Unilateral Candida parapsilosis interface keratitis after laser in situ keratomileusis: case report and review of the literature

In Vivo Confocal Microscopy Characterization of Candida parapsilosis Keratitis

ABSTRACT

The present clinical case concerns two patients with mycotic keratitis because of Candida parapsilosis in which corneal confocal microscopy presented a characteristic feature of this pathogen. Both described patients used a therapeutic contact lens and administered a therapy with steroid eye drops which are well known predisposing factors for the onset of corneal mycoses. This report can be useful for correctly identifying the pathologic condition and quickly directing the therapy.

Challenges in the diagnosis and management of atypical fungal keratitis during the COVID-19 pandemic: a case series

Fungal keratitis is a time-sensitive ocular infection that often requires a high index of suspicion followed by intensive medical/surgical interventions to achieve a successful clinical outcome. COVID-19 pandemic-related restrictions, necessitated the modification of conventional protocols and guidelines associated with the treatment of keratomycosis. We report four cases of atypical fungal keratitis with poorly differentiated clinical characteristics. The challenges faced during their management were (1) the dilemma of clinically differentiating fungal (Scedosporium and Purpureocillium lilacinum) and bacterial keratitis; (2) treatment of Scedosporium and Trichosporon keratitis with natamycin monotherapy; (3) mixed infection of Candida albicans and Aureobasidium pullulans and continuing medications before rescraping the corneal ulcer against the recommended treatment guidelines; (4) phenotypic identification and differentiation among morphologically resembling fungi; and (5) decision making arising out of disparities between KOH and fungal culture results. Three patients responded well to conservative treatments. The fourth patient underwent therapeutic keratoplasty but was lost to follow-up due to travel-related pandemic restrictions. This case series seeks to broaden the clinician's knowledge of rare and emerging moulds as presumptive aetiologies of keratomycosis. It also intends to emphasize the significance of early microbiological investigations, (direct microscopy and culture), in resource-limited settings, for initiating empirical treatment for a better visual prognosis.

Infectious Keratitis After Keratorefractive Surgery: Update and Review of the Literature

OBJECTIVES

To summarize the clinical manifestations, microbiological profile, treatment, and prognosis of corneal infections after different keratorefractive surgery.

METHODS

To obtain relevant studies, English-language databases, including PubMed, Ovid Embase, Web of Science, and CLNAHL, were searched from January 1979 to March 2022. The fundamentals of the literature, clinical characteristics, pathogens, and treatments were retrieved for each included article.

RESULTS

Eighty-four studies involving 306 infectious eyes were included in this review. Risk factors of potential infection included a history of blepharitis, contact lens usage, and contaminated surgical instruments. The mean onset time was 22.9±38.7 days (range: 1 day to 3 years). The most common organism isolated from infectious keratitis after keratorefractive surgery were Staphylococcus aureus , followed by Mycobacterium and coagulase-negative Staphylococcus . Most of the infections after refractive procedures were sensitive to medical treatment alone, and the ultimate best-corrected visual acuity after medical treatment was as follows: 20/20 or better in 82 cases (37.0%), 20/40 or better in 170 cases (76.5%), and worse than 20/40 in 52 cases (23.5%). Surgical interventions including flap lift, flap amputation, ring removal, and keratoplasty were performed in 120 eyes (44.5%).

CONCLUSIONS

Most infections after keratorefractive surgery occur within a week, whereas more than half of the cases after laser-assisted in situ keratomileusis happen after about a month. Gram-positive cocci and mycobacterium are the most common isolates. Infections after LASIK, intracorneal ring (ICR) implantation, and small incision lenticule extraction, which primarily occur between the cornea layers, require irrigation of the tunnels or pocket with antibiotics.

Bilateral Trichosporon asahii keratitis after ptosis correction: A case report

RATIONALE

Fungal keratitis (FK) is a severe vision-threatening disease that can lead to corneal perforation or endophthalmitis despite proper treatment. It is important to diagnose the disease promptly due to its indolent nature and disproportionate disease symptoms. Trichosporon asahii is reported rarely as the causative organism of FK. We report a case of highly unusual bilateral T asahii keratitis following ptosis surgery.

PATIENT CONCERNS

An 86-year-old female underwent bilateral levator resection surgery for ptosis. Postoperatively, the patient complained of gradually worsening bilateral ocular pain and a decrease in visual acuity associated with a chronic non-healing epithelial defect.

DIAGNOSES

Both eyes of the patient were evaluated using best-corrected visual acuity, intraocular pressure, slit-lamp examination, fundus examination, and corneal culture. Multifocal deep stromal infiltrates were found in both corneas. Cultures from both corneal ulcers revealed growth of T asahii. Optical coherence tomographic examination showed bilateral macular edema.

INTERVENTIONS

The patient was treated with revisional ptosis surgery, an antifungal agent for the corneal ulcer, and intravitreal injection of steroid for macular edema.

OUTCOMES

Both eyes recovered well. Her best-corrected visual acuity improved from 20/200 to 20/40 in the right eye and from 20/100 to 20/40 in the left eye.

LESSONS

FK can develop in the cornea when certain risk factors are present, including recent lid surgery, chronic keratitis, and steroid eye drop use. Identification and correction of risk factors can be beneficial in the treatment of FK.

Case Series of Perforated Keratomycosis after Laser-Assisted In Situ Keratomileusis

Background

Fungal keratitis is an extremely rare complication of laser vision correction resulting in poor visual outcomes. Amniotic membrane transplantation should be kept in mind in eyes with corneal perforation prior to penetrating keratoplasty.

Aim

To assess the outcomes of multilayered fresh amniotic membrane transplantation (MLF-AMT) in patients with severe keratomycosis after laser-assisted in situ keratomileusis (LASIK). Study design. Hospital-based prospective interventional case series.

Methods

Five eyes of 5 patients were included in the study. All cases underwent microbiological scrapings from residual bed and intrastromal injections of amphotericin (50 mcg/mL), with flap amputation if needed, followed by topical 5% natamycin and 0.15% amphotericin. MLF-AMT was performed after corneal perforation. Later, penetrating keratoplasty (PK) was performed when corneal opacity compromised visual acuity. The outcome measures were complete resolution of infection, corneal graft survival, and best-corrected visual acuity (BCVA).

Results

The mean age of patients was 22 ± 1.2 years with 4/5 (80%) were females. The mean interval between LASIK and symptom onset was 8.8 ± 1 day, and the mean interval between symptom onset and referral was 14 ± 1.4 days. Potassium hydroxide (KOH) smears showed filamentous fungi, and Sabouraud's medium grew Aspergillus in all cases. Melted flaps were amputated in 4 (80%) cases. MLF-AMT was performed in all cases due to corneal perforation after a mean time of 12.4 ± 1.2 days of antifungals. In all cases, complete resolution of infection was seen 26 ± 1.8 days after MLF-AMT, and optical PK was done at a mean of 2.4 months later. No postoperative complications after MLF-AMT or PK were observed, with a 0% incidence of corneal graft rejection, and a final BCVA ranged from 20/20 to 20/80 after a mean follow-up of 14 ± 1.1 months.

Conclusion

MLF-AMT is a safe and valid option to manage corneal perforation during keratmycosis treatment to avoid emergency therapeutic keratoplasty.

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.

Delayed-onset Candida parapsilosis cornea tunnel infection and endophthalmitis after cataract surgery: Histopathology and clinical course

Purpose

To describe a patient with late post-operative endophthalmitis and clear cornea tunnel infection caused by Candida parapsilosis that was masquerading as chronic anterior uveitis.

Observations

A 62-year old woman with history of uncomplicated cataract surgery 7 months prior and chronic postoperative anterior uveitis, presented with an endothelial plaque, hypopyon, and infiltrates in the capsular bag and within the clear corneal tunnel. Anterior chamber cultures identified C. parapsilosis and pathology of the endothelial plaque showed fungus. Anterior chamber washout, scraping of the endothelial plaque, serial intracameral and intravitreal injections with amphotericin B (10 mcg) failed to control the infection. Pars plana vitrectomy, removal of the intraocular lens and capsular bag, a corneal patch graft, and administration of intravitreal antifungal agents were performed. One year later the patient remains free of recurrence and her best-corrected vision is 20/25 with a rigid gas permeable contact lens.

Conclusions

and Importance: Persistent intraocular and intracorneal inflammation after cataract surgery should raise suspicion of endophthalmitis caused by fungi non-responsive to topical and intravitreal antibiotics. Surgical intervention and removal of the nidus of infection, which is often the intraocular lens and capsular bag, may be necessary for a successful outcome.

Identification of the Infection Source of an Outbreak of Mycobacterium Chelonae Keratitis After Laser in Situ Keratomileusis

PURPOSE

Nontuberculous mycobacteria keratitis is a rare but challenging complication of laser in situ keratomileusis (LASIK). This study was conducted to determine the source(s) of infection in a cluster of cases of keratitis after LASIK and to describe this outbreak and patients' outcomes.

METHODS

In this retrospective, case series, single-center study, 86 patients were included who underwent LASIK or photorefractive keratectomy between December 2011 and February 2012. Corneal scrapes from the affected eyes, samples of tap and distilled water, water from the reservoir of the distilling equipment, steamer, and autoclave cassette; antiseptic and anesthetic solutions and surgical instrument imprints were cultivated in liquid and on solid media. Gram-negative bacteria and yeasts were identified using automated systems and mycobacteria by polymerase chain reaction-restriction enzyme analysis of the hsp65 gene (PRA-hsp65) and DNA sequencing. Mycobacterial isolates were typed by pulsed-field gel electrophoresis. The cases and outcomes are described. The main outcome measure was identification of the source(s) of the mycobacterial infections.

RESULTS

Eight (15 eyes) of 86 patients (172 eyes) who underwent LASIK developed infections postoperatively; no patients who underwent photorefractive keratectomy developed infections. Mycobacterium chelonae was isolated from 4 eyes. The distilled water collected in the surgical facility contained the same M. chelonae strain isolated from the patients' eyes. Different gram-negative bacteria and yeasts were isolated from samples collected at the clinic but not from the patients' eyes.

CONCLUSIONS

Tap water distilled locally in surgical facilities may be a source of infection after ocular surgery and its use should be avoided.

Candida parapsilosis keratitis treated successfully with topical and oral fluconazole

A 73-year-old male patient presented with ocular pain, redness, and blurred vision in the left eye, which had been ongoing for more than 2 months. An oval-shaped paracentral corneal ulcer with stromal infiltration and a mild anterior chamber reaction were found. Despite treatment with empiric antibiotics, the lesion progressed and corneal thinning in the middle area was noted. The culture yielded Candida parapsilosis. We therefore prescribed topical 0.2% fluconazole (FCZ) in combination with oral FCZ as an antifungal treatment, following which the stromal infiltration gradually subsided. Complete epithelial-ization was noted on the 8^th day after initiating FCZ therapy. There was no recurrent disease in the subsequent 2 years. Our case demonstrates that topical FCZ 0.2% in combination with oral FCZ can successfully treat C. parapsilosis keratitis and result in a good visual outcome.

Post-laser in situ keratomileusis interface fungal keratitis

PURPOSE

To report outcomes of post-laser in situ keratomileusis (LASIK) interface filamentous fungal keratitis.

METHODS

This retrospective interventional case series included 6 eyes of 5 patients with microbiologically proven post-LASIK interface fungal keratitis from August 2008 to August 2013. Patients presenting with concurrent bacterial/viral keratitis, systemic illness, prior ocular pathology, or those without a minimum follow-up of 3 months were excluded. Every case underwent microbiological scrapings from residual bed and undersurface of the flap after flap lift at presentation followed by voriconazole interface wash. Flap amputation was performed when required. The outcome measure was complete resolution of infection.

RESULTS

The mean age was 24 ± 3.1 years. The male:female ratio was 4:1. The mean interval between LASIK and symptom onset was 4.16 ± 2 days; and the mean interval between symptom onset and patient referral was 3.16 ± 1.16 days. Interface scrapings showed filamentous fungal filaments in KOH wet mount. The culture grew Aspergillus in case 1 and case 5. Infiltrated LASIK flap needed to be amputated in 4 eyes of 3 patients. Voriconazole wash (100 μg/mL) of the stromal bed was performed in all cases. A positive response to therapy with resolution of infection was seen in all cases at a mean of 6.5 ± 4.6 days. No intraoperative or postoperative complications after interface scraping or voriconazole wash were observed. The final best-corrected visual acuity ranged from 20/20 to 20/80 at a mean follow-up of 9.1 ± 6.5 months.

CONCLUSIONS

Post-LASIK interface fungal filamentous keratitis can present early and gives good outcomes with early microbiological diagnosis and appropriate management. Voriconazole is an efficient and probably safe adjunct in the armamentarium of corneal surgeons to treat such cases.

Microbial keratitis after corneal laser refractive surgery

Corneal laser refractive surgery is increasingly being performed on patients with the aim of improving unaided vision. Most candidates for surgery have excellent spectacle- or contact lens-corrected vision. Although microbial keratitis following refractive surgery is a rare complication, and usually has a good visual outcome, it can be sight-threatening. The spectrum of pathogens differs to other causes of microbial keratitis, such as contact lens-associated keratitis, and a different management approach is required. Postoperatively, patients are prescribed topical steroids and broad-spectrum topical antibiotics, typically fluoroquinolones. These do not cover unusual organisms, such as fungi, Nocardia, Acanthamoeba and some atypical mycobacteria. In post-laser-assisted in situ keratomileusis microbial keratitis, the lamellar flap should be lifted to acquire samples for specific microbiological examination, including these atypical organisms. Confocal microscopy is a noninvasive test that provides morphological information, and is operator dependent, but may assist in the rapid diagnosis of fungal, Acanthamoeba or Norcardia keratitis. PCR is not in widespread use, but has high sensitivity and specificity, and may facilitate early diagnosis and specific treatment of the causative organism, which is critical in obtaining the best clinical outcome.

Microbial keratitis trends following refractive surgery: results of the ASCRS infectious keratitis survey and comparisons with prior ASCRS surveys of infectious keratitis following keratorefractive procedures

In 2008, the American Society of Cataract and Refractive Surgery (ASCRS) surveyed its 9121 United States and international members to evaluate the changing trends and incidence, culture results, treatment, and visual outcomes of infectious keratitis following keratorefractive procedures worldwide. This paper presents and analyzes the results with comparisons to the data in surveys conducted in 2001 and 2004. Nineteen infections were reported by 14 surgeons who had performed an estimated 20,941 keratorefractive procedures, an incidence of 1 infection in every 1102 procedures. Sixteen cases presented in the first postoperative week, 1 case during the second week, 1 case between the second and fourth weeks, and 1 case at 1 month or later. The 16 cases that presented in the first week were diagnosed at initial presentation. The most common organism cultured was methicillin-resistant Staphylococcus aureus (MRSA). Microbial keratitis following refractive surgery is an increasingly recognized sight-threatening complication.

Calcineurin controls drug tolerance, hyphal growth, and virulence in Candida dubliniensis

Candida dubliniensis is an emerging pathogenic yeast species closely related to Candida albicans and frequently found colonizing or infecting the oral cavities of HIV/AIDS patients. Drug resistance during C. dubliniensis infection is common and constitutes a significant therapeutic challenge. The calcineurin inhibitor FK506 exhibits synergistic fungicidal activity with azoles or echinocandins in the fungal pathogens C. albicans, Cryptococcus neoformans, and Aspergillus fumigatus. In this study, we show that calcineurin is required for cell wall integrity and wild-type tolerance of C. dubliniensis to azoles and echinocandins; hence, these drugs are candidates for combination therapy with calcineurin inhibitors. In contrast to C. albicans, in which the roles of calcineurin and Crz1 in hyphal growth are unclear, here we show that calcineurin and Crz1 play a clearly demonstrable role in hyphal growth in response to nutrient limitation in C. dubliniensis. We further demonstrate that thigmotropism is controlled by Crz1, but not calcineurin, in C. dubliniensis. Similar to C. albicans, C. dubliniensis calcineurin enhances survival in serum. C. dubliniensis calcineurin and crz1/crz1 mutants exhibit attenuated virulence in a murine systemic infection model, likely attributable to defects in cell wall integrity, hyphal growth, and serum survival. Furthermore, we show that C. dubliniensis calcineurin mutants are unable to establish murine ocular infection or form biofilms in a rat denture model. That calcineurin is required for drug tolerance and virulence makes fungus-specific calcineurin inhibitors attractive candidates for combination therapy with azoles or echinocandins against emerging C. dubliniensis infections.

A rare devastating complication of LASIK: bilateral fungal keratitis

Purpose. To report an unusual case of severe bilateral fungal keratitis following laser in situ keratomileusis (LASIK). Method. A 48-year-old man developed bilateral diffuse corneal infiltration two weeks after LASIK. The corneal scrapings revealed fungal filaments but cultures were negative. Results. The corneal ulceration was improved on the left eye whereas spontaneous perforation occurred and finally evisceration was needed on the right eye despite topical and systemic antifungal treatment. Conclusions. Fungal keratitis, especially with bilateral involvement, is a very rare and serious complication of LASIK surgery. Clinical suspicion is crucial because most of fungal keratitis are misdiagnosed as bacterial keratitis and can lead serious visual results, even eye loss.