Post-laser in situ keratomileusis interface fungal keratitis

Smart Contact Lenses for Healthcare Monitoring and Therapy

The eye contains a wealth of physiological information and offers a suitable environment for noninvasive monitoring of diseases via smart contact lens sensors. Although extensive research efforts recently have been undertaken to develop smart contact lens sensors, they are still in an early stage of being utilized as an intelligent wearable sensing platform for monitoring various biophysical/chemical conditions. In this review, we provide a general introduction to smart contact lenses that have been developed for disease monitoring and therapy. First, different disease biomarkers available from the ocular environment are summarized, including both physical and chemical biomarkers, followed by the commonly used materials, manufacturing processes, and characteristics of contact lenses. Smart contact lenses for eye-drug delivery with advancing technologies to achieve more efficient treatments are then introduced as well as the latest developments for disease diagnosis. Finally, sensor communication technologies and smart contact lenses for antimicrobial and other emerging bioapplications are also discussed as well as the challenges and prospects of the future development of smart contact lenses.

Very late onset LASIK flap Acremonium fungal keratitis confirmed by metagenomic deep sequencing

Purpose

To describe a unique case of LASIK flap fungal keratitis confirmed by next generation sequencing.

Observations

A 56-year-old female presented with refractory keratitis involving her LASIK flap 21 years after surgery. Confocal was positive for filamentous structures. The patient underwent immediate flap amputation followed by topical antifungal treatment. Corneal culture was positive for Acremonium sp. Metagenomic deep sequencing confirmed Acremonium as the primary source of infection and also identified Fusarium as a likely contributor of a mixed fungal infection. Sequencing also identified hay as the likely source of the infection. Treatment resulted in eradication of the infection. The patient's final best corrected visual acuity was 20/30 with rigid contact lens overrefraction.

Conclusions

Metagenomic deep sequencing is a novel diagnostic tool that is increasingly being utilized for diagnosis of refractory keratitis. This case demonstrates the diagnostic potential of deep sequencing for identifying post-LASIK keratitis and reinforces the utility of LASIK flap amputation in the setting of tectonic flap instability due to keratolysis.

Importance

This case highlights several important clinical points for treating LASIK flap keratitis and highlights the emerging role metagenomic sequencing has in the diagnosis of infectious keratitis. This is first known case using next generation sequencing to diagnose a post-LASIK infectious keratitis.

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.

Histone deacetylase inhibitor attenuates experimental fungal keratitis in mice

Fungal keratitis is one of the leading causes of blindness of infected corneal diseases, but the pathogenesis of fungal keratitis is not fully understood and therefore the treatment of the disease by medication is still under investigation. In the current study, we sought to study the effect of HDAC inhibitor suberoylanilide hydroxamic acid (SAHA) on experimental fungal keratitis in mice. SAHA (25 mg/kg) (n = 30) or vehicle (DMSO) (n = 30) was delivered through intraperitoneal injection (IP) 24 hours after the fungal inoculation, and the same amount of SAHA injection or DMSO was followed at day 2. The expression of histone H3 (H3), acetylated histone H3 (AC-H3), histone deacetylase 1 (HDAC)1, tumor necrosis factor-α (TNFα), and Toll-like receptor 4 (TLR4) in surgically excised specimens from the patients and mice with fungal keratitis were detected by immunohistochemistry. The expression of mRNAs for Interleukin-1β (IL-1β), TNFα, and TLR4 were evaluated in the corneas of the mice with fungal infection and the control corneas by real-time PCR. The quantification of IL-1β and TNFα in the corneas of the mice with fungal infection was determined by ELISA. The inhibitory effect of SAHA on mice fungal keratitis was revealed by GMS and H&E staining. We found that the downregulation of histone acetylation and upregulation of HDAC1 expression were associated with the increased inflammation response in fungal keratitis not only in humans but also in experimental animals. SAHA was able to inhibit experimental fungal keratitis in mouse by suppressing TLR4 and inflammatory cytokines such as TNFα and IL-1β; the inhibition of HDAC may be a potential therapeutic approach for the treatment of fungal keratitis.

Rapamycin liposome gutta inhibiting fungal keratitis of rats

AIM

To study the therapeutic effect of rapamycin liposome eyedrops on fungal keratitis (FK) and its effect on the expression of monocyte chemotactic protein-1 (MCP-1).

METHODS

This study adopted the thin film dispersion method to prepare rapamycin liposomes eyedrops, as well as used the orthogonal design to analyze and study main influencing factors that affected the quality of liposomes. Totally 96 healthy Wistar rats were randomly divided into four groups: normal control group (A), FK blank control group (B), FK blank liposomes control group (C), and 30 FK rapamycin liposome treatment group (D). Groups B, C, and D were first prepared as FK animal models. The corneal response was recorded in details on day 1, 3, 5, 7, and 14 after modeling. Six rats were obtained and immunohistochemistry and semi-quantitative reverse transcription polymerase chain reaction (RT-PCR) were used to detect the expression of MCP-1 protein and mRNA, respectively.

RESULTS

The severity of corneal lesions in the rapamycin treatment group was reduced, and the clinical score of the slit lamp examination was lower than that of Groups B and C (P<0.01). The expression of MCP-1 in rapamycin treatment group was significantly inhibited, comparing to that of groups B and C (P<0.01).

CONCLUSION

Liposome is a good drug carrier for rapamycin. Rapamycin has a good therapeutic effect on FK. It can reduce FK fungal burden and significantly inhibit the expression of MCP-1 protein and mRNA.