Monitoring the inflammatory process in active herpetic keratitis by in vivo confocal microscopy (IVCM): Clinical relevance.

Rationale:

Confocal microscopy is a non-invasive, real-time, in vivo imaging technique which has been put forward as an additional clinical tool for inspection of the cornea. Presently disease activity of herpetic keratitis is evaluated by slit lamp inspection. For an objective follow up of the inflammatory process, however, this method does not meet the standards of sufficient accuracy and reproducibility. A large study on endothelial involvement in herpetic keratitis showed that In Vivo Confocal Microscopy (IVCM) has an additional role in detecting active endotheliitis which remains undetected in slit lamp examination. In a pilot study we investigated the role of confocal microscopy as reliable quantitative parameter for a more adequate follow up of the inflammatory process of active herpetic keratitis.



Objective:

Testing the hypothesis that IVCM is a clinical relevant tool to monitor the inflammatory process due to herpetic keratitis.



Study design:

Prospective randomised study.



Study population:

All patients with herpetic stromal keratitis (HSK) already known to the Rotterdam Eye Hospital, and all new patients presenting with herpetic keratitis.



Main study parameters:

BCVA at 12 and 24 months follow up. Number of recurrences recognized in an earlier state by IVCM compared to slit lamp examination.



Secondary study parameters:

Side effects of treatment. Amount of steroids used during 24 months follow up. Dose of antiviral treatment used during 24 months follow up.



Nature and extent of the burden and risks associated with participation, benefit and group relatedness:

The normal frequency of consultations in HSK following a recurrence is 7 times during the first year (i.e. day 0, week 1, months 1, 3, 6, 9, 12), and two times during the second year. Patients with inactive disease are normally followed every 6 months.



Study-related measurements will be performed during all normally planned clinical visits, with a minimum frequency of 4 times a year. Thus, 2 extra visits are anticipated for the 'recurrent HSK' group (i.e. during the second year of follow-up); 'inactive HSK' patients will have to pay 4 extra visits during the entire 2-year follow-up period.



The study-related measurements will take about 40 minutes during the first visit and 20 minutes during the subsequent visits (total extra time for the 'recurrent' group: 40 + 10 x 20 = 240 minutes; total extra time for the 'inactive' group 40 + 7 x 20 = 180 minutes).



Participants of this study do not benefit from the results of this study. Risks are considered to be negligible.

IVCM is a clinical relevant tool to monitor the inflammatory process due to herpetic keratitis.

D0, W1, M1, M3, M6, M9, M12, M15, M18, M21, M24.

The diagnostic method used in this study to adjust medication will depend on the study-arm. Diagnostic outcome (active versus inactive HSK) will determine whether treatment is (re)started or stepped up.