Optical coherence tomography angiography in herpetic leucoma.

BACKGROUND: Herpes simplex virus (HSV) keratitis remains a leading infectious cause of blindness worldwide. Although all forms of HSV keratitis are commonly recurrent, the risk is greatest in stromal keratitis, which is the most likely to result in corneal scarring, thinning, and neovascularization. Recent studies showed the ability of Optical Coherence Tomography Angiography (OCTA) to detect and study vascular abnormalities in the anterior segment, including abnormal corneal vessels. This study intends to investigate the potential of OCTA device to image and describe quantitatively the vascularization in eyes diagnosed with herpetic leucoma and to discuss and review the usefulness of this technique in this pathology. METHODS: A Cross-sectional study was made, including 17 eyes of 15 patients with leucoma secondary to herpetic keratitis. All eyes underwent anterior segment Slit-Lamp photography (SLP), and OCTA with en-face, b-scans and c-scans imaging. The vessel density (VD) was analyzed in the inferior, nasal and temporal corneal margin in all patients, and in the central area, in eyes with central corneal neovascularization (CoNV). The measurements were calculated after binarization with ImageJ software, using OCTA scans with 6 × 6 mm in a depth of 800 µm. RESULTS: Patients included had a mean age 53.267 ± 21.542 (years ± SD). The mean total vessel area was 50.907% ± 3.435%. VD was higher in the nasal quadrant (51.156% ± 4.276%) but there were no significant differences between the three analyzed areas (p = 0.940). OCTA was able to identify abnormal vessels when SLP apparently showed no abnormal vessels; OCTA was able to distinguish between larger and smaller vessels even in central cornea; OCTA scans allowed the investigation of several corneal planes and the relation of them with clinical findings. CONCLUSIONS: OCTA can be useful in both qualitative and quantitative follow-up of patients and may become a non-invasive alternative to objectively monitor treatment response in eyes with corneal vascularization due to herpetic infection.

Bilateral Limbal Stem Cell Alterations in Patients With Unilateral Herpes Simplex Keratitis and Herpes Zoster Ophthalmicus as Shown by In Vivo Confocal Microscopy.

Purpose: The purpose of this study was to investigate the limbal changes in the palisades of Vogt (POV) in patients with herpes simplex keratitis (HSK) and herpes zoster ophthalmicus (HZO) with the application of in vivo confocal microscopy (IVCM). Methods: We enrolled 35 eyes of 35 consecutive patients with HSK and 4 patients with HZO in this observational study. Thirty-five participants were also recruited from a healthy population as the control group. All subjects were examined by IVCM in addition to routine slit-lamp biomicroscopy. The IVCM images of the corneal basal epithelial cells, corneal nerve, and the corneoscleral limbus were acquired and then were analyzed semiquantitatively. Results: The rate of absent and atypical POV was significantly higher in the affected eyes of patients with HSK than in the contralateral eyes and eyes of controls (88.57% vs. 65.71% vs. 17.14%, P < 0.01). In the HZO group, the rate of absent and atypical POV was 100% in the affected eyes and 50% in the contralateral eyes. When compared to the contralateral unaffected eyes and control eyes, the average density of the central basal epithelial cells and the sub-basal nerve plexus density and the total number of nerves in the central area of the affected eyes were significantly lower in the HSK group (1541 ± 704.4 vs. 2510 ± 746.8 vs. 3650 ± 746.1 cells/mm2, P < 0.0001). Spearman's rank correlation showed that the presence of absent and atypical POV had a significant negative correlation with central corneal basal epithelial cells (rs = -0.44979, P < 0.0001), the density of total nerves (rs = -0.49742, P < 0.0001), and the total nerve numbers (rs = -0.48437, P < 0.0001). A significant positive correlation was established between the presence of absent and atypical POV and HSK severity in affected eyes in the superior, inferior, nasal, and temporal quadrants (rs = 0.68940, rs = 0.78715, rs = 0.65591, and rs = 0.75481, respectively, P < 0.0001) and the contralateral eyes (rs = 0.51636, rs = 0.36207, rs = 0.36990, rs = 0.51241, correspondingly, P < 0.0001). Conclusions: Both eyes of patients with unilateral HSK and HZO demonstrated a profound and significant loss of limbal stem cells, which may explain the fact that HSK and HZO are risk factors for limbal stem cell deficiency (LSCD) in both eyes. The loss of LSCs was strongly correlated with the sub-basal nerve plexus and central basal epithelial cell alterations as shown by IVCM.

Polluted Air Exposure Compromises Corneal Immunity and Exacerbates Inflammation in Acute Herpes Simplex Keratitis.

Air pollution is a serious environmental issue worldwide in developing countries' megacities, affecting the population's health, including the ocular surface, by predisposing or exacerbating other ocular diseases. Herpes simplex keratitis (HSK) is caused by the herpes simplex virus type 1 (HSV-1). The primary or recurring infection in the ocular site causes progressive corneal scarring that may result in visual impairment. The present study was designed to study the immunopathological changes of acute HSK under urban polluted air, using the acute HSK model combined with an experimental urban polluted air exposure from Buenos Aires City. We evaluated the corneal clinical outcomes, viral DNA and pro-inflammatory cytokines by RT-PCR and ELISA assays, respectively. Then, we determined the innate and adaptive immune responses in both cornea and local lymph nodes after HSV-1 corneal by immunofluorescence staining and flow cytometry. Our results showed that mice exposed to polluted air develop a severe form of HSK with increased corneal opacity, neovascularization, HSV-1 DNA and production of TNF-α, IL-1ß, IFN-γ, and CCL2. A high number of corneal resident immune cells, including activated dendritic cells, was observed in mice exposed to polluted air; with a further significant influx of bone marrow-derived cells including GR1+ cells (neutrophils and inflammatory monocytes), CD11c+ cells (dendritic cells), and CD3+ (T cells) during acute corneal HSK. Moreover, mice exposed to polluted air showed a predominant Th1 type T cell response over Tregs in local lymph nodes during acute HSK with decreased corneal Tregs. These findings provide strong evidence that urban polluted air might trigger a local imbalance of innate and adaptive immune responses that exacerbate HSK severity. Taking this study into account, urban air pollution should be considered a key factor in developing ocular inflammatory diseases.

Imagenología diferencial por microscopia confocal in vivo entre la epiteliopatía por acanthamoeba y la queratitis por herpes simple / In vivo confocal microscopy imaging for the differential diagnosis of Acanthamoeba epitheliopathy and herpes simplex keratitis

La queratitis por Acanthamoeba es una infección corneal de baja incidencia, condicionada por varios factores, pero con manifestación clínica variada y sintomatología típica. En su fase epitelial debe ser diferenciada de otras queratitis, específicamente de la queratitis por herpes simple, por la similitud entre ambas en cuanto a las características de la lesión corneal. La microscopia confocal in vivo constituye una alternativa diagnóstica. Es una biopsia fotográfica en cuyas imágenes podemos describir los quistes y trofozoítos de Acanthamoeba desde etapas iniciales, que nos ayudan a diferenciarla de otros tipos de queratitis e iniciar el tratamiento precoz. Se realizó una búsqueda de artículos publicados, con el objetivo de mostrar las imágenes por microscopia confocal de la fase epitelial de la infección corneal por Acanthamoeba y herpes simple. Se utilizó la plataforma Infomed, específicamente la Biblioteca Virtual de Salud(AU)

Acanthamoeba keratitis is a low-incidence corneal infection caused by several factors and characterized by a variety of clinical manifestations and typical symptoms. In its epithelial phase, it should be differentiated from other keratitis, particularly from herpes simplex keratitis, due to the similar characteristics of the corneal lesion. In vivo confocal microscopy is a diagnostic alternative consisting in a photographic biopsy showing images of Acanthamoeba cysts and trophozoites since their initial stages, thus allowing differentiation from other types of keratitis and the initiation of early treatment. A search was conducted of published papers with the purpose of showing confocal microscopy images of the epithelial phase of Acanthamoeba and herpes simplex corneal infection. Use was made of the platform Infomed, specifically the Virtual Health Library(AU)

Piezoelectric 3D bioprinting for ophthalmological applications: process development and viability analysis of the technology.

Piezoelectric inkjet 3D bioprinting technology is a viable technique for ophthalmological applications. It provides versatility, high sensibility and accuracy, required in ophthalmological procedures. A process flow for biofabrication was described in detail and validated, using piezoelectric inkjet technology, for ophthalmological applications, in vitro and in situ, based on complex images. Ophthalmological problems were documented by diagnostic examinations and were fed to the flow as complex images. The Concept Mapping methodology and the Conceptual Design approach were utilized to elaborate the 3D bioprinting process flow. It was developed a bioink with corneal epithelial cells. To simulate an in situ bioprinting process, eyes of pigs were selected as the substrate to print the cells. Print scripts used the digitally treated images. In order to print on predefined locations, alignment devices and sample holders were built. The proposed process flow has shown to be a potential tool for the biofabrication of ophthalmological solutions.

The CT appearance of a corneal melt: report of 2 cases.

When the cornea of the eye dissolves, most commonly secondary to infection or trauma, the ventral wall of the anterior chamber of the eye is no longer supported and thus bulges forward, enlarging the anterior chamber volume. This is referred to as a corneal melt, and it has a unique CT appearance that has not been previously described.