Herpetic Eye Disease Study: A Controlled Trial of Topical Corticosteroids for Herpes Simplex Stromal Keratitis.

PURPOSE: To evaluate the efficacy of topical corticosteroids in treating herpes simplex stromal keratitis. METHODS: The authors performed a randomized, double-masked, placebo-con- trolled, multicenter clinical trial of 106 patients with active herpes simplex stromal keratitis who had not received any corticosteroids for at least 10 days before study enrollment. Patients were assigned to the placebo group (n = 49) or the steroid group (topical prednisolone phosphate; n = 57); both regimens were tapered over 10 weeks. Both groups received topical trifluridine. Visual acuity assessment and slit-lamp biomicroscopy were performed weekly for 10 weeks, every other week for an additional 6 weeks or until removal from the trial, and at 6 months after randomization. RESULTS: The time to treatment failure (defined by specific criteria as persistent or progressive stromal keratouveitis or an adverse event) was significantly longer in the steroid group compared with the placebo group. Compared with placebo, corticosteroid therapy reduced the risk of persistent or progressive stromal keratouveitis by 68%. The time from randomization to resolution of stromal keratitis and uveitis was significantly shorter in the steroid group compared with the placebo group even though both groups included patients who were removed from the study and treated with topical corticosteroids according to best medical judgment. Nineteen (33%) of the steroid-treated patients and 11 (22%) of the placebo-treated patients completed the 10 weeks of protocol therapy and had stable, noninflamed corneas after 16 weeks. At 6 months after randomization, no clinically or statistically significant differences in visual outcome or recurrent herpetic eye disease were identified between the steroid and placebo groups. CONCLUSIONS: The topical corticosteroid regimen used in this study was significantly better than placebo in reducing persistence or progression of stromal inflammation and in shortening the duration of herpes simplex stromal keratitis. Postponing steroids during careful observation for a few weeks delayed resolution of stromal keratitis but had no detrimental effect as assessed by visual outcome at 6 months.

Dendritiform Keratopathy Associated with Exposure to Polyquarternium-1, a Common Ophthalmic Preservative.

PURPOSE: To describe dendritiform keratopathy associated with exposure to polyquaternium-1, a common preservative found in contact lens solutions and tear replacement products. DESIGN: Case series. PARTICIPANTS: Sixteen patients who demonstrated dendritiform keratopathy during topical ophthalmic exposure to polyquaternium-1. METHODS: Records were reviewed of all patients diagnosed with dendritiform keratopathy between 1999 and 2014 who had documented exposure to contact lens care disinfecting solutions or artificial tear solutions containing polyquaternium-1. Patients were excluded who had coexisting potential causes for dendritiform keratopathy, such as prior herpes simplex keratitis, varicella-zoster viral keratitis, the linear form of Thygeson's superficial keratitis, epithelial regeneration line, Acanthamoeba keratitis, mucus plaque keratopathy, medication-related keratopathy, or limbal stem cell deficiency characterized by conjunctivalization of the corneal epithelium. MAIN OUTCOME MEASURES: Effect of discontinuation of exposure to polyquaternium-1 on the dendritiform keratopathy. RESULTS: Sixteen patients demonstrated dendritiform keratopathy after exposure to the preservative polyquaternium-1. Thirteen patients had a history of recent exposure to contact lens disinfecting solutions (Opti-Free, Equate) containing polyquaternium-1. Three patients used a tear replacement product (Systane) containing a polyquaternium-1 preservative. Four patients were treated with antiviral medications for presumed herpes simplex keratitis; 4 patients underwent diagnostic testing for Acanthamoeba keratitis. Two additional patients were diagnosed sequentially with herpes simplex keratitis, then Acanthamoeba keratitis before referral. All dendritiform lesions resolved within 2 to 6 weeks after elimination of exposure to polyquaternium-1. CONCLUSIONS: Ophthalmic products containing polyquaternium-1 may cause dendritiform keratopathy that may be confused with infections of the superficial cornea, such as herpes simplex virus keratitis or Acanthamoeba keratitis.

Antiviral treatment and other therapeutic interventions for herpes simplex virus epithelial keratitis.

BACKGROUND: Eye disease due to herpes simplex virus (HSV) commonly presents as epithelial keratitis which, though usually self-limiting, may persist or progress without treatment. OBJECTIVES: To compare the relative effectiveness of antiviral agents, interferon, and corneal debridement in the treatment of HSV epithelial keratitis. SEARCH METHODS: We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (2014, Issue 12), PubMed (January 1946 to 31 December 2014), EMBASE (January 1980 to 31 December 2014), Latin American and Caribbean Health Sciences Literature Database (LILACS) (January 1982 to 31 December 2014), System for Information on Grey Literature in Europe (OpenGrey) (January 1995 to 31 December 2014), BIOSIS (January 1926 to 5 May 2014), Scopus (January 1966 to 31 December 2014), Japan Science and Technology Institute (J-Global) (January 1975 to 31 December 2014), China National Knowledge Infrastructure (CNKI) (January 1979 to 31 December 2014), British Library's Electronic Table of Contents (Zetoc) (January 1993 to 7 May 2014). We looked for trials listed on the the metaRegister of Controlled Trials (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov), the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en), Chinese Clinical Trial Registry, the U.S. Food and Drug Administration (FDA) (www.fda.gov/), National Institute for Health and Clinical Excellence (NICE) (www. EVIDENCE: nhs.uk) and the European Medicines Agency (EMA) (www.ema.europa.eu/ema/) as of 31 December 2014. There were no language or date restrictions in the search for trials. We also culled literature digests and conference proceedings as of 15 April 2014. There were no language or date restrictions in the search for trials. SELECTION CRITERIA: Randomised and quasi-randomised trials of HSV dendritic or geographic epithelial keratitis were included that reported the proportion of eyes healed at one week, two weeks, or both after enrolment. DATA COLLECTION AND ANALYSIS: We tabulated data on study characteristics, risk of bias, and outcomes and used direct comparisons to estimate a risk ratio (RR) and, when feasible, a hazard ratio (HR) with a 95% confidence interval (CI). Heterogeneity was assessed by an inconsistency index. A multiple treatment comparison meta-analysis consolidated direct and indirect comparisons of relative healing at 14 days. MAIN RESULTS: One hundred thirty-seven studies involving 8333 eyes met the inclusion criteria. Placebo-controlled studies were heterogeneous in comparison with idoxuridine (RR 1.74; 95% CI 1.03 to 2.91) and few in number for vidarabine (RR 1.81; 95% CI 1.09 to 3.01), interferon (RR 1.32; 95% CI 1.06 to 1.64), and debridement. Vidarabine (RR 1.13; 95% CI 1.02 to 1.25), trifluridine (RR 1.30; 95% CI 1.18 to 1.43), acyclovir (RR 1.23; 95% CI 1.14 to 1.34), and brivudine (RR 1.34; 95% CI 1.18 to 1.51) were more effective than idoxuridine. Trifluridine (RR 1.17; 95% CI 1.03 to 1.32) and acyclovir (RR 1.11; 95% CI 1.03 to 1.19) were more effective than vidarabine. No significant differences in healing emerged among trifluridine, acyclovir, brivudine, and foscarnet although few studies compared brivudine or foscarnet with other antivirals. Any potential advantage of ganciclovir compared to acyclovir was mitigated by study heterogeneity and possible publication bias. Only one study evaluated the joint use of two topical antivirals. In a limited number of studies, oral acyclovir (RR 0.92; 95% CI 0.79 to 1.07) or the combination of oral acyclovir with a topical antiviral (RR 1.36; 95% CI 0.68 to 2.74) appeared as effective as a single topical antiviral agent. Compared to topical antiviral monotherapy, the combination of an antiviral with either interferon or debridement had inconsistent effects on expediting healing and improving outcome. AUTHORS' CONCLUSIONS: Placebo-controlled studies of HSV epithelial keratitis are limited to superseded interventions. Trifluridine and acyclovir are more effective than idoxuridine or vidarabine and similar in therapeutic effectiveness. Brivudine and foscarnet do not substantially differ in effectiveness from trifluridine or acyclovir. Ganciclovir is at least as effective as acyclovir. The addition of interferon to a nucleoside antiviral agent and the combination of debridement with antiviral treatment need to be further assessed to substantiate any possible advantage in healing.

Association between unprotected ultraviolet radiation exposure and recurrence of ocular herpes simplex virus.

Studies have suggested that exposure to ultraviolet (UV) light may increase risk of herpes simplex virus (HSV) recurrence. Between 1993 and 1997, the Herpetic Eye Disease Study (HEDS) randomized 703 participants with ocular HSV to receipt of acyclovir or placebo for prevention of ocular HSV recurrence. Of these, 308 HEDS participants (48% female and 85% white; median age, 49 years) were included in a nested study of exposures thought to cause recurrence and were followed for up to 15 months. We matched weekly UV index values from the National Oceanic and Atmospheric Administration to each participant's study center and used marginal structural Cox models to account for time-varying psychological stress and contact lens use and selection bias from dropout. There were 44 recurrences of ocular HSV, yielding an incidence of 4.3 events per 1,000 person-weeks. Weighted hazard ratios comparing persons with ≥8 hours of time outdoors to those with less exposure were 0.84 (95% confidence interval (CI): 0.27, 2.63) and 3.10 (95% CI: 1.14, 8.48) for weeks with a UV index of <4 and ≥4, respectively (ratio of hazard ratios = 3.68, 95% CI: 0.43, 31.4). Though results were imprecise, when the UV index was higher (i.e., ≥4), spending 8 or more hours per week outdoors was associated with increased risk of ocular HSV recurrence.

Proinflammatory chemokines during Candida albicans keratitis.

Chemotactic cytokines mediate the recruitment of leukocytes into infected tissues. This study investigated the profile of chemokines during experimental Candida albicans keratitis and determined the effects of chemokine inhibition on leukocyte infiltration and fungal growth during murine keratomycosis. Scarified corneas of BALB/c mice were topically inoculated with C. albicans and monitored daily over one week for fungal keratitis. After a gene microarray for murine chemokines compared infected corneas to controls, real-time reverse transcription polymerase chain reaction (RT-PCR) and immunostaining assessed chemokine expression in infected and mock-inoculated corneas. An anti-chemokine antibody was then administered subconjunctivally and evaluated for effects on clinical severity, corneal inflammation, fungal recovery, and cytokine expression. Of 33 chemokine genes examined by microarray, 6 CC chemokines and 6 CXC chemokines were significantly (P<0.05) upregulated more than two-fold. Chemokine (CC-motif) ligand 3 (CCL3) was upregulated 108-fold (P=0.03) by real-time RT-PCR within one day after fungal inoculation and remained increased 28-fold (P=0.02) at one week, and its in situ expression increased in the epithelium and stroma of infected corneas. Compared to the control antibody-treated group, eyes treated with anti-CCL3 antibody showed reduced clinical severity (P<0.05), less corneal neovascularization (P=0.02), and fewer inflammatory cells infiltrating corneal tissue, but the amount of recoverable fungi was not significantly (P=0.4) affected. Anti-CCL3 treatment significantly (P=0.01) reduced the expression of tumor necrosis factor and interleukin-1beta in infected corneas. These results indicate that chemokines, especially the CC chemokine CCL3, play important roles in the acute inflammatory response to C. albicans corneal infection.

Antiviral treatment and other therapeutic interventions for herpes simplex virus epithelial keratitis.

BACKGROUND: Eye disease due to herpes simplex virus (HSV) commonly presents as epithelial keratitis. OBJECTIVES: To compare the relative effectiveness of antiviral agents, interferon, and corneal débridement in the treatment of acute HSV epithelial keratitis. SEARCH STRATEGY: We searched CENTRAL (The Cochrane Library 2010, Issue 4), MEDLINE (January 1950 to October 2010), EMBASE (January 1980 to October 2010), Latin American and Caribbean Literature on Health Sciences (LILACS) (January 1982 to October 2010), Zetoc (British Library's Electronic Table of Contents), System for Information on Grey Literature in Europe (openSIGLE), Biosciences Information Service (BIOSIS), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov), Japan Information Center of Science and Technology (JICST-EPlus), and China Academic Journals database (CAJ) via China National Knowledge Infrastructure (CNKI) with citations confirmed using China/Asia On Demand (COAD). There were no language or date restrictions in the search for trials. All databases except CNKI and COAD were last searched on 27 October 2010, CNKI and COAD were searched on 1 April 2010. We also searched literature digests, conference proceedings and reference lists. SELECTION CRITERIA: Of 152 eligible studies,106 comparative treatment trials involving 5872 eyes with dendritic or geographic epithelial keratitis were analysed for corneal healing over two weeks. DATA COLLECTION AND ANALYSIS: Interventions were compared at 14 days after trial enrolment by calculating a risk ratio (RR) that was adjusted with indirect RR, assessed by an inconsistency index (I(2) ) and supplemented by a seven-day RR and a hazard ratio (HR). MAIN RESULTS: Idoxuridine, though uncertainly better in healing outcome than control because of few trials with 14-day follow up, allowed earlier corneal re-epithelialisation. Vidarabine resulted in a significantly better outcome than placebo in one trial (RR 1.96; 95% CI 1.10 to 3.49). Compared to idoxuridine, in combined direct and indirect analyses, vidarabine (RR 1.11; 95% CI 1.03 to 1.19), trifluridine (RR 1.31; 95% CI 1.20 to 1.42), acyclovir (RR 1.23; 95% CI 1.16 to 1.31), brivudine (RR 1.38; 95% CI 1.18 to 1.61), and ganciclovir (RR 1.40; 95% CI 1.25 to 1.57) were significantly more effective. Trifluridine (RR 1.12; 95% CI 1.04 to 1.21) and acyclovir (RR 1.11; 95% CI 1.05 to 1.19) appeared more effective than vidarabine. No significant differences were found in comparisons between acyclovir, trifluridine and brivudine. The comparison of ganciclovir to acyclovir was limited by heterogeneity and possible publication bias. The joint use of two topical antivirals (RR 1.00; 95% CI 0.89 to 1.12) and the use of oral acyclovir alone (RR 0.92; 95% CI 0.79 to 1.07) or combined with a topical antiviral (RR 1.08; 95% CI 0.99 to 1.17) appeared as effective as topical antiviral therapy. Compared to antiviral monotherapy, the combination of an antiviral with interferon (RR 1.03; 95% CI 0.99 to 1.07) or with débridement (RR 1.04; 95% CI 0.95 to 1.14) did not yield significantly better outcomes but may have accelerated healing. The corneal epithelial healing outcome was improved when antiviral therapy was added to débridement (RR 1.21; 95% CI 1.04 to 1.42). AUTHORS' CONCLUSIONS: Trifluridine and acyclovir are more effective than idoxuridine or vidarabine, and similar in therapeutic effectiveness. Brivudine and ganciclovir are at least as effective as acyclovir. While not improving outcome, the combination of interferon and an antiviral agent may speed healing. The effectiveness of corneal epithelial débridement is improved by an antiviral agent.

Corneal neovascularization during experimental fungal keratitis.

PURPOSE: To investigate the development of corneal neovascularization, the corneal expression of vascular endothelial growth factor (VEGF), and the antiangiogenic effects of a VEGF-inhibitory antibody during experimental keratomycosis. METHODS: Scarified corneas of BALB/c mice were topically inoculated with Candidaalbicans and monitored daily for corneal neovascularization. A murine gene microarray compared infected corneas to controls 1 day after inoculation. Real-time reverse transcriptase polymerase chain reaction (RT-PCR) determined levels of genes encoding VEGF-A, VEGF-B, VEGF-C, and VEGF-D and placental growth factor in infected, mock-inoculated, and normal corneas. Immunostaining localized VEGF-A in corneal sections. An anti-VEGF-A antibody that binds to murine VEGF was evaluated for effects on corneal neovascularization and fungal recovery. RESULTS: Eyes with C. albicans keratitis manifested limbal capillary budding on the second postinoculation day, and intrastromal neovascular tufts subsequently grew at a mean rate of 250+/-80 microm/day. One day after the onset of C. albicans keratitis, VEGF-A was upregulated 12.5 fold (p=0.01) by microarray and 8.8 fold (p=0.004) by real-time RT-PCR, followed by a measured decline toward baseline over one week. VEGF-A was present in the epithelium and stroma of infected corneas. Scarification alone did not alter VEGF expression compared to the normal cornea. Anti-VEGF-A antibody significantly (p<0.01) decreased the formation of new corneal blood vessels during experimental keratomycosis without adversely affecting the fungal load of C. albicans keratitis. CONCLUSIONS: Untreated C. albicans keratitis induces VEGF-A and leads to progressive corneal neovascularization that is preventable by a VEGF-blocking antibody.

Morphogenic and genetic differences between Candida albicans strains are associated with keratomycosis virulence.

PURPOSE: To correlate the morphogenic and molecular traits that affect fungal virulence in human corneas. METHODS: C. albicans wild-type strains SC5314 and VE175 were compared using in vitro growth kinetics, filamentation assays, and microarray analysis. Corneal virulence was assessed ex vivo by inoculating C. albicans onto superficially scarified human corneas that were processed after 1 and 3 days to measure hyphal penetration. For comparison, DSY459, a C. albicans homozygous deletion mutant deficient in secreted aspartyl proteinases (SAP) 4, 5, and 6, was evaluated. RESULTS: C. albicans strain SC5314 was highly filamentous in vitro and more invasive in human corneal explants while VE175 demonstrated limited filamentation and less corneal invasion. Among 6,655 C. albicans genes, 9.0% significantly (p<.05) differed by 2 fold or more between SC5314 and VE175. Genes involved in fungal filamentation that were upregulated in strain SC5314 compared to VE175 included SAP5, SAP6, and other hypha-associated genes. Compared to wild-type strains, DSY459 had intermediate filamentation and stromal penetration. CONCLUSIONS: Fungal genes involved in filamentation likely contribute to virulence differences between wild-type strains of C. albicans. The corneal pathogenicity of C. albicans involves the morphogenic transformation of yeasts into hyphae.

Gene profiling and signaling pathways of Candida albicans keratitis.

PURPOSE: To compare the global gene expression patterns in uninfected and fungus-infected mouse corneas at the onset of Candida albicans keratitis. METHODS: Fungal keratitis was generated by scarifying the corneal epithelium of BALB/c mice followed by topical inoculation with Candida albicans. Corneal infection was allowed to progress for one day, and total RNA was then extracted from excised corneas. Microarray was performed to detect 45,102 murine genes and processed to identify genetic regulation of signaling pathways. Selected genes encoding interleukins (IL), chemokine ligands, and other cytokines were confirmed by quantitative real-time reverse transcriptase polymerase chain reaction (RT-PCR). RESULTS: Compared to mock-inoculated control eyes, genetic microarray analysis of Candida albicans keratitis showed that 3,977 genes (8.8%) changed at least twofold and 1,672 genes (3.7%) changed at least fourfold. Hierarchical clustering identified that upregulated genes affected immune and inflammatory responses, intercellular signaling, and cellular proliferation. Pathways having more than 20% of their genes significantly upregulated signaled leukocyte extravasation, increased interleukin production, and affected toll-like receptors. Upregulated transcript levels for IL-1beta and IL-6 were confirmed by real-time RT-PCR. CONCLUSIONS: Host gene expression during the initial stage of Candida albicans keratitis involves pathways contributing to acute inflammation mediated by interleukins and other signals of leukocyte recruitment. This murine study confirms the involvement of innate immunity in the cornea during the initiation of Candida albicans keratitis.

Rapidly progressive cataract and iris atrophy during treatment of Acanthamoeba keratitis.

PURPOSE: To identify characteristics associated with cataract occurring during the course of Acanthamoeba keratitis. DESIGN: Retrospective observational case series. PARTICIPANTS: Eighty-one laboratory-confirmed patients with Acanthamoeba keratitis. METHODS: Review of clinical records. MAIN OUTCOME MEASURES: Development of cataract during management of Acanthamoeba keratitis. RESULTS: Rapidly progressive crystalline lens opacification occurred in 9 eyes within 4 to 15 weeks after diagnosis of Acanthamoeba keratitis. Three were associated with inflammatory complications, including anterior scleritis (2 eyes) and iridocyclitis (1 eye). Six others had the abrupt onset of a dense cataract, including 5 with iris atrophy, that occurred during the initial 6 months of therapy with chlorhexidine, a diamidine, and adjunctive corticosteroid. Extracapsular cataract extraction was performed with or after penetrating keratoplasty. Secondary glaucoma developed in 6 of 9 eyes subsequent to iris atrophy (4 eyes) or a cyclitic membrane (2 eyes), and 3 eyes underwent trabeculectomy. CONCLUSIONS: Cataract may occur and progress during the management of Acanthamoeba keratitis in association with anterior segment inflammation, iris atrophy, and secondary glaucoma.

Infectious disease risk factors of corneal graft donors.

OBJECTIVE: To determine how donor health status affects the risk of infection after corneal transplant. METHODS: An adverse reaction surveillance registry was used to conduct a matched case-control study among transplanted donor corneas from January 1, 1994, to December 31, 2003. Cases comprised 162 reports of endophthalmitis after penetrating keratoplasty including 121 with microbial recovery, of which 59 had concordant donor and recipient microbial isolates. Two controls were matched to each case by surgery date. Conditional logistic regression estimated adjusted odds ratios with 95% confidence intervals according to the premortem status of decedent donors. RESULTS: Postkeratoplasty endophthalmitis was associated with recent hospitalization (odds ratio, 2.84; 95% confidence interval, 1.61-4.98) and fatal cancer (odds ratio, 2.46; 95% confidence interval, 1.53-3.97) among donors. Endophthalmitis appeared more likely with tissues transplanted longer than 5 days after donation (odds ratio, 1.55; 95% confidence interval, 1.02-2.35). The prevalence of concordant microbial isolates from donors and recipients was greater among fungal endophthalmitis than among bacterial endophthalmitis (P < .001). CONCLUSIONS: Corneal grafts with eye tissue obtained from donors dying in the hospital or with cancer may have an increased risk of postsurgical endophthalmitis, possibly due to donor-to-host microbial transmission. Together with donor screening and processing, improvements in microbiological control may reduce infection associated with corneal transplant.

Bilateral acanthamoeba keratitis.

PURPOSE: To determine the prevalence and characteristics of binocular involvement among patients with Acanthamoeba keratitis. DESIGN: Retrospective case series. METHODS: Risk factors and outcomes of bilateral infection were explored among consecutive cases of Acanthamoeba keratitis diagnosed at a single institution from 1997 through mid 2007. RESULTS: Fifty eyes were confirmed to have Acanthamoeba keratitis by microbiologic or histopathologic testing; two-thirds occurred during a regional outbreak beginning in 2004. Five (11%) of 45 patients had infection of both eyes, including three with concurrent involvement and two with successive disease of the contralateral cornea. Three binocularly infected patients used soft contact lenses, and two wore rigid gas-permeable lenses. Nine of 10 eyes achieved visual acuity of 20/30 or better after antiamebic therapy. CONCLUSIONS: Bilateral Acanthamoeba keratitis is an infectious complication of contact lens wear. With laboratory confirmation, vision often can be restored with medical therapy.

Corneal virulence of Candida albicans strains deficient in Tup1-regulated genes.

PURPOSE: To evaluate the role of rbt genes downstream of Tup1p, a transcription factor regulating fungal filamentation, in experimental Candida albicans keratitis. METHODS: Corneas of BALB/c mice were scarified and topically inoculated with 10(5) or 10(6) colony-forming units (CFU) of a wild-type human isolate of C. albicans (SC5314), a mutant strain with a transposon-induced homozygous disruption of the rbt1 gene (Tn7-rbt1), its control (DAY286), homozygous rbt knockout mutants deficient in rbt1 (BCa7-4) or rbt4 (BCa11-3), or their parental control (CAF2-1). Eyes were scored daily for clinical severity of fungal keratitis and were examined histopathologically. RESULTS: With a 10(5) CFU inoculum, the CAF2-1 control and its mutant derivatives (BCa7-4 and BCa11-3) produced significantly lower keratitis scores than did the moderately severe keratitis induced by control strains SC5314 and DAY286 and the Tn7-rbt1 mutant (P < 0.05). At a 10(6) CFU inoculum, all strains induced severe disease except for the rbt4-deficient mutant. Fungal keratitis caused by Tn7-rbt1 was as severe as that of control strains (P > 0.2), and the BCa7-4 mutant initially caused severe disease that gradually waned (P < 0.02). However, the BCa11-3 mutant produced moderate disease that was significantly less severe than that induced by control strains (P < 0.04) and resolved within 1 week. CONCLUSIONS: The rbt4 gene of C. albicans is a potential virulence factor in posttraumatic corneal infection. Genetically regulated hyphal morphogenesis appears to be involved in the initial pathogenesis of experimental keratomycosis.

The role of secreted aspartyl proteinases in Candida albicans keratitis.

PURPOSE: To evaluate virulence in a murine keratitis model using Candida albicans homozygous mutants deficient in one or more secreted aspartyl proteinases encoded by SAP genes or in transcriptional factors encoded by EFG1 and CPH1 genes. METHODS: Corneas of BALB/c mice were scarified and topically inoculated with 10(6) colony-forming units of a C. albicans human isolate (SC5314), triple SAP-null mutants (SAP1-3(-/-) and SAP4-6(-/-)), double mutants (SAP4/5(-/-), SAP4/6(-/-), SAP5/6(-/-), and SAP9/10(-/-) and EFG1(-/-)/CPH1(-/-)), single mutants (SAP4(-/-), SAP5(-/-) and SAP6(-/-), EFG1(-/-), and CPH1(-/-)), SAP6 rescuant, or parental controls (CAF2-1 and CAI-4). Animals were evaluated daily for up to 8 days after inoculation. RESULTS: Wild-type C. albicans induced severe, sustained ulcerative keratitis, and the fungal strains (CAF2-1 and CAI-4) used to generate mutants had similar corneal pathogenicity. SAP1-3(-/-), SAP4/5(-/-), and SAP9/10(-/-) mutants produced moderate keratitis similar to the virulent parental strain. SAP4-6(-/-), SAP4/6(-/-), and SAP5/6(-/-) gave rise to significantly less severe corneal inflammation. The SAP6(-/-) single mutant resulted in mild nonulcerative keratitis that resolved spontaneously within 5 days, and the SAP6 rescuant reestablished moderate disease severity. The EFG1(-/-)/CPH1(-/-) and EFG1(-/-) mutants had reduced corneal virulence, but the CPH1(-/-) strain resulted in persistent keratitis similar to control corneas. CONCLUSIONS: The EFG1-regulated SAP6 gene of C. albicans encodes a unique secreted aspartyl proteinase that contributes to corneal pathogenicity. The role of SAP6 during corneal infection appears to be associated with the morphogenic transformation of C. albicans yeasts into invasive filamentous forms.

Candida albicans strain-dependent virulence and Rim13p-mediated filamentation in experimental keratomycosis.

PURPOSE: To compare the virulence of wild-type Candida albicans strains in a murine model of corneal candidiasis and to investigate the role of fungal filamentation in disease progression. METHODS: Scarified corneas of immunocompetent or cyclophosphamide-treated BALB/c mice were topically inoculated with one of three human isolates of C. albicans, a homozygous mutant of the pH-dependent filamentation gene rim13 or a mutant reference strain control. Mock-inoculated eyes served as negative controls. Corneal disease was categorized daily for 8 days with quantitative fungal culturing of eyes at 6 hours, 1 day, 4 days, and 8 days after infection and histopathologic examination at 1 day and 4 days after infection. RESULTS: Corneal disease severity differed significantly among wild-type strains (P < or = 0.02). The rim13(-/-) mutant Tn7-rim13 was fully attenuated, whereas the mutant control DAY286 was fully virulent. Pretreatment of mice with cyclophosphamide increased susceptibility to wild-type C. albicans and partially rescued the attenuated phenotype of the genetically deficient rim13(-/-) fungal mutant. All strains replicated with similar kinetics in vitro, and wild-type strains had similar clearance from infected eyes. Histopathologic findings correlated with disease severity. CONCLUSIONS: Wild-type strains of C. albicans that differ significantly in ocular pathogenicity correlate with the ability of yeast to produce pseudohyphae and hyphae and to invade corneal tissue. Full attenuation of the fungal rim13(-/-) mutant is the first direct demonstration of a hyphal morphogenesis-related gene as a specific virulence factor for C. albicans during corneal infection.

The prognostic role of donor corneoscleral rim cultures in corneal transplantation.

PURPOSE: To examine the discriminatory performance of donor corneoscleral rim cultures for predicting endophthalmitis after corneal transplantation. DESIGN: Systematic literature review. PARTICIPANTS: Studies that reported the prevalence of donor rim cultures after refrigerated preservation of donor corneas distributed for keratoplasty. METHODS: Random-effects meta-analysis estimated pooled sensitivity, specificity, likelihood ratios, and diagnostic odds ratios. Meta-regression and stratification explored study-level reasons for diagnostic performance. MAIN OUTCOME MEASURES: Incidence of postkeratoplasty endophthalmitis. RESULTS: Of 17,614 corneal grafts, 2459 (14%) had a positive donor rim culture and 31 (0.2%) developed endophthalmitis. Twenty-one had concordant donor and recipient isolates, including 10 with Candida species. The sensitivity of donor rim cultures among 10 studies reporting postsurgical endophthalmitis was 67% (95% confidence interval [CI], 47%-83%), and specificity averaged 85%. Endophthalmitis occurred 12 (95% CI, 5-29) times more often among recipients of a culture-positive donor cornea. With Bayesian analysis, a culture-positive donor cornea would raise the infection risk to 1%, whereas fungal isolation from the donor rim predicts a 3% probability of fungal endophthalmitis. Pooling of studies was limited by a significant discrepancy among reports that could not be explained by differences in antibiotic supplementation of the preservation medium, method of culture inoculation, or type of culture medium. CONCLUSION: Endophthalmitis after penetrating keratoplasty is more likely with a culture-positive donor rim, notably candidal endophthalmitis from fungal contaminants, but better evidence is needed to determine the prognostic value and manner of routine microbiological screening.

Redundant publication of clinical trials on herpetic keratitis.

PURPOSE: To examine reported clinical trials on herpes simplex virus epithelial keratitis as a case study for the configuration and possible motives of overlapping publications in the ophthalmic literature. DESIGN: Cross-sectional bibliometric survey. METHODS: One hundred and forty-four reports of 98 randomized clinical trials that formed the framework for a systematic review on dendritic and geographic keratitis were assembled by electronic and manual searching of biomedical journals and transactions, excluding meeting abstracts. Overlapping reports were identified by comparing methods and results. Main articles giving the most detailed results among overlapping reports were contrasted with trial reports without duplication. Annual citation rates since publication were estimated from the number of times each report was cited by subsequent scientific articles indexed in an online citation database. RESULTS: Sixty-one articles were published once, while 83 articles overlapped in 23 clusters, of which 14 (50%) lacked bibliographic cross-reference. Of 55 secondary reports, 34 (62%) had a smaller sample size than their corresponding main report. Secondary articles were less likely to appear in an ophthalmological publication than main reports (P < .001) and were later cited less often (P = .01). Compared to trial reports published once, main articles with an overlapping report had a significantly higher citation rate (P = .04). CONCLUSION: Overlapping publications of therapeutic trials on herpetic keratitis often had undisclosed or fragmentary interconnections. Subsequent authors cited articles having an overlapping report more often than trials published once.

The clinical diagnosis of microbial keratitis.

PURPOSE: To evaluate the ability of ophthalmologists to predict the laboratory results of presumed microbial keratitis and to explore which findings may influence diagnostic prognostication. DESIGN: Prospective, cross-sectional study. METHODS: Fifteen ophthalmologists completed study forms at the initial presentation of patients with presumed microbial keratitis. After predicting the category of microbial recovery, clinicians submitted corneal scrapings for masked laboratory processing. The relative effects of ocular inflammatory signs on correct microbial diagnosis were explored with Poisson regression. RESULTS: Clinical examiners correctly predicted the presence or absence of microbial recovery in 79 (76%) of 104 ulcerative keratitis cases and successfully distinguished among bacterial, fungal, and amebic keratitis for 54 (73%) of 74 culture-positive infections, although only 31 (42%) were subcategorized properly. The positive predictive value of clinical diagnosis was 65% (95% confidence interval [CI], 43% to 84%) for 20 eyes with Pseudomonas keratitis cases, 48% (95% CI, 32% to 63%) for 38 other bacterial keratitis, 45% (95% CI, 17% to 77%) for 13 fungal keratitis, and 89% (95% CI, 52% to 100%) for nine Acanthamoeba keratitis cases. The recognition of Pseudomonas keratitis significantly improved by the occurrence of a larger infiltrate (P = .02), and correctly predicting Acanthamoeba keratitis was enhanced by observing a ring infiltrate (P < .001). Antimicrobial use before referral significantly attenuated clinical diagnosis (P = .03) and hampered microbial recovery (P = .004). CONCLUSIONS: Established Pseudomonas keratitis and Acanthamoeba keratitis can be suspected before laboratory confirmation, but overlapping inflammatory features and recent empiric antimicrobial treatment limits etiologic recognition of most microbial corneal infections.

Clinical characteristics and outcome of Candida keratitis.

PURPOSE: To characterize the clinical features and therapeutic outcome of Candida keratitis. DESIGN: Retrospective, observational case series. METHODS: We reviewed 26 patients treated for Candida keratitis, including two with recurrent keratitis and one with bilateral infection. RESULTS: Of 29 keratitis episodes resulting from Candida albicans (n = 20) or Candida parapsilosis (n = 9), 16 (55%) complicated chronic ocular surface disease, and nine (31%) followed previous keratoplasty. Only two were clinically suspected to have keratomycosis at initial presentation, and 21 (72%) used antibacterial therapy before corneal scrapings. Reconstructive keratoplasty occurred more often in previously grafted eyes (P = .03). Visual outcome was 20/60 or better in six (100%) medically treated eyes with good presenting visual acuity but in only five eyes (24%) with worse initial vision (P = .002). CONCLUSIONS: Candida keratitis is an opportunistic infection of a compromised cornea that often is misdiagnosed initially and, despite antifungal therapy, occasionally requires corneal grafting.

Quality assessment and microbiologic screening of donor corneas.

PURPOSE: To identify possible predictors of donor corneal contamination. METHODS: Relationships between eye-banking characteristics of donor corneas and surgical corneoscleral rim culture results were examined in a retrospective case-control study by using logistic regression to estimate odds ratios (ORs) with 95% confidence intervals (CIs). RESULTS: Of 263 donor corneal rims, microbial recovery occurred from 23 (9%), including 6 yielding Clostridium perfringens. After adjusting for outdoor temperature and death-to-preservation duration, a positive rim culture occurred more often among tissues having an acceptable but less favorable biomicroscopic rating (OR, 4.22; 95% CI, 1.27-13.98). CONCLUSIONS: This exploratory study suggests that slit-lamp assessment of corneal appearance may correlate with subsequent microbiologic results. Ensuring optimal selection and preservation of the donor cornea may contribute to the safety of eye banking.