Corneal confocal microscopy alterations in Sjögren's syndrome dry eye

Oral Administration of Vitamin D3 Prevents Corneal Damage in a Knock-Out Mouse Model of Sjögren's Syndrome

BACKGROUND

Vitamin D deficiency has been associated with dry eye development during Sjögren's syndrome (SS). Here, we investigated whether repeated oral vitamin D3 supplementation could prevent the corneal epithelium damage in an SS mouse model.

METHODS

30 female mouse knock-out for the thrombospondin 1 gene were randomized (six per group) in untreated mice euthanized at 6 weeks as negative control (C-) or at 12 weeks as the positive control for dry eye (C+). Other mice were sacrificed after 6 weeks of oral vitamin D3 supplementation in the drinking water (1000, 8000, and 20,000 IU/kg/week, respectively).

RESULTS

The C+ mice showed alterations in their corneal epithelial morphologies and thicknesses (p < 0.01 vs. C-), while the mice receiving 8000 (M) and 20,000 (H) IU/kg/week of vitamin D3 showed preservation of the corneal epithelium morphology and thickness (p < 0.01 vs. C+). Moreover, while the C+ mice exhibited high levels and activity of corneal tumor necrosis factor alpha converting enzyme (TACE), neovascularization and fibrosis markers; these were all reduced in the M and H mice.

CONCLUSIONS

Oral vitamin D3 supplementation appeared to counteract the negative effect of TACE on corneal epithelium in a mouse model of SS-associated dry eye.

Corneal subbasal nerve analysis in patients with primary Sjogren's syndrome: a novel objective grading method and clinical correlations

PURPOSE

To investigate corneal sub-basal nerve morphology changes in primary Sjogren's syndrome (SS) dry eye (SSDE) patients and determine the association with disease severity at microstructural level.

METHODS

Twenty-eight eyes of 17 SSDE and 82 eyes of 47 age- and sex-matched non-SS dry eye (NSSDE) patients were included. The Ocular Surface Disease Index questionnaire (OSDI), Schirmer's test (ST), tear meniscus height (TMH), non-invasive breakup time (NIBUT), meibomian gland (MG) morphology, and ocular staining score (OSS) were assessed. In vivo confocal microscopy was performed to observe corneal sub-basal nerve morphology (length, reflectivity, width, and tortuosity). Associations between clinical features and nerve parameters were analysed.

RESULTS

SSDE patients more frequently had increased nerve reflectivity (151.12 ± 17.07 vs. 139.37 ± 14.31 grey value), width (4.45 ± 0.87 vs. 3.92 ± 0.81 μm), tortuosity (132.90 ± 8.04 vs. 129.50 ± 7.33 degree), and higher reflectivity, width, and total nerve grades than NSSDE individuals (all P < 0.05). Significant associations were found between nerve reflectivity/width and anti-SSA [OR = 1.139 (1.013-1.281)/1.802 (1.013-4.465)]/labial gland biopsy [OR = 1.046 (1.002-1.161)/1.616 (1.020-3.243)]. Higher nerve width was associated with increased OSDI [β = 0.284 (0.187-0.455)], MG score [β = 0.185 (0.109-0.300)] and OSS [β = 0.163 (0.020-0.345)], but decreased NIBUT [β =  - 0.247 (- 0.548 ~  - 0.154)]. Higher nerve total grade was associated with increased OSDI [β = 0.418 (0.157-0.793)] and OSS [β = 0.287 (0.027-0.547)], but decreased ST [β =  - 0.410 (-0.857 ~  - 0.138)].

CONCLUSIONS

Corneal nerve morphology changes associated with clinical features in SS patients. These changes may facilitate severity evaluation and management of the disease.

In Vivo Confocal Microscopy in Different Types of Dry Eye and Meibomian Gland Dysfunction

In vivo confocal microscopy (IVCM) imaging is increasingly popular in ocular surface disease diagnosis and management. We conducted a systematic review to update the use of IVCM in the diagnosis and treatment of dry eye and meibomian gland dysfunction (MGD). A literature review was conducted on IVCM studies in MGD, dry eye disease, systemic disease causing dry eye, dry eye in glaucoma patients, contact lens-associated ocular conditions, graft-versus-host disease, and Sjogren’s syndrome-related dry eye. The articles were identified through PubMed and a total number of 63 eligible publications were analyzed in detail. All primary research studies on confocal microscopy on dry eye and related conditions from 2017 onwards were included. The reports were reviewed for their contribution to the existing literature as well as potential biases and drawbacks. Despite limitations such as small field of view, lack of population-based norms, and lack of standardization of image acquisition, interpretation, and quantification, IVCM is useful as a complementary technique for clinical diagnosis in various ocular surface disorders related to dry eye. With advances in hardware and software in the near future, it has the potential for further practical impact.

Analysis of Globular Cells in Corneal Nerve Vortex

Purpose

Less was known about globular cells which were a type of dendritic cells (DCs) in cornea. We aimed to investigate the morphological and distribution characteristics of globular cells in corneal vortex and their clinical correlations with ocular surface.

Methods

Case records of patients who underwent in vivo confocal microscopy (IVCM) were evaluated retrospectively. The morphology and distribution features of globular cells in cornea nerve vortex and their co-existence status with Langerhans cells (LCs) were analyzed. Data of ocular surface symptoms and signs were collected and their correlations with globular cells distribution patterns and dendritic forms were performed. Dry eye patients without LCs were treated with preservative-free artificial tears, while patients with LCs were treated with artificial tears and fluoromethalone until the activated LCs disappeared.

Results

A total of 836 eyes from 451 individuals were included. Three distribution patterns of globular cells in vortex were investigated, type 1 scattered globular cells (57.66%), type 2 large amounts of globular cells (≥50 cells) gathering in vortex and along some fixed vortex direction horizontally (13.52%) and type 3 no globular cells (28.83%). Their location and cell count altered slightly in the follow-ups but would not disappear. LCs could co-exist with globular cells and could fade after treatment. The type 2 distribution pattern was associated with older age (p = 0.000) and higher upper eyelid Meiboscore (p = 0.006). Dendritic globular cells had higher Meiboscore than Non-dendritic forms.

Conclusions

Globular cells had characteristic distribution patterns and biological features different from LCs. They were associated with long-term irritation of the meibomian gland dysfunction.