Methicillin-Resistant Staphylococcus aureus Ocular Infection after Corneal Cross-Linking for Keratoconus: Potential Association with Atopic Dermatitis

A Case Series of Infectious Keratitis After Corneal Cross-linking

PURPOSE

To present the 7-year experience of a tertiary eye hospital while exploring possible risk factors and incidence of infectious keratitis in patients undergoing standard corneal cross-linking (CXL).

METHODS

This retrospective cohort study included patients with progressive keratoconus undergoing standard CXL in the Farabi Eye Hospital and all other patients who had undergone CXL in other facilities and were diagnosed as having infectious keratitis in the 7-year period of the study.

RESULTS

Among the total of 4,863 eyes that underwent CXL, 6 eyes developed infectious keratitis, yielding an incidence rate of 0.12%. Additionally, 13 eyes from 10 patients with a CXL history in other facilities who developed infectious keratitis were included. The mean age was 23.75 years, and 75% of patients were men and 25% were women. Gram-positive bacteria and Staphylococcus aureus were the most prevalent pathogens. Meibomian gland dysfunction, dry eye disease, or blepharitis were present in 12 patients. Medical treatment did not arrest the disease progress in 5 patients, which eventually required cases to undergo keratoplasty.

CONCLUSIONS

This study supports the need for proper patient selection by using a comprehensive medical history. It also highlights the imperative role of rigorous patient education and follow-up, particularly in the first postoperative week. Finally, the study emphasizes aggressive early therapy for patients with suspicious findings. [J Refract Surg. 2023;39(8):564-572.].

Polymicrobial keratitis after accelerated corneal collagen cross-linking in keratoconus: Case reports and literature review

PURPOSE

To report two cases of polymicrobial keratitis following corneal collagen cross-linking for keratoconus and to review the literature.

METHODS

Retrospective case note and literature review.

RESULTS

The first case involved a 27-year-old male who presented with amebic corneal ulcers 3 days after the collagen cross-linking procedure. Some gram-negative (gram-ve) cocci were found upon staining, and cysts were observed by confocal microscopy at 7 days after surgery. Acanthamoeba infection mixed with gram-ve organisms was diagnosed. In the second case, a 14-year male developed Staphylococcus aureus corneal infection with anterior chamber empyema 3 days after the collagen cross-linking procedure for keratoconus. Occasional gram-positive (gram + ve) cocci and gram-ve bacilli were observed under a microscope. The mixed keratitis in the two patients resolved after systemic and topical antibiotic therapy, but the infection ultimately resulted in corneal scarring. Follow-up keratoplasty was needed to improve vision acuity in both patients.

CONCLUSION

Although ultraviolet irradiation and the reactive oxygen released by riboflavin during collagen cross-linking have bactericidal effects, a lack of a corneal epithelial barrier, bandage contact lens usage, perioperative hygiene, and an abnormal immune state are risk factors for infectious keratitis after collagen cross-linking. Perioperative management of collagen cross-linking is important to prevent infection.

Infectious keratitis after corneal crosslinking for keratoconus caused by levofloxacin-resistant microorganisms

Introduction

We present seven cases of infectious keratitis after corneal crosslinking (CXL) to attenuate keratoconus progression.

Methods

Of 524 consecutive patients who underwent CXL, 7 cases (4 males and 3 females; 21.5 ± 7.1 years) developed postoperative infectious keratitis were retrospectively reviewed. CXL was performed using the Dresden protocol or an accelerated protocol involving epithelial removal.

Results

All cases appeared normal on the day after surgery, but subsequently developed eye pain, blurred vision, corneal infiltration, inflammation of the anterior chamber, and ciliary injection on day 2 or 3. Methicillin-resistant Staphylococcus aureus was cultured from two eyes, methicillin-sensitive Staphylococcus aureus from two eyes, and Streptococcus pneumoniae from one eye. All detected bacteria were resistant to levofloxacin (LVFX). Five of the seven cases, especially four of the five severe cases with hypopyon, had a history of atopic dermatitis. All cases were observed after 2015.

Conclusions

Infectious keratitis after CXL caused by microbes resistant to LVFX is increasing. In addition to careful postoperative observation of the cornea, preoperative evaluation of bacteria within the conjunctival sac evident on nasal swab cultures may be useful to identify potentially problematic microbes and inform the selection of appropriate antibiotics.

Repeated intracranial empyema following cranioplasty in a patient with atopic dermatitis: a case report

Background

Atopic dermatitis is a chronic inflammatory skin disease associated with pruritus. Skin affected by atopic dermatitis not only shows a high percentage of Staphylococcus aureus colonization, but corneal barrier dysfunction is also known to occur. It is considered a risk factor for bacterial infections in various areas of the body. However, the relationship between atopic dermatitis and bacterial infection following neurological surgery has not yet been reported. Here, we present a case of atopic dermatitis in which the surgical site became infected twice and finally resolved only after the atopic dermatitis was treated.

Case presentation

A 50-year-old Japanese woman with atopic dermatitis underwent cerebral aneurysm clipping to prevent impending rupture. Postoperatively, she developed repeated epidural empyema following titanium cranioplasty. As a result of atopic dermatitis treatment with oral antiallergy medicines and external heparinoids, postoperative infection was suppressed by using an absorbable plastic plate for cranioplasty. The patient’s postoperative course was uneventful for 16 months.

Conclusions

Atopic dermatitis is likely to cause surgical-site infection in neurosurgical procedures, and the use of a metal implant could promote the development of surgical-site infection in patients with dermatitis.

Chemical Cross-Linking of Corneal Tissue to Reduce Progression of Loss of Sight in Patients With Keratoconus

Purpose

We aimed to develop a novel chemical cross-linker treatment for keratoconus by reacting dicarboxylic acid spacer molecules and amine functional groups on protein structure of the tissue using carbodi-imide chemistry. We propose this as an alternative to conventional cross-linking treatment for keratoconus.

Methods

The study involved optimization of the cross-linker formulation. Mechanical stiffness of ex vivo porcine and human corneas after application of the cross-linker was measured. Histochemical analysis was performed to record changes in gross morphology after cross-linker treatment on ex vivo porcine and human and in vivo rabbit corneas. Terminal deoxynucleotidyl transferase-mediated dUTP-X nick-end-labeling (TUNEL) staining was performed to study apoptotic effects of cross-linker. Cytotoxicity potential of cross-linker was evaluated by studying explant cultures for cellular outgrowth and immunostaining assays on porcine and human corneas after treatment.

Results

We demonstrated a clinically relevant increase in stiffness in ex vivo experiments using porcine and human cornea without removal of corneal epithelium. Histological analysis showed no change in gross morphology of cornea and no evidence of apoptosis. In vivo treatment of rabbit eyes demonstrated initial thinning of corneal epithelium that recovered after seven days although with abnormal regularity of cells. Cellular outgrowth from corneal explant cultures after treatment further confirmed cell survival after treatment.

Conclusions

This chemical cross-linking of corneal tissue has potential advantages over current therapeutic options including lower cytotoxicity to stromal cells than ultraviolet A treatment.

Translational Relevance

The cross-linker has potential to become a treatment for keratoconus because it overcomes the need for procedures using specialized equipment and ensures accessibility to large populations.

Ophthalmic manifestations of atopic dermatitis

Atopic dermatitis is a chronic condition of complex etiology, whose clinical course involves remission and recurrence. It is not an isolated disease entity affecting only the skin, but one that co-occurs with disorders of other organs. Numerous literature reports have long confirmed the relationship between the disorder and a growing number of ophthalmic manifestations such as keratoconus and retinal detachment. Further studies are required to establish the cause of correlations and to allow for implementation of appropriate prophylaxis and treatment. The aim of the present paper is to review published literature regarding the correlation between atopic dermatitis and ophthalmic manifestations in adults and children.

A new treatment for presumed corneal epithelial inclusion cyst in a shih-tzu dog

An 8-year-old female shih-tzu was assessed for a 3-year history of yellow intrastromal material in the right eye. Slit-lamp biomicroscopy showed a yellow lesion in the upper half of the cornea, superficial corneal neovascularisation and oedema with negative fluorescein staining in the right eye. Ultrasound biomicroscopy revealed a nearly anechoic cystic space surrounded by hyperechoic oedematous cornea separating the stroma at three-quarters of the corneal depth. Two partial-thickness corneal incisions were performed around the lesion under topical anaesthesia. After cytology and culture sampling, intrastromal flushing was performed. A yellow viscous necrotic tissue was identified with no microorganism or evidence of tumour formation. Antibiotics, anti-inflammatories and a bandage contact lens were applied. Ultrasound biomicroscopy confirmed no recurrence 8 days later. Corneal neovascularisation and oedema gradually resolved through a 2-week follow-up. There was no recurrence in the subsequent 8 months.

Bilateral corneal perforation due to MRSA keratitis in a crosslinking patient

Introduction: The cornea may become infected and perforated after epithelium-on collagen crosslinking. Case presentation: A healthy 33-year-old male who underwent corneal collagen crosslinking in both eyes developed a purulent keratitis and bilateral corneal perforations, requiring bilateral penetrating keratoplasties. He was exposed to methicillin resistant staphylococcus aureus (MRSA) by a family member with a tracheostomy and was treated with MRSA-directed antibiotics. After prolonged recovery and treatment of his infection, he had acceptable but limited uncorrected visual acuity, with excellent corrected visual acuity. Conclusion: While epithelium-on crosslinking is commonly thought to be associated with a lower risk of postoperative infection, this case illustrates that even epithelium-on treatment may present the patient with a risk of infection. Patients in higher risk groups who are exposed to infectious disease may be more predisposed.

[Hygiene in ophthalmological practices : Results from ophthalmological practices in Frankfurt am Main in 2012-2015]

BACKGROUND

Hygiene regulations must be taken into consideration for all diagnostic and therapeutic measures in order to avoid transfer of pathogens and infections. The Infection Protection Act assigns the responsibility for prevention of infections to managers of medical institutions, i.e. the owners of a practice and public health authorities are obligated to counsel and monitor medical institutions with respect to hygiene and prevention of infections. This article presents the results of the surveillance of all ophthalmological practices in Frankfurt am Main in 2012-2015, which are assessed and discussed against the background of the valid recommendations of the Committee for Hospital Hygiene (KRINKO).

METHODS

Based on a checklist, all 35 ophthalmological practices in Frankfurt am Main received counseling and were monitored by an official from the Public Health Office.

RESULTS

The basic principles of hygiene organization as well as the prerequisites for appropriate hand hygiene and surface disinfection were present in the majority of practices. In 11 practices (31.4 %) disposable medical products were exclusively utilized but medical products were prepared in-house in 24 practices (68.6 %). Contact pads for tonometry were prepared in-house in 13 (37.1 %) practices of which 6 were deficient so that improvements had to be implemented. In 6 out of the 7 practices where even critical medical products were prepared, this preparation was prohibited due to significant errors and the practices had to switch to disposable materials.

DISCUSSION

In total, the practices could be certified as having a good general level of hygiene; however, in some cases major errors were found in the preparation of medical products, which had to be immediately corrected.