Candida albicans interface infection after deep anterior lamellar keratoplasty

Clinical and in vivo confocal microscopy characteristics of Candida keratitis following keratoplasty

BACKGROUND

We present six patients who developed Candida keratitis postoperatively. The clinical features, diagnostic testing including in vivo confocal microscopy, and outcomes are presented.

METHODS

Six patients who developed Candida keratitis following penetrating and endothelial keratoplasty, were referred to Tianjin Medical University Eye Hospital between 2018 to 2021.The diagnosis was established following cultures of either corneal scraping or biopsy. In vivo confocal microscopy examination was also performed to confirm the diagnosis and characterize the morphology, distribution and the depth of Candida spp. All patients were treated with topical voriconazole (VCZ) 1% and natamycin (NTM) 5%. Patients with mid/deep stromal keratitis or interface infection were treated additionally with intrastromal or interface VCZ irrigation (0.05 mg/0.1mL).

RESULTS

The cultures of corneal scrapings (4 cases) or biopsies (2 cases) were all positive for Candida spp. In vivo confocal microscopy examination was positive for fungal elements in five of the six patients. The infection resolved in five of the six patients. The patients' final uncorrected visual acuity (UCVA) ranged from hand movements (HM) to 20/80.

CONCLUSION

In vivo confocal microscopy is a useful non-invasive clinical technique for confirming the diagnosis of Candida keratitis. Intrastromal and interface irrigated VCZ injections are effective treatment options.

Corneal Perforation as a Complication of Fungal Interface Infectious Keratitis after Deep Anterior Lamellar Keratoplasty

Deep anterior lamellar keratoplasty (DALK) is a surgical intervention for corneal diseases that do not affect the endothelium. The creation of an interface between the donor graft and recipient bed is a typical feature of DALK. Interface infectious keratitis (IIK) is an uncommon complication that originates at this point of contact. The onset of IIK following lamellar keratoplasty can cause delayed visual loss and subsequent endophthalmitis, with primarily fungal etiology (e.g., Candida spp.) and occasionally bacterial etiology. Infection of the lamellar interface may be attributed to contamination of the donor material or to precipitating factors such as loose sutures, persistent epithelial defects, and prolonged topical steroid use; fungal IIK is frequently resistant to medical treatment. Here, we describe the previously unreported occurrence of corneal perforation as a complication of fungal IIK after DALK. A 26-year-old otherwise healthy woman underwent uneventful DALK for advanced keratoconus in the left eye. She was discharged with instructions to apply topical prednisolone acetate and topical moxifloxacin. Culture of the donor corneoscleral rim showed growth of Candida glabrata, although the patient exhibited no clinical signs of infection. Approximately 3 months later, the patient exhibited mild blurring of vision in her left eye. Therefore, treatment was modified to topical amphotericin B and oral voriconazole. One week later, the patient developed multiple, sheath-like whitish creamy infiltrates, primarily in the lamellar interface; a positive Seidel test result indicated the presence of corneal perforation. As treatment for IIK, excisional penetrating keratoplasty (PK) was performed, followed by topical amphotericin B and topical prednisolone acetate treatment. During 12 months of follow-up after PK, the corneal graft was clear and there was no clinical evidence of recurrent keratitis. Prompt excisional PK prevented the progression of IIK to endophthalmitis in our patient. Early intervention with excisional PK should be considered when a diagnosis of fungal IIK is suspected in a patient with a positive donor rim culture, and in whom the condition does not respond to medical treatment. This early intervention is essential to prevent delayed treatment, which could result in corneal perforation and endophthalmitis, with ultimately poor visual outcomes.

Post-keratoplasty Infectious Keratitis: Epidemiology, Risk Factors, Management, and Outcomes

Post-keratoplasty infectious keratitis (PKIK) represents a unique clinical entity that often poses significant diagnostic and therapeutic challenges. It carries a high risk of serious complications such as graft rejection and failure, and less commonly endophthalmitis. Topical corticosteroids are often required to reduce the risk of graft rejection but their use in PKIK may act as a double-edged sword, particularly in fungal infection. The increased uptake in lamellar keratoplasty in the recent years has also led to complications such as graft-host interface infectious keratitis (IIK), which is particularly difficult to manage. The reported incidence of PKIK differs considerably across different countries, with a higher incidence observed in developing countries (9.2-11.9%) than developed countries (0.02-7.9%). Common risk factors for PKIK include the use of topical corticosteroids, suture-related problems, ocular surface diseases and previous corneal infection. PKIK after penetrating keratoplasty or (deep) anterior lamellar keratoplasty is most commonly caused by ocular surface commensals, particularly Gramme-positive bacteria, whereas PKIK after endothelial keratoplasty is usually caused by Candida spp. Empirical broad-spectrum antimicrobial treatment is the mainstay of treatment for both PKIK, though surgical interventions are required in medically refractory cases (during the acute phase) and those affected by visually significant scarring (during the late phase). In this paper, we aim to provide a comprehensive overview on PKIK, encompassing the epidemiology, risk factors, causes, management and outcomes, and to propose a treatment algorithm for systematically managing this challenging condition.

Early postoperative infection following lamellar keratoplasty: a review

With the growing popularity of lamellar keratoplasty for selective replacement of diseased corneal tissue, it is important to understand the risk of developing an infection after the procedure. Although lesser than that postpenetrating keratoplasty, the reports on post lamellar keratoplasty infectious keratitis are not negligible. Trends of acute infections arising within 2 months of surgery are a subject of interest. Most of these infections are reported post Descemet's stripping endothelial keratoplasty with a preponderance of Candida species. A donor to host transmission of infection is not uncommon. Among the Candida cases, about 80% seem to occur due to a donor to host transmission. Infections presenting as or progressing to endophthalmitis lead to a poor visual outcome. Strict aseptic measures and protocols during corneal tissue harvesting, tissue processing, tissue storage and surgery are essential to prevent occurrence of these infections. After the infection has occurred, determining the aetiology and drug susceptibility through microbiological testing is vital. This helps to guide treatment protocols and hence determines final outcome of these cases. Most cases require some form of surgical management for resolution of infection, most often a graft removal and therapeutic keratoplasty. Secondary surgical interventions are performed to restore graft clarity and achieve a good final visual outcome.

Infectious keratitis after lamellar keratoplasty

Infectious keratitis after lamellar keratoplasty is a potentially devastating complication that may severely limit the visual and anatomical outcomes. The deep-seated location of the infiltrates, sequestration of the pathogenic microorganisms and limited penetration of the currently available antimicrobial agents often results in delayed diagnosis that may jeopardize the management in these cases. Fungal keratitis is more common as compared with bacterial or viral keratitis and classically presents as white interface infiltrates that may not be associated with significant inflammation. Confocal microscopy may help to establish a rapid diagnosis in such cases, and anterior segment optical coherence tomography may be used to determine the extent of infection and monitor its progression. Conservative measures such as topical antimicrobials and interface irrigation with antimicrobial agents may be done. Surgical intervention in the form of partial excision/removal of the graft in endothelial keratoplasty or a full-thickness keratoplasty is often required for the effective management of deep-seated infections. Timely diagnosis and intervention may result in complete resolution of infection in both anterior lamellar and endothelial keratoplasty. Infections after anterior lamellar keratoplasty have a fair prognosis, and a clear graft with functional visual acuity may be achieved in most cases. By contrast, infections after endothelial keratoplasty have a guarded prognosis, and the presence of concomitant endophthalmitis may further complicate the graft survival and visual outcomes.

Multi-drug resistant Enterococcus faecium in late-onset keratitis after deep anterior lamellar keratoplasty: A case report and review of the literature

RATIONALE

Interface keratitis after lamellar keratoplasty is one of the causes of graft failure. We report the first case of microbiologically proven Enterococcus faecium infection following deep anterior lamellar keratoplasty (DALK) and review the available literature.

PATIENT CONCERNS

A 37-years-old Caucasian man presented with pain, redness and severe vision loss in his right eye. Five weeks before, he underwent DALK using the FEMTO LDV Z8 in the same eye for the surgical correction of keratoconus.

DIAGNOSES

Upon presentation, slit-lamp biomiscroscopy revealed corneal graft edema with multiple infiltrates located in the graft-host interface.

INTERVENTIONS

Therapeutic penetrating keratoplasty (PKP) was carried out in addition with cultures of the donor lenticule removal. Laboratory results isolated a multi-resistant Enterococcus faecium interface infection. According to the antibiogram, the patient was treated with systemic Tigecycline and Linezolid for 7 days.

OUTCOMES

During the following weeks, clinical features improved over time and no signs of active infection were visible seven months postoperatively.

LESSONS

Early PKP showed to be a good therapeutic option with great anatomic and functional outcomes.

Interface infectious keratitis after anterior and posterior lamellar keratoplasty. Clinical features and treatment strategies. A review

Interface infectious keratitis (IIK) is a novel corneal infection that may develop after any type of lamellar keratoplasty. Onset of infection occurs in the virtual space between the graft and the host where it may remain localised until spreading with possible risk of endophthalmitis. A literature review identified 42 cases of IIK. Thirty-one of them occurred after endothelial keratoplasty and 12 after deep anterior lamellar keratoplasty. Fungi in the form of Candida species were the most common microorganisms involved, with donor to host transmission of infection documented in the majority of cases. Donor rim cultures were useful to address the infectious microorganisms within few days after surgery. Due to the sequestered site of infection, medical treatment, using both topical and systemic antimicrobials drugs, was ineffective on halting the progression of the infection. Injection of antifungals, right at the graft–host interface, was reported successful in some cases. Spreading of the infection with development of endophthalmitis occurred in five cases after Descemet stripping automated endothelial keratoplasty with severe sight loss in three cases. Early excisional penetrating keratoplasty showed to be the treatment with the highest therapeutic efficacy, lowest rate of complications and greater visual outcomes.

Component corneal surgery: An update

Several decades ago, penetrating keratoplasty was a challenge to corneal surgeons. Constant effort by the corneal surgeon to improve the outcomes as well as utilization of the available resources has led to a revolutionary change in the field of keratoplasty. All these efforts have led to the evolution of techniques that allow a corneal surgeon to disease-specific transplant of individual layers of corneal “so-called component corneal surgery” depending on the layer of cornea affected. This has led to an improvement in corneal graft survival as well as a better utilization of corneal tissues. This article reviews the currently available literature on component corneal surgeries and provides an update on the available techniques.

Current Concepts in the Management of Unique Post-keratoplasty Infections

As corneal transplantation has evolved, the spectrum of post-surgical infection has changed and often presents a diagnostic and therapeutic challenge. Lamellar techniques hold the potential of improved outcomes and decreased post-operative complications, however, they create a lamellar interface, which is a potential space for sequestration of infectious organisms. In addition, while keratoprosthesis offers vision to patients who are poor candidates for traditional keratoplasty, infectious complications can be severe and sight threatening. Although antimicrobials remain the mainstay of treatment, definitive management often requires surgical intervention.

Intrastromal antifungal injection with secondary lamellar interface infusion for late-onset infectious keratitis after DSAEK

PURPOSE

The aim of this study was to report the successful medical management of 2 cases of late-onset endothelial keratoplasty-related stromal interface infections.

METHODS

All cases of endothelial keratoplasty-related infections treated with intrastromal antifungal injections were compiled. The following information was collected: demographic data, surgical indications, donor rim cultures, donor mate outcomes, clinical course, diagnostic tests, and clinical outcome.

RESULTS

Two cases of interface fungal keratitis diagnosed on clinical appearance and confocal microscopy were identified. Both patients refused to undergo further surgery and failed systemic and/or topical therapy. Each received 3 to 4 intrastromal injections, with secondary infusion into the graft-host interface, which resulted in the complete involution of their interface opacities.

CONCLUSIONS

Intrastromal antifungal injection may be an effective alternative to surgical intervention in late-onset fungal Descemet stripping endothelial keratoplasty interface keratitis. Early treatment may preserve graft viability and result in a good visual outcome without the need for either penetrating keratoplasty or potential pathogen exposure to the anterior chamber.

Fungal interface keratitis by Candida orthopsilosis following deep anterior lamellar keratoplasty

A 39-year-old male patient underwent uncomplicated deep anterior lamellar keratoplasty due to keratoconus. On day 5 after surgery, small whitish infiltrates developed in the corneal interface. The diagnosis of fungal keratitis was made when the culture medium of the graft grew Candida after the surgical intervention. Despite intensive antimycotic treatment and irrigation of the interface, the infiltrates persisted and eventually enlarged. Therefore, revision surgery with penetrating keratoplasty was performed. Microbiological analysis showed Candida orthopsilosis in the culture of the excised graft button. Histopathological staining of the excised graft showed periodic acid-Schiff-positive and Grocott methenamine silver-positive clusters of yeast between Descemet's membrane and the deep corneal stroma with focal perforations through Descemet's membrane. The treatment of mycotic keratitis caused by C orthopsilosis is challenging. Antimycotic treatment was unsuccessful in this case. Progression of the keratitis and perforation of Descemet's membrane suggest that early surgical intervention by penetrating keratoplasty is required.