Stage Of Keratitis Research Articles

Corneal lymphangiogenesis ameliorates corneal inflammation and edema in late stage of bacterial keratitis

Lymphatic vessels play a crucial role in systemic immune response and regulation of tissue fluid homeostasis. Corneal lymphangiogenesis in bacterial keratitis has not been studied. In this study, we investigated the mechanism and the role of corneal lymphangiogenesis in a murine bacterial keratitis model using Pseudomonas aeruginosa. We first demonstrated that corneal lymphangiogenesis was enhanced mainly in the late stage of bacterial keratitis, contrary to corneal angiogenesis that started earlier. Corresponding to the delayed lymphangiogenesis, expression of the pro-lymphangiogenic factors VEGF-C and VEGFR-3 increased in the late stage of bacterial keratitis. We further found that F4/80 and CD11b positive macrophages played an essential role in corneal lymphangiogenesis. Notably, macrophages were specifically involved in corneal lymphangiogenesis in the late stage of bacterial keratitis. Finally, we demonstrated the beneficial role of corneal lymphangiogenesis in ameliorating the clinical course of bacterial keratitis. Our study showed that bacterial activity was not directly involved in the late stage of keratitis, while corneal lymphangiogenesis reduced corneal edema and clinical manifestation in the late stage of bacterial keratitis. These findings suggest that the process of lymphangiogenesis in bacterial keratitis ameliorates corneal inflammation and edema in the late stage of bacterial keratitis.

The Role of Connexin-43 in the Inflammatory Process: A New Potential Therapy to Influence Keratitis.

The studies outlined in this review highlight the relationship between inflammatory signaling molecules and connexin-43 (Cx43). Gap junction (GJ) channels and hemichannels (HCs) participate in the metabolic activity between intra- and extracellular space. Some ions and small molecules are exchanged from cell to cell or cell to extracellular space to affect the process of inflammation via GJ. We analyzed the effects of signaling molecules, such as innate immunity messengers, transcription factors, LPS, cytokine, inflammatory chemokines, and MMPs, on Cx43 expression during the inflammatory process. At the same time, we found that these signaling molecules play a critical role in the pathogenesis of keratitis. Thus, we assessed the function of Cx43 during inflammatory corneal disease. Corneal healing plays an essential role in the late stage of keratitis. We found that Cx43 is involved in wound healing. Studies have shown that the decrease of Cx43 can decrease the time of healing. We also report several Cx43 mimic peptides which can inhibit the activity of Cx43 Hc to mediate the releasing of adenosine triphosphate (ATP), which may in turn influence the inflammatory process.

In Vivo Confocal Microscopy Analysis of the Corneal Layers in Adenoviral Epidemic Keratoconjunctivitis

Objectives:To describe the clinical features and microstructural characteristics assessed by in vivo confocal microscopy (IVCM) in patients with adenoviral epidemic keratoconjunctivitis (EKC).Materials and Methods:The study included 20 eyes of 12 patients who presented to the Kocaeli University Medical Faculty, Department of Ophthalmology with complaints of watering, crusting, and stinging, were clinically diagnosed EKC, and were examined by slit-lamp biomicroscopy and IVCM during the prodromal phase and the punctate keratitis, deep epithelial keratitis, and subepithelial infiltration stages of EKC.Results:While biomicroscopic examination findings were normal during the prodromal period of EKC, IVCM showed an increase in Langerhans cell numbers in the subbasal plexus. After onset of clinical EKC, the punctate epithelial keratitis stage was characterized by findings of hyperreflective cell clusters in the basal epithelium layer, increased accumulation of Langerhans cells in Bowman’s layer, and hyperreflectivity in the anterior stromal layers. In the deep epithelial keratitis stage, the basal epithelial cells displayed peripheral hyperreflectivity and the hyperreflectivity of the anterior stromal surface increased and became more rounded. In the subepithelial keratitis stage, these findings persisted in addition to increased anterior stromal surface hyperreflectivity and focal round plaques.Conclusion:This study shows that the inflammatory process in the cornea starts in the prodromal period of EKC. Massive inflammation of the epithelium and stroma was observed in the active phase and focal changes were observed on the anterior stromal surface starting in the subepithelial infiltration period.

Assessment of Confocal Microscopy for the Diagnosis of Polymerase Chain Reaction–Positive Acanthamoeba Keratitis: A Case-Control Study

To determine invivo confocal microscopy diagnostic criteria to diagnose Acanthamoeba keratitis (AK) using polymerase chain reaction (PCR) as the reference diagnostic technique. Retrospective case-control study. Data were recorded prospectively and analyzed retrospectively. Fifty patients with PCR-positive AK (study group) and 50 patients with bacterial, fungal, viral, or immune keratitis featuring negative Acanthamoeba PCR results (control group). Invivo confocal microscopy performed at the acute stage of keratitis. Presence of invivo confocal microscopy images suggestive of AK. Multivariate logistic regression was used to determine the relationship between types of images and presence of PCR-positive AK. The following 4 types of images were associated significantly with PCR-positive AK (P < 0.05): bright spots (round or ovoid hyperreflective objects with no double wall; diameter, <30 μm); target images (hyperreflective objects with hyporeflective halo; diameter, <30 μm); clusters of hyperreflective objects (diameter, <30 μm); and trophozoite-like objects (diameter, >30 μm). Specificity of both target and trophozoite images was 100%. This figure was 98.2% for clusters and 48.2% for bright spots. If the diagnosis of AK was made on presence of target images, clusters or trophozoite images (at least 1 of the 3 features), the positive predictive value of confocal microscopy was 87.5% and the negative predictive value was 58.5%. Acanthamoeba keratitis is a serious vision-threatening disease. Invivo confocal microscopy can help in this challenging diagnosis, especially when PCR is delayed, shows negative results, or is not available. Target images and trophozoite-like images are pathognomonic of AK. Clusters of hyperreflective objects are highly specific of AK. However, the overall sensitivity of invivo confocal microscopy features of AK is low. In addition to the clinical features, microbiological tests (direct examination and cultures of corneal scrapings), and PCR, invivo confocal microscopy allows for more rapid diagnosis and treatment initiation, potentially leading to an improved outcome.

Results of therapeutic penetrating keratoplasty for bacterial and fungal keratitis.

This study aimed to report the results of therapeutic penetrating keratoplasty (TPKP) performed at early and late stage of keratitis. The study involved patients who underwent TPKP surgery due to bacterial, fungal, or mixed (bacterial and fungal) keratitis. The patients were divided into two groups. Group 1 (13 patients) was the patients operated at early stage of corneal abscess formation or in 15days after the start of keratitis and group 2 (12 patients) was the patients operated at late stage of keratitis or after at least 15days after the initial appearance of symptoms. Preoperative clinical signs and postoperative results were presented. At the end of the follow-up period, 13 (100%) of grafts in the early TPKP group and 10 (83.3%) of grafts in the late TPKP group remained clear (p=0.125). Recurrence of infection at last visit after TPKP was 0 (0%) of cases in group 1, and was 2 (16.7%) of cases in group 2 (p=0.125) Therapeutic success was achieved and the eyes were preserved in 23 patients of both groups. Evisceration was performed for a case and phthisis bulbi was seen in a case in group 2. The groups were statistically different regarding the presence of postoperative complications (p=0.015). TPKP performed in cases that do not respond medical treatment, in the early phase of the disease, before the lesions reach to limbus and without waiting corneal perforation, may yield better clinical results and less postoperative complications.

Is There Blinding Onchocerciasis in Northern Uganda?

Background: Onchocerciasis is a filarial nematode Onchocerca volvulus transmitted by female black flies which breeds in fast flowing rivers. Clinical manifestations is ocular or skin lesions. The long-term armed conflict in northern Uganda deprived research on onchocerciasis and no attempts have been made to establish the clinical manifestation of the disease in the region. Objective: To establish whether Simulium damnosum transmitted onchocerciasis in this region was blinding. Participants: Persons from thirteen endemic parishes in Pader district in northern Uganda were examined for clinical, parasitological and ocular manifestations of onchocerciasis. Results: A total of 675 persons were examined and microfilaria prevalence in skin snips was 28%, while nodules and onchodermatitis were 30% and 29% respectively. The commonest skin lesion was Chronic Papular Onchodermatitis (17.5%). However, the prevalence of both microfilaria in the anterior chamber of the eye and reversible ocular lesions was 4%. The reversible ocular lesions of onchocerciasis observed were punctate keratitis stage B (0.1%), punctate keratitis stage D (0.1%) and punctate keratitis stage E (3.7%). While 16.1% of the respondents had irreversible ocular lesions attributed mainly to Optic atrophy (6.4%) and sclerosing keratitis (5.2%). There was significant association between irreversible onchocerciasis lesions and visual loss (p< 0.0001). Conclusion: This study confirmed the occurrence of blinding onchocerciasis in Pader district, the first ever reported in indigenous populations in Uganda.

Late-onset Severe Diffuse Lamellar Keratitis Associated With Uveitis After LASIK in a Patient With Ankylosing Spondylitis

To report a case of diffuse lamellar keratitis (DLK) associated with acute anterior uveitis that occurred 3 years after uneventful LASIK in a patient with a history of ankylosing spondylitis and recurrent acute anterior uveitis. A 36-year-old man presented with pain and decreased vision in the left eye. Left eye visual acuity was 20/100. He had undergone bilateral LASIK 3 years prior to presentation to treat moderate myopia. Slit-lamp examination revealed aqueous flare and cells, vertical corneal folds, and cell aggregates at the central interface. Flattening and thinning of the cornea were observed with Pentacam (Oculus Optikgeräte GmbH). Diffuse lamellar keratitis stage III was diagnosed and intensive corticosteroid and anticollagenolytic treatment was started with satisfactory results. Acute anterior uveitis may be a predisposing factor for late-onset DLK after LASIK surgery. Indication of LASIK in patients at high risk of developing recurrent flares of acute anterior uveitis, such as those with spondyloarthropathies, should be carefully considered.

Spontaneous Bilateral, Recurrent, Late-onset Diffuse Lamellar Keratitis After LASIK in a Patient With Cogan's Syndrome

To report a patient with severe and progressive bilateral deafness who suffered recurrent episodes of diffuse lamellar keratitis (DLK) in both eyes > or = 4 months after undergoing uneventful LASIK for myopia. Four months after LASIK, the patient presented with blurred vision in the left eye. Best spectacle-corrected visual acuity was 0.9. Slit-lamp examination revealed aggregates of white cells at the paracentral and mid-peripheral interface without affecting the visual axis. Diffuse lamellar keratitis stage II was diagnosed and intensive corticosteroid treatment was started. Uncorrected visual acuity (UCVA) in the right eye was 1.2 with no signs of DLK. One week after initiating corticosteroid treatment, UCVA improved (1.2) in the left eye. Diffuse lamellar keratitis was diagnosed in the left eye again at 9 months and in the right eye at 15 months after LASIK. The patient was later diagnosed with atypical Cogan's syndrome. Recurrent and late-onset DLK may be due to other patient systemic conditions predisposing to interstitial keratitis, such as Cogan's syndrome.

Incidence of diffuse lamellar keratitis after laser in situ keratomileusis associated with the IntraLase 15 kHz femtosecond laser and Moria M2 microkeratome

To analyze the incidence of diffuse lamellar keratitis (DLK) after laser in situ keratomileusis (LASIK) performed with an IntraLase 15 kHz femtosecond laser (IntraLase, Corp.) or a Moria M2 mechanical microkeratome (Moria SA). Vissum Madrid, Madrid, Spain. This retrospective study compared the incidence of DLK in consecutive LASIK procedures performed with the IntraLase 15 kHz femtosecond laser (study group) or the Moria M2 microkeratome (control group). Two surgeons performed both types of surgeries (femtosecond laser and microkeratome) using the same excimer laser (Technolas 217, Bausch & Lomb). During the first week postoperatively, topical dexamethasone drops were applied 8 times daily in the femtosecond group and 4 times daily in the mechanical microkeratome group. A total of 2000 consecutive eyes were analyzed (1000 eyes in each group). Diffuse lamellar keratitis stage 2 developed in 1 patient in each group; DLK stage 3 developed in 4 patients in the study group and in no patient in the control group (P = .03). Despite more intense postoperative steroid treatment, DLK seemed to occur more frequently after LASIK performed with the IntraLase 15 kHz femtosecond laser than after LASIK performed with the Moria M2 microkeratome.