Abstract
Purpose :
To investigate the efficacy of dual therapy with corneal cross-linking (PACK-CXL) and natamycin in the management of Fusarium infections and to evaluate the effect of intervention timing with PACK-CXL or natamycin in the combined treatment regime as opposed to monotherapy with natamycin.
Methods :
Twenty-four ex vivo human corneas were divided into 6 groups: C: Control; I: Inoculated with Fusarium oxysporum spores; IN: Inoculated, treated with natamycin at 24h post-inoculation; IXN: Inoculated, treated with combined PACK-CXL and natamycin at 24h post-inoculation; IX-48h-N: Inoculated, treated with PACK-CXL at 24h post-inoculation, then treated with natamycin at 48h post-inoculation; IN-72h-X: Inoculated, treated with natamycin at 24h post-inoculation, treated with PACK-CXL at 72h post-inoculation. The corneas were imaged daily by confocal microscopy and Fusarium hyphal volume was calculated for the duration of the experiment (7 days) following inoculation. Corneas were sectioned, haematoxylin and eosin stained, imaged, and the hyphal penetration depth within the stromal tissue was measured.
Results :
All treated groups (IN, IXN, IX-48h-N and IN-72h-X) had a statistically significant reduction in both Fusarium hyphal volume and hyphal penetration depth on day 7 compared to the un-treated group (I) (p=0.001). The PACK-CXL/natamycin dual treatment had a higher impact in controlling the progression of fungal infection and completely eradicating of the Fusarium agents in the IXN group (which had early intervention at 24h post-inoculation with both natamycin and PACK-CXL) and IN-72h-X group (which had early intervention of natamycin at 24h but late PACK-CXL treatment at 72h), when compared to either IX-48-N group (which had early intervention of PACK-CXL at 24h but late natamycin at 48h) or IN group (which had natamycin only from 24h post-inoculation).
Conclusions :
The dual therapy of PACK-CXL with natamycin is more effective in the management of corneal infection caused by Fusarium than treatment with natamycin alone. Delaying the natamycin treatment reduces dual therapy efficacy more than delaying the PACK-CXL treatment.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.