Validation of a Novel Technique to Measure Tarsal Conjunctival Thickness Using Anterior Segment Optical Coherence Tomography

Theme: Cornea, external disease & refractive surgery
What: Cornea, external disease & refractive surgery
Part of: Cornea II: Medical Cornea and Ocular Surface / Cornée II: Cornée médicale et surface oculaire
When: 5/31/2024, 02:00 PM - 03:30 PM
Where: Room | Salle 713 AB

Abstract

Purpose: This study aimed to validate a novel technique for measuring tarsal conjunctival thickness (TCT) using anterior segment optical coherence tomography (AS-OCT). By providing an objective measurement, we aim to improve the current subjective grading system for tarsal conjunctival disorders, such as allergic conjunctivitis and vernal keratoconjunctivitis.

Study Design: This was a prospective study.  

Methods: AS-OCT (Heidelberg Engineering) was performed on 10 eyes of 10 healthy adult volunteers to image the superior tarsal conjunctiva after lid eversion. Consistent alignment and centration were achieved using marking of the lower eyelid margin with TCT measurements in micrometers (µm) taken at nine marked points centrally. Validation of measurements were carried out for inter-observer, intra-observer, intra-session, and inter-session variability using intra-class correlation and Bland-Altman analysis. The study received ethical approval, and all volunteers provided consent.

Results: The study demonstrated excellent inter-observer reliability (ICC = 0.91), with individual points exhibiting varying reliability. Bland-Altman analysis indicated a mean bias of -1.91 µm, with differences primarily falling within -26.97 to +23.15 µm. Intra-observer measurements showed excellent reliability (ICC = 0.92), a mean bias of 2.30 µm, and differences mainly within -21.31 to +25.91µm. Intra-session reliability was excellent (ICC = 0.91) with a mean bias of -2.01 µm and differences between -16.67 to +12.65µm. Inter-session reliability was good (ICC = 0.89) with a mean bias of -1.97 µm and differences between -18.79 to +14.85 µm.

Conclusion: This study successfully validated a standardized AS-OCT technique for measuring TCT, demonstrating excellent reliability and inter-observer consistency. This method has the potential to enhance grading and clinical management of tarsal conjunctival disorders by providing an objective and accurate measurement of TCT for clinical and research purposes.

Presenter(s)

Presenting Author: Manokamna Agarwal

Additional Author(s):

Sara Williams, The Hospital for Sick Children

Larissa Gouvea, The Hospital for Sick Children

Asim Ali, The Hospital for Sick Children

Kamiar Mireskandari, The Hospital for Sick Children

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