A Novel Quantitative Index of Meibomian Gland Dysfunction, the Meibomian Gland Tortuosity

Abstract

To quantitatively measure meibomian gland (MG) tortuosity in meibomian gland dysfunction (MGD) patients and normal controls and to observe the efficacy of evaluating MG tortuosity for the diagnosis of MGD. Methods: This cross-sectional study enrolled 32 obstructive MGD patients and 28 normal volunteers. Clinical assessments were performed, including symptom questionnaires, tear meniscus height, tear break-up time (TBUT), corneal fluorescein staining, lid margin abnormality, MG expressibility, and meibography. The meibomian gland tortuosity and meibomian gland density were measured by VIA software. Results: The mean age of the patients in the MGD group was 33.28 ± 9.28 years, and that of the normal controls was 25.25 ± 11.19 years. The average tortuosity of all MGs in the MGD patients was significantly larger than in the normal controls (P < 0.05). We further stratified the MGD patients into symptomatic MGD and asymptomatic groups. The average tortuosity of all MGs and of the central eight MGs was significantly higher in the symptomatic MGD patients than in the asymptomatic MGD patients (P < 0.05). Significant linear correlations were found between MG tortuosity and the lid margin score, meiboscore, meibum expressibility score, and TBUT (P < 0.05). When the diagnosis of obstructive MGD was based on the tortuosity of the central eight MGs of both eyelids, the sensitivity and specificity were 100% and 100%, respectively. Conclusions: MG tortuosity is an effective index to delineate MG morphology and to diagnose MGD, especially for the diagnosis of early-stage MGD. Translation Relevance: Calculating tortuosity quantitatively may play an important role in the diagnosis of MGD.

Meibomian Gland Morphology Among Patients Presenting for Refractive Surgery Evaluation

“…Studies involving the presence of gland tortuosity or degrees of the most bent gland have suggested a correlation between tortuosity and MGD, lid margin scores, meiboscores, meibum expressibility scores, and TBUT, demonstrating the clinical importance of identifying patients with significant gland tortuosity. 11 …”

“…Similar to other studies, we also found a correlation between the severity of meibomian gland atrophy and tortuosity (p <0.001). 8 , 11 Currently, the mechanism of association between gland atrophy and tortuosity is not fully understood. Additionally, as gland atrophy grades become higher there are fewer glands to assess for tortuosity.…”

“… 9 , 10 Another morphological gland feature, tortuosity, has also been found to be significantly greater in patients with MGD compared to controls and correlates with lid margin scores, meiboscores, TBUT, and meibum expressibility scores, suggesting that both gland atrophy and tortuosity can be useful in assessing ocular surface health. 11 Given the important role meibomian glands play in maintaining a healthy ocular surface, understanding the overall structure of the meibomian glands is important, particularly when evaluating a patient for refractive surgery. 3 , 4 , 12 A recent study found a higher degree of atrophy in post-refractive surgery patients compared to controls, suggesting refractive surgery may adversely affect meibomian glands chronically and serve as a potential contributing mechanism for post-operative DED.…”

A Novel Meibomian Gland Morphology Analytic System Based on a Convolutional Neural Network

“…Asymptomatic MGD has been documented as a preclinical stage of MGD with clinical changes but without lid-related symptoms [36]. Using this MGs analysis method, our team found in earlier study that MG tortuosity was significantly higher in asymptomatic MGD subjects than in normal controls and that MG tortuosity showed a significant correlation with TBUT, lid margin score, meiboscore, and meibum expressibility score [37]. Based on these findings, MG tortuosity may serve as a good index for diagnosing MGD.…”

Comparative of Meibomian Gland Morphology in Patients With Evaporative Dry Eye Versus Non-Dry Eye

“…In our ndings, there was also a statistically signi cant positive correlation of the presence of tortuous glands in the UL with a better initial and average NIKBUT. Since we focus on subjects with evaporative dry eye and that in the new DEWS II 1 report the use of the Schirmer test is not suggested, we did not carry out this study so we cannot corroborate the nding described by Daniel et al 19 Other studies have reported other morphological alterations, in patients with dry eye and other ocular surface diseases, Mathers et al suggest that that MG distortion is the rst-stage morphological alteration that occurs in MG. 20 Lin et al 21 reported that the average tortuosity of all MGs was signi cantly increased in the MGD group compared to the normal controls, and higher in the symptomatic MGD patient group compared to the asymptomatic MGD patient group. MG tortuosity has been associated with contact-lens wear and more commonly observed in Caucasians.…”