Herpetic stromal disease: response to acyclovir/steroid therapy

Ganciclovir ophthalmic gel 0.15% for the treatment of acute herpetic keratitis: background, effectiveness, tolerability, safety, and future applications

Eye disease due to herpes simplex virus (HSV) is a leading cause of ocular morbidity and the number one infectious cause of unilateral corneal blindness in the developed parts of the globe. Recurrent keratitis can result in progressive corneal scarring, thinning, and vascularization. Antiviral agents employed against HSV have primarily been nucleoside analogs. Early generation drugs included idoxuridine, iododesoxycytidine, vidarabine, and trifluridine. While effective, they tended to have low bioavailability and measurable local cellular toxicity due to their nonselective mode of action. Acyclovir 0.3% ointment is a more selective agent, and had become a first-line topical drug for acute HSV keratitis in Europe and other places outside of the US. Ganciclovir 0.15% gel is the most recently approved topical treatment for herpes keratitis. Compared to acyclovir 0.3% ointment, ganciclovir 0.15% gel has been shown to be better tolerated and no less effective in several Phase II and III trials. Additionally, topical ganciclovir does not cause adverse systemic side effects and is therapeutic at lower concentrations. Based on safety, efficacy, and tolerability, ganciclovir 0.15% gel should now be considered a front-line topical drug in the treatment of dendritic herpes simplex epithelial keratitis. Topics of future investigation regarding other potential uses for ganciclovir gel may include the prophylaxis of recurrent HSV epithelial keratitis, treatment of other forms of ocular disease caused by herpesviruses and adenovirus, and ganciclovir gel as an adjunct to antitumor therapy.

Clinical outcomes of keratitis

OBJECTION

To analyse the patient, clinical and microbiological variables associated with poor outcomes from keratitis in patients presenting to a major public hospital in Australia.

METHODS

A retrospective audit of the records of all patients who had a corneal scraping in 5 years at Princess Alexandra Hospital (Brisbane, Australia) was carried out. The outcome of a patient's episode of keratitis was classified as poor if they had final visual acuity of 6/60 or worse; had vision loss during treatment; or a complication of keratitis; or needed surgical intervention.

RESULTS

A final outcome was established in 207 cases during the 5-year period. Final vision of 6/12 or better was found in 48% (100) of cases while a poor outcome was seen in 28% (58). Linear regression showed poor outcomes were directly associated with age (P < 0.001) and disease severity (P < 0.001). Univariate analysis indicated that poor outcomes were more likely in patients who had had prior ocular surgery (P = 0.005) or ocular surface disease (P = 0.01) and were also associated with presenting visual acuity of worse than 6/60 (P < 0.001) and isolation of Streptococcus pneumoniae (P = 0.002). While patients with traumatic keratitis, contact lens-related keratitis or negative corneal cultures (P = 0.009) were more likely to have good outcomes. Multivariate analysis showed that the relative risk of a patient having a poor outcome was 4.3x (CI 2.0-9.5) if they had severe keratitis, 4.1x (CI 1.8-9.5) if they had keratitis related to ocular surface disease and 3.8x (CI 1.8-8.3) if they were over 50 years old.

CONCLUSIONS

An outcome of poor vision, vision loss during treatment, surgical intervention or complication of keratitis is more likely in patients with severe keratitis, keratitis related to prior ocular surface disease or older age.

Corneal Thickness Changes During Herpes Simplex Virus Disciform Keratitis

OBJECTIVE

To describe the changes in corneal thickness determined by ultrasonic pachymetry during follow-up of herpes simplex virus disciform corneal edema.

METHODS

Thirty-five patients with herpetic keratitis underwent slit-lamp biomicroscopy and ultrasonic pachymetry. Measurements during follow-up and at clinical resolution of corneal inflammation were compared with the initial corneal thickness.

RESULTS

Corneal thickness of disciform stromal keratitis decreased 15% (95% confidence interval 10% to 20%) during follow-up, and 65% (95% confidence interval 43% to 88%) of this decrease occurred during the first 2 weeks. Increased central corneal thickness measured by pachymetry was associated with biomicroscopic detection of corneal edema (P = 0.03).

CONCLUSIONS

Corneal pachymetry supplements clinical assessment of herpetic disciform edema.