Purpose: To investigate the role of in vivo confocal microscopy (IVCM) in the detection of inflammatory activity and follow-up of herpetic stromal keratitis (HSK). Design: Prospective observational cohort study. Participants: Thirty-eight patients with active HSK. Methods: Within 7 days after diagnosis of active HSK, both eyes of each patient were examined by slit-lamp biomicroscopy and white-light IVCM (Confoscan 4; Nidek Technologies, Padova, Italy). The HSK-affected eyes were followed up at 1, 3, 6, and 12 months, whereas the unaffected fellow eyes were reexamined after 12 months. Three patients did not complete follow-up and were excluded for data analyses. All IVCM examinations were assessed for morphologic alterations characteristic of inflammatory activity and for corneal backscatter. As secondary outcome parameters, best-corrected visual activity (BCVA), central corneal thickness (CCT), intraocular pressure (IOP), and endothelial cell density (ECD) were determined at each study visit. We used repeated-measures analysis of variance to assess changes during the 12-month follow-up period and paired t tests to compare HSK-affected eyes with fellow eyes. Main Outcome Measures: Presence of dendriform cells, pseudoguttae, and keratic precipitates, and follow-up of mean corneal backscatter. Results: An increase of dendriform cells and pseudoguttae often accompanied stromal infiltration. Because these IVCM parameters were indiscernible or overlooked at slit-lamp examination, they proved to be excellent indicators of inflammatory activity. At 12 months' follow-up, mean corneal backscatter had decreased significantly by 36%, but still fell outside the normal range in 24 (69%) of the HSK-affected eyes. By using slit-lamp in conjunction with IVCM, we detected 17 recurrences in 14 of 35 patients (40%). Three of these recurrences were missed by slit-lamp, and 6 of these were missed by IVCM. At 12 months' follow-up, BCVA (-9 letters), CCT (-36 μm), and ECD (-313 cells/mm2) were significantly lower, whereas IOP (1.8 mmHg) was significantly higher, in HSK-affected eyes compared with fellow eyes. Conclusions: The data presented demonstrate that IVCM is complementary to slit-lamp examination in the follow-up of HSK, particularly because of its power to detect early signs of intracorneal inflammatory activity. Therapy guidance based on morphologic assessment and corneal backscatter measurement by combined IVCM and slit-lamp examination may improve the outcome of HSK. Financial Disclosure(s): The author(s) have no proprietary or commercial interest in any materials discussed in this article.

adult, aged, article, cell density, cell infiltration, clinical article, cohort analysis, confocal microscopy, cornea thickness, disease activity, endothelium cell, female, follow up, herpes simplex keratitis, herpetic stromal keratitis, human, in vivo confocal microscopy, in vivo study, intraocular pressure, male, microscope, observational study, outcome assessment, patient monitoring, recurrent disease, slit lamp, visual acuity
dx.doi.org/10.1016/j.ophtha.2011.12.002, hdl.handle.net/1765/39091
Erasmus MC: University Medical Center Rotterdam

Hillenaar, T, van Cleynenbreugel, H, Verjans, G.M.G.M, Wubbels, R.J, & Remeijer, L. (2012). Monitoring the inflammatory process in herpetic stromal keratitis: The role of in vivo confocal microscopy. Ophthalmology, 119(6), 1102–1110. doi:10.1016/j.ophtha.2011.12.002