Course Of Keratitis Research Articles

A proof-of-concept study for the efficacy of dispirotripiperazine PDSTP in a rabbit model of herpes simplex epithelial keratitis

Herpes simplex keratitis is an important infectious cause of blindness worldwide. The mainstay of antiviral therapy is treatment with long-established nucleoside analogues orally or topically. However, the emergence of resistant strains may become a major health concern in the future. Therefore, the development of backup antiherpetic medicines is urgently needed. Small molecule PDSTP is known to be active against herpes simplex type 1 strains in vitro, affecting early host-pathogen interactions. Here, we evaluated its preclinical efficacy in a rabbit model of herpes simplex epithelial keratitis. The mean course of keratitis and the corneal lesions in the 1.0% PDSTP gel group was statistically significantly less than in the negative control group and was comparable to that in the aciclovir group. These findings open up new opportunities for the development of antiherpetic drugs with an original mechanism of action.

Keratitis associated with contact lens correction in children and adolescents

To study the prevalence of keratitis associated with contact lenses, its clinical manifestations, microbial etiology, and sensitivity to antibiotics. The study analyzes case histories of 171 patients with infectious keratitis treated at the Children's Republican Clinical Hospital of the Ministry of Health of the Republic of Tatarstan in 2016-2018. The retrospective analysis revealed an increase in both the number of infectious keratitis and the keratitis associated with contact correction. All patients had a severe course of keratitis with the formation of gross opacity. The leading pathogens were Pseudomonas aeruginosae and Klebsiella oxytoca. The pathogens were not 100% sensitive to any one of the 7 studied antibiotics. The smallest percentage of resistant strains (12.5%) was determined for fluoroquinolones of the 2nd and 3rd generation (ciprofloxacin and levofloxacin), as well as meropenem. Considering the number of contact lens users in the world, keratitis associated with contact lenses poses a serious problem.

Особенности клинического течения и комплексной терапии кератита Тайджесона, обусловленного цитомегаловирусным поражением

Purpose . Analysis of clinical course of corneal lesion in case of Thygeson’s superficial punctate keratitis. Material and methods . The study performed an analysis of literature and also an algorithm of current diagnosis and treatment of patient with Thygeson’s superficial punctate keratitis is shown. Results . In application of corticosteroids in a low concentration, 0.05% Cyclosporine A, non-steroid anti-inflammatory drugs in combination with the tear substitute therapy it was possible to obtain a regression of symptoms. Conclusions . The observation of the course of keratitis proposed an immune theory of disease and also a connection with cytomegalovirus infection.

Experimental Intrastromal Antibiotic Injection for Refractory Keratits Caused by Biofilm Forming Pseudomonas Aeruginosa

Background: Refractory keratitis is a major ophthalmic concern, unresponsive patients to ordinary or fortified eye drops or even specific antibiotic drops according to the cultures taken from the lesions may necessitate therapeutic keratoplasty with poor prognosis. Biofilm is an important virulence mechanism for bacterial infections and is a major cause of antibiotic resistance. Treatment of biofilm requires delivering of higher antibiotic concentration than normal. Objectives: This study aims to evaluate the role of biofilm in formation of keratitis and to consider intrastromal antibiotic injection to deliver higher concentration of antibiotics to treat keratitis caused by biofilm forming pseudomonas. Methodology: We used 40 New Zealand white female rabbits in this prospective in-vivo experimental study. Rabbits were classified in to four groups: one eye (the right one) in all rabbits was used for the inoculation with the organism as a test eye while the left eye was used as a control. The right eye of group (1) was inoculated with biofilm forming Pseudomonas aeruginosa and treated with intrastromal ciprofloxacin injection, while, first eye of group (2) was inoculated with biofilm forming Pseudomonas aeruginosa and treated with ciprofloxacin eye drops, Meanwhile, the first eye of group (3) was inoculated with non- biofilm forming Pseudomonas aeruginosa and treated with intrastromal ciprofloxacin injection, At last, the first eye of the group (4) was inoculated with biofilm forming Pseudomonas aeruginosa and treated with ciprofloxacin eye drops, the second eye was always the control eye. Results: Using ANOVA and LSD tests to compare the means of ulcer diameters in different groups, we found that biofiom is a virulence factor that plays an important role keratitis and there is a great reduction in ulcer size in group receiving intrastromal antibiotic injection compared with the those received eye drops. Conclusion: Biofilm is an important virulence factor that have to be investigated during the diagnostic course of keratitis and intrastromal ciprofloxacin injection is an effective mean of treating keratitis that can provide an alternative way for surgery to treat refractory keratitis.

Bacterial Keratitis

Worldwide inflammatory corneal diseases are considered to be one of the leading causes of monocular blindness. Bacterial infectious are still predominant and are found in 80 % of patients with ulcerative keratitis. In recent years, both changes in risk conditions and changes in the bacterial spectrum can be observed. Contact lenses and refractive surgery are factors that have increased in importance according to some studies. Microorganisms especially Pseudomonas spp. and atypical mycobacteria are detectable in these patients. In contrast, the bacterial keratitis is observed less frequently after trauma. The broad, often unsighted use of highly effective antimicrobial agents, especially of fluoroquinolones is assumed to be a factor in the transformation of the microbial spectrum. Due to the frequent course of keratitis and a targeted, effective therapy to initiate a pathogen is desirable. The possibilities of diagnostics have been expanded in recent years by molecular biological techniques, but cannot replace established methods. The aim of this paper is to provide a positioning on current aspects of bacterial keratitis.

Emerging Prevalence of Microsporidial Keratitis in Singapore: Epidemiology, Clinical Features, and Management

To investigate the incidence and epidemiologic factors involved in the development of microsporidial keratitis. The association of host immune status and clinical pattern, clinical features, and the role of fluoroquinolone monotherapy in treatment are also examined. Retrospective, noncomparative case series. All cases (124 patients, 134 eyes) of microsporidial keratitis confirmed with modified trichrome stain positive of corneal scrape over a 4-year period. Epidemiologic factors were observed. Host immune status with human immunodeficiency virus (HIV) serology and CD4/CD8 analysis was performed when consent was obtained. Visual acuity (VA) and slit-lamp examination throughout the course of keratitis was recorded. Treatment used included topical fluoroquinolones (ciprofloxacin 0.3%, moxifloxacin 0.5%, gatifloxacin 0.5%, levofloxacin 0.5%, or norfloxacin 0.3%) as monotherapy or in combination with topical fumagillin and/or systemic albendazole. Where corneal edema developed, ultrasound corneal pachymetry was recorded. Demographic features and epidemiologic factors, including host immune status. Clinical features and disease course, including the response to different therapeutic regimes. Patients ranged in age from 11 to 68 years (mean, 31.9; median, 30) with a male:female ratio of 8:1 (females n = 17 [13.7%]). We performed HIV serology and CD4/CD8 in 45.9% of cases (n = 57); all the cases tested were negative with normal T-cell indices. Epidemiologic factors included soil exposure (50%), contact lens wear (21.1%), and topical steroid treatment (17.1%). The VA on presentation ranged from 20/20 to 20/100 (median, 20/30) with no loss in lines of VA on resolution. Common features were follicular papillary conjunctivitis and coarse punctate epithelial lesions in 3 patterns--diffuse, peripheral, and paracentral--evolving into nummular keratitis before resolution. Resolution occurred in 99% of cases on topical fluoroquinolone monotherapy. Four patients had recurrent disease that resolved with repeat fluoroquinolone or fluoroquinolone/oral albendazole combination. Two new clinical features were identified--diffuse endotheliitis (19.4%) with corneal edema and limbitis. This study identifies an increasing incidence of microsporidial keratitis in Singapore with a strong correlation with prior soil exposure. Diffuse endotheliitis and limbitis have not been described and resolves with topical steroid therapy. Topical fluoroquinolone monotherapy is a valid treatment option.

Amniotic membrane transplantation improves herpetic keratitis by local and not by systemic effects

The immune mediated HSV-1 stromal keratitis (HSK) rapidly improves after amniotic membrane transplantation (AMT). This study investigated whether AMT modulates the T cell response and whether the anti-inflammatory action of AMT is due to local or systemic effects. Corneas of BALB/c mice were infected with 10(5) (PFU) of HSV-1. Animals with ulcerating keratitis on day 14 post-infection were divided into 4 groups: group 1 ( n=12): right eye AMT;group 2 ( n=12): right eye tarsorrhaphy; group 3 ( n=8): right eye tarsorrhaphy, left eye AMT;group 4 ( n=8): both eyes tarsorrhaphy. The mice were examined for clinical signs of HSV keratitis after 2 days. Corneal sections were studied histologically and the inflammatory cell infiltration was studied by immunohistochemical staining. DTH response and the HSV-specific 3H-thymidin-uptake were compared between the groups. Compared to group 2, ulceration and stromal inflammation was profoundly improved in group 1 ( p<0.01). The corneas in the AMT mice had fewer inflammatory cells, CD3+,CD4+ and CD8+ cells than the control mice ( p<0.01). There were no significant differences between groups 1 and 2 with respect to the delayed type hypersensitivity reaction (DTH response) and the HSV-specific 3H-thymidin uptake. AMT or tarsorrhaphy on the left eyes in groups 3 and 4 had no influence on the course of keratitis or the T cell response. Ulcerating herpetic keratitis markedly improves after AMT. Our observations indicate that this is caused predominantly by local and not by systemic AMT-related effects.

Kinetics of corneal fluorescence in experimental keratitis

It was shown by the method of scanning photometry suggested by the authors that rabbits with experimentally-induced keratitis displayed a three-phasic reaction of the area of the corneal burn: that of the enhanced fluorescein sorption at the reactive phase: that of the loss of the sorption capacity in the dystrophic stage, and that of the secondary absorption intensification during the regenerative stage. The mentioned phasic changes can be used for the diagnosis and objective assessment of the clinical course of keratitis.

Effect of human leukocyte interferon on vaccinia-and herpes virus-infected cell cultures and monkey corneas

Pretreatment of human fibroblast cultures with human leukocyte interferon (HIF, 1,000 IU/ml) resulted in a 24-h delay of virus replication after infection with vaccinia virus and herpes simplex virus type 1 and type 2. Additional HIF treatment 24 h after infection effectively lowered the maximum yield of viral infectivity. Equal results were obtained in simian cells with 3,000 IU of HIF per ml. The spread of two cell-bound herpesviruses, varicella zoster virus and Medical Lake macaque herpesvirus, was inhibited by 2,000 IU of HIF per ml in human fibroblasts and Vero cells, respectively. Varicella zoster virus infectivity was notably reduced by HIF, whereas the latter system showed a low sensitivity. To study the effect of HIF in the infected cornea, keratitis was induced experimentally in both eyes of 12 rhesus monkeys and 12 African green monkeys by inoculation with vaccinia virus and herpes simplex virus, respectively. In each monkey one eye served as a control for the full cycle of disease. In the other eye HIF treatment was initiated prophylactically 15 h before or simultaneously with the challenge virus infection or 6 to 20 h postinfectionally or therapeutically after onset of the disease, and the treatment was continued for 2 to 7 days. Prophylactic and simultaneous administration equally resulted in inhibition of both vaccinia and herpes keratitis. Postinfectional and therapeutic administration of interferon moderated the course of keratitis slightly and shortened the period of virus shedding.