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.

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.

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.

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.

Diagnosis and Management of Idiopathic Persistent Iritis after Cataract Surgery (IPICS).

PURPOSE: To investigate the diagnosis and management of patients with idiopathic persistent iritis after cataract surgery (IPICS). DESIGN: Retrospective interventional case series. METHODS: Patients diagnosed with IPICS were evaluated for demographic and clinical characteristics and immune blood markers. Those with more than 6 months of follow-up were evaluated for treatment efficacy to achieve remission (ie, absence of inflammation for 3 months), with either exclusive slow tapering of topical steroids or the need for systemic immunosuppression. RESULTS: Forty-five patients presented with IPICS. Most were African American (39, 86.7%) or female (33, 77.3%). Antinuclear antibodies were present in 23 (69.9%) of patients. Main complications were steroid dependency (38,84.4%), glaucoma (24,53.5%), and macular edema (11,37.5%). Thirty two patients presented treatment follow up. On these,the proposed treatment strategy achieved remission in 30 (93.8%) of cases in a mean of 6.1 months via tapering of topical steroids in 15 (46.9%) of patients. However, in 17 (53.1%) of cases, adjuvant anti-inflammatory systemic medication was indicated. Meloxicam use was associated with remission in 11 (64.7%) of these patients and, in a minority with persistent iritis, treatment was escalated to methotrexate, which was successful in 4 (100%) of the cases. CONCLUSIONS: IPICS is a distinct clinical anterior uveitis most common in African American and female patients, characterized by an unexpected onset of iritis after cataract surgery and high rates of steroid dependency, glaucoma, and macular edema. It is best treated with an initial slow taper of topical steroids; although adjuvant systemic anti-inflammatory therapy may be necessary to obtain remission and avoid complications.

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.

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.

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.