Akanthamöbenendophthalmitis – Ein Fallbericht

Use of In Vivo Corneal Confocal Microscopy to Guide Excimer Laser With Adjunctive Mitomycin C for Treatment of Recalcitrant Acanthamoeba Keratitis

PURPOSE

The aim of this study was to describe 3 cases of recalcitrant Acanthamoeba keratitis (AK) that were successfully treated using in vivo corneal confocal microscopy (IVCM) to guide excimer laser ablation depth with adjunctive mitomycin C 0.02%.

METHODS

Three patients diagnosed with AK did not respond to several weeks of intensive topical therapy with antiamoebic agents. The patient underwent phototherapeutic keratectomy with topical mitomycin C 0.02% application. The maximum stromal depth of cysts measured by IVCM was 80 μm, 100 μm, and 240 μm, and the stromal ablation depths were 80 μm, 100 μm, and 100 μm, respectively.

RESULTS

In all 3 eyes, AK resolved after a single excimer laser application, and topical treatment was gradually discontinued within 6 weeks afterward. In 1 eye, penetrating corneal transplantation was performed 6 weeks after phototherapeutic keratectomy because of ongoing severe corneal pain. IVCM and histology of the corneal transplant did not reveal any Acanthamoeba cysts within the excised corneal button. No recurrence was observed during the follow-up period of 19 to 34 months.

CONCLUSIONS

IVCM-guided phototherapeutic keratectomy with mitomycin C 0.02% seems to be a safe and successful approach for the treatment of AK, especially in cases of resistance to topical treatment. Corneal IVCM should be performed before laser application to measure cyst depth, determine ablation depth, and assess postoperative treatment success.

Acanthamoeba-associated retinitis successfully treated with intravitreal and systemic antimicrobials

Purpose

To describe a case of unilateral Acanthamoeba-associated retinitis in the absence of concomitant corneal infection in an immunocompetent host without risk factors.

Observations

A 37-year-old woman presented with unilateral multifocal retinitis with minimal vitritis. Anterior segment was normal. Conventional diagnostics of bacterial, fungal, viral, Toxoplasma and Toxocara etiologies all returned negative. Empiric treatments were unsuccessful, including oral valacyclovir, oral fluconazole, as well as intravitreal injection of vancomycin and ceftazidime. Metagenomic deep sequencing (MDS) identified Acanthamoeba genomic fragments in the vitreous sample. Multiple intravitreal voriconazole injections were performed and achieved partial suppression of lesion growth. Subsequent dual therapy of oral voriconazole and trimethoprim-sulfamethoxazole led to resolution of the lesions and vision improvement without further injections.

Conclusions and importance

This is an unusual case of unilateral Acanthamoeba-associated retinitis without concomitant corneal infection, diagnosed via unbiased DNA and RNA deep sequencing, with other etiologies ruled out by conventional approaches. Treatment with systemic and intravitreal therapy led to a successful resolution of retinitis and vision improvement. Our case demonstrates the potential of MDS as an unbiased diagnostic tool for rare ocular pathogens and the therapeutic effect of oral voriconazole with trimethoprim-sulfamethoxazole for Acanthamoeba intraocular infection.

Oral Miltefosine as Salvage Therapy for Refractory Acanthamoeba Keratitis

PURPOSE

To report a case series of patients with treatment-resistant Acanthamoeba keratitis (AK) using oral miltefosine, often as salvage therapy.

DESIGN

Descriptive, retrospective multicenter case series.

METHODS

We reviewed 15 patients with AK unresponsive to therapy who were subsequently given adjuvant systemic miltefosine between 2011 and 2017. The main outcome measures were resolution of infection, final visual acuity, tolerance of miltefosine, and clinical course of disease.

RESULTS

All patients were treated with biguanides and/or diamidines or azoles without resolution of disease before starting miltefosine. Eleven of 15 patients retained count fingers or better vision, and all were considered disease free at last follow-up. Eleven of 15 patients had worsening inflammation with miltefosine, with 10 of them improving with steroids. Six patients received multiple courses of miltefosine. Most tolerated oral miltefosine well, with mild gastrointestinal symptoms as the most common systemic side effect.

CONCLUSIONS

Oral miltefosine is a generally well-tolerated treatment adjuvant in patients with refractory AK. The clinician should be prepared for a steroid-responsive inflammatory response frequently encountered during the treatment course.