://www.journals.elsevier.com/ophthalmology-science/

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