Purpose
We have recently developed and characterized a unique model of herpetic keratitis reproducing dendritic or geographic ulceration on human corneas stored in our corneal Bioreactor (BR). The BR is a multi‐application experimentation platform developed to keep the cornea alive for prolonged periods of time in a physiological environment of intraocular pressure and environmental renewal.
Aim
To evaluate whether this model can be used to test the efficacy of antiviral eye drops.
Methods
HSV‐1 keratitis was obtained as previously described: paired corneas discarded from our eye bank were stored in the BR for 14 days (D) at 21 mmHg and 2.6 µl/min of medium renewal (CorneaMax, Eurobio, France) to allow epithelial regeneration. A superficial linear epithelial lesion was then made in the centre, followed incubation of the epithelial surface for 1 hr in a solution of 106 Plaque‐Forming Unit/mL HSV‐1. Three days post‐infection, 0.15% ganciclovir ophthalmic gel used with active molecule at 3.75 µg/ml was instilled on the cornea inside the BR, 3 times/day during 14D and 2 times/day during 5D. The gel was rinsed after 10 min with BSS. The paired cornea was treated similarly with the vehicle (carbomer 974P). Changes in epithelial ulceration size were monitored daily by non‐invasive imaging through the transparent BR windows. Histology and immunolabeling (HSV‐1 gpB, epithelial markers) were done at D40.
Results
For the control corneas, the entire epithelium desquamated at D10. At D40 all keratocytes expressed gpB and endothelial cells partly disappeared. For ganciclovir‐treated corneas, only half of the epithelium desquamated at D14, then it began to regenerate during the third week to reach 1 to 3 epithelial layers at D40. Epithelial and endothelial cells were not infected (gpB‐). Some keratocytes were infected only in the periphery.
Conclusions
Model of herpetic keratitis in the BR has a high potential to evaluate antiviral eye drops efficacy.