Bilateral Effect of the Unilateral Corneal Nerve Cut on Both Ocular Surface and Lacrimal Gland

Structural and functional changes of binocular corneal innervation and ocular surface function after unilateral SMILE and tPRK

AIMS

To evaluate the bilateral changes in the sub-basal nerve plexus of the cornea and ocular surface function after unilateral small incision lenticule extraction (SMILE) and transepithelial photorefractive keratectomy (tPRK) procedures.

METHODS

34 patients were enrolled in the study and underwent unilateral SMILE (21 of 34 patients) or unilateral tPRK (13 of 34 patients). Complete ophthalmic examinations, tear film function tests and Cochet-Bonnet esthesiometry were conducted to assess the effects of the surgeries on the corneal nerves and tear function. Morphological changes were assessed using in vivo confocal microscopy to evaluate the corneal sub-basal nerve plexus and dendritic cells. ELISA was used to measure the tear neuromediators. Clinical and morphological data at each follow-up point were compared with preoperative baseline values.

RESULTS

All patients who underwent unilateral SMILE or tPRK procedures exhibited bilateral corneal nerve degenerative changes, decreased corneal sensitivity, worsening of dry eye symptoms and changes in bilateral tear neuromediators. In the SMILE group, bilateral corneal sensitivity was positively correlated with corneal nerve fibre length and negatively correlated with dendritic cell area. The dry eye severity was negatively correlated with corneal sensitivity. Tear levels of substance P and nerve growth factor were positively correlated with mean dendritic cell area and dry eye severity, but negatively correlated with corneal sensitivity. In the tPRK group, bilateral corneal sensitivity was positively correlated with corneal nerve fibre density.

CONCLUSIONS

Unilateral refractive surgery may bilaterally affect the morphology and function of corneal nerves and ocular surface status postoperatively.

Ocular surface parameter changes in the untreated fellow eye after unilateral cataract surgery with short-term administration of anti-inflammatory eye drops

This study aimed to investigate the changes in clinical parameters of dry eye disease and meibomian gland dysfunction in both the operated and untreated fellow eyes of patients who underwent unilateral cataract surgery with the short-term administration of anti-inflammatory eye drops in the surgical eye. The medical charts of 57 consecutive patients who underwent unilateral cataract surgery and received 1% prednisolone acetate and non-steroidal anti-inflammatory drug (NSAID, 0.1% bromfenac sodium) eye drops were reviewed. The preoperative ocular surface disease index questionnaire score (38.9 ± 20.5) decreased significantly to 15.2 ± 16.4 at post-surgical 1 week and further to 12.8 ± 11.4 after 1 month. Although meibum quality grade increased and corneal sensitivity decreased at 1 week in operated eyes, corneal erosion scores and Sjogren's International Collaborative Clinical Alliance ocular staining scores even improved over a month in the untreated fellow eyes. The tear matrix metalloproteinase (MMP)-9 grade decreased in both operated eyes and untreated fellow eyes after 1 month from surgery. In conclusion, the short-term topical anti-inflammatory treatment using steroid and NSAID eye drops in the operated eye after cataract surgery decreased subjective ocular surface discomfort and improved ocular surface staining scores and tear MMP-9 expression in the untreated fellow eyes.

In-vivo corneal confocal microscopy: Imaging analysis, biological insights and future directions

In-vivo corneal confocal microscopy is a powerful imaging technique which provides clinicians and researcher with the capabilities to observe microstructures at the ocular surfaces in significant detail. In this Mini Review, the optics and image analysis methods with the use of corneal confocal microscopy are discussed. While novel insights of neuroanatomy and biology of the eyes, particularly the ocular surface, have been provided by corneal confocal microscopy, some debatable elements observed using this technique remain and these are explored in this Mini Review. Potential improvements in imaging methodology and instrumentation are also suggested.

Ferroptosis in the Lacrimal Gland Is Involved in Dry Eye Syndrome Induced by Corneal Nerve Severing

Purpose

Dry eye syndrome (DES) is a prevalent postoperative complication after myopic corneal refractive surgeries and the main cause of postoperative dissatisfaction. Although great efforts have been made in recent decades, the molecular mechanism of postoperative DES remains poorly understood. Here, we used a series of bioinformatics approaches and experimental methods to investigate the potential mechanism involved in postoperative DES.

Methods

BALB/c mice were randomly divided into sham, unilateral corneal nerve cutting (UCNV) + saline, UCNV + vasoactive intestinal peptide (VIP), and UCNV + ferrostatin-1 (Fer-1, inhibitor of ferroptosis) groups. Corneal lissamine green dye and tear volume were measured before and two weeks after the surgery in all groups. Lacrimal glands were collected for secretory function testing, RNA sequencing, ferroptosis verification, and inflammatory factor detection.

Results

UCNV significantly induced bilateral decreases in tear secretion. Inhibition of the maturation and release of secretory vesicles was observed in bilateral lacrimal glands. More importantly, UCNV induced ferroptosis in bilateral lacrimal glands. Furthermore, UCNV significantly decreased VIP, a neural transmitter, in bilateral lacrimal glands, which increased Hif1a, the dominant transcription factor of transferrin receptor protein 1 (TfR1). Supplementary VIP inhibited ferroptosis, which decreased the inflammatory reaction and promoted the maturation and release of secretory vesicles. Supplementary VIP and Fer-1 improved tear secretion.

Conclusions

Our data suggest a novel mechanism by which UCNV induces bilateral ferroptosis through the VIP/Hif1a/TfR1 pathway, which might be a promising therapeutic target for DES-induced by corneal refractive surgeries.

Role of tear vasoactive intestinal peptide on dry eyes after laser keratorefractive surgery

BACKGROUND

To explore the changes in vasoactive intestinal peptide (VIP) concentration in tears post laser-assisted sub-epithelial keratomileusis (LASEK) and femtosecond laser-assisted in situ keratomileusis (FS-LASIK) surgeries and related factors, possible association between postoperative dry eye symptoms and VIP concentration in tears, and factors influencing dry eye symptoms after different periods post LASEK and FS-LASIK surgeries.

METHODS

In this prospective, non-randomized, longitudinal cohort study, 23 and 22 subjects were recruited and underwent LASEK and FS-LASIK, respectively. After conducting an intact ophthalmic examination and collecting relevant surgical data, all subjects were examined for VIP concentration in their tears using ELISAs, tear-film breakup time, ocular staining and ocular surface disease index questionnaire before surgery and 1 day, 1 week, and 1 month post-surgery.

RESULTS

Tear VIP concentration increased significantly after both LASEK and FS-LASIK, with the highest concentration observed 1 week post-surgery (P ≤ 0.05). Tear VIP concentration correlated negatively with corneal ablation depth (AD). The extent of dry eyes was related to the operation method employed and postoperative recovery period. In FS-LASIK and LASEK subjects, dry eyes were mainly affected by the basic ocular surface status before surgery, and VIP concentration. Furthermore, in LASEK subjects, dry eyes were negatively correlated with AD.

CONCLUSION

VIP was stimulated and mobilized as an emergency protection post-refractive surgery and a trauma model affected by AD. It can indirectly indicate the inevitable relationship between postoperative dry eye and nerve injury. Elevated post-surgery tear VIP relieves dry eye symptoms, showing its neuroimmune role in regulating adverse injury stimulation. The present study provides a solution to the pathogenesis of postoperative dry eyes.

TRIAL REGISTRATION

The trial registration number: 2021JS22. Date of registration: 10 May 2021.

Topical Decorin Reduces Corneal Inflammation and Imparts Neuroprotection in a Mouse Model of Benzalkonium Chloride-induced Corneal Neuropathy

Purpose

We evaluated the neuroprotective and immunomodulatory effects of topical decorin in a murine model of benzalkonium chloride (BAK)-induced corneal neuropathy.

Methods

Topical BAK (0.1%) was administered daily to both eyes of female C57BL/6J mice (n = 14) for 7 days. One group of mice received topical decorin (1.07 mg/mL) eye drops to one eye and saline (0.9%) to the contralateral eye; the other group received saline eye drops to both eyes. All eye drops were given three times daily over the experimental period. A control group (n = 8) received daily topical saline only, instead of BAK. Optical coherence tomography imaging was performed before (at day 0) and after (day 7) treatment to evaluate the central corneal thickness. Whole-mount immunofluorescence staining was performed to evaluate the density of corneal intraepithelial nerves and immune cells.

Results

BAK-exposed eyes showed corneal epithelial thinning, infiltration of inflammatory macrophages and neutrophils, and a lower density of intraepithelial nerves. No change to the corneal stromal thickness or dendritic cell density was observed. After BAK exposure, decorin-treated eyes had a lower density of macrophages and less neutrophil infiltration and a higher nerve density than the saline-treated group. Contralateral eyes from the decorin-treated animals showed fewer macrophages and neutrophils relative to saline-treated animals. A negative correlation was found between corneal nerve density and macrophage or neutrophil density.

Conclusions

Topical decorin provides neuroprotective and anti-inflammatory effects in a chemical model of BAK-induced corneal neuropathy. The attenuation of corneal inflammation by decorin may contribute to decreasing corneal nerve degeneration induced by BAK.

Neuroimmune crosstalk in the cornea: The role of immune cells in corneal nerve maintenance during homeostasis and inflammation

In the cornea, resident immune cells are in close proximity to sensory nerves, consistent with their important roles in the maintenance of nerves in both homeostasis and inflammation. Using in vivo confocal microscopy in humans, and ex vivo immunostaining and fluorescent reporter mice to visualize corneal sensory nerves and immune cells, remarkable progress has been made to advance our understanding of the physical and functional interactions between corneal nerves and immune cells. In this review, we summarize and discuss recent studies relating to corneal immune cells and sensory nerves, and their interactions in health and disease. In particular, we consider how disrupted corneal nerve axons can induce immune cell activity, including in dendritic cells, macrophages and other infiltrating cells, directly and/or indirectly by releasing neuropeptides such as substance P and calcitonin gene-related peptide. We summarize growing evidence that the role of corneal intraepithelial immune cells is likely different in corneal wound healing versus other inflammatory-dominated conditions. The role of different types of macrophages is also discussed, including how stromal macrophages with anti-inflammatory phenotypes communicate with corneal nerves to provide neuroprotection, while macrophages with pro-inflammatory phenotypes, along with other infiltrating cells including neutrophils and CD4⁺ T cells, can be inhibitory to corneal re-innervation. Finally, this review considers the bidirectional interactions between corneal immune cells and corneal nerves, and how leveraging this interaction could represent a potential therapeutic approach for corneal neuropathy.

Impact of Lacrimal Gland Extraction on the Contralateral Eye in an Animal Model for Dry Eye Disease

Purpose

Although there is still no consensus on the best animal model for dry eye disease research, a model based on lacrimal gland extraction (LGE) model is widely used. In this study, we aimed to investigate the histopathological changes taking place on the contralateral eye after unilateral LGE to determine whether it is useful as a control.

Methods

Seven-week-old male C57BL/6 mice were divided into naive control, environmental chamber model, and LGE groups. Corneal fluorescein staining was scored to quantify the severity of damage. Morphological changes in the cornea, conjunctiva, and lacrimal gland (LG) were determined by hematoxylin and eosin staining and compared to those on naive control animals.

Results

Compared to naive subjects, the unilateral LGE model showed enhanced corneal erosion scores and loss of conjunctival goblet cells, not only on the ipsilateral but also on the contralateral side. These changes in the ocular surface became more pronounced in a time-dependent manner. Furthermore, loss of LG acinar cells and leukocyte infiltration were detected in the contralateral LGs of the LGE model.

Conclusions

Considering the changes observed in the ocular surface and LGs, the contralateral side of the LGE model may not offer proper control conditions for the experimental comparison of the effects of dry eye disease in vivo. There may be regulatory feedback or crosstalk system between both eyes activated in response to LGE.

The effect of topical decorin on temporal changes to corneal immune cells after epithelial abrasion

BACKGROUND

Corneal immune cells interact with corneal sensory nerves during both homeostasis and inflammation. This study sought to evaluate temporal changes to corneal immune cell density in a mouse model of epithelial abrasion and nerve injury, and to investigate the immunomodulatory effects of topical decorin, which we have shown previously to promote corneal nerve regeneration.

METHODS

Bilateral corneal epithelial abrasions (2 mm) were performed on C57BL/6J mice. Topical decorin or saline eye drops were applied three times daily for 12 h, 24 h, 3 days or 5 days. Optical coherence tomography imaging was performed to measure the abrasion area. The densities of corneal sensory nerves (β-tubulin III) and immune cells, including dendritic cells (DCs; CD11c⁺), macrophages (Iba-1⁺) and neutrophils (NIMP-R14⁺) were measured. Cx3cr1^gfp/gfp mice that spontaneously lack resident corneal intraepithelial DCs were used to investigate the specific contribution of epithelial DCs. Neuropeptide and cytokine gene expression was evaluated using qRT-PCR at 12 h post-injury.

RESULTS

In decorin-treated corneas, higher intraepithelial DC densities and lower neutrophil densities were observed at 24 h after injury, compared to saline controls. At 12 h post-injury, topical decorin application was associated with greater re-epithelialisation. At 5 days post-injury, corneal stromal macrophage density in the decorin-treated and contralateral eyes was lower, and nerve density was higher, compared to eyes treated with saline only. Lower expression of transforming growth factor beta (TGF-β) and higher expression of CSPG4 mRNA was detected in corneas treated with topical decorin. There was no difference in corneal neutrophil density in Cx3cr1^gfp/gfp mice treated with or without decorin at 12 h.

CONCLUSIONS

Topical decorin regulates immune cell dynamics after corneal injury, by inhibiting neutrophils and recruiting intraepithelial DCs during the acute phase (< 24 h), and inhibiting macrophage density at the study endpoint (5 days). These immunomodulatory effects were associated with faster re-epithelialisation and likely contribute to promoting sensory nerve regeneration. The findings suggest a potential interaction between DCs and neutrophils with topical decorin treatment, as the decorin-induced neutrophil inhibition was absent in Cx3cr1^gfp/gfp mice that lack corneal epithelial DCs. TGF-β and CSPG4 proteoglycan likely regulate decorin-mediated innate immune cell responses and nerve regeneration after injury.

Bilateral Increase of the Matrix Metalloproteinase-9 Expression in Tears After the Unilateral Decrease of Corneal Sensitivity

PURPOSE

The purpose of this study is to analyze bilateral changes of matrix metalloproteinase-9 (MMP-9) expression in the tear film in patients with unilateral neurotrophic keratitis.

METHODS

We included 24 eyes from 24 subjects with normal corneal sensitivity according to Cochet-Bonnet corneal esthesiometry in the control group and 25 subjects with the unilateral neurotrophic keratitis in the unilateral decrease of corneal sensitivity (UDCS) group. The expression of MMP-9 in tears was assessed using point-of-care immunoassay. The clinical parameters including meibomian gland plugging, quality of the secreted meibum, tear secretion using Schirmer I without anesthesia, and corneal erosions were evaluated among the control, affected, and contralateral unaffected eyes in the UDCS group.

RESULTS

Tear MMP-9 grades in affected (2.5 ± 1.0) and contralateral eyes (2.6 ± 0.9) in the UDCS group were higher than those in control eyes (1.5 ± 0.7, P = 0.0003 and P = 0.0006, respectively). The lacrimal secretion decreased in the affected eyes but preserved in the contralateral eyes. There was no difference in corneal erosion scores between control eyes and contralateral eyes in the UDCS group. Tear MMP-9 grades in the contralateral eyes were significantly correlated with the meibum quality grades in the contralateral eyes (r = 0.525 and P = 0.025).

CONCLUSIONS

Patients with the unilateral neurotrophic keratitis demonstrated a significant bilateral increase of the MMP-9 expression in the tear film as compared with controls. Despite the tearing reflex and corneal surface barrier being preserved in the unaffected contralateral eyes, it is necessary to pay attention to the possible attenuation of meibomian gland function in the opposite eyes as well.

Time-Dependent Serial Changes of Antigen-Presenting Cell Subsets in the Ocular Surface Are Distinct between Corneal Sterile Inflammation and Allosensitization in a Murine Model

The kinetics of antigen-presenting cells (APCs) vary depending on their resident tissues and the manner of immunization. We investigated the long-term changes in mature APC and T-cell subsets over 4 weeks in the ocular surface in murine models of corneal quiescent or potent sterile inflammation, and allosensitization using partial (PT), syngeneic (Syn), and allogeneic (Allo) corneal transplantation. In PT, CD11b^intCD11c^hiMHCII^hiCD86^hi cells increased until 4 weeks with an increase in IFNγ^hi T cells. In Syn, both CD11b^intCD11c^hiMHCII^hiCD86^hi and CD11b^hiCD11c^hiMHCII^hiCD86^hi APC subsets increased until 4 weeks with a brief increase in CD69^hi T cells at 2 weeks. In Allo, CD11b^intCD11c^hiMHCII^hiCD86^hi and CD11b^hiCD11c^hiMHCII^hiCD86^hi APC subsets increased until 4 weeks, and an early increase in CD69^hi T cells was observed at 2 weeks followed by a late increase in IFNγ^hi T cells at 4 weeks. The frequency of the IFNγ^hi T cell subset was positively correlated with the frequency of the CD11b^intCD11c^hiMHCII^hiCD86^hi subset, indicating the existence of APC–T cell interaction in the ocular surface. Together, the results indicate that allosensitization in mature APCs leads to T-cell activation in the ocular surface, whereas sterile inflammation merely induces a brief and non-specific T-cell activation in the ocular surface.

Morphological and Functional Changes of Corneal Nerves and Their Contribution to Peripheral and Central Sensory Abnormalities

The cornea is the most densely innervated and sensitive tissue in the body. The cornea is exclusively innervated by C- and A-delta fibers, including mechano-nociceptors that are triggered by noxious mechanical stimulation, polymodal nociceptors that are excited by mechanical, chemical, and thermal stimuli, and cold thermoreceptors that are activated by cooling. Noxious stimulations activate corneal nociceptors whose cell bodies are located in the trigeminal ganglion (TG) and project central axons to the trigeminal brainstem sensory complex. Ocular pain, in particular, that driven by corneal nerves, is considered to be a core symptom of inflammatory and traumatic disorders of the ocular surface. Ocular surface injury affecting corneal nerves and leading to inflammatory responses can occur under multiple pathological conditions, such as chemical burn, persistent dry eye, and corneal neuropathic pain as well as after some ophthalmological surgical interventions such as photorefractive surgery. This review depicts the morphological and functional changes of corneal nerve terminals following corneal damage and dry eye disease (DED), both ocular surface conditions leading to sensory abnormalities. In addition, the recent fundamental and clinical findings of the importance of peripheral and central neuroimmune interactions in the development of corneal hypersensitivity are discussed. Next, the cellular and molecular changes of corneal neurons in the TG and central structures that are driven by corneal nerve abnormalities are presented. A better understanding of the corneal nerve abnormalities as well as neuroimmune interactions may contribute to the identification of a novel therapeutic targets for alleviating corneal pain.

Lacrimal gland excision in male and female mice causes ocular pain and anxiety-like behaviors

Lacrimal gland excision (LGE) induced dry eye produces more severe corneal damage in female mice, yet signs of LGE-induced ocular pain and anxiety in male and female mice have not been characterized. Excision of either the extraorbital gland (single LGE), or both the extraorbital and intraorbital glands (double LGE) was performed in male and female C57BL/6J mice to induce moderate and severe dry eye. Ongoing pain was assessed by quantifying palpebral opening and evoked nociceptive responses after corneal application of capsaicin and menthol. The open-field and plus maze were used to assess anxiety. Single LGE caused a reduction in palpebral opening and an increase in capsaicin and menthol-evoked responses only in female mice. Furthermore, single LGE produced signs of increased anxiety in female but not male mice. Overall, female mice appear more susceptible to signs of ocular pain, irritation, and anxiety in response to aqueous tear deficiency.

Correlations between tear fluid and aqueous humor cytokine levels in bullous keratopathy

PURPOSE

To evaluate the correlation between tear fluid and aqueous humor (AqH) cytokine levels in eyes with bullous keratopathy (BK) and with normal endothelium.

METHODS

This prospective consecutive case-series study included 71 eyes of 71 patients: 31 eyes with BK, 18 eyes with non-BK corneal diseases, and 22 eyes with uncomplicated cataract (healthy controls). Total protein and cytokine (interleukin [IL]-1α, IL-1β, IL-4, IL-6, IL-8, IL-10, MIP-1α, MIP-1β, monocyte chemotactic protein [MCP]-1, E-selectin, P-selectin, soluble intercellular adhesion molecule [sICAM]-1, and IP-10) levels in the tear fluid and AqH were measured using multiplex beads immunoassay. The correlations between tear and AqH cytokine levels were assessed.

RESULTS

The AqH protein level was significantly higher in BK eyes (1.09 ± 0.08 mg/mL) than in non-BK (0.63 ± 0.11, P = 0.0004) and healthy control (0.62 ± 0.06, P = 0.0002) eyes. The tear total protein and IL-4 levels were significantly higher in the BK group compared to healthy controls (P = 0.0374 and 0.0032, respectively). The AqH IL-8 and sICAM-1 levels were significantly higher in the BK group compared to controls (P = 0.0001 and 0.0083, respectively). In BK eyes, the tear IL-4 level was significantly correlated with the MCP-1(r = 0.563, P = 0.001) and total protein (r = 0.589, P = 0.001) AqH levels. The tear IL-8 level was significantly correlated with the MCP-1(r = 0.598, p = 0.001) and IL-4 (r = 0.781, p < 0.0001) AqH levels in BK eyes. However, no significant correlations were found between tear and AqH cytokine levels in non-BK and healthy controls eyes.

CONCLUSIONS

The tear cytokine levels are correlated with those of AqH only in BK, but not in non-BK and healthy controls.

Comparative Analysis of Age-Related Changes in Lacrimal Glands and Meibomian Glands of a C57BL/6 Male Mouse Model

It is not known how biological changes in the lacrimal (LGs) and meibomian (MGs) glands contribute to dry eye disease (DED) in a time-dependent manner. In this study, we investigated time-sequenced changes in the inflammation, oxidative stress, and senescence of stem cells in both glands of an aging-related DED mouse model. Eight-week (8W)-, one-year (1Y)-, and two-year (2Y)-old C57BL/6 male mice were used. MG areas of the upper and lower eyelids were analyzed by transillumination meibography imaging. The number of CD45⁺, 8-OHdG⁺, Ki-67⁺, and BrdU⁺ cells was compared in both glands. Increased corneal staining and decreased tear secretion were observed in aged mice. The MG dropout area increased with aging, and the age-adjusted MG area in lower lids was negatively correlated with the National Eye Institute (NEI) score. Increased CD4⁺ interferon (IFN)-γ⁺ cells in LGs were found in both aged mice. An increase in 8-OHdG⁺ cells in both glands was evident in 2Y-old mice. Reduced Ki-67⁺ cells, but no change in CD45⁺ cells, was observed in the MGs of 1Y-old mice. Increased BrdU⁺ cells were observed in the LGs of aged mice. This suggests that age-dependent DED in C57BL/6 mice is related to inflammation of the LGs, the development of MG atrophy, and oxidative stress in both glands.

Bilateral morphometric analysis of corneal sub-basal nerve plexus in patients undergoing unilateral cataract surgery: a preliminary in vivo confocal microscopy study

AIMS

To evaluate bilateral morphometric changes of corneal sub-basal nerve plexus (CSNP) occurring after unilateral cataract surgery by in vivo confocal microscopy (IVCM) images analysed with automated software.

METHODS

IVCM was performed before (V0) and 1 month after surgery (V1) in both operated eyes (OEs) and unoperated eyes (UEs) of 30 patients. Thirty age and sex-matched subjects acted as controls. Corneal nerve fibre density (CNFD), corneal nerve branch density (CNBD), corneal nerve fibre length (CNFL), corneal nerve total branch density (CTBD), corneal nerve fibre area (CNFA), corneal nerve fibre width, corneal nerve fractal dimension (CNFrD) and dendritic cells density were calculated.

RESULTS

Mean CNFD, CNBD, CNFL, CTBD, CNFA and CNFrD significantly decreased at V1 versus V0 in both eyes (respectively, 15.35±7.00 vs 21.21±6.56 n/mm² in OEs and 20.11±6.69 vs 23.20±7.26 in UEs; 13.57±12.16 vs 26.79±16.91 n/mm² in OEs and 24.28±14.88 vs 29.76±15.25 in UEs; 9.67±3.44 mm/mm² vs 13.49±3.42 in OEs and 12.53±3.60 vs 14.02±3.82 in UEs; 22.81±18.77 vs 42.25±24.64 n/mm² in OEs and 38.06±20.52 vs 43.93±22.27 in UEs; 0.0040±0.0021 vs 0.0058±0.0020 mm²/mm² in OEs and 0.0049±0.0016 vs 0.0057±0.0019 in UEs; 1.418±0.058 vs 1.470±0.037 in OEs and 1.466±0.040 vs 1.477±0.036 in UEs; always p<0.049).

CONCLUSION

Patients undergoing cataract surgery exhibit bilateral alterations of CSNP. This finding could have broad implications in the setting of sequential cataract surgery.

Topographical and Morphological Differences of Corneal Dendritic Cells during Steady State and Inflammation

PURPOSE

We report novel differences in mouse corneal DC morphology and density during local and systemic inflammation.

METHODS

Local inflammation was induced by topical application of saline or TLR9 agonist CpG-ODN on abraded C57BL6J mouse corneas. Systemic inflammation was induced by intraperitoneal injection of lipopolysaccharide (LPS) in CD11c-YFP mice. Corneal epithelial DCs from uninjured, injured and contralateral eyes were analysed by confocal microscopy.

RESULTS

Following local CpG delivery on the injured cornea, the DC density and size increased in both central and peripheral regions. Contralateral uninjured eyes displayed enlarged DC morphology in the central cornea compared to naïve cohorts. After systemic LPS, the size of DCs in the central cornea was lower at 2 hours, returning to baseline after 24 hours.

CONCLUSIONS

Corneal DCs respond differently in terms of shape and distribution during local and systemic inflammation. These features can serve as in vivo indicators in ocular and systemic diseases.