Abstract
Purpose :
Meibomian glands (MG) play a pivotal role in maintaining the stability of the tear film, and dysfunction in these glands is implicated in various ocular surface disorders. Dry eye disease is often characterized by blockage of MG ducts, thickening of gland contents, cysts, and the eventual degeneration of damaged glands. Understanding the vascular changes around meibomian gland dysfunction (MGD) is essential for targeted treatments of both inflammatory and vascular conditions. Optical coherence tomography (OCT) and angiography (OCTA) provide detailed, non-invasive visuals to the structure and blood flow dynamics around the meibomian glands.
Methods :
We scanned 10 healthy and 10 diseased eyes (both eyes of 5 healthy, 5 MGD patients) using swept source OCT with an anterior segment (AS) add-on lens with PLEX® Elite 9000 (ZEISS, Dublin, CA). Two scans at 6mm depth and 200kHz were acquired on the internal lower eyelid: AS Angio 12x18 mm 600 A-lines x 400 B-scans, and AS Angio 6x6 mm 500 A-lines x 500 B-scans. An expert evaluated the images for gland structure, distribution, and vessel density around the glands.
Results :
En face OCT, en face OCTA, and cross-sectional B-scans of MG openings in healthy and MGD subjects were compared. Normal MG spacing, openings, and vasculature around the glands are shown in Figure 1, a-c. A MG cyst and the accumulation of meibum is shown in Fig. 1, d-f. Altered gland structure (Fig. 1, i) and thickening of the gland opening (Fig. 1, l) is likely due to obstruction of MG orifices over time. Increased vascularization and hyperemia (Fig. 1, g,j,m) could be due to chronic inflammation impacting the surrounding vasculature. Gland dropout and patchy or localized distribution of the meibomian glands are more pronounced in severe MGD (Fig 1, m-o). Table 1 summarizes the pathologies of the subjects in this study.
Conclusions :
Visualization of MG structure and surrounding vasculature is beneficial for diagnostic and monitoring MGD progression or treatment. OCT and OCTA imaging of the eyelid provides detailed vascular and three-dimension information. Quantitative studies are needed to determine the correlation between vasculature and structural measures of the glands with MGD progression.
This abstract was presented at the 2024 ARVO Imaging in the Eye Conference, held in Seattle, WA, May 4, 2024.