In vivo confocal microscopy assessment of meibomian glands microstructure in patients with Graves’ orbitopathy

Abstract

Background To evaluate microstructural changes in the meibomian glands (MGs) in patients with active and inactive Graves’ orbitopathy (GO), using in vivo confocal microscopy (IVCM), and to investigate the correlations between clinical and confocal findings. Methods Forty patients (80 eyes) with GO (34 eyes with active GO, 46 eyes with inactive GO), and 31 age- and sex-matched control participants (62 eyes) were enrolled consecutively. A researcher recorded the clinical activity score (CAS) for each patient. A complete ophthalmic examination was then performed, including external eye, ocular surface and MGs. IVCM of the MGs was performed to determine the MG acinar density (MAD), MG longest and shortest diameters (MALD and MASD), MG orifice area (MOA), MG acinar irregularity (MAI), meibum secretion reflectivity (MSR), acinar wall inhomogeneity (AWI), acinar periglandular interstices inhomogeneity (API), and severity of MG fibrosis (MF). Results All confocal microscopy assessments of MGs significantly differed among groups (all P = 0.000). Compared to controls, GO groups showed lower MOA (1985.82 ± 1325.30 μm2 in active GO and 2021.59 ± 1367.45 μm2 in inactive GO vs. 3896.63 ± 891.90 μm2 in controls, all P = 0.000) and MAD (87.21 ± 32.69 /mm2 in active GO and 80.72 ± 35.54 /mm2 in inactive GO vs. 114.69 ± 34.90 /mm2 in controls, P = 0.001 and 0.000, respectively); greater MALD (118.11 ± 30.23 μm in active GO and 120.58 ± 27.64 μm in inactive GO vs. 58.68 ± 20.28 μm in controls, all P = 0.000) and MASD (44.77 ± 19.16 μm in active GO and 46.02 ± 20.70 μm in inactive GO vs. 27.80 ± 9.90 μm in controls, all P = 0.000); and higher degrees of MAI, MSR, and MF (all P<0.05). Eyes with active GO had higher degrees of MAI (P = 0.015), AWI (P = 0.000), and API (P = 0.000), while eyes with inactive GO had higher degrees of MSR (P = 0.000) and MF (P = 0.017). In GO groups, AWI and API were positively correlated with CAS (r = 0.640, P = 0.000; r = 0.683, P = 0.000, respectively), and MF was negatively correlated with CAS (r = − 0.228, P = 0.042). Conclusions IVCM effectively revealed microstructural changes of MGs in eyes with GO and provided strong in vivo evidence for the roles of obstruction and inflammation in the ocular surface disease process. Furthermore, it revealed discernible patterns of MG abnormalities in eyes with active GO and inactive GO, which are not easily distinguishable by typical clinical examinations.

Presentation of Meibomian Acini Compared to Dermal Papillae of the Eyelid Margin, Using Confocal Laser Scanning Microscopy and Corresponding Histology

“…Based on previous results, morphological alterations of dermal papillae – even if presented mistakenly as MGs – can be revealed in various clinical conditions, thus, their relevance should not be underestimated 25 , 26 , 27 . Remarkably, the specificity and sensitivity of CLSM of the eyelid in the diagnosis of MGD ranges from 80 to 100% 24 .…”

Efficacy of vector thermal pulsation treatment in reducing postcataract surgery dry eye disease in patients affected by meibomian gland dysfunction

“…[39][40][41] IVCM has become of great interest in the setting of MGD because it represents the only tool to integrate microscopic findings with other instrumentation able to image structure and quantify the function of glands associated with the eyelid. [30][31][32][33] We performed IVCM to assess the direct effect of surgery on MG functionality, investigating the degree of postoperative inflammation, alteration of the morphology of MG orifices and acini, and presence and composition of intraluminal secretions. Our investigation showed a lower prevalence of inflammatory signs of the MG and MG orifice alterations in LipiFlow patients.…”

“…30–32 Patients' lower eyelid was everted, and the instrument probe positioned to contact the tarsal conjunctival surface of the eyelid. The focus and depth of imaging was adjusted to identify MG orifices and ducts as previously performed by Cheng et al 33 We acquired images in 3 areas along the tarsal conjunctiva (medial, middle, and lateral third), and acquisitions were singularly compared, with the most prevalent findings chosen to grade the image. We identified in each patient: (1) the regularity of the MG orifice shape, (2) the presence of inflammation at MG orifice borders, and (3) meibum secretion reflectivity.…”

“…We evaluated at the MG acini the following parameters: (1) MG acinar irregularity and (2) acinar periglandular interstices inhomogeneity. 33…”

“…We evaluated at the MG acini the following parameters: (1) MG acinar irregularity and (2) acinar periglandular interstices inhomogeneity. 33 A masked experienced operator performed the examinations and assessed the 5 best images, and the mean value of the 5 images was recorded.…”