Antiviral Treatomt of Herpes Simplex Stromal Disease. In: Maudgal PC, Missotten L, editors. Herpetic Eye Diseases. Dordrecht: Springer Netherlands; 1985. pp. 217-25. [DOI: 10.1007/978-94-009-5518-9_31]

Combinations of antiviral and anti-inflammatory preparations for the topical treatment of herpes simplex virus assessed using a murine zosteriform infection model

Recently we have reported a zosteriform murine infection model which employs the adoptive transfer of immune cells (ATI) to recipient infected mice to produce a disease that mimics human recurrent herpes simplex virus (HSV) disease. Mice were infected with HSV-1 by scarification at the lateroventral line of the neck; 2 days later, the mice received immune cells from HSV-1-infected syngeneic mice. Although virus was cleared more quickly from the target tissues of virus replication in recipient mice, ATI resulted in a heightened inflammatory response and delayed healing. This model was used to test the effects of topical formulations containing foscarnet and/or the anti-inflammatory agent, hydrocortisone. Virus clearance and clinical signs, including ear thickness and zosteriform spread of lesions, were studied. Treatment with 3% foscarnet accelerated virus clearance but had little effect on clinical parameters. By contrast, 0.5% hydrocortisone increased the titre and extended the presence of infectious virus for at least 6 days, although the reduction in clinical signs was greater than that obtained with topical foscarnet. Foscarnet in combination with hydrocortisone produced a marked reduction in clinical signs while virus replication was reduced. These results are discussed in relation to the inflammation and discomfort experienced by patients and a possible role for anti-inflammatory formulations in the treatment of HSV reactivation episodes in man.

Herpetic stromal disease: response to acyclovir/steroid therapy

The efficacy of combined acyclovir and steroid therapy in the treatment of herpetic stromal disease was evaluated by clinical evaluation of disease, the rebound of disease following termination of therapy, and the recovery of virus and viral DNA from corneas in a rabbit model. Therapy with acyclovir alone produced a significant reduction in corneal thickness in 10% of eyes. Addition of steroid to acyclovir therapy decreased the severity of stromal disease as measured by corneal thickness and increased the frequency of response to treatment to 63% of eyes. All eyes receiving acyclovir alone experienced rebound of disease following termination of therapy. Combined therapy increased the severity of rebound of corneal disease. Virus was recovered from cell cultures established after recovery from rebound in 50% of untreated and treated eyes. Viral DNA was detected by PCR in five of the nine corneal cultures which did not produce infectious virus.

The development of corneal edema in herpes simplex virus type 1-infected rabbits following termination of therapy for corneal stromal disease

One complication of combined antiviral/corticosteroid therapy for herpetic stromal disease in patients is rebound of disease upon termination of therapy. To develop a model of steroid rebound, rabbits were injected intrastromally with 10(3) pfu of HSV-1 (RE strain). Therapy with 1% trifluorothymidine (F3TdR) alone or in combination with immunosuppressive agents was initiated 7 days post-infection, at a time when epithelial disease had reached its peak and corneal thickness had begun to increase. Therapy was continued 5 times daily through day 18 post-infection. Following cessation of therapy 13 of 16 eyes receiving both 1% F3TdR and 0.125% prednisolone acetate experienced rebound of disease characterized by an increase in corneal thickness from 514 +/- 106 microns to 743 +/- 189 microns, reaching a maximum at 27 +/- 3 days post-infection. Rabbits receiving therapy with either phosphate buffered saline or F3TdR alone displayed rebound in 2 and 3 of 12 eyes, respectively. Rabbits receiving F3TdR combined with either cyclosporine or deoxycoformycin experienced rebound of disease in 9 of 20 and 6 of 16 eyes, respectively. Cultures of eye washings taken from eyes at the time of rebound were negative in all cases. The data indicate that only steroids significantly increased the proportion of eyes with rebounding stromal disease and corneal edema. These studies document steroid rebound of stromal disease in an animal model.

Bromovinyldeoxyuridine treatment of herpetic keratitis clinically resistant to other antiviral agents

Patients suffering from dendritic and geographic corneal ulcers or herpetic stromal keratitis were treated with topical BVDU [(E)-5-(2-bromovinyl)-2'-deoxyuridine, bromovinyldeoxyuridine] 0.1% eyedrops administered during the day only at 1-hour intervals. Treatment with other antiviral drugs, i.e., idoxuridine, trifluridine, vidarabine or Zovirax had failed to ameliorate the ocular disease in 102 patients when their treatment was switched to BVDU eyedrops. Under BVDU therapy, dendritic keratitis in 44 patients healed within an average 7.8 days. Similarly, geographic corneal ulcers in 26 patients and stromal keratitis in 32 patients healed within an average period of 11.2 days and 30.7 days, respectively. Associated therapy with topical corticosteroids was stopped in 65 patients when the antiviral treatment was switched. However, topical corticosteroids had to be used together with BVDU drops to arrest stromal inflammation in 49 patients. Ultimately, 36 patients became corticosteroid-dependent. Except for local hypersensitivity reaction in three patients, BVDU eyedrops did not cause any toxic side effects.