Risk factors influencing survival of acellular porcine corneal stroma in infectious keratitis: a prospective clinical study.

BACKGROUND: A worldwide lack of donor corneas demands the bioengineered corneas be developed as an alternative. The primary objective of the current study was to evaluate the efficacy of acellular porcine corneal stroma (APCS) transplantation in various types of infectious keratitis and identify risk factors that may increase APCS graft failure. METHODS: In this prospective interventional study, 39 patients with progressive infectious keratitis underwent therapeutic lamellar keratoplasty using APCS and were followed up for 12 months. Data collected for analysis included preoperative characteristics, visual acuity, graft survival and complications. Graft survival was evaluated by the Kaplan-Meier method and compared with the log-rank test. RESULTS: The percentage of eyes that had a visual acuity of 20/40 or better increased from 10.3% preoperatively to 51.2% at 12 months postoperatively. Twelve patients (30.8%) experienced graft failure within the follow-up period. The primary reasons given for graft failure was noninfectious graft melting (n = 5), and the other causes included recurrence of primary infection (n = 4) and extensive graft neovascularization (n = 3). No graft rejection was observed during the follow-up period. A higher relative risk (RR) of graft failure was associated with herpetic keratitis (RR = 8.0, P = 0.046) and graft size larger than 8 mm (RR = 6.5, P < 0.001). CONCLUSIONS: APCS transplantation is an alternative treatment option for eyes with medically unresponsive infectious keratitis. Despite the efficacy of therapeutic lamellar keratoplasty with APCS, to achieve a good prognosis, restriction of surgical indications, careful selection of patients and postoperative management must be emphasized. Trial registration Prospective Study of Deep Anterior Lamellar Keratoplasty Using Acellular Porcine Cornea, NCT03105466. Registered 31 August 2016, ClinicalTrails.gov.

Development of lacrimal gland inflammation in the mouse model of herpes stromal keratitis.

Herpes stromal keratitis (HSK) is a chronic immunoinflammatory condition which develops in response to recurrent herpes simplex virus-1 (HSV-1) infection of the cornea. Patients with HSK often demonstrate the concurrence of corneal desiccation and the loss of blink reflex. However, the relationship between severity of HSK, level of basal tears and inflammation of the lacrimal gland is mostly unexplored. In this study, we compared these variables in extraorbital lacrimal gland (EoLG) after corneal HSV-1 infection in the C57BL/6J mouse model. Our results showed a significant reduction in the volume of tears in infected eyes during the development of HSK. Extensive architectural damage to EoLG, presumably caused by a massive influx of interferon-gamma secreting T cells, was observed during clinical disease period of HSK. A positive correlation between the decrease in tear volume, severity of HSK and the damage to EoLG were evident in infected mice. The presence of infectious virus measured in EoLG during pre-clinical, but not clinical disease period of HSK, suggested that viral cytopathic effects are not the major contributors of extensive damage seen in EoLG. Furthermore, topical administration of lacritin peptide delayed but did not prevent the decrease in tears in HSV-1 infected mice, and had no significant effect in either reducing the severity of HSK or T cell infiltration in EoLG of infected mice. Together, our results showed an interplay between the severity of HSK, inflammation of EoLG, and the reduced level of tears after corneal HSV-1 infection.

Subclinical Herpes Simplex Virus Type 1 Infections Provide Site-Specific Resistance to an Unrelated Pathogen.

HSV-1 infections of the cornea range in severity from minor transient discomfort to the blinding disease herpes stromal keratitis, yet most patients experience a single episode of epithelial keratitis followed by re-establishment of a clear cornea. We asked whether a single transient episode of HSV-1 epithelial keratitis causes long-term changes in the corneal microenvironment that influence immune responses to subsequent corneal infection or trauma. We showed that C57BL/6 mouse corneas infected with HSV-1 KOS, which induces transient herpes epithelial keratitis without herpes stromal keratitis sequelae, possessed a significant leukocytic infiltrate composed primarily of CD4+ T cells and macrophages along with elevated chemokines and cytokines that persisted without loss of corneal clarity (subclinical inflammation). Chemokine and cytokine expression was CD4+ T cell dependent, in that their production was significantly reduced by systemic CD4+ T cell depletion starting before infection, although short-term (3-d) local CD4+ T cell depletion postinfection did not influence chemokine levels in cornea. Corneas with subclinical inflammation developed significantly greater trauma-induced inflammation when they were recipients of syngeneic corneal transplants but also exhibited significantly increased resistance to infections by unrelated pathogens, such as pseudorabies virus. The resistance to pseudorabies virus was CD4+ T cell dependent, because it was eliminated by local CD4+ T cell depletion from the cornea. We conclude that transient HSV-1 corneal infections cause long-term alterations of the corneal microenvironment that provide CD4-dependent innate resistance to subsequent infections by antigenically unrelated pathogens.

The Plasticity and Stability of Regulatory T Cells during Viral-Induced Inflammatory Lesions.

Ocular infection with HSV causes a chronic T cell-mediated inflammatory lesion in the cornea. Lesion severity is affected by the balance of different CD4 T cell subsets, with greater severity occurring when the activity of regulatory T cells (Tregs) is compromised. In this study, fate-mapping mice were used to assess the stability of Treg function in ocular lesions. We show that cells that were once Foxp3+ functional Tregs may lose Foxp3 and become Th1 cells that could contribute to lesion expression. The instability primarily occurred with IL-2Rlo Tregs and was shown, in part, to be the consequence of exposure to IL-12. Lastly, in vitro-generated induced Tregs (iTregs) were shown to be highly plastic and capable of inducing stromal keratitis when adoptively transferred into Rag1-/- mice, with 95% of iTregs converting into ex-Tregs in the cornea. This plasticity of iTregs could be prevented when they were generated in the presence of vitamin C and retinoic acid. Importantly, adoptive transfer of these stabilized iTregs to HSV-1-infected mice prevented the development of stromal keratitis lesions more effectively than did control iTregs. Our results demonstrate that CD25lo Treg and iTreg instability occurs during a viral immunoinflammatory lesion and that its control may help to avoid lesion chronicity.

Ocular manifestations of herpes simplex virus.

PURPOSE OF REVIEW: To review ocular manifestations and complications of herpes simplex virus (HSV) and discuss recent advancements in diagnostic and treatment strategy. RECENT FINDINGS: In-vivo confocal microscopy has expanded our understanding of corneal nerve degeneration, corneal dendritic cell activity, and changes in biomechanical properties in HSV keratitis. Although currently available only as a research tool, metagenomic deep sequencing has the potential to improve diagnostic accuracy beyond the well established PCR technology, especially in atypical cases. Development of an HSV vaccine has shown some encouraging results in a murine model. New treatment options for neurotrophic cornea offer promise, specifically cenegermin nerve growth factor. SUMMARY: Ocular herpes simplex infection and its complications continue to cause significant visual burden and decreased quality of life. Familiarity with its clinical features, wider adoption of viral PCR diagnostic technology, and recognition of the need for long-term maintenance medications for recurrent or chronic cases form the basis for effective management. Metagenomic deep sequencing, the development of a herpes vaccine, and cenegermin nerve growth factor offer promise as diagnostic, preventive, and therapeutic options, respectively.

[Research progress of corneal neovascularization in herpes stromal keratitis].

Herpes simplex virus (HSV) infection can cause inflammatory reactions and angiogenesis of the cornea, which significantly reduce corneal transparency. Herpes stromal keratitis (HSK) is an immune mediated disease caused by HSV infection, and is associated with inflammation and angiogenesis of the cornea. It is difficult to control HSK therapeutically. Repeated episodes of HSK can result in chronic inflammatory disease in the corneal stroma. Neovascularization plays a key role in the pathogenesis of HSK, so inhibiting the angiogenesis will help to control HSK disease. In this review, the pathomechanism of HSK is described. The roles of multiple cytokines and soluble mediators in corneal vascularization are discussed, and the potential ways of preventing and controlling corneal vascularization induced by HSK are summarized. (Chin J Ophthalmol, 2019, 55:956-960).

Loss of Neurokinin-1 Receptor Alters Ocular Surface Homeostasis and Promotes an Early Development of Herpes Stromal Keratitis.

Substance P neuropeptide and its receptor, neurokinin-1 receptor (NK1R), are reported to present on the ocular surface. In this study, mice lacking functional NK1R exhibited an excessive desquamation of apical corneal epithelial cells in association with an increased epithelial cell proliferation and increased epithelial cell density, but decreased epithelial cell size. The lack of NK1R also resulted in decreased density of corneal nerves, corneal epithelial dendritic cells (DCs), and a reduced volume of basal tears. Interestingly, massive accumulation of CD11c+CD11b+ conventional DCs was noted in the bulbar conjunctiva and near the limbal area of corneas from NK1R-/- mice. After ocular HSV-1 infection, the number of conventional DCs and neutrophils infiltrating the infected corneas was significantly higher in NK1R-/- than C57BL/6J mice. This was associated with an increased viral load in infected corneas of NK1R-/- mice. As a result, the number of IFN-γ-secreting virus-specific CD4 T cells in the draining lymph nodes of NK1R-/- mice was much higher than in infected C57BL/6J mice. An increased number of CD4 T cells and mature neutrophils (CD11b+Ly6ghigh) in the inflamed corneas of NK1R-/- mice was associated with an early development of severe herpes stromal keratitis. Collectively, our results show that the altered corneal biology of uninfected NK1R-/- mice along with an enhanced immunological response after ocular HSV-1 infection causes an early development of herpes stromal keratitis in NK1R-/- mice.

Impact of herpetic stromal immune keratitis in corneal biomechanics and innervation.

PURPOSE: To study corneal innervation in eyes with history of herpetic keratitis and its correlation with corneal sensitivity and biomechanical properties. METHODS: A total of 56 eyes were included, of which 16 had a history of unilateral immune stromal herpetic keratitis, 16 were their contralateral eyes, and 20 were healthy controls. Structural analysis of corneal nerve plexus was performed by confocal microscopy. Biomechanical properties were measured with the Ocular Response Analyzer. Corneal sensitivity was assessed by contact (Cochet-Bonnet) and non-contact (Belmonte) esthesiometry. RESULTS: The eyes with a history of herpetic keratitis had reduced sensitivity for mechanical stimuli when compared to healthy eyes (1441.88 ± 83 ml/min vs. 67.9 ± 7.86 ml/min). Nerve fiber density in the corneas with a history of herpetic disease was lower (4.13 ± 2.19 U/image) than in the contralateral eyes (7.44 ± 2.9 U/image, p value = 0.01) and than in healthy controls (10.35 ± 2.01, p value < 0.0001). The best structural and functional correlation was established between the total length of nerves per section and mechanic threshold assessed by Belmonte esthesiometer (Coef. -0.58 p value < 0.0001) and between total length of nerves and corneal resistance factor (CRF) (Coef. -0.64, p value < 0.0001). CONCLUSIONS: The corneal sensitivity impairment in eyes with immune stromal herpetic keratitis can be explained by the loss of nerve fibers. Biomechanical corneal properties are affected as well. Corneal hysteresis (CH) and CRF are lower for the eyes with a history of herpetic keratitis, and also for the contralateral eye when compared to healthy controls.

PEDF plus DHA modulate inflammation and stimulate nerve regeneration after HSV-1 infection.

Herpes simplex virus type-1 (HSV-1) infection leads to impaired corneal sensation and, in severe cases, to corneal ulceration, melting and perforation. Here, we explore the potential therapeutic action of pigment epithelial-derived factor (PEDF) plus docosahexaenoic acid (DHA) on corneal inflammation and nerve regeneration following HSV-1 infection. Rabbits inoculated with 100,000 PFU/eye of HSV-1 strain 17Syn+ were treated with PEDF + DHA or vehicle. PEDF + DHA treatment resulted in a biphasic immune response with stronger infiltration of CD4+T cells, neutrophils and macrophages at 7-days post-treatment (p.t.) that was significantly decreased by 14 days, compared to the vehicle-treated group. Screening of 14 immune-related genes by q-PCR showed that treatment induced higher expression of IFN-γ and CCL20 and inhibition of IL-18 by 7 days in the cornea. PEDF + DHA-treated animals developed less dendritic corneal lesions, opacity and neovascularization. Corneal nerve density increased at 12-weeks p.t. with functional recovery of corneal sensation. Treatment with PEDF + DHA that was postponed by 3 weeks also showed increased nerve density when compared to vehicle. Our data demonstrate that PEDF + DHA promotes resolution of the inflammatory response to the virus and, most importantly, induces regeneration of damaged corneal nerves vital for maintaining ocular surface homeostasis.

[Lamellar minikeratoplasty for recurrent herpes keratitis in the late post-LASIK period].

The article presents a case report of sutureless lamellar minikeratoplasty for progressive corneal ulceration associated with herpes simplex infection in the late period after LASIK.

Impairment of lacrimal secretion in the unaffected fellow eye of patients with recurrent unilateral herpetic keratitis.

PURPOSE: To assess the impact of recurrent unilateral herpetic keratitis (HK) on the tear secretion of the unaffected fellow eye. DESIGN: Prospective, noninterventional study. PARTICIPANTS AND CONTROLS: Thirty-five patients with a history of recurrent unilateral HK (clinically quiescent for at least 3 months) (HK group) and 35 patients who were age- and sex-matched with no history of corneal disease (control group). METHODS: Tear osmolarity, tear instability (tear break-up time [TBUT]), tear reflex (Schirmer's I test), and central corneal sensitivity with the Cochet-Bonnet esthesiometer (Luneau, France) were measured in the HK and control groups. MAIN OUTCOME MEASURES: Tear osmolarity, TBUT, Schirmer's I, and central corneal sensitivity were compared between the affected and unaffected eyes of the HK and control groups. RESULTS: Tear osmolarity and tear secretion reflex were similar between the affected and unaffected eyes of the HK group. Corneal sensitivity and TBUT were statistically lower in the affected eyes compared with the unaffected eyes in the HK group (P = 0.001 and P<0.001, respectively). The central corneal sensitivity of unaffected eyes in the HK group was not significantly different from that in the control group (P>0.05). The tear stability and tear secretion reflex were decreased and tear osmolarity was increased in the unaffected eyes of the HK group compared with the control group (P<0.05, all cases). The difference between unaffected and control eyes varied according to the type of HK. All 4 tests were modified in patients with neurotrophic keratitis (KN). In the keratouveitis subgroup, only corneal sensitivity was normal, whereas Schirmer's I results were also normal in patients with archipelago keratitis. Tear osmolarity was consistently affected in both eyes of herpetic patients. CONCLUSIONS: Tear function is impaired in the unaffected eyes of patients with unilateral recurrent HK, even when the disease is apparently quiescent. The higher severity of results in the unaffected fellow eye of patients with KN in comparison with other herpes subgroups suggests that recurrent HK induces a reduction in the afferent pathways of the tear secretion reflex from the affected eye, leading to tear dysfunction in the unaffected eye. FINANCIAL DISCLOSURE(S): The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Impact of Adherence (Compliance) to Oral Acyclovir Prophylaxis in the Recurrence of Herpetic Keratitis: Long-Term Results From a Pediatric Cohort.

PURPOSE: To evaluate the long-term role of adherence to oral acyclovir prophylaxis in reducing the risk for recurrent herpes simplex virus keratitis (HSK) in children. METHODS: A retrospective cohort study was performed including all pediatric patients 16 years or younger) with their first HSK diagnosis and treatment at our center. Children were started on a standardized oral acyclovir prophylactic regimen after the acute phase. Adherence to prophylaxis was assessed monthly through parent interviews. The possible association between any recurrence (not only the first) and exposure to acyclovir prophylaxis was evaluated using random-effects multivariate logistic regression. RESULTS: A total of 20 eyes of 17 patients (8 boys and 9 girls) were included. The mean follow-up time was 3.5 years. Adherence to acyclovir prophylaxis was registered in 100% of patients with no recurrences and in 36.4% of patients with 1 or more recurrences (P = 0.035). All other tested variables (time of follow-up, sex, age, infectious diseases, underlying hematological diseases, eye, and HSK type) did not differ between the 2 groups. The multivariate model confirmed the lower risk for recurrence in patients who were compliant to therapy (adjusted odds ratio 0.04, 95% confidence intervals 0.00-0.42, P = 0.008). No adverse effects were recorded during follow-up. CONCLUSIONS: Oral acyclovir prophylaxis is a safe and an effective medical treatment for recurrent HSK and its long-term efficacy is associated with compliance to the therapy.

Interferons regulate the phenotype of wild-type and mutant herpes simplex viruses in vivo.

Mechanisms responsible for neuroattenuation of herpes simplex virus (HSV) have been defined previously by studies of mutant viruses in cultured cells. The hypothesis that null mutations in host genes can override the attenuated phenotype of null mutations in certain viral genes was tested. Mutants such as those in infected cell protein (ICP) 0, thymidine kinase, ribonucleotide reductase, virion host shutoff, and ICP34.5 are reduced in their capacity to replicate in nondividing cells in culture and in vivo. The replication of these viruses was examined in eyes and trigeminal ganglia for 1-7 d after corneal inoculation in mice with null mutations (-/-) in interferon receptors (IFNR) for type I IFNs (IFN-alpha/betaR), type II IFN (IFN-gammaR), and both type I and type II IFNs (IFN-alpha/beta/gammaR). Viral titers in eyes and ganglia of IFN-gammaR-/- mice were not significantly different from congenic controls. However, in IFN-alpha/betaR-/- or IFN-alpha/beta/gammaR-/- mice, growth of all mutants, including those with significantly impaired growth in cell culture, was enhanced by up to 1,000-fold in eyes and trigeminal ganglia. Blepharitis and clinical signs of infection were evident in IFN-alpha/betaR-/- and IFN-alpha/beta/gammaR-/- but not control mice for all viruses. Also, IFNs were shown to significantly reduce productive infection of, and spread from intact, but not scarified, corneas. Particularly striking was restoration of near-normal trigeminal ganglion replication and neurovirulence of an ICP34.5 mutant in IFN-alpha/betaR-/- mice. These data show that IFNs play a major role in limiting mutant and wild-type HSV replication in the cornea and in the nervous system. In addition, the in vivo target of ICP34.5 may be host IFN responses. These experiments demonstrate an unsuspected role for host factors in defining the phenotypes of some HSV mutants in vivo. The phenotypes of mutant viruses therefore cannot be interpreted based solely upon studies in cell culture but must be considered carefully in the context of host factors that may define the in vivo phenotype.

Role of TH17 Responses in Increasing Herpetic Keratitis in the Eyes of Mice Infected with HSV-1.

Purpose: TH17 cells play an important role in host defense and autoimmunity yet very little is known about the role of IL17 in herpes simplex virus (HSV)-1 infectivity. To better understand the relationship between IL17 and HSV-1 infection, we assessed the relative impact of IL17A-deficiency and deficiency of its receptors on HSV-1 responses in vivo. Methods: We generated IL17RA-/- and IL17RA-/-RC-/- mice in-house and infected them along with IL17A-/- and IL17RC-/- mice in the eyes with 2 × 105 PFU/eye of wild type (WT) HSV-1 strain McKrae. WT C57BL/6 mice were used as control. Virus replication in the eye, survival, corneal scarring (CS), angiogenesis, levels of latency-reactivation, and levels of CD8 and exhaustion markers (PD1, TIM3, LAG3, CTLA4, CD244, and CD39) in the trigeminal ganglia (TG) of infected mice were determined on day 28 postinfection. Results: No significant differences in virus replication in the eye, survival, latency, reactivation, and exhaustion markers were detected among IL17A-/-, IL17RA-/-, IL17RC-/-, IL17RA-/-RC-/-, and WT mice. However, mice lacking IL17 had significantly less CS and angiogenesis than WT mice. In addition, angiogenesis levels in the absence of IL17RC and irrespective of the absence of IL17RA were significantly less than in IL17A- or IL17RA-deficient mice. Conclusions: Our results suggest that the absence of IL17 protects against HSV-1-induced eye disease, but has no role in protecting against virus replication, latency, or reactivation. In addition, our data provide rationale for blocking IL17RC function rather than IL17A or IL17RA function as a key driver of HSV-1-induced eye disease.

IL-17 receptor signaling influences virus-induced corneal inflammation.

IL-17 has been associated with selected inflammatory and autoimmune diseases. We characterized the expression of this proinflammatory cytokine following HSV-1 corneal infection and investigated whether IL-17R signaling modulated the host response to the viral pathogen at early time-points postinfection. IL-17 was elevated in the murine cornea 24 h after high-dose virus infection and subsequently persisted at low levels during the first week. Immunofluorescent studies showed that the IL-17R was expressed by cultured mouse corneal fibroblasts. Exposure of corneal cells to IL-17 led to production of IL-6 and MIP-2 in vitro and in vivo, indicating that the IL-17R was functional. Mice lacking IL-17R displayed significantly reduced neutrophil infiltration and corneal opacity. However, this effect was transient, as corneal pathology and neutrophil influx resembled that of wild-type (WT) hosts 4 days postinfection. HSV-1 growth and clearance in IL-17R(-/-) hosts were similar to that of the WT controls. Infection of IFN-gamma gene knockout mice was associated with elevated IL-17 levels and accelerated corneal opacity, suggesting that IFN-gamma negatively regulated IL-17 expression. Collectively, our results establish that IL-17 is rapidly produced in the cornea after HSV-1 infection and is regulated at least in part by IFN-gamma. The absence of IL-17 signaling results in a transient decrease in the expression of proinflammatory mediators, neutrophil migration, and corneal pathology, but control of virus growth in the cornea and trigeminal ganglia is not compromised. Thus, IL-17 actively influences early virus-induced corneal inflammation.

CCL3 protects mice from corneal pathology during recurrent HSV-1 infection.

CCL2 and CCL3 are proinflammatory chemokines that are produced during the early stages of inflammation and are known to stimulate the migration of mononuclear cells to the site of inflammation,. Previous studies addressing the role of these chemokines during primary herpetic stromal keratitis (HSK), have suggested that CCL2 is involved in reducing corneal disease and that CCL3 is involved in promoting this disease. We addressed the role that these chemokines play in a recurrent model of HSK. Results from these studies did not demonstrate a significant role for CCL2 except for very early time points following reactivation of virus. Surprisingly, mice deficient in CCL3 did not have significantly reduced recurrent disease, , but in fact showed significantly enhanced disease. This argues that CCL3 might play an ameliorative role during recurrent HSK. In addition, we observed that these same CCL3 deficient mice showed increased resistance to viral-induced mortality following infection with HSV-1. Taken together, these results suggest that CCL3 plays a significant protective role during recurrent HSK and is involved in enhancing lethality.

Keratitis in children as seen in a tertiary hospital in Africa.

BACKGROUND: Blindness studies have shown that keratitis complicated by the use of traditional eye medications is a major factor of childhood blindness in developing countries. Most cases of such keratitis were presumably due to nutritional causes or bacterial infection. The patterns of outcome that are seen in hospitals may be different. OBJECTIVE: To determine the clinical types of keratitis seen in children at a tertiary hospital and compare with other reports. METHOD: A retrospective analysis was conducted using the records of children who presented with keratitis to the eye unit of the University College Hospital, Ibadan, Nigeria, over a three-year period from January 2003 to December 2005. Information obtained were the demographic data, the etiological type of keratitis and visual outcome of management. RESULT: Ninety-five patients with keratitis seen during this three-year period were children. Of these, 47 (49.5%) patients had presumed herpes simplex keratitis; 78.9% of children with herpes simplex keratitis presented with combined epithelial and stromal disease; 21 (22.1%) had keratitis that was associated with a recent measles infection and protein calorie malnutrition. Fifteen (15.8%) had keratitis associated with phlyctenular keratoconjunctivitis, eight (8.4%) patients had bacterial/fungal keratitis, while four (4.2%) had vernal ulcers. Both the right and left eyes were affected in 47.6% and 52.4% of cases, respectively. Bilateral keratitis occurred in eight of the children with measles, and six patients with herpes simplex keratitis. Fifty-nine eyes had visual acuity recorded after the keratitis healed. Of these, the visual outcome was very poor in six (20.0%) eyes with herpes simplex keratitis and eight (100%) eyes with bacterial/fungal keratitis. All eyes with suppurative keratitis associated with measles developed dense corneal scars or were perforated. CONCLUSION: Herpes simplex keratitis was the leading cause of keratitis in children seen at this tertiary hospital, and clinical presentations do not differ from those reported in other populations. Very poor visual outcome was associated with all types of keratitis except those with herpes keratitis. Blindness studies may underrepresent the burden of herpes simplex keratitis in the location of this study.

[The clinical features of piarenchymatous keratitis depending on its etiology].

Social, pharmacological, and environmental alterations were responsible for a change in the classical clinical picture of many long-forgotten diseases. The authors comparatively analyzed the clinical picture of parenchymatous keratitis of varying genesis in 16 patients (20 cases) with this condition. The distinguishing characteristics of keratitis were noted in herpes, tuberculosis, syphilis, sarcoidosis, the knowledge of which allows ophthalmologists to make an etiological diagnosis in earlier periods.

Dendritic cells in the cornea during Herpes simplex viral infection and inflammation.

Herpes simplex keratitis is commonly caused by Herpes simplex virus type 1, which primarily infects eyelids, corneas, or conjunctiva. Herpes simplex virus type 1-through sophisticated interactions with dendritic cells (DCs), a type of antigen-presenting cell)-initiates proinflammatory responses in the cornea. Corneas were once thought to be an immune-privileged region; however, with the recent discovery of DCs that reside in the cornea, this long-held conjecture has been overturned. Therefore, evaluating the clinical, preclinical, and cell-based studies that investigate the roles of DCs in corneas infected with Herpes simplex virus is critical. With in vivo confocal microscopy, animal models, and cell culture experiments, we may further the understanding of the sophisticated interactions of Herpes simplex virus with DCs in the cornea and the molecular mechanism associated with it. It has been shown that specific differentiation of DCs using immunohistochemistry, flow cytometry, and polymerase chain reaction analysis in both human and mice tissues and viral tissue infections are integral to increasing understanding. As for in vivo confocal microscopy, it holds promise as it is the least invasive and a real-time investigation. These tools will facilitate the discovery of various targets to develop new treatments.

The Association between Diabetes and Herpes Simplex Eye Disease.

PURPOSE: To evaluate the association between diabetes mellitus (DM) and presence and severity of Herpes simplex eye disease (HSED). METHODS: We conducted two sub-studies. We included the patients seen on the Cornea Service of the Wills Eye Hospital from January 2008 to August 2012. Study 1 included 541 patients with HSED and 3226 controls. Study 2 involved 40 diabetic and 120 non-diabetic ocular surface HSED patients. Severity of ocular surface HSED was graded as mild, moderate, or severe, based on best-corrected visual acuity (BCVA). Patients were excluded if they had fewer than two office visits or had non-Herpes simplex-related vision-threatening conditions. Diabetes was graded as: diet group (DM controlled with diet), oral group (DM controlled with oral medications), and insulin group (DM control required insulin). RESULTS: Five of 541 (0.93%) HSED patients had type 1 DM, similar to 19/3246 (0.59%) controls (p = 0.375); 48 of 541 (8.88%) HSED patients had type 2 DM, similar to 287/3246 (8.84%) controls (p = 0.981). Using multinomial logistic regression analyses, the probability/risk of being in the severe ocular surface HSED group as opposed to the mild ocular surface HSED group were not statistically significantly different between DM patients and those without DM (p = 0.120; OR, 1.900; 95% CI, 0.846-4.266). CONCLUSIONS: There may not be a positive association between type 2 DM and HSED.