Antimicrobial efficacy of corneal cross-linking in vitro and in vivo for Fusarium solani: a potential new treatment for fungal keratitis

Abstract

BackgroundFungal keratitis is one of the major causes of visual impairment worldwide. However, the effectiveness of corneal collagen cross-linking (CXL) for fungal keratitis remains controversial. In this study, we developed an in vitro and an in vivo models to assess the efficacy of CXL for Fusarium keratitis.MethodsThe effect of in vitro CXL fungicidal was evaluated on the cultures of Fusarium solani which were exposed to irradiation for different durations. Viability of fungal was appraised under four conditions: no treatment (control); CXL: UVA (365 nm)/riboflavin; riboflavin and UVA (365 nm). Each batch of sterile plate culture was irradiated for different CXL durations.The in vivo Therapeutic effect was studied on a mouse keratitis model. The animals were divided randomly into three groups: group A with no treatment (control); Group B with CXL treatment for two minutes and group C with CXL treatment for three minutes. The CXL procedure was performed 24 h post inoculation in each group. All mice with corneal involvement were scored daily for 7 days and 10 days after infection. Corneals were extracted at various time points for quantitative fungal recovery. Histological evaluations were conducted to calculate the number of polymorphonuclear cells.ResultsViability of fungal decreased significantly in CXL group with 30-min irradiation compared with that in control, riboflavin and UVA groups (P < 0.01).The colony-forming units (CFUs) of fungal solutions in culture significantly decreased with CXL treatment (P < 0.05). Clinical scores, corneal lesion, corneal opacity, neovascularization and the depth of ulceration scores in group B and group C were remarkably lower than that in group A (P < 0.05, P = 0.001, P = 0.001, P = 0.034 and P = 0.025 respectively). Scores of group C were much lower than that in group B. Histological revealed that destruction of corneal collagen fibers and infiltration of inflammatory cells into corneal tissue in group B and group C were much lower than that in group A.ConclusionsWe believe that CXL treatment may be applied to fungal keratitis, therapeutic efficacy will improve with longer treatment duration.

Analysis of tear film spatial instability for pediatric myopia under treatment

“…Only a healthy ocular surface can provide a smooth optical surface for visual function and a normal tear film plays a dominant role in it 31 . Though tear film instability, which might be the initiator of severe ocular surface disease, has not yet been reported in myopic children under atropine control, it was recently announced and noticed as an unignorable risk in children under orthokeratology control 12,13,15,32 . Some researchers debated about the ocular surface alterations after overnight wearing of orthokeratology lenses.…”

“…Wang et al 12 reported that overnight wearing of orthokeratology lenses could decrease TMH and TBUT but did not affect the function of the meibomian glands. However, Li et al 32 and Xie et al 13 pointed out that basal tear secretion and ocular surface inflammation were unaffected after orthokeratology treatment and there was only a short-term decrease in TBUT. They believed that the increase in tear evaporation may be related to the distribution of tear film caused by transient morphological changes in the tear film.…”

Experimental Models for Fungal Keratitis: An Overview of Principles and Protocols

“…One such experimental workflow in this regard is as follows: a 2 mm diameter trephine is used to mark the central cornea, and then a size-11 scalpel blade is used to cut into the epithelium within the marked area. Then, a sharpened bamboo toothpick is used to debride and smear F. solani mycelium onto the ocular surface [ 42 , 43 , 44 , 45 , 46 ]. Such a method can also be used for A. fumigatus as demonstrated in Figure 2 B (unpublished data).…”

ATF4 Involvement in TLR4 and LOX-1-Induced Host Inflammatory Response to Aspergillus fumigatus Keratitis

“…Separate from Acanthamoeba keratitis, the typical clinical features of fungal keratitis are difficult to ascertain in the early stage of infection, leading to common misdiagnoses and delayed treatment [4, 5]. Although there are new therapies used in clinical application, fungal keratitis remains a challenge to ophthalmologists due to a lack of effective drugs after late initiation of treatment secondary to delayed diagnosis [6, 7].…”