Suppression of Neovascularization by Topical and Subconjunctival Bevacizumab After High-Risk Corneal Transplantation

Purpose

To assess the effectiveness of topical and subconjunctival bevacizumab in suppressing vascularization in graft and host bed after high-risk corneal transplantation.

Design

Secondary analysis of prospective, randomized, double-blind, placebo-controlled multicentric clinical trial.

Participants

The study includes patients aged > 18 years who underwent high-risk penetrating keratoplasty, which was defined as corneal vascularization in ≥ 1 quadrants of the corneal graft and host bed, excluding the limbus.

Methods

Patients were randomized to treatment and control groups. The patients in the treatment group received subconjunctival injection of bevacizumab (2.5 mg/0.1 ml) on the day of the procedure, followed by topical bevacizumab (10 mg/ml) 4 times per day for 4 weeks. The patients in control group received injection of vehicle (0.9% sodium chloride) on the day of procedure, followed by topical vehicle (carboxymethylcellulose sodium 1%) 4 times a day for 4 weeks.

Main Outcome Measures

Vessel and invasion area of vessels in the corneal graft and host beds.

Results

This study included 56 eyes of 56 patients who underwent high-risk corneal transplantation, with equal numbers in the bevacizumab and vehicle (control) treatment groups. The mean age of patients who received bevacizumab was 61.2 ± 15.9 years, and the mean age of those treated with vehicle was 60.0 ± 16.1 years. The vessel area at baseline was comparable in the bevacizumab (16.72% ± 3.19%) and control groups (15.48% ± 3.12%; P = 0.72). Similarly, the invasion areas were also similar in the treatment (35.60% ± 2.47%) and control (34.23% ± 2.64%; P = 0.9) groups at baseline. The reduction in vessel area was significantly higher in the bevacizumab-treated group (83.7%) over a period of 52 weeks compared with the control group (61.5%; P < 0.0001). In the bevacizumab-treated group, invasion area was reduced by 75.8% as compared with 46.5% in the control group. The vessel area was similar at 52 weeks postprocedure in cases of first (3.54% ± 1.21%) and repeat (3.80% ± 0.40%) corneal transplantation in patients who received bevacizumab treatment. In the vehicle-treated patients, the vessel area was significantly higher in repeat (9.76% ± 0.32%) compared with first (8.06% ± 1.02%; P < 0.0001) penetrating keratoplasty. In the bevacizumab treatment group, invasion areas at week 52 were comparable in first (11.70% ± 3.38%) and repeat (11.64% ± 1.74%) procedures, whereas invasion area was significantly higher in repeat (27.87% ± 2.57%) as compared with first (24.11% ± 2.17%) penetrating keratoplasty in vehicle-treated patients.

Conclusions

In patients undergoing vascularized high-risk corneal transplantation, bevacizumab is efficacious in reducing vascularization of corneal graft and host bed, thereby reducing the risk of corneal graft rejection in vascularized host beds.

Financial Disclosures

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Clinical Course and Outcomes of Autoimmune Versus Non-Autoimmune Surgically Induced Scleral Necrosis: A Multicentric Comparative Study

BACKGROUND

To analyze the clinical course and outcomes of autoimmune vs. non-autoimmune surgically induced scleral necrosis (SISN).

METHODS

Multicentric, retrospective, comparative cohort study. Eighty-two eyes of 70 patients with SISN were classified according to pathogenic mechanism into autoimmune vs. non-autoimmune. Main outcome measures included necrosis onset, type of surgery, associated systemic disease, visual acuity, and treatment were analysed in patients followed for ≥ 6 months.

RESULTS

Forty-six (65.7%) patients were women, and the median age was 66 (range: 24-90) years. Most patients (82.9%) had unilateral disease. The median time between surgery and SISN onset was 58 (1-480) months. Thirty-one (37.8%) eyes were classified as autoimmune, and 51 (62.2%) as non-autoimmune SISN. Autoimmune SISN was associated with a shorter time between the surgical procedure and SISN onset than non-autoimmune cases (median of 26 vs. 60 months, p = 0.024). Also, autoimmune SISN was associated with cataract extraction (93.5% vs. 25.5%, p < 0.001), severe scleral inflammation (58.1% vs. 17.6%, p < 0.001), and higher incidence of ocular complications (67.7% vs. 33.3%, p = 0.002) than non-autoimmune cases. Remission was achieved with medical management alone in 44 (86.3%) eyes from the non-autoimmune and in 27 (87.1%) from the autoimmune group (p = 0.916). Surgical management was required in 11 (13.4%) eyes, including two requiring enucleations due to scleral perforation and phthisis bulbi.

CONCLUSIONS

Eyes with autoimmune SISN had a higher rate of cataract surgery, severe scleral inflammation, and ocular complications. Early SISN diagnosis and appropriate management, based on clinical features and pathogenic mechanisms, are critical to avoid sight-threatening complications.

Retinal transplant immunology and advancements

Several gaps and barriers remain for transplanting stem cells into the eye to treat ocular disease, especially diseases of the retina. While the eye has historically been considered immune privileged, recent thinking has identified the immune system as both a barrier and an opportunity for eye stem cell transplantation. Recent approaches leveraging scaffolds or cloaking have been considered in other tissues beyond immune suppression. This perspective paper outlines approaches for transplantation and proposes opportunities to overcome barriers of the immune system in stem cell transplantation in the eye.

Lessons Learned From Ocular Graft versus Host Disease: An Ocular Surface Inflammatory Disease of Known Time of Onset

ABSTRACT

The ocular surface inflammatory disorders (OSIDs) comprise a group of conditions characterized by persistent inflammation of the ocular surface and adnexal tissues. Systemic autoimmune diseases and hypersensitivity reactions cause them, and, if left untreated, can result in severe inflammatory dry eye, corneal damage, and vision loss. Ocular graft-versus-host disease (oGVHD) forms part of the ocular surface inflammatory disease umbrella. It is a condition occurring after allogeneic hematopoietic stem cell or bone marrow transplantation, usually in chronic graft-versus-host disease. oGVHD can virtually affect any ocular adnexal tissue, especially the meibomian glands, and cause persistent inflammation, tissue fibrosis, and subsequent chronic, severe dry eye disease. Among the OSIDs, oGVHD has the particularity that it has a "time zero," meaning we know when the disease started. As such, preclinical models have leveraged this to investigate the molecular mechanisms involved in the damage oGVHD causes to the ocular surface. In oGVHD, establishing a "time zero" allows for predicting the clinical course and establishing adequate treatment. This is also possible because the inflammatory infiltration occurs in ocular surface tissues, which are readily accessible. Using oGVHD, we might be able to understand the immune response mechanisms in other OSIDs better (i.e., Sjögren syndrome, Stevens-Johnson syndrome, among others). This review presents an up-to-date overview of the pathogenesis, clinical presentation, and treatment of oGVHD. In addition, we will discuss the value of the "time zero" concept in the study of oGVHD.

The Yin and Yang of non-immune and immune responses in meibomian gland dysfunction

Meibomian gland dysfunction (MGD) is a leading cause of dry eye disease and one of the most common ophthalmic conditions encountered in eye clinics worldwide. These holocrine glands are situated in the eyelid, where they produce specialized lipids, or meibum, needed to lubricate the eye surface and slow tear film evaporation - functions which are critical to preserving high-resolution vision. MGD results in tear instability, rapid tear evaporation, changes in local microflora, and dry eye disease, amongst other pathological entities. While studies identifying the mechanisms of MGD have generally focused on gland obstruction, we now know that age is a major risk factor for MGD that is associated with abnormal cell differentiation and renewal. It is also now appreciated that immune-inflammatory disorders, such as certain autoimmune diseases and atopy, may trigger MGD, as demonstrated through a T cell-driven neutrophil response. Here, we independently discuss the underlying roles of gland and immune related factors in MGD, as well as the integration of these two distinct mechanisms into a unified perspective that may aid future studies. From this unique standpoint, we propose a revised model in which glandular dysfunction and immunopathogenic pathways are not primary versus secondary contributors in MGD, but are fluid, interactive, and dynamic, which we likened to the Yin and Yang of MGD.

Ocular Mucous Membrane Pemphigoid: The Effect of Risk Factors at Presentation on Treatment Outcomes

PURPOSE

Analyze the influence of risk factors at presentation in the long-term immunosuppressive therapy (IMT) outcomes of ocular mucous membrane pemphigoid (OMMP).

DESIGN

Retrospective multicenter study.

PARTICIPANTS

Patients with OMMP seen at the Duke Eye Center, Tecnologico de Monterrey, and Hospital Clinic of Barcelona from 1990 to 2022.

METHODS

Data at presentation on demographics, direct immunofluorescence, ocular findings, sites of extraocular manifestations (EOMs), and previous treatments in patients with a clinical or laboratory diagnosis of OMMP, were analyzed with multivariable analysis and Kaplan-Meier plots to identify factors associated with adverse outcomes.

MAIN OUTCOME MEASURES

(1) Inflammatory control (no conjunctival inflammation in both eyes at 3 months on IMT); (2) relapse (new-onset inflammation after absolute control in either eye); (3) progression (≥ 1 cicatrizing stage progression in either eye); and (4) vision loss (≥ 2 Snellen lines).

RESULTS

A total of 117 patients (234 eyes), 61% (71/117) of whom were women, with a mean age of 66.6 (SD: 12.4) years (range: 37-97 years) and median follow-up of 34 months (interquartile range: 16-66 months; range: 3-265 months), were enrolled. Inflammatory control was achieved in 57% of patients (67/117), with high-risk EOM (HR-EOM), including esophageal, nasopharyngeal, and/or genital involvement (adjusted odds ratio [aOR]: 12.51; 95% confidence interval [CI]: 2.61-59.99; P = 0.002) and corneal scarring (aOR: 3.06; 95% CI, 1.15-8.14; P = 0.025), as significant risk factors for persistent inflammation. Disease relapse, progression, and vision loss occurred in 20% of patients (23/117), 12% of patients (14/117), and 27% of patients (32/117), respectively. Baseline corneal scarring was a risk factor for relapse (adjusted hazard ratio: 4.14; 95% CI: 1.61-10.62; P = 0.003), progression (aOR: 11.46; 95% CI: 1.78-73.75; P = 0.010), and vision loss (aOR: 3.51; 95% CI: 1.35-9.10; P = 0.010). HR-EOM was associated with stage progression (aOR, 34.57; 95% CI, 6.57-181.89; P<0.001) and vision loss (aOR, 8.42; 95% CI, 2.50-28.42; P = 0.001). No significant differences were found between IMT regimes and relapse (P = 0.169).

CONCLUSIONS

Ocular mucous membrane pemphigoid presenting with HR-EOMs and corneal scarring has an increased risk of stage progression and vision loss. Corneal scarring and severe inflammation at baseline were associated with an increased risk of relapse. A disease progression staging system incorporating both the HR-EOMs and corneal involvement is required to predict the visual outcome of OMMP better.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Pharmacogenomic Analysis of Response to Topical Tumor Necrosis Factor α Antagonist Licaminlimab (OCS-02) in Dry Eye Disease

PURPOSE

The purpose of this study was to evaluate the pharmacogenomics of response to topical ocular tumor necrosis factor α (TNFα) inhibitor licaminlimab in patients with DED.

METHODS

Three single-nucleotide polymorphisms (SNPs) associated with Sjögren syndrome, 3 in the TNFα gene and 1 in the TNF receptor 1 (TNFR1) gene, were assessed for association with response to licaminlimab in participants from a randomized, vehicle-controlled, Phase 2 study in which adults with DED and severe ocular discomfort persisting despite treatment with artificial tears received licaminlimab or vehicle for 6 weeks. Response was assessed for change from baseline in Global Ocular Discomfort score at Day 29 of treatment. The pharmacogenomic analysis was a prospectively specified exploratory objective of the study. mRNA expression for TNFα, interleukin (IL) 1β, and IL8 in conjunctival epithelium cells was determined. The relationship between SNPs and response to licaminlimab was assessed using a mixed model repeated measures analysis.

RESULTS

SNP rs1800693 in the TNFR1 gene showed a significant effect on response to licaminlimab (P < 0.0001, initial association test); no effect was seen for any of the other SNPs tested. The CC genotype of rs1800693 was associated with much greater response to licaminlimab than the CT or TT genotypes: LS mean changes from baseline to Day 29 in Global Ocular Discomfort score were -29.5, -0.09, and -3.90, in patients with the CC, CT, and TT genotypes, respectively (P < 0.0001). No significant effect was observed in vehicle-treated patients. Improvements from baseline were seen in 3/4 licaminlimab-treated participants with the CC genotype. Conjunctival epithelium cell levels of mRNA for TNFα, IL1β, and IL8 decreased from baseline in participants with the CC genotype, but not with the CT or TT genotypes. Between-genotype differences in mRNA levels were not observed in participants receiving vehicle.

CONCLUSIONS

The CC genotype of rs1800693, relatively common in patients with DED, was strongly associated with response to licaminlimab and decreased inflammatory cytokine gene expression in ocular surface cells during treatment. This study is one of the first to our knowledge to investigate pharmacogenomics in the treatment of DED.

Validation of the C-DU(KE) Calculator as a Predictor of Outcomes in Patients Enrolled in Steroids for Corneal Ulcer and Mycotic Ulcer Treatment Trials

PURPOSE

The aim of this study was to validate the C-DU(KE) calculator as a predictor of treatment outcomes on a data set derived from patients with culture-positive ulcers.

METHODS

C-DU(KE) criteria were compiled from a data set consisting of 1063 cases of infectious keratitis from the Steroids for Corneal Ulcer Trial (SCUT) and Mycotic Ulcer Treatment Trial (MUTT) studies. These criteria include corticosteroid use after symptoms, visual acuity, ulcer area, fungal etiology, and elapsed time to organism-sensitive therapy. Univariate analysis was performed followed by multivariable logistic regressions on culture-exclusive and culture-inclusive models to assess for associations between the variables and outcome. The predictive probability of treatment failure, defined as the need for surgical intervention, was calculated for each study participant. Discrimination was assessed using the area under the curve for each model.

RESULTS

Overall, 17.9% of SCUT/MUTT participants required surgical intervention. Univariate analysis showed that decreased visual acuity, larger ulcer area, and fungal etiology had a significant association with failed medical management. The other 2 criteria did not. In the culture-exclusive model, 2 of 3 criteria, decreased vision [odds ratio (OR) = 3.13, P < 0.001] and increased ulcer area (OR = 1.03, P < 0.001), affected outcomes. In the culture-inclusive model, 3 of 5 criteria, decreased vision (OR = 4.9, P < 0.001), ulcer area (OR = 1.02, P < 0.001), and fungal etiology (OR = 9.8, P < 0.001), affected results. The area under the curves were 0.784 for the culture-exclusive model and 0.846 for the culture-inclusive model which were comparable to the original study.

CONCLUSIONS

The C-DU(KE) calculator is generalizable to a study population from large international studies primarily taking place in India. These results support its use as a risk stratification tool assisting ophthalmologists in patient management.

A Randomized, Controlled Trial Comparing Tearcare® and Cyclosporine Ophthalmic Emulsion for the Treatment of Dry Eye Disease (SAHARA)

Purpose

We compare outcomes in eyes with dry eye disease (DED) treated with TearCare (TC) or topical cyclosporine 0.05% (RESTASIS; CsA).

Setting

Nineteen ophthalmic and optometric practices in 11 US states.

Design

Multicenter, randomized, assessor-masked, controlled IRB-approved trial. Eligible subjects: ≥22 years of age, dry eye symptoms within 3-6 months, Tear Break-up Time (TBUT) ≥1 to ≤7 s, Meibomian Gland Secretion Score (MGSS) ≤12, Ocular Surface Disease Index (OSDI) of 23-79. Randomized (1:1) to TC or CsA. TC subjects treated at baseline and month 5; CsA was twice daily for 6 months.

Methods

Follow-up visits were scheduled for Day 1, Week 1, Months 1, 3, and 6 with primary inference at Month 6. Primary outcomes: TBUT and OSDI; secondary outcomes: MGSS, conjunctival and corneal staining, eye dryness score (EDS), symptoms assessment in dry eye (SANDE) score, and Schirmer tear score (STS). Safety assessments included adverse events, best corrected visual acuity, intraocular pressure, and slit-lamp findings.

Results

Overall, 345 subjects, 172 TC and 173 CsA. TBUT improved at all time points in both groups (p<0.0001), with statistically greater improvement for TC versus CsA (p=0.0006). OSDI improved significantly at all time points in both groups (p<0.0001) with no significant differences between treatments. MGSS and other measures of meibomian gland function improved significantly more with TC eyes versus CsA; other secondary outcomes showed significant improvements in both groups with no difference between groups. Treatment-related adverse events were uncommon (10 total, 8 in the CsA group consistent with prior CsA studies); most (9/10) mild.

Conclusion

TC provides statistically superior and sustained improvement in TBUT and multiple measures of meibomian gland secretion, and non-inferior improvement in OSDI, corneal and conjunctival staining, SANDE, EDS, and STS versus CsA. TC should be a preferred treatment for DED associated with MGD.

Long-Term Comprehensive Management of Bilateral Limbal Stem Cell Deficiency Secondary to Severe Chemical Burn: 10 Years of Follow-Up

PURPOSE

To describe the long-term management of bilateral limbal stem cell deficiency secondary to a severe chemical burn.

METHODS

Descriptive case report.

IMPORTANCE

This case highlights the importance of early intervention in ocular chemical burns for the preservation of tissue integrity and avoidance of perforation. We also review the use of proper ocular surface reconstructive techniques to restore the function of the limbal area, as well as the immunomodulatory strategies and follow-up needed for these interventions.

Open-Source Automated Segmentation of Neuronal Structures in Corneal Confocal Microscopy Images of the Subbasal Nerve Plexus With Accuracy on Par With Human Segmentation

PURPOSE

The aim of this study was to perform automated segmentation of corneal nerves and other structures in corneal confocal microscopy (CCM) images of the subbasal nerve plexus (SNP) in eyes with ocular surface diseases (OSDs).

METHODS

A deep learning-based 2-stage algorithm was designed to perform segmentation of SNP features. In the first stage, to address applanation artifacts, a generative adversarial network-enabled deep network was constructed to identify 3 neighboring corneal layers on each CCM image: epithelium, SNP, and stroma. This network was trained/validated on 470 images of each layer from 73 individuals. The segmented SNP regions were further classified in the second stage by another deep network as follows: background, nerve, neuroma, and immune cells. Twenty-one-fold cross-validation was used to assess the performance of the overall algorithm on a separate data set of 207 manually segmented SNP images from 43 patients with OSD.

RESULTS

For the background, nerve, neuroma, and immune cell classes, the Dice similarity coefficients of the proposed automatic method were 0.992, 0.814, 0.748, and 0.736, respectively. The performance metrics for automatic segmentations were statistically better or equal as compared to human segmentation. In addition, the resulting clinical metrics had good to excellent intraclass correlation coefficients between automatic and human segmentations.

CONCLUSIONS

The proposed automatic method can reliably segment potential CCM biomarkers of OSD onset and progression with accuracy on par with human gradings in real clinical data, which frequently exhibited image acquisition artifacts. To facilitate future studies on OSD, we made our data set and algorithms freely available online as an open-source software package.

Murine models of graft versus host disease (GVHD): Focus on ocular GVHD

Graft versus host disease (GVHD) remains a major and serious complication of allogeneic hematopoietic stem cell transplantation. Based on the time of onset, clinical phenotypes, progression kinetics, and pathophysiology, GVHD is stratified into acute, chronic, and overlapping types. The eyes are among the most commonly affected organs in GVHD. Mouse models have played an important role in understanding the several key elements of GVHD pathobiology. The current review discusses the immunology, pathology, and key phenotypic features of mouse models of systemic GVHD. Furthermore, a critical appraisal of mouse models of ocular GVHD (oGVHD) is provided. The disease mechanisms underlying the ocular surface, meibomian gland, and lacrimal gland injury in these models are reviewed, and the relevance of oGVHD murine models to clinical oGVHD is also included.

Delayed presentation of surgically induced scleral necrosis after I-BRITE procedure treated with immunosuppressive therapy

Surgically induced scleral necrosis (SISN) is an uncommon complication of ocular procedures. Cosmetic eye-whitening surgery involves conjunctival and Tenon's capsule dissection, cautery, and mitomycin C application. We report the case of a 36-year-old white woman referred to our clinic for severe pain, scleral inflammation, and necrosis in both eyes 9 years after I-BRITE, an elective eye-whitening procedure. An extensive workup yielded negative results. The patient improved with aggressive lubrication and topical and high-dose systemic prednisone (60 mg), with recurrence upon steroid tapering. Concomitant weekly methotrexate was added, resulting in inflammatory control and allowing discontinuance of topical and oral steroids.

Ocular surface disease: a known yet overlooked side effect of topical glaucoma therapy

Ocular surface disease (OSD), a disorder affecting the lacrimal and meibomian glands and the corneal and conjunctival epithelium, is a well-known complication of topical glaucoma therapy. OSD can present as a new or pre-existing condition that virtually any anti-glaucoma formulation can exacerbate. As such, both glaucoma and OSD frequently coexist. Typical OSD symptoms include ocular discomfort, redness, burning, and dryness, whereas signs include periorbital and eyelid skin pigmentation, conjunctival scarring, and superficial punctate keratitis. Pressure-lowering eyedrops can cause toxic, allergic, and inflammatory reactions on the ocular surface. The latter can result from either preservatives or direct toxicity from the active molecule. Although usually mild, OSD can cause significant symptoms that lead to poor quality of life, decreased compliance to therapy, glaucoma progression, and worse visual outcomes. Given the chronic nature of glaucoma, lack of curative therapy, and subsequent lifelong treatment, addressing OSD is necessary. This manuscript aims to provide an up-to-date overview of OSD's signs, symptoms, and pathogenic mechanisms from glaucoma therapy toxicity.

TFOS Lifestyle: Impact of elective medications and procedures on the ocular surface

The word "elective" refers to medications and procedures undertaken by choice or with a lower grade of prioritization. Patients usually use elective medications or undergo elective procedures to treat pathologic conditions or for cosmetic enhancement, impacting their lifestyle positively and, thus, improving their quality of life. However, those interventions can affect the homeostasis of the tear film and ocular surface. Consequently, they generate signs and symptoms that could impair the patient's quality of life. This report describes the impact of elective topical and systemic medications and procedures on the ocular surface and the underlying mechanisms. Moreover, elective procedures performed for ocular diseases, cosmetic enhancement, and non-ophthalmic interventions, such as radiotherapy and bariatric surgery, are discussed. The report also evaluates significant anatomical and biological consequences of non-urgent interventions to the ocular surface, such as neuropathic and neurotrophic keratopathies. Besides that, it provides an overview of the prophylaxis and management of pathological conditions resulting from the studied interventions and suggests areas for future research. The report also contains a systematic review investigating the quality of life among people who have undergone small incision lenticule extraction (SMILE). Overall, SMILE refractive surgery seems to cause more vision disturbances than LASIK in the first month post-surgery, but less dry eye symptoms in long-term follow up.

Increasing Rates of Herpes Zoster Ophthalmicus and the COVID-19 Pandemic

Purpose

This epidemiologic study evaluates the variance in incidence of Herpes Zoster (HZ) and Herpes Zoster Ophthalmicus (HZO) within a single healthcare system with an aim to analyze their relationship to the COVID-19 pandemic.

Methods

All patients attending the Duke University Health System (DUHS) from January 1, 2018, to December 31, 2021, were included. General and COVID-related trends of HZO and HZ were analyzed based on new ICD-9 or ICD-10 diagnosis codes, compared with the total number of patients seen at DUHS during this period, and the number of reported COVID-19 cases in North Carolina obtained using the CDC data tracker.

Results

This study included 16,287 cases of HZ of whom 1,294 (7.94%) presented with HZO. The overall incidence of HZO showed an average yearly increase of 5.6%, however HZ incidence decreased by 5.3% per year. When comparing incidence rates of HZO in the 12-months before and after the COVID-19 pandemic onset in the United States (March 2020), the average incidence from March 2020 to February 2021 was 27.6 ± 11.6 compared to 18.0 ± 2.7 from March 2019 to February 2020 (p = 0.01). Moreover, 10/12 (83.3%) of the months had a higher incidence rate of HZO in the post-COVID onset year compared to their corresponding month in the pre-COVID year.

Conclusion

The results show HZO incidence may be increasing, despite an overall lower HZ incidence. This could suggest a distinct mechanism for HZO appearance. The COVID pandemic, directly or indirectly, may have accelerated the already increasing HZO incidence.

Wessely corneal ring phenomenon: An unsolved pathophysiological dilemma

The cornea is a densely innervated, avascular tissue showing exceptional inflammatory and immune responses. The cornea is a site of lymphangiogenic and angiogenic privilege devoid of blood and lymphatic vessels that limits the entry of inflammatory cells from the adjacent and highly immunoreactive conjunctiva. Immunological and anatomical differences between the central and peripheral cornea are also necessary to sustain passive immune privilege. The lower density of antigen-presenting cells in the central cornea and the 5:1 peripheral-to-central corneal ratio of C1 are 2 main features conferring passive immune privilege. C1 activates the complement system by antigen-antibody complexes more effectively in the peripheral cornea and, thus, protects the central corneas' transparency from immune-driven and inflammatory reactions. Wessely rings, also known as corneal immune rings, are non-infectious ring-shaped stromal infiltrates usually formed in the peripheral cornea. They result from a hypersensitivity reaction to foreign antigens, including those of microorganism origin. Thus, they are thought to be composed of inflammatory cells and antigen-antibody complexes. Corneal immune rings have been associated with various infectious and non-infectious causes, including foreign bodies, contact lens wear, refractive procedures, and drugs. We describe the anatomical and immunologic basis underlying Wessely ring formation, its causes, clinical presentation, and management.

Anti-Inflammatories in the Treatment of Dry Eye Disease: A Review

Inflammation is an important driver of dry eye disease (DED) pathogenesis. An initial insult that results in the loss of tear film homeostasis can initiate a nonspecific innate immune response that leads to a chronic and self-sustaining inflammation of the ocular surface, which results in classic symptoms of dry eye. This initial response is followed by a more prolonged adaptive immune response, which can perpetuate and aggravate inflammation and result in a vicious cycle of chronic inflammatory DED. Effective anti-inflammatory therapies can help patients exit this cycle, and effective diagnosis of inflammatory DED and selection of the most appropriate treatment are therefore key to successful DED management and treatment. This review explores the cellular and molecular mechanisms of the immune and inflammatory components of DED, and examines the evidence base for the use of currently available topical treatment options. These agents include topical steroid therapy, calcineurin inhibitors, T cell integrin antagonists, antibiotics, autologous serum/plasma therapy, and omega-3 fatty acid dietary supplements.

Meibomian Gland Dysfunction: A Route of Ocular Graft-Versus-Host Disease Progression That Drives a Vicious Cycle of Ocular Surface Inflammatory Damage

PURPOSE

To investigate the role of aggressive meibomian gland dysfunction (MGD) in the immune pathogenesis of ocular graft-vs-host disease (GVHD).

METHODS

In mice, an allogeneic GVHD model was established by transferring bone marrow (BM) and purified splenic T cells from C57BL/6J mice into irradiated C3-SW.H2b mice (BM+T). Control groups received BM only. Mice were scored clinically across the post-transplantation period. MGD severity was categorized using the degree of atrophy on harvested lids. Immune disease was analyzed using flow cytometry of tissues along with fluorescent tracking of BM cells onto the ocular surface. In humans, parameters from 57 patients with ocular GVHD presenting to the Duke Eye Center were retrospectively reviewed. MGD was categorized using the degree of atrophy on meibographs. Immune analysis was done using high-parameter flow cytometry on tear samples.

RESULTS

Compared with BM only, BM+T mice had higher systemic disease scores that correlated with tear fluid loss and eyelid edema. BM+T had higher immune cell infiltration in the ocular tissues and higher CD4+-cell cytokine expression in draining lymph nodes. BM+T mice with worse MGD scores had significantly worse corneal staining. In patients with ocular GVHD, 96% had other organs affected. Patients with ocular GVHD had abnormal parameters on dry eye testing, high matrix metalloproteinase-9 positivity (92%), and abundance of immune cells in tear samples. Ocular surface disease signs were worse in patients with higher MGD severity scores.

CONCLUSIONS

Ocular GVHD is driven by a systemic, T-cell-dependent process that causes meibomian gland damage and induces a robust form of ocular surface disease that correlates with MGD severity. NOTE: Publication of this article is sponsored by the American Ophthalmological Society.

Noxious effects of riot control agents on the ocular surface: Pathogenic mechanisms and management

Riot Control Agents (RCAs) are chemical compounds used by law enforcement agencies to quell violent demonstrations as an alternative to lethal force and as part of police/military training. They are also known as tear gases because of the hallmark ocular irritation and lacrimation they cause. The most common RCAs include oleoresin capsicum (contained in Mace and pepper spray), chlorobenzylidene malononitrile, dibenzoxazepine, and chloroacetophenone (previously the main content of Mace); some of which have been in use for decades. Their immediate incapacitating effects are mediated through polymodal afferent fibers innervating the corneal surface, inducing the release of peptides that cause neurogenic inflammation. Although previously thought to have only transient effects on exposed patients more severe complications such as corneal stromal opacities, corneal neovascularization, neurotrophic keratopathy, conjunctival necrosis, and pseudopterygium can occur. Concerningly, the lack of research and specific therapies restrict the current management to decontamination and symptom-tailored support. This manuscript will provide an overview of the toxic mechanisms of RCAs, their clinical manifestations, and current therapy after exposure to tear gases.

Establishment of a bi-layered tissue engineered conjunctiva using a 3D-printed melt electrowritten poly-(ε-caprolactone) scaffold

PURPOSE

To utilize melt electrowriting (MEW) technology using poly-(ε-caprolactone) (PCL) coupled with a 2-step co-culturing strategy for the development of a conjunctival bi-layer synthetic construct.

METHODS

Melt electrowritten scaffolds using PCL were fabricated using an in-house-built MEW printer. Human conjunctival stromal cells (CjSCs) and epithelial cells (CjECs) were isolated from donor tissue. A 2-step co-culture method was done by first seeding the CjSCs and culturing for 4 weeks to establish a stromal layer, followed by CjECs and co-culturing for 2 more weeks. Cultured cells were each characterized by morphology and marker expression on immunofluorescence and qPCR. The produced construct was assessed for cellular proliferation using viability assays. The bi-layer morphology was assessed using scanning electron microscopy (SEM), confocal microscopy, and immunofluorescence imaging. The expression of extracellular matrix components and TGF-b was evaluated using qPCR.

RESULTS

CjSCs were spindle-shaped and vimentin + while CjECs were polygonal and CK13 + . CjSCs showed consistent proliferation and optimal adherence with the scaffold at the 4-week culture mark. A 2-layered construct consisting of a CjSC-composed stromal layer and a CjEC-composed epithelial layer was appreciated on confocal microscopy, SEM, and immunofluorescence. CjSCs secreted collagens (types I, V, VI) but at differing amounts from natural tissue while TGF-b production was comparable.

CONCLUSION

The 3D-printed melt electrowritten PCL scaffold paired with the 2-step co-culturing conditions of the scaffold allowed for the first approximation of a bi-layered stromal and epithelial reconstruction of the conjunctiva that can potentially improve the therapeutic arsenal in ocular surface reconstruction.

Fluorescein CorneoGraphy (FCG): Use of a repurposed fluorescein imaging technique to objectively standardize corneal staining

Punctate epithelial erosion (PEE) is a corneal sign of dry eye disease (DED), which is observable via staining with fluorescein on slit lamp as a standard of clinical practice and clinical research. There are currently many limitations for detecting PEE, such as lack of optimal excitation with cobalt blue light, difficulty to focus on the whole cornea, observer dependency and no available automatized quantification. We propose to reduce these limitations through repurposing the use of fluorescein angiography mode of optical coherence tomography (OCT, Heidelberg Spectralis II, Germany), as “fluorescein corneography” (FCG) for imaging PEE. A standard methodology was created using 50 patients with corneal staining and 10 healthy volunteers who were imaged on both slit lamp and FCG on two centers. Subsequently, two masked cornea specialists graded slit lamp and FCG images of 15 patients using the National Eye Institute (NEI) scale.

FCG showed both a higher interobserver agreement (IOA), and a higher intraclass correlation coefficient (ICC) than slit lamp (0.96 vs 0.86, p<0.001). Light- colored iris patients showed a statistically significant lower mean of epitheliopathy on slit lamp compared to FCG (6.11 vs 8.94; p=0.026), which was not the case with dark-colored iris patients (8.16 vs 8.25; p=0.961)

In conclusion we present an OCT-FA system for robust detection of PEE which has major implications in both clinical practice and research endpoints since it is highly sensitive, rigorous, reproducible in different facilities and offers potential for a numerical quantification and automatization of dry-eye corneal staining

Multicenter prospective validation study for international chronic ocular graft-versus-host disease consensus diagnostic criteria

PURPOSE

To validate the international chronic ocular graft-versus-host disease (GVHD) diagnostic criteria (ICCGVHD) compared to the National Institute of Health diagnostic criteria 2014 (NIH2014) for chronic ocular GVHD.

METHODS

Between 2013 and 2019, the study enrolled 233 patients with or without chronic ocular GVHD combined with the presence or absence of systemic chronic GVHD in an internationally prospective multicenter and observational cohort from 9 institutions. All patients were evaluated for four clinical parameters of ICCGVHD.

RESULTS

The relation between the ICCGVHD score (0-11) and NIH2014 eye score (0-4) was relatively high (r = 0.708, 95% CI: 0.637-0.767, p < 0.001). The sensitivity and specificity of ICCGVHD for NIH 2014 for 233 patients were 94.3% (95% CI: 89.6%-98.1%) and 71.7% (95% CI: 63.0-79.5%), respectively (cutoff value of the ICCGVHD score = 6). The positive predictive value was 77.1% (95% CI: 71.1%-82.1%), and the negative predictive value was 87.0% (95% CI:81.6-92.5%). For the patients with systemic GVHD (n = 171), the sensitivity and specificity were 94.2% and 67.2%, respectively (ICCGVHD-score cutoff value = 6). By receiver operating characteristic (ROC) curve analysis, the area under the curve (AUC) was 0.903 (95% CI: 0.859-0.948). For patients without systemic GVHD (n = 62), the sensitivity and specificity were 100% and 76.7%, respectively (ICCGVHD-score cutoff value = 6). The AUC was 0.891 (95% CI 0.673-1.000).

CONCLUSIONS

Good sensitivity, specificity, predictive value and correlation were found between ICCGVHD and NIH2014. ICCGVHD scores ≥6 can be useful to diagnose ocular GVHD with or without systemic GVHD for clinical research.

Bevacizumab in High-Risk Corneal Transplantation: A Pilot Multicenter Prospective Randomized Control Trial

PURPOSE

To determine the efficacy of local (subconjunctival and topical) bevacizumab (Avastin) treatment in patients undergoing vascularized high-risk corneal transplantation.

DESIGN

Pilot, prospective, randomized, double-blind, placebo-controlled clinical trial conducted at 5 clinical centers in the United States, India, and Brazil.

PARTICIPANTS

Patients aged > 18 years undergoing high-risk penetrating keratoplasty, defined as corneal neovascularization (NV) in 1 or more quadrants ≥2 mm from the limbus or extension of corneal NV to the graft-host junction in a previously failed graft.

METHODS

Patients were randomized to receive subconjunctival bevacizumab (2.5 mg/0.1 ml) or placebo at the time of surgery, followed by topical bevacizumab (10 mg/ml) or topical placebo, administered 4 times per day for 4 weeks.

MAIN OUTCOME MEASURE

The 52-week endothelial immune rejection rate.

RESULTS

Ninety-two patients were randomized to receive bevacizumab (n = 48) or control (n = 44). The 52-week endothelial rejection rate was 10% in the bevacizumab group and 19% in the control group (P = 0.20). Post hoc, extended follow-up at the lead study site showed an endothelial rejection rate of 3% in the bevacizumab group and 38% in the control group (P = 0.003). Treatment with bevacizumab was found to have a hazard ratio of 0.15 (95% confidence interval, 0.03-0.65, P = 0.01) in a post hoc Cox regression analysis.

CONCLUSIONS

In patients undergoing vascularized high-risk corneal transplantation, there was no statistically significant difference in the rate of endothelial rejection at 1 year in the bevacizumab treatment group compared with the control group. This study may have been underpowered to detect a difference between treatment groups, and taken together, our data suggest that, in the current trial design, bevacizumab has a positive but not (yet) significant effect on endothelial rejection.

Ocular Surface Inflammatory Disorders (OSID): A Collective of Systemic Etiologies Which Cause or Amplify Dry Eye Syndrome

The ocular surface inflammatory disorders (OSID) are caused by systemic disorders that conduct a persistent inflammatory reaction in the ocular adnexal connective tissues, such as the conjunctiva, lacrimal gland (LG) and meibomian glands (MGs), which cause an inflammatory dry eye. The etiologies of OSID are a subset of systemic pathologies such as graft versus host disease, Sjögren’s syndrome, allergies, cicatrizing conjunctivitis, and more. These cause a purely inflammatory dry eye syndrome as a consequence of the persistent surrounding inflammation in the adnexal tissues, which is distinct from the age-related dry eye disease. A limitation toward management of these conditions is the lack of available biomarkers that can detect presence of inflammation and quantify damage on the conjunctiva and LG, even though these are considered to be drivers of the inflammatory milieu. The OSID and dry eye syndrome are caused by different immune cells which are not exclusively limited to T cell lymphocytes, but rather derive from an orchestrated multicellular immunologic response. Recognition of this syndrome is crucial to direct research in a direction that clarifies the potential role of inflammation and its associated immune phenotype on the conjunctiva and adnexal ocular tissues in OSID and dry eye syndrome. On this paper, we review the basic and clinical research evidence for the existence of OSID with focus on the different immune cells involved, the target tissues and potential consequences and OSIDs diagnostic and therapeutic implications.

Recipient Tregs: Can They Be Exploited for Successful Hematopoietic Stem Cell Transplant Outcomes?

Human and mouse CD4⁺FoxP3⁺ T cells (Tregs) comprise non-redundant regulatory compartments which maintain self-tolerance and have been found to be of potential therapeutic usefulness in autoimmune disorders and transplants including allogeneic hematopoietic stem cell transplantation (allo-HSCT). There is substantial literature interrogating the application of donor derived Tregs for the prevention of graft versus host disease (GVHD). This Mini-Review will focus on the recipient's Tregs which persist post-transplant. Although treatment in patients with low dose IL-2 months post-HSCT are encouraging, manipulating Tregs in recipients early post-transplant is challenging, in part likely an indirect consequence of damage to the microenvironment required to support Treg expansion of which little is understood. This review will discuss the potential for manipulating recipient Tregs in vivo prior to and after HSCT (fusion proteins, mAbs). Strategies that would circumvent donor/recipient peripheral blood harvest, cell culture and ex-vivo Treg expansion will be considered for the translational application of Tregs to improve HSCT outcomes.

A multicenter report of the use of plasma rich in growth factors (PRGF) for the treatment of patients with ocular surface diseases in North America

PURPOSE

To investigate the efficacy and safety of plasma rich in growth factors (PRGF) eyedrops in the management of patients with ocular surface diseases in North America.

METHODS

Multicenter interventional case series of patients using PRGF eyedrops for the first time. A cohort of patients was analyzed for corneal staining score at initial visit and at 3 months of therapy with PRGF. Another cohort responded to a 10-item questionnaire that evaluated patients' satisfaction and safety, which included the symptom assessment questionnaire in dry eye (SANDE) score, after 6 months of PRGF treatment.

RESULTS

A total of 153 patients were analyzed. Of these, 102 were reviewed for corneal epitheliopathy and 99 patients responded to the questionnaire. The mean (±SD) age of the population was 63.7 ± 17 years and 72.5% were female. The clinical indications for PRGF usage were dry eye (60%), neurotrophic keratopathy (15%), dormant corneal ulcers (12%), limbal stem cell deficiency (10%), and cicatrizing conjunctivitis (4%). At the final visit, 74.3% of patients showed an improvement of their corneal staining. Those who had punctate epithelial erosions or epithelial defects were reduced from 76.5% to 47% and 23.5%-7.8% respectively (p < 0.0001). Symptoms, measured via SANDE score, significantly decreased from a median of 90 to 34.6 out of 100 points on follow-up (p < 0.0001). Only one patient (0.98%) complained of ocular burning sensation as a side effect.

CONCLUSIONS

This multicentric study demonstrates the safety and efficacy of the use of PRGF for treating signs and symptoms in patients with significant ocular surface diseases.

Recognizing vitamin A deficiency: special considerations in low-prevalence areas

PURPOSE OF REVIEW

Although vitamin A deficiency (VAD) is rare in well resourced countries, there is a growing trend of VAD in at-risk pediatric populations. Early diagnosis is critically important to prevent its associated morbidity and mortality. This review highlights key lessons for evaluation, diagnosis, and management of children with xerophthalmia in the United States. It synthesizes the latest findings from the literature on the pathophysiology, epidemiology, risk factors, evaluation, and management of VAD in low-prevalence areas.

RECENT FINDINGS

Vitamin A is crucial for maintaining the functional integrity of the eye, immune system, skin, and mucous membranes. Despite the scarcity of VAD in developed countries, there are increasing reports of VAD in at-risk children, including those with autism spectrum disorder and gastrointestinal conditions. There is a broad range of manifestations of VAD, posing a diagnostic challenge. Familiarity with the variable presentations of VAD and having a high index of suspicion in at-risk populations can aid in its early diagnosis. Systemic vitamin A supplementation and a multidisciplinary approach are important components of the management of VAD.

SUMMARY

Even in well resourced countries, VAD should remain on the differential in patients with risk factors who present with relevant signs and symptoms. Early diagnosis and appropriate involvement of a multidisciplinary care team can help prevent morbidity and mortality associated with VAD.

Risk Factors for Corneal Striae in Eyes After Glaucoma Surgery

PRCIS

Eyes with corneal striae had steeper cornea, induced astigmatism, and higher corneal hysteresis (CH), which implies a relationship between striae, corneal shape, and the cornea's resistance to deformation at low intraocular pressures (IOPs).

BACKGROUND

Anterior corneal striae (ACS) are associated with low IOP. However, the clinical significance of ACS is unclear. Here, we aim to evaluate differences in eyes with striae compared with eyes without striae.

METHODS

Adults with ACS (cases) and without ACS (controls) ≥8 weeks after glaucoma surgery with an IOP ≤10 mm Hg were enrolled. Optical coherence tomography and optical biometry were performed. CH, defined as the difference in pressure between corneal indentation and reformation in response to an air jet, was obtained by the ocular response analyzer. Hypotony maculopathy (HM) was defined as optic disc swelling, vascular tortuosity attributed to hypotony, or clinical presence of chorioretinal folds confirmed on OCT.

RESULTS

One hundred sixteen eyes (76 cases, 40 controls) were included. Cases had a lower IOP compared with controls (6.5±2.3 vs. 8.5±1, P<0.0001). A 1 mm Hg increase in CH increased ACS odds [odds ratio (OR)=1.51, P=0.01]. A 1 D increase in the flattest presurgical and postsurgical corneal power increased ACS odds by 1.83 (P=0.01) and 1.41 (P=0.02), respectively. Astigmatism increased in eyes with ACS by 1.11 D (P<0.001). ACS odds were increased with every 1 minute increase in mitomycin-C duration (OR=1.58, P=0.047) and decreased with the use of topical glaucoma medication (OR=0.62, P=0.03). Visual acuity decreased from logarithm of the minimal angle of resolution 0.22 (20/33 Snellen) presurgery to 0.28 (20/38) postsurgery (P=0.008), independent of ACS. HM occurred in 19% of cases (P=0.05). A higher postsurgical CH increased HM odds (OR=1.8, P=0.003). HM predicted a 0.41 mm decrease in axial length (P<0.0001), independent of IOP.

CONCLUSION

ACS were associated with a steeper cornea, induced astigmatism, and higher CH, suggesting a relationship between striae, corneal shape, and the cornea's ability to resist deformations at lower IOP. CH, HM, and axial length shortening were associated independently of IOP.

Analyses and Correlation of Pathologic and Ocular Cutaneous Changes in Murine Graft versus Host Disease

Graft versus host disease (GVHD) is initiated by donor allo-reactive T cells activated against recipient antigens. Chronic GVHD (cGVHD) is characterized by immune responses that may resemble autoimmune features present in the scleroderma and Sjogren's syndrome. Unfortunately, ocular involvement occurs in approximately 60-90% of patients with cGVHD following allo-hematopoietic stem cell transplants (aHSCT). Ocular GVHD (oGVHD) may affect vision due to ocular adnexa damage leading to dry eye and keratopathy. Several other compartments including the skin are major targets of GVHD effector pathways. Using mouse aHSCT models, the objective was to characterize cGVHD associated alterations in the eye and skin to assess for correlations between these two organs. The examination of multiple models of MHC-matched and MHC-mismatched aHSCT identified a correlation between ocular and cutaneous involvement accompanying cGVHD. Studies detected a "positive" correlation, i.e., when cGVHD-induced ocular alterations were observed, cutaneous compartment alterations were also observed. When no or minimal ocular signs were detected, no or minimal skin changes were observed. In total, these findings suggest underlying cGVHD-inducing pathological immune mechanisms may be shared between the eye and skin. Based on the present observations, we posit that when skin involvement is present in aHSCT patients with cGVHD, the evaluation of the ocular surface by an ophthalmologist could potentially be of value.

Associated Neurotrophic Keratopathy in Complex Regional Pain Syndrome

PURPOSE

To report a case of neurotrophic keratopathy (NK) in a patient with complex regional pain syndrome (CRPS) with ipsilateral facial involvement.

METHODS

Case report.

RESULTS

An 18-year old woman with a 5-year history of CRPS type I, a systemic disorder with a neuropathic component with associated limb and right facial involvement, presented with an insidious onset of blurred vision and pain in the right eye. Ocular examination revealed decreased corneal sensation, as measured by Cochet-Bonnet testing, associated with recurrent epithelial defects and whorl-like superficial corneal epitheliopathy. NK was suspected and confirmed by in vivo confocal microscopy (IVCM), which revealed rarefaction of the subbasal nerve plexus in the affected eye. To enhance corneal nerve health, plasma rich in growth factors drops were used. Persistence of NK prompted a superficial keratectomy with placement of an amniotic membrane graft and a course of cenegermin 0.002% (Oxervate; Dompé Farmaceutici SpA, Italy) in the postoperative period. This combination therapy resulted in successful epithelial closure and vision improvement after 8 weeks of therapy with no recurrence of disease for 11 months. Importantly, at that final visit, IVCM demonstrated growth of corneal nerves for the first time in this patient.

CONCLUSIONS

This is the first case report of NK occurring in the context of CRPS, a neuropathy with ipsilateral facial pain involvement. IVCM was important in the diagnosis of NK, which responded successfully to ocular surface treatments focused on nerve health stimulation that ultimately resulted in corneal nerve growth.

Tissue engineering of corneal stroma via melt electrowriting

The cornea serves as the main refractive component of the eye with the corneal stroma constituting the thickest component in a stratified layered system of epithelia, stroma, and endothelium. Current treatment options for patients suffering from corneal diseases are limited to transplantation of a human donor cornea (keratoplasty) or to implantation of an artificial cornea (keratoprosthesis). Nevertheless, donor shortage and failure of artificial corneas to integrate with local tissue constitute important problems that have not been yet circumvented. Recent advances in biofabrication have made great progress toward the manufacture of tailored biomaterial templates with the potential of guiding partially or totally the regeneration process of the native cornea. However, the role of the corneal stroma on current tissue engineering strategies is often neglected. Here, we achieved a tissue-engineered corneal stroma substitute culturing primary keratocytes on scaffolds prepared via melt electrowriting (MEW). Scaffolds were designed to contain highly organized micrometric fibers to ensure transparency and encourage primary human keratocytes to self-orchestrate their own extracellular matrix deposition and remodeling. Results demonstrated reliable cell attachment and growth over a period of 5 weeks and confirmed the formation of a dense and highly organized de novo tissue containing collagen I, V, and VI as well as Keratocan, which resembled very closely the native corneal stoma. In summary, MEW brings us closer to the biofabrication of a viable corneal stroma substitute.

Prediction of corneal graft rejection using central endothelium/Descemet's membrane complex thickness in high-risk corneal transplants

To determine whether measurements of Endothelium/Descemet complex thickness (En/DMT) are of predictive value for corneal graft rejection after high-risk corneal transplantation, we conducted this prospective, single-center, observational case series including sixty eyes (60 patients) at high risk for corneal graft rejection (GR) because of previous immunologic graft failure or having at least two quadrants of stromal vascularization. Patients underwent corneal transplant. At 1st, 3rd, 6th, 9th, and 12th postoperative month, HD-OCT imaging of the cornea was performed, and the corneal status was determined clinically at each visit by a masked cornea specialist. Custom-built segmentation tomography algorithm was used to measure the central En/DMT. Relationships between baseline factors and En/DMT were explored. Time dependent covariate Cox survival regression was used to assess the effect of post-operative En/DMT changes during follow up. A longitudinal repeated measures model was used to assess the relationship between En/DMT and graft status. Outcome measures included graft rejection, central Endothelium/Descemet's complex thickness, and central corneal thickness (CCT). In patients with GR (35%), the central En/DMT increased significantly 5.3 months (95% CI: 2, 11) prior to the clinical diagnosis of GR, while it remained stable in patients without GR. During the 1-year follow up, the rejected grafts have higher mean pre-rejection En/DMTs (p = 0.01), compared to CCTs (p = 0.7). For En/DMT ≥ 18 µm cut-off (at any pre-rejection visit), the Cox proportional hazard ratio was 6.89 (95% CI: 2.03, 23.4; p = 0.002), and it increased to 9.91 (95% CI: 3.32, 29.6; p < 0.001) with a ≥ 19 µm cut-off. In high-risk corneal transplants, the increase in En/DMT allowed predicting rejection prior to the clinical diagnosis.

Understanding Immune Responses to Surgical Transplant Procedures in Stevens Johnsons Syndrome Patients

Stevens Johnsons syndrome (SJS) is a mucocutaneous disorder caused by an autoimmune response most commonly to medications. Unless it is properly managed in the acute setting, this entity can affect the ocular surface causing chronic cicatrizing conjunctivitis with limbal stem cell deficiency and lid anomalies which ultimately result in corneal opacities that may limit patients' visual acuity. When this stage is reached, some patients might need to undergo some form of corneal and/or limbal stem cell transplantation that exposes an already sensitized immune system to a new alloantigen. While the innate immunity plays a role in corneal graft survival, adaptive immune responses play a major part in corneal graft rejection and failure, namely through CD4+ T cell lymphocytes. Hence, the management of the immune response to surgical transplant procedures in SJS patients, involves a dual approach that modulates the inflammatory response to a new alloantigen in the context of an autoimmune sensitized patient. This review will explore and discuss current perspectives and future directions in the field of ocular immunology on how to manage SJS immune responses to ocular surgical procedures, reviewing systemic and local immunosuppressive therapies and protocols to adequately manage this debilitating condition.

Aftermarket effects of cenegermin for neurotrophic keratopathy in pediatric patients

PURPOSE

Neurotrophic keratopathy (NK) is a rare condition characterized by poor corneal sensation and healing. Cenegermin (topical recombinant nerve growth factor) has gained traction as a medical therapy for NK in recent years, and is FDA-approved for patients over two years old. However, no major trials have demonstrated the drug's efficacy in children. This study reviews the outcomes of cenegermin therapy in a pediatric patient population.

METHODS

Retrospective case series of patients from three tertiary referral institutions who 1) initiated an 8-week course of cenegermin therapy, and 2) were 18 years or less at time of treatment initiation.

RESULTS

Eight pediatric patients, with a total of nine affected eyes, underwent cenegermin therapy. All eight patients had previously trialed other NK-specific treatments, none of which had been entirely successful. Five patients (63%) completed the full eight-week therapy course. Five patients (63%) experienced clinical improvement not attributed to another treatment, through improved corneal ulcer stage (n = 5) and best-corrected visual acuity (n = 2). Clinical improvements persisted through a mean recurrence-free period of 10 months. Adverse effects reported during therapy included ocular pain, difficulty sleeping, and continued corneal thinning.

CONCLUSION

The results provide modest support for the use of cenegermin in pediatric patients with neurotrophic keratopathy. The primary benefit was an improvement in corneal epithelial stability. Clinicians should be aware that pre-existing corneal scarring in NK may significantly limit the ability of cenegermin alone to improve visual acuity, and should closely monitor the corneal epithelial status during therapy in pediatric patients.

In vivo quantitative analysis of anterior chamber white blood cell mixture composition using spectroscopic optical coherence tomography

Anterior uveitis is the most common form of intraocular inflammation, and one of its main signs is the presence of white blood cells (WBCs) in the anterior chamber (AC). Clinically, the true composition of cells can currently only be obtained using AC paracentesis, an invasive procedure to obtain AC fluid requiring needle insertion into the AC. We previously developed a spectroscopic optical coherence tomography (SOCT) analysis method to differentiate between populations of RBCs and subtypes of WBCs, including granulocytes, lymphocytes and monocytes, both in vitro and in ACs of excised porcine eyes. We have shown that different types of WBCs have distinct characteristic size distributions, extracted from the backscattered reflectance spectrum of individual cells using Mie theory. Here, we further develop our method to estimate the composition of blood cell mixtures, both in vitro and in vivo. To do so, we estimate the size distribution of unknown cell mixtures by fitting the distribution observed using SOCT with a weighted combination of reference size distributions of each WBC type calculated using kernel density estimation. We validate the accuracy of our estimation in an in vitro study, by comparing our results for a given WBC sample mixture with the cellular concentrations measured by a hemocytometer and SOCT images before mixing. We also conducted a small in vivo quantitative cell mixture validation pilot study which demonstrates congruence between our method and AC paracentesis in two patients with uveitis. The SOCT based method appears promising to provide quantitative diagnostic information of cellular responses in the ACs of patients with uveitis.

Meibomian gland dysfunction is suppressed via selective inhibition of immune responses by topical LFA-1/ICAM antagonism with lifitegrast in the allergic eye disease (AED) model

PURPOSE

The etiology of meibomian gland dysfunction (MGD) is incompletely understood, despite being a common ophthalmic condition and an area of unmet medical need. It is characterized by an insufficiency in glandular provision of specialized lipids (meibum) to the tear film and is a major cause of dry eye. Work in the allergic eye disease (AED) mouse model has revealed an immunopathogenic role in MGD causation, now raising interest in the applicability of immunomodulatory therapies. As such, we herein ask whether inhibition of lymphocyte function associated antigen (LFA)-1/intracellular adhesion molecules (ICAM)-1 signaling via topical lifitegrast administration has a therapeutic effect on MGD in AED mice.

METHODS

Mice were induced with AED by i.p. injection of ovalbumin (OVA) mixed with alum and pertussis toxin, followed 2 weeks later by once daily topical OVA challenges for 7 days. Mice were treated topically with 5% lifitegrast ophthalmic solution or vehicle (PBS) 30 min prior to challenge. We developed a clinical ranking method to assess MGD severity, and also scored clinical allergy. Conjunctivae and draining lymph nodes were collected for flow cytometry.

RESULTS

Topical lifitegrast significantly inhibited clinical MGD severity, which was associated with diminished pathogenic T_H17 cell and neutrophil numbers in the conjunctiva. No significant change in conjunctival T_H2 cells or eosinophils, and only marginal differences in ocular allergy were observed.

CONCLUSIONS

In AED mice, lifitegrast inhibited MGD severity marked by a reduction in select immune populations in the conjunctiva. Our findings warrant future examination of lifitegrast in the treatment of patients with forms of MGD.

Use of autologous plasma rich in growth factors fibrin membrane in the surgical management of ocular surface diseases

PURPOSE

To evaluate the safety and efficacy of the surgical use of autologous plasma rich in growth factors fibrin membrane (mPRGF) in improving corneal wound healing and regeneration in a variety of complex ocular surface defects.

METHODS

Chart review on 15 eyes of 14 included patients undergoing ocular surface intervention using intraoperative mPRGF at the Bascom Palmer Eye Institute and at the Instituto Oftalmológico Fernández-Vega was performed. Patients were grouped based on type of intervention or condition (penetrating keratoplasty, superficial keratectomy, neurotrophic or persistent corneal ulcers, and corneal perforation). Patients were followed for an average of 11 ± 5 months. Main outcomes measured were mPRGF dissolving time, best-corrected visual acuity, and evidence of any persistent epithelial defects, rejections, or complications.

RESULTS

All 15 eyes underwent successful placement of mPRGF. Average dissolving time for fibrin membrane was 21 ± 3 days. mPRGF resulted in total healing of the corneal defects in 13/15 (86.7%) of the treated eyes and partial healing in 2/15 (13.3%) eyes in which persistent epithelial defects were noted on follow-up. Visual acuity improvement was seen in 9/15 (60%) of the cases.

CONCLUSION

The use of autologous mPRGF in the healing and regeneration of the ocular surface is a secure and efficacious surgical option. Our data demonstrate that PRGF fibrin membrane should be contemplated as an important tool to optimize ocular surface regeneration in complex cases.

Use of Post-transplant Cyclophosphamide Treatment to Build a Tolerance Platform to Prevent Liquid and Solid Organ Allograft Rejection

Corneal transplantation (CT) is the most frequent type of solid organ transplant (SOT) performed worldwide. Unfortunately, immunological rejection is the primary cause of graft failure for CT and therefore advances in immune regulation to induce tolerance remains an unmet medical need. Recently, our work and others in pre-clinical studies found that cyclophosphamide (Cy) administered after (“post-transplant,” PTCy) hematopoietic stem cell transplantation (HSCT), i.e., liquid transplants is effective for graft vs. host disease prophylaxis and enhances overall survival. Importantly, within the past 10 years, PTCy has been widely adopted for clinical HSCT and the results at many centers have been extremely encouraging. The present studies found that Cy can be effectively employed to prolong the survival of SOT, specifically mouse corneal allografts. The results demonstrated that the timing of PTCy administration is critical for these CT and distinct from the kinetics employed following allogeneic HSCT. PTCy was observed to interfere with neovascularization, a process critically associated with immune rejection of corneal tissue that ensues following the loss of ocular “immune privilege.” PTCy has the potential to delete or directly suppress allo-reactive T cells and treatment here was shown to diminish T cell rejection responses. These PTCy doses were observed to spare significant levels of CD4⁺ FoxP3⁺ (Tregs) which were found to be functional and could readily receive stimulating signals leading to their in vivo expansion via TNFRSF25 and CD25 agonists. In total, we posit future studies can take advantage of Cy based platforms to generate combinatorial strategies for long-term tolerance induction.

The cornea IV immunology, infection, neovascularization, and surgery chapter 1: Corneal immunology

PURPOSE

of Review: This review offers an informed and up-to-date insight on the immune profile of the cornea and the factors that govern the regulation of such a unique immune environment.

SUMMARY

The cornea is a unique tissue that performs the specialized task of allowing light to penetrate for visual interpretation. To accomplish this, the ocular surface requires a distinct immune environment that is achieved through unique structural, cellular and molecular factors. Not only must the cornea be able to fend off invasive infectious agents but also control the inflammatory response as to avoid collateral, and potentially blinding damage; particularly of post-mitotic cells such as the corneal endothelium. To combat infections, both innate and adaptive arms of the inflammatory immune response are at play in the cornea. Dendritic cells play a critical role in coordinating both these responses in order to fend off infections. On the other side of the spectrum, the ocular surface is also endowed with a variety of anatomic and physiologic components that aid in regulating the immune response to prevent excessive, potentially damaging, inflammation. This attenuation of the immune response is termed immune privilege. The balance between pro and anti-inflammatory reactions is key for preservation of the functional integrity of the cornea.

RECENT FINDINGS

The understanding of the molecular and cellular factors governing corneal immunology and its response to antigens is a growing field. Dendritic cells in the normal cornea play a crucial role in combating infections and coordinating the inflammatory arms of the immune response, particularly through coordination with T-helper cells. The role of neuropeptides is recently becoming more highlighted with different factors working on both sides of the inflammatory balance.

Granulicatella Adiacens as an Unusual Cause of Microbial Keratitis and Endophthalmitis: A Case Series and Literature Review

Purpose: To report two cases of microbial keratitis and/or endophthalmitis involving Granulicatella adiacens.Methods: Case series.Results: 24-year-old female with a history of Herpes simplex virus 1 (HSV-1) and Candida parapsilosis keratitis presented with a geographic epithelial defect and infiltrate in the left eye. Cultures were positive for HSV-1 and G. adiacens. Keratitis resolved with topical vancomycin and oral valacyclovir. A 65-year-old female with a history of type II diabetes and failed therapeutic penetrating keratoplasty presented with inferior corneal graft haze and vitreous inflammation of the right eye. Therapeutic penetrating keratoplasty and pars plana vitrectomy were performed, and the corneal button returned positive for G. adiacens. The patient was treated with topical and intravitreal vancomycin as well as topical and systemic steroids.Conclusions: These cases expand the literature on G. adiacens keratitis and endophthalmitis and corroborate the role of steroid use and prior surgery as paramount risk factors.

Inflammatory basis for dry eye disease flares

Most patients with chronic dry eye disease (DED) have episodic flares, which can be triggered by a variety of activities and environmental stresses. These flares are typically associated with rapid exacerbation of discomfort symptoms, followed by prolonged elevation of inflammation. In an acute flare, ocular surface inflammation begins with a nonspecific innate immune response, in some cases followed by a slower but more specific adaptive immune response. At the ocular surface, epithelial cells are central to the innate immune response, and we discuss their role in DED flares alongside the other core components. Epithelial cells and other cells of the innate response (neutrophils, monocytes, macrophages and dendritic cells) trigger flares in response to increased osmolarity, detected via pattern receptors on their cell surface. Ultimately, downstream signaling pathways activate innate and adaptive immune responses, with consequent inflammation and symptoms. In chronic DED, pathogenic T cells have infiltrated the ocular surface tissues. The established adaptive immune response is likely to lead to flare-ups at lower thresholds of stress, with inflammation maintained over a longer period. Increased understanding of the inflammatory cascades activated during a flare may guide management and improve outcomes.

Matrix metalloproteinase 9 positivity predicts long term decreased tear production

PURPOSE

To investigate long-term correlations between Matrix Metalloproteinase-9 (MMP-9) testing and dry eye (DE) parameters. Additionally, to evaluate variability in MMP-9 results over time and with anti-inflammatory treatment.

METHODS

Retrospective cohort study of DE patients with equal MMP-9 testing results (positive or negative) in both eyes and a minimum of 6 months of follow up. Our main outcome measure was to examine whether initial MMP-9 status affected change in DE parameters over time. Secondarily, we evaluated the frequency of MMP-9 status change over time and examined whether MMP-9 status change was impacted by treatment.

RESULTS

67 patients (76% female) fit the inclusion criteria. Mean age was 63 years with a mean follow up of 10.6 months. The majority (37/67, 55%) had concomitant systemic immune disease. MMP-9 testing was positive in both eyes in 39 individuals (58%) and negative in both eyes in 27 (42%) individuals. Of all DE parameters, initial MMP status predicted change in tear production. Individuals in the MMP-9 positive group had a greater decrease in production from baseline to final visit compared to the negative group (-2.6 vs 2.1, P = 0.013). In those initially MMP-9 positive, the frequency of becoming MMP-9 negative was higher in eyes treated with anti-inflammatory therapy compared to artificial tears (22.9% vs 3.3%, P = 0.106). However, only Lifitegrast 5% showed statistical significance compared to artificial tears (31.3% vs 3.3%, P = 0.044).

CONCLUSIONS

Eyes with detectable MMP-9 had significantly decreased tear production over time compared to those without detectable MMP-9. Anti-inflammatory treatment more frequently normalized MMP-9 compared to PFATs.

The Immunological Basis of Dry Eye Disease and Current Topical Treatment Options

Homeostasis of the lacrimal functional unit is needed to ensure a well-regulated ocular immune response comprising innate and adaptive phases. When the ocular immune system is excessively stimulated and/or immunoregulatory mechanisms are disrupted, the balance between innate and adaptive phases is dysregulated and chronic ocular surface inflammation can result, leading to chronic dry eye disease (DED). According to the Tear Film and Ocular Surface Society Dry Eye Workshop II definition, DED is a multifactorial disorder of the ocular surface characterized by impairment and loss of tear homeostasis (hyperosmolarity), ocular discomfort or pain, and neurosensory abnormalities. Dysregulated ocular immune responses result in ocular surface damage, which is a further contributing factor to DED pathology. Several therapeutics are available to break the vicious circle of DED and prevent chronic disease and progression, including immunosuppressive agents (steroids) and immunomodulators (cyclosporine and lifitegrast). Given the chronic inflammatory nature of DED, each of these agents is commonly used in clinical practice. In this study, we review the immunopathology of DED and the molecular and cellular actions of current topical DED therapeutics to inform clinical decision making.