Effects of methylprednisolone and cyclosporine A on fungal growth in vitro

Steroids in the Management of Infectious Keratitis

PURPOSE

To summarize the evidence base on the use of topical corticosteroids for infectious keratitis.

METHODS

Narrative review.

RESULTS

Infectious keratitis is a painful condition that often results in visually significant corneal stromal scarring, even when antimicrobial therapy is successful. Corticosteroids may reduce inflammation and subsequent scar formation and while relieving the acute ocular pain associated with a corneal ulcer. However, corticosteroids also reduce the host immune response, which could hinder the ability to clear infection. The safety and effectiveness of corticosteroids depends to a large part on the efficacy of the antimicrobials being used to treat the underlying infection. Randomized trials have found that corticosteroids are safe and effective for herpetic keratitis when used with appropriate antiviral therapy, and are safe for bacterial keratitis when used with broad spectrum topical antibiotics. The effectiveness of corticosteroids for bacterial keratitis has not been shown conclusively, although more advanced bacterial corneal ulcers may do better with corticosteroids. No randomized trials have assessed the safety and effectiveness of steroids for fungal or acanthamoeba keratitis. Animal studies suggest corticosteroids may be harmful in fungal keratitis, and observational human studies have found that steroids are harmful for fungal and acanthamoeba keratitis when started prior to anti-amoebics.

CONCLUSIONS

Topical corticosteroids, when used as an adjunct to antimicrobial therapy, may be beneficial if the antimicrobial being used can effectively clear or suppress the infection, such as in bacterial and herpetic keratitis. Randomized trials would be helpful to further delineate the role of corticosteroids for infectious keratitis.

Natural and Man-Made Cyclic Peptide-Based Antibiotics

In recent years, an increasing number of drug-resistant bacterial strains have been identified due to the abuse of antibiotics, which seriously threatens human and animal health. Antimicrobial peptides (AMPs) have become one of the most effective weapons to solve this problem. AMPs have little tendency to induce drug resistance and have outstanding antimicrobial effects. The study of AMPs, especially cyclic peptides, has become a hot topic. Among them, macrocyclic AMPs have received extensive attention. This mini-review discusses the structures and functions of the dominant cyclic natural and synthetic AMPs and provides a little outlook on the future direction of cyclic AMPs.

Potential Antifungal Targets for Aspergillus sp. from the Calcineurin and Heat Shock Protein Pathways

Aspergillus species, especially A. fumigatus, and to a lesser extent others (A. flavus, A. niger, A. terreus), although rarely pathogenic to healthy humans, can be very aggressive to immunocompromised patients (they are opportunistic pathogens). Although survival rates for such infections have improved in recent decades following the introduction of azole derivatives, they remain a clinical challenge. The fact that current antifungals act as fungistatic rather than fungicide, that they have limited safety, and that resistance is becoming increasingly common make the need for new, more effective, and safer therapies to become more acute. Over the last decades, knowledge about the molecular biology of A. fumigatus and other Aspergillus species, and particularly of calcineurin, Hsp90, and their signaling pathway proteins, has progressed remarkably. Although calcineurin has attracted much interest, its adverse effects, particularly its immunosuppressive effects, make it less attractive than it might at first appear. The situation is not very different for Hsp90. Other proteins from their signaling pathways, such as protein kinases phosphorylating the four SPRR serine residues, CrzA, rcnA, pmcA-pmcC (particularly pmcC), rfeF, BAR adapter protein(s), the phkB histidine kinase, sskB MAP kinase kinase, zfpA, htfA, ctfA, SwoH (nucleoside diphosphate kinase), CchA, MidA, FKBP12, the K27 lysine position from Hsp90, PkcA, MpkA, RlmA, brlA, abaA, wetA, other heat shock proteins (Hsp70, Hsp40, Hsp12) currently appear promising and deserve further investigation as potential targets for antifungal drug development.

Use of Topical Cyclosporine 0.1% in Therapeutic Penetrating Keratoplasty for Fungal Keratitis

PURPOSE

The efficacy and safety of topical cyclosporine 0.1% in preventing early graft failure after therapeutic penetrating keratoplasty (TPK) in eyes with fungal keratitis were evaluated.

METHODS

This prospective case series included patients with fungal keratitis undergoing TPK from May to December 2019 who were treated with cyclosporine A 0.1% eye drops (tCSA group). We compared the outcome with a historical cohort of patients who were treated conventionally (CT group) with topical prednisolone acetate 1% eye drops started 3 weeks after surgery.

RESULTS

There were 20 patients (male: 13; female: 7) in the tCSA group and 28 patients in the CT group (male: 23; female: 5). The number of clear grafts 3 months postoperatively was 10 (50%) in the tCSA group and 4 (14.3%) in the CT group ( P = 0.011). The mean logarithm of the minimum angle of resolution best-corrected visual acuity was 1.49 ± 0.74 in the tCSA group and 2.10 ± 0.62 in the CT group ( P = 0.003). There were 5 patients (17.9%) with recurrence of the primary fungal infection in the CT group, 4 of whom were using topical prednisolone. There was no recurrence in the tCSA group. A logistic regression analysis revealed higher odds of a clear graft at 3 months postoperatively with topical cyclosporine 0.1% [odds ratio: 14.35 (95% confidence interval, 2.38-86.5), P = 0.004].

CONCLUSIONS

Postoperative treatment with topical cyclosporine 0.1% seems to increase graft survival and postoperative vision with reduced risk of recurrence of primary infection in eyes with fungal keratitis undergoing TPK.

Candida Keratitis: Epidemiology, Management, and Clinical Outcomes

PURPOSE

To examine the epidemiological characteristics, trends, risk factors, management strategies, and clinical outcomes of Candida albicans and non-albicans keratitis over a 15-year period in a tertiary Canadian eye center.

METHODS

In a retrospective observational case series of Candida keratitis from 2003 to 2017, demographics, risk factors, corrected distance visual acuity (CDVA) at initial and final consultations, medical and surgical management, and follow-up duration were recorded.

RESULTS

Twenty-one cases of Candida keratitis were identified (62.5% of total fungal keratitis; 10 C. albicans and 11 non-albicans). The most commonly associated risk factors were topical steroid use (16 patients, 76%), ocular surface disease (15 patients, 71%), contact lens use (11 patients, 52%), and previous corneal surgery (8 patients, 38%); all patients had 2 or more combined risk factors. The number of patients with a visual acuity of 20/200 or better remained the same before and after the treatment (5/21, 24%). The mean duration of the antifungal treatment was 98 ± 126 days. Sixteen patients ultimately required surgical management (76%; 12 therapeutic keratoplasties, 3 enucleation, and 1 optical keratoplasty). When comparing C. albicans with non-albicans keratitis, we found no difference in presenting visual acuity, final visual acuity, or requirement for surgical management.

CONCLUSIONS

Candida keratitis accounts for the most identified fungal keratitis cases in this temperate climate area. An exposure to multiple risk factors appears necessary. A surgical intervention is required for the resolution of most cases. Different subspecies of Candida ultimately resulted in similar clinical outcomes.

Keratitis Caused by Candida parapsilosis and Subsequent Corynebacterium macginleyi Infection: Case Report and Short Review

Keratitis due to Candida parapsilosis or Corynebacterium macginleyi is uncommon. We present a patient with several risk factors who suffered two subsequent corneal infections caused by these pathogens and healed with topical conservative therapy. The important factor was the early detection of infection. Fluconazole solution administered topically as eye drops combined with regular debridement proved in this case a successful alternative to systemic antifungal treatment. With a perceived recurrence of the keratitis, one must take into account the involvement of other pathogens present. The previous use of an antifungal solution other than a conventional eye drop could be an additional risk factor for a second bacterial infection, but the benefits should still rule in favor of such a treatment.

Intraocular minocycline for the treatment of ocular pythiosis

PURPOSE

A case of ocular pythiosis successfully treated with surgery and intraocular and oral minocycline is reported.

SUMMARY

A 30-year-old man who wore corrective contact lenses traveled to Brazil and Colombia where he swam in salt and fresh waters while wearing contact lenses. He sought treatment at an emergency department after 2 weeks of suffering with a painful corneal ulcer, redness, and loss of vision in his right eye that had been treated at other centers with ophthalmic moxifloxacin for 10 days and with fortified topical antibiotics (amikacin and vancomycin) for 2 days. Examination using a slit lamp revealed a deep central corneal ulcer with surrounding white infiltrate, endothelial plaque, and hypopyon. Due to infection severity, the patient was admitted and received empirical antibiotic therapy and i.v. and topical antifungals. During the first corneal transplantation, the patient's original infection relapsed and was treated with voriconazole and liposomal amphotericin B intraocular injections. A subsequent infection developed, and a second keratoplasty was performed. One month after hospital admission, the patient was diagnosed with ocular pythiosis and therapy with oral minocycline was initiated. After severe infection relapse in the anterior chamber, the patient underwent a third penetrating keratoplasty, where minocycline intraocular injection was administered. After this intervention, complete infection control was achieved, and the patient was discharged 45 days after admission with oral minocycline and 1% cyclosporine and 0.3% ofloxacin eye drops.

CONCLUSION

A patient with ocular pythiosis was successfully treated with penetrating keratoplasty and 2 months of treatment with intracameral and oral minocycline.

Fungal scleritis masquerading as surgically induced necrotizing scleritis: a case report

Introduction

The object of this case is to report the clinical findings, microbiological findings and management of a case of fungal scleritis following cataract surgery, which mimicked surgically induced necrotizing scleritis.

Case presentation

A 72-year-old Asian (Indian) man presented with scleritis following cataract surgery at another facility. He had been treated elsewhere for suspected scleritis, primarily with steroids followed by empiric antibiotic and antifungal agents. At our institute he underwent a complete microbiological workup and a scleral patch graft. The scleral scraping revealed fungal filaments. He was treated postoperatively with topical and systemic antifungal agent along with topical cyclosporine. The follow-up examination at 5 months revealed that the scleral patch graft was successful in maintaining the integrity of his globe and restoring partial vision.

Conclusions

Fungal scleritis may mimic surgically induced necrotizing scleritis. Early diagnosis and prompt management can prevent progression of the disease and further devastating complications.

Pharmacological treatment for infectious corneal ulcers

INTRODUCTION

Cornea ulceration and infectious keratitis are leading causes of corneal morbidity and blindness. Infectious causes are among the most frequent and most severe. Management strategies for bacterial corneal ulcers have changed significantly over the last decades, however with a more limited progress in the treatment and management of nonbacterial, infectious ulcers.

AREAS COVERED

This paper provides an overview of the current principles, strategies and treatment choices for infectious corneal ulcers in adults.

EXPERT OPINION

Topical application with a broad-spectrum antimicrobial remains the preferred method for the pharmacological management of infectious corneal ulcers. Increasing reports of clinical failures and in vitro resistance to antibiotics to treat the most common infectious (bacterial) corneal ulcers are increasing concerns. New approaches for improvement in the pharmacological management of corneal ulcers should focus on strategies for a more rational and evidence-based use of current antimicrobials and development of products to modulate the host immune response and to neutralize microbial toxins and other immune modulators.

Dry eye disease and microbial keratitis: is there a connection?

Dry eye is a common ocular surface disease of multifactorial etiology characterized by elevated tear osmolality and inflammation leading to a disrupted ocular surface. The latter is a risk factor for ocular surface infection, yet overt infection is not commonly seen clinically in the typical dry eye patient. This suggests that important innate mechanisms operate to protect the dry eye from invading pathogens. This article reviews the current literature on epidemiology of ocular surface infection in dry eye patients and laboratory-based studies on innate immune mechanisms operating at the ocular surface and their alterations in human dry eye and animal models. The review highlights current understanding of innate immunity in dry eye and identifies gaps in our knowledge to help direct future studies to further unravel the complexities of dry eye disease and its sequelae.

Infectious keratitis progressing to endophthalmitis: a 15-year study of microbiology, associated factors, and clinical outcomes

PURPOSE

To describe the incidence, microbiology, associated factors, and clinical outcomes of patients with infectious keratitis progressing to endophthalmitis.

DESIGN

Nonrandomized, retrospective, consecutive case series.

PARTICIPANTS

All patients treated for culture-proven keratitis and endophthalmitis between January 1, 1995 and December 31, 2009, at the Bascom Palmer Eye Institute.

METHODS

Ocular microbiology and medical records were reviewed on all patients with positive corneal and intraocular cultures over the period of the study. Univariate analysis was performed to obtain P values described in the study.

MAIN OUTCOME MEASURES

Microbial isolates, treatment strategies, and visual acuity (VA) outcomes.

RESULTS

A total of 9934 corneal cultures were performed for suspected infectious keratitis. Only 49 eyes (0.5%) progressed to culture-proven endophthalmitis. Fungi (n = 26) were the most common responsible organism followed by gram-positive bacteria (n = 13) and gram-negative bacteria (n = 10). Topical steroid use (37/49 [76%]) was the most common associated factor identified in the current study, followed by previous surgery (30/49 [61%]), corneal perforation (17/49 [35%]), dry eye (15/49 [31%]), relative immune compromise (10/49 [20%]), organic matter trauma (9/49 [18%]), and contact lens wear (3/49 [6%]). There were 27 patients in whom a primary infectious keratitis developed into endophthalmitis, and 22 patients in whom an infectious keratitis adjacent to a previous surgical wound progressed into endophthalmitis. Patients in the primary keratitis group were more likely to be male (22/27 [81%] vs 8/22 [36%]; P = 0.001), have history of organic matter trauma (8/27 [30%] vs 1/22 [5%]); P = 0.030), and have fungal etiology (21/27 [78%] vs 5/22 [23%]; P<0.001). Patients in the surgical wound-associated group were more likely to use topical steroids (20/22 [91%] vs 17/27 [63%]; P = 0.024). A VA of ≥ 20/50 was achieved in 7 of 49 patients (14%), but was <5/200 in 34 of 49 (69%) at last follow-up. Enucleation or evisceration was performed in 15 of 49 patients (31%).

CONCLUSIONS

Progression of infectious keratitis to endophthalmitis is relatively uncommon. The current study suggests that patients at higher risk for progression to endophthalmitis include patients using topical corticosteroids, patients with fungal keratitis, patients with corneal perforation, and patients with infectious keratitis developing adjacent to a previous surgical wound. Patients with sequential keratitis and endophthalmitis have generally poor visual outcomes.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found after the references.

Successful salvage therapy of Fusarium endophthalmitis secondary to keratitis: an interventional case series

Purpose

To describe a combination of treatment modalities used for the successful eradication of Fusarium endophthalmitis.

Design

Interventional case series.

Participants

Three consecutive patients with keratitis-associated Fusarium endophthalmitis.

Methods

After failure of traditional management options, a combination of intravitreal and long-term, high-dose systemic voriconazole, topical antifungal medications, and surgical intervention, with penetrating keratoplasty, lensectomy, and endoscopic-guided pars plana vitrectomy, was administered to each patient.

Results

All three cases achieved full resolution of the infection, with a final Snellen visual acuity score of 20/50 to 20/70.

Conclusions

An aggressive combination of therapeutic modalities, including the removal of subiris abscesses, might be needed for the successful resolution of Fusarium endophthalmitis.

[Fungal keratitis caused by Cylindrocarpon lichenicola]

We report a case of a 67-year-old woman with no significant past ocular history, who was referred for management of an unresponsive microbial keratitis resulting from trauma with a piece of clothing fabric 1 month previously in Portugal and worsening despite topical fortified antibiotics. On examination, visual acuity was limited to "light perception". Slit lamp examination revealed an 11×11mm full-thickness corneal infiltrate. Confocal images showed branching hyphae suggestive of a fungal infection. Fungal cultures of corneal scrapings revealed growth of Cylindrocarpon lichenicola, a saprophytic, filamentous fungus, which is an unusual cause of keratitis. Despite aggressive antifungal therapy with voriconazole and amphotericin B, she required penetrating keratoplasty for impending corneal perforation. Follow-up was uneventful, with no recurrence at 1 year. Fungal infections must be suspected in all corneal ulcers of traumatic etiology. Specific cultures and confocal microscopy must be performed early, so as to enable early treatment modification.

Cyclosporin A treatment and decreased fungal load/antigenemia in experimental murine paracoccidioidomycosis

Paracoccidioidomycosis (PCM) is a systemic mycosis caused by the fungus Paracoccidioides brasiliensis (Pb). The cyclosporin A (CsA) is an immunosuppressant drug that inhibits calcineurin and has been described as a potential antifungal drug. The present study investigated the effect of CsA on the immune response, fungal load/antigenemia in experimental murine PCM. It was used four groups of BALB/c mice: (a) infected with 1 x 10⁵ Pb18 yeast cells (Pb), (b) infected and treated with CsA every other day 10 mg/kg of CsA (s.c.) during 30 days (Pb/CsA), (c) treated with CsA (CsA) and (d) no infected/treated (PBS). The immune response was evaluated by lymphocyte proliferation, DTH assays to exoAgs, ELISA for IgG anti-gp43 (specific immune responses) and cytokine serum levels (IFN-γ, TNF-α, IL-4 and IL-10). Fungal load was determined by lung colony-forming units (CFU) counts, lung and liver histopathology analysis and antigenemia determined by inhibition-ELISA. As expected, CsA was able to inhibit the specific cellular and humoral immune response (P < 0.05), with decrease in serum IFN-γ, TNF-α and IL-4 levels (P < 0.05). Cyclosporin A treatment also resulted in significantly decreased lung Pb CFU (P < 0.05) as well as a lower number of yeasts in the lung and liver (P < 0.05) by histopathology. In concordance, the decreased antigenemia was observed in Pb/CsA group (P < 0.05). In conclusion, even with immunosuppressive action, treatment with CsA results in decreased lung fungal load/antigenemia in experimental PCM in BALB/c mice. Further study is required to determine whether this represents less severe disease or protection by CsA.

Calcineurin target CrzA regulates conidial germination, hyphal growth, and pathogenesis of Aspergillus fumigatus

The calcineurin pathway is a critical signal transduction pathway in fungi that mediates growth, morphology, stress responses, and pathogenicity. The importance of the calcineurin pathway in fungal physiology creates an opportunity for the development of new antifungal therapies that target this critical signaling pathway. In this study, we examined the role of the zinc finger transcription factor Crz1 homolog (CrzA) in the physiology and pathogenicity of the opportunistic human fungal pathogen Aspergillus fumigatus. Genetic replacement of the crzA locus in A. fumigatus resulted in a strain with significant defects in conidial germination, polarized hyphal growth, cell wall structure, and asexual development that are similar to but with differences from defects seen in the A. fumigatus DeltacnaA (calcineurin A) strain. Like the DeltacnaA strain, the DeltacrzA strain was incapable of causing disease in an experimental persistently neutropenic inhalational murine model of invasive pulmonary aspergillosis. Our results suggest that CrzA is an important downstream effector of calcineurin that controls morphology in A. fumigatus, but additional downstream effectors that mediate calcineurin signal transduction are likely present in this opportunistic fungal pathogen. In addition, the importance of CrzA to the production of disease is critical, and thus CrzA is an attractive fungus-specific antifungal target for the treatment of invasive aspergillosis.

[Fungal keratitis caused by Scedosporium apiospermum]

INTRODUCTION

We report a case of posttraumatic keratomycosis caused by Scedosporium apiospermum that was treated with oral and topical voriconazole and penetrating keratoplasty.

CASE REPORT

A patient was admitted to the hospital with a corneal abscess of his right eye due to trauma while gardening. No improvement was noted with topical fortified antibiotics (vancomycin, gentamicin, and cefazolin) and antimycotic (amphotericin B 1%) and oral itraconazole (200 mg/day). Fungal cultures of corneal scrapings revealed growth of Scedosporium apiospermum, a strain for which the main antifungals showed high minimal inhibitory concentrations (MICs), whereas the MIC of voriconazole was 0.125 microg/mL. Despite some improvement with topical 1% voriconazole and oral voriconazole (200 mg/day) treatment, a therapeutic penetrating keratoplasty was performed because of the high risk of corneal perforation. The graft remained clear without fungal recurrence with topical 2% cyclosporine A, dexamethasone, and voriconazole treatment.

CONCLUSION

Scedosporium apiospermum is an uncommon cause of mycotic keratitis in humans. Prognosis is generally poor because of delayed diagnosis and resistance to conventional antifungals. Voriconazole is a triazole broad-spectrum antifungal agent. In conjunction with its oral administration, topical application of voriconazole extends the current armamentarium of antifungal agents for keratomycosis.

Harnessing calcineurin as a novel anti-infective agent against invasive fungal infections

The number of immunocompromised patients with invasive fungal infections continues to increase and new antifungal therapies are not keeping pace with the growing incidence of these infections and their associated mortality. Calcineurin inhibition is currently used to exert effective immunosuppression following organ transplantation and in treating various other conditions. However, the calcineurin pathway is also intricately involved in the growth and pathogenesis of the three major fungal pathogens of humans, Cryptococcus neoformans, Candida albicans and Aspergillus fumigatus, and the exploitation of fungal calcineurin pathways holds great promise for the future development of novel antifungal agents. This Review summarizes our current understanding of calcineurin biology in these fungal species, and its exciting potential role in treating invasive fungal infections.

Fungal keratitis in Melbourne

BACKGROUND

Description of the clinical and microbiological spectrum of fungal keratitis at a tertiary eye care hospital in Melbourne, Australia.

METHODS

Retrospective review of all patients with keratitis with positive fungal cultures from corneal or associated samples presenting to the Royal Victorian Eye and Ear Hospital, Melbourne, Australia from July 1996 to May 2004. Demographic data, predisposing factors, features on presentation, management, outcomes and microbiological data were collected and analysed.

RESULTS

The study included 56 eyes of 56 patients. Thirty-five patients were treated as 'typical' fungal keratitis and used for description and analysis, with a mean follow up of 18 months. Ocular trauma (37.1%), chronic steroid use (31.4%) and poor ocular surface (25.7%) were the major predisposing factors. Perforation was seen in 25.7% of patients, penetrating keratoplasty was required in 9 (25.7%) patients and evisceration was performed in 2 (5.7%) patients. Candida albicans (13 patients, 37.2%) was the most common fungal isolate accounting for more than one-third of all organisms followed by Aspergillus fumigatus (six patients, 17.1%) and Fusarium sp. (five patients, 14.3%).

CONCLUSIONS

The present study describes the clinical patterns of fungal keratitis in Melbourne, Australia and contrasts them with reports from other areas of the world. A high incidence of C. albicans infection and the prior use of steroids in high proportion of the patients are highlighted in this study.

Successful Topical Application of a New Antifungal Agent, Micafungin, in the Treatment of Refractory Fungal Corneal Ulcers

PURPOSE

To report the efficacy of topical application of a new antifungal agent, micafungin (MCFG), in the treatment of yeast-related corneal ulcers.

DESIGN

Noncomparative interventional case reports.

PARTICIPANTS

Three patients with yeast-related corneal ulcer after keratoplasty recalcitrant to conventional antifungal treatment for 4 weeks were recruited in this study.

METHODS

Topical 0.1% antifungal MCFG eye drops were applied in 3 patients with yeast-related corneal ulcer every hour while awake until epithelialization. After epithelialization, the frequency of eye drops was reduced to 5 times a day. MCFG eye drops were discontinued 1 month after the disappearance of stromal infiltration in each case. The patients underwent best corrected visual acuity (BCVA) measurements, slit-lamp examination, fluorescein-dye staining, and anterior segment photography. Corneal scrapings and cultures of surgical materials were also performed.

MAIN OUTCOME MEASURES

Changes in ulcer size, stromal infiltration, fluorescein dye staining, and BCVA were looked for.

RESULTS

All corneal ulcers epithelialized within 14 days after commencement of application of 0.1% MCFG eye drops. Yeasts were detected from corneal smears in all eyes. Two cases revealed positive culture isolates for Candida albicans and Candida parapsilosis. No recurrence of fungal keratitis was observed in any of the cases throughout the follow-up periods.

CONCLUSION

Topical 0.1% MCFG eye drops seem to be an effective and a promising option in the treatment of refractory yeast-related corneal ulcers.

Antifungal therapy for keratomycoses

Keratomycoses have recently emerged as an important cause of ocular morbidity, especially in third-world countries. Available antifungal agents are limited in their efficacy, due to limited penetration into the cornea, the fungistatic nature and the development of drug resistance. Effective usage of the available drugs is hampered by the inefficiency of currently available antibiotic sensitivity tests for fungal organisms. There is also limited knowledge regarding the ideal combination(s) of antifungal agents, including issues of synergism and antagonism. Despite these problems, recent publications indicate encouraging outcomes in the treatment of a large series of fungal keratitis. Advances include better drug formulations, new agents and novel methods of drug delivery into the eye. As our ability to deal with advanced fungal keratitis remains limited, the importance of early diagnosis has been stressed and molecular biological techniques may play an important role in the future. This article summarises the important new advances in these areas in the past 2 years and provides guidelines for the management of these serious corneal infections.

In vitro interactions between antifungals and immunosuppressants against Aspergillus fumigatus isolates from transplant and nontransplant patients

We performed in vitro antifungal checkerboard testing on 12 Aspergillus fumigatus clinical isolates (6 transplant recipients and 6 nontransplant patients) with three antifungal agents (amphotericin B, voriconazole, and caspofungin) and three immunosuppressants (FK506, cyclosporine, and rapamycin). We were not able to detect a difference in calcineurin inhibitor antifungal activity against isolates from transplant recipients and nontransplant patients.

Candida parapsilosis keratitis

PURPOSE

To present clinical, microbiologic, and histopathologic features of keratitis due to Candida parapsilosis.

METHODS

Clinicomicrobiologic evaluation of four patients (four eyes) with culture-proven C. parapsilosis keratitis. The patients were evaluated for symptoms, visual acuity, clinical observations, microbiologic examination of corneal scrapings, and pathologic examination of corneal buttons.

RESULTS

Three cases were observed after penetrating keratoplasty, and one case occurred after inhalation of corticosteroids. Clinical presentation of C. parapsilosis keratitis showed a great diversity. There was one case of crystalline keratopathy and three cases of suppurative corneal infiltrate. Histopathology of corneal buttons showed interlamellar accumulations of yeast. Medical treatment included topical amphotericin B and systemic triazoles. Penetrating keratoplasty was required in three patients.

CONCLUSION

Risk factors for C. parapsilosis keratitis may include corticosteroid use and prior corneal transplantation. The prognosis of C. parapsilosis keratitis with antifungal and surgical therapy may vary from good visual outcome to intraocular extension with phthisis bulbi.

Fungal keratitis associated with vernal keratoconjunctivitis

PURPOSE

To report a case of fungal keratitis associated with vernal keratoconjunctivitis.

CASE REPORT

A 22-year-old man with a history of vernal keratoconjunctivitis since October 1999 developed a shield ulcer in the left eye in June 2000, which resolved with intensive topical steroid therapy. He presented in August 2001 with onset of acute pain, redness, and decreased vision. The tarsal conjunctiva in the left eye showed large papillae. The cornea showed a white plaque-like lesion with an underlying stromal infiltrate involving the upper half of the cornea. The overlying epithelial defect measured 4.5 x 2.5 mm. The anterior chamber showed 1+ flare and cells and hypopyon measuring about 1 mm.

RESULTS

Corneal scrapings were performed for microbiologic investigations. Smears of corneal scrapings revealed septate fungal filaments, and the culture showed a significant growth of Aspergillus flavus.

CONCLUSIONS

Fungal keratitis may be associated with vernal keratoconjunctivitis. Though rare, fungal keratitis should be considered in the differential diagnosis of infections associated with vernal keratoconjunctivitis.

Topical cyclosporin A in the management of therapeutic keratoplasty for mycotic keratitis

PURPOSE

To investigate the efficacy of topical cyclosporine A 0.5% as a substitute for corticosteroids in the management of therapeutic keratoplasties for mycotic keratitis.

METHODS

Prospective, nonrandomized interventional case series. Three patients with culture-proven mycotic keratitis underwent therapeutic keratoplasties. All were treated with topical cyclosporine A 0.5% postoperatively as a primary or an adjunctive therapy for prevention of allograft rejection. The patients were followed up from 15 to 42 months for maintenance of graft clarity and best-corrected visual acuity.

RESULTS

Two of three patients maintained clear grafts while using topical cyclosporine A 0.5% twice daily with best-corrected visual acuity of 20/40 and 20/50. One patient developed an opacified graft secondary to preexisting ocular surface disease.

CONCLUSIONS

Topical cyclosporine A 0.5% may be a useful adjunct in the management of therapeutic keratoplasties for mycotic keratitis.

Recurrent fungal keratitis and endophthalmitis

PURPOSE

To report a case of recurrent fungal sclerokeratitis and endophthalmitis with a very successful outcome due to aggressive combined surgical and medical therapy. To discuss the management of this potentially devastating infection.

METHODS

A 65-year-old man presented with 6 months of left eye redness and irritation after injury from organic matter propelled from an airboat. Initially, he had been treated with foreign body removal, antibiotics, and steroids. He was diagnosed with reactive sclerokeratitis at presentation and was treated with steroids. However, when he did not improve, cultures were obtained and Acremonium species filamentous fungi was identified. Despite treatment with appropriate topical and systemic antifungals, his fungal sclerokeratitis progressed to endophthalmitis. Two therapeutic penetrating keratoplasties (PKs) with iridectomy and intraocular amphotericin B were necessary to eradicate the fungal infection.

RESULTS

Visual acuity was restored to 20/25-3 with correction 9 months after initial presentation. There was no recurrence of fungal infection after the second therapeutic PK.

CONCLUSION

The possible reasons for recurrence of fungal infection are discussed. The role of timely and aggressive medical and surgical intervention for fungal sclerokeratitis and endophthalmitis in restoring excellent vision is emphasized.