A case of interface keratitis following anterior lamellar keratoplasty

Incidence and management of early postoperative complications in lamellar corneal transplantation

PURPOSE

To provide a comprehensive review of the incidence, risk factors, and management of early complications after deep anterior lamellar keratoplasty (DALK), Descemet stripping automated keratoplasty (DSAEK), and Descemet membrane endothelial keratoplasty (DMEK).

METHODS

A literature review of complications, that can occur from the time of the transplant up to 1 month after the transplant procedure, was conducted. Case reports and case series were included in the review.

RESULTS

Complications in the earliest postoperative days following anterior and posterior lamellar keratoplasty have shown to affect graft survival. These complications include, but are not limited to, double anterior chamber, sclerokeratitis endothelial graft detachment, acute glaucoma, fluid misdirection syndrome, donor-transmitted and recurrent infection, and Uretts-Zavalia syndrome.

CONCLUSION

It is essential for surgeons and clinicians to not only be aware of these complications but also know how to manage them to minimize their impact on long-term transplant survival and visual outcomes.

Suture-Related Fungal Interstitial Interface Keratitis in Deep Anterior Lamellar Keratoplasty: A Case Report

Interstitial interface keratitis (IIK) in lamellar keratoplasty is a term used to describe infectious keratitis that primarily involves the graft-host interface. It poses specific challenges due to impaired access for microbiological testing and poor penetration of antimicrobial drugs, as well as ease of deeper extension of the microorganism. A 33-year-old male with a medical history of left eye deep anterior lamellar keratoplasty (DALK) with keratoconus, subsequently complicated with steroid-induced glaucoma controlled with Xen tube insertion, presented with acute left eye pain and redness for two days due to one broken corneal graft suture at 5 o’clock position with infiltrate at the graft-host junction. He was treated for suture-related bacterial keratitis (culture-negative) with intensive single broad-spectrum topical antibiotic after suture removal. However, the condition worsened, with dense stromal infiltrate extending into the graft-host interface junction which further progressed to an endothelial plaque. Systemic and topical antifungal treatments were started with adjunctive intracameral and subconjunctival voriconazole before improvement was observed. The condition was resolved with localized scarring without the need for repeat keratoplasty. The best-corrected vision was maintained at 6/36 due to residual sutured-related astigmatism with no signs of corneal graft rejection. Lamellar keratoplasty poses an increased risk of fungal IIK even after several years if there is a predisposing factor e.g., steroid usage and broken suture. Timely diagnosis and intervention are the keys to ensure an optimal outcome.

Paradox of complex diversity: Challenges in the diagnosis and management of bacterial keratitis

Bacterial keratitis continues to be one of the leading causes of corneal blindness in the developed as well as the developing world, despite swift progress since the dawn of the "anti-biotic era". Although, we are expeditiously developing our understanding about the different causative organisms and associated pathology leading to keratitis, extensive gaps in knowledge continue to dampen the efforts for early and accurate diagnosis, and management in these patients, resulting in poor clinical outcomes. The ability of the causative bacteria to subdue the therapeutic challenge stems from their large genome encoding complex regulatory networks, variety of unique virulence factors, and rapid secretion of tissue damaging proteases and toxins. In this review article, we have provided an overview of the established classical diagnostic techniques and therapeutics for keratitis caused by various bacteria. We have extensively reported our recent in-roads through novel tools for accurate diagnosis of mono- and poly-bacterial corneal infections. Furthermore, we outlined the recent progress by our group and others in understanding the sub-cellular genomic changes that lead to antibiotic resistance in these organisms. Finally, we discussed in detail, the novel therapies and drug delivery systems in development for the efficacious management of bacterial keratitis.

Ex vivo photoactivated chromophore for keratitis-corneal crosslinking on inverted graft: new approach to manage interface infectious keratitis after deep anterior lamellar keratoplasty

A 44-year-old man affected by keratoconus underwent deep anterior lamellar keratoplasty (DALK). Two weeks postoperatively, slitlamp examination showed grayish-white lesions in the donor-host interface. Corneal scraping and donor broth culture tested negative for both bacteria and fungi. In vivo confocal microscopy showed elongated particles resembling Candida pseudofilaments. Despite antimicrobial therapy, the clinical picture worsened, and surgical approach was chosen: the graft was peeled off and inverted (epithelium facing down), and ex vivo photoactivated chromophore for infectious keratitis-corneal crosslinking (PACK-CXL) was performed; the recipient bed was washed with antibiotics/antifungals and the graft resutured. Microbiological and histological evaluations of biopsy specimen tested positive for Candida albicans. Postoperative slitlamp examination revealed a progressive recovery of graft transparency with disappearance of the infiltrates. To the authors' knowledge, this is the first report of ex vivo PACK-CXL on inverted DALK graft for the treatment of interface infectious keratitis. This technique allowed the resolution of the infection while sparing the use of new donor tissue.

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.

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.

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.

Recurrent non-tuberculous mycobacterial keratitis after deep anterior lamellar keratoplasty for keratoconus

A 26-year-old farmer underwent deep anterior lamellar keratoplasty (DALK) for keratoconus. After 3 months, he presented with interface keratitis. Medical treatment failed and he underwent a repeat DALK. Microbiological scrapings from the interface revealed an infection caused by non-tuberculous mycobacteria. Despite the use of intensive antibiotic therapy and a repeat lamellar keratoplasty, the infiltrates recurred. The patient underwent therapeutic penetrating keratoplasty. Microbiology of the corneal tissue revealed growth of Mycobacterium chelonae, and on histopathology, the acid-fast bacilli were noted to be located deep at the pre-Descemet level. There was complete resolution of the infection with no episodes of recurrence and final best-corrected visual acuity was 20/40 at 1 year of follow-up. Medical therapy is unlikely to succeed in post-DALK interface keratitis and penetrating rather than lamellar keratoplasty may be considered the surgery of choice.