Abstract
Purpose :
Laser scanning in vivo confocal microscope (IVCM) is widely used in ophthalmology to provide non-invasive, high-resolution cornea images. However, the effect of the IVCM laser beam on the cornea itself is seldom investigated. Here we compared the rat cornea change before and after the IVCM exam at various intervals.
Methods :
A commercial model HRT3-RCM (Heidelberg Engineering) was used to assess rat cornea change. At three individual locations, we acquired IVCM images of the whole cornea through three continuous volume acquisitions. Laser beams were applied on the cornea for 2 minutes/location and less than 10 minutes/eye. Based on the anatomic landmark in posterior stroma, we re-examed the same location of the cornea in all the follow-up assessments. The IVCM exam was taken at the following intervals between two exams: 1 day, 4 days, 7 days, 14 days, and 30 days. The SNP layer, basal epithelium, and endothelium layers were analyzed at those time points. In the SNP layer, the inflammatory cells were manually counted, and the results were analyzed by Student’s t-tests.
Results :
One day after the IVCM (imaging interval = 1 day), there was a significant inflammatory cell infiltration in the SNP layer (Pre vs 1 day: 1.0±1.32 vs 8.1±3.3 cells/images, p<0.0001). The inflammatory cells were dramatically decreased to baseline level when the imaging interval was increased to 4 days or longer. In the basal epithelium and endothelium layer, there was no inflammatory cell infiltration, and no significant change in cell size at all the exam intervals.
Conclusions :
IVCM could induce a temporary inflammatory cell infiltration in the SNP layer, which resolved spontaneously if the imaging interval was equal to or more than 4 days. In IVCM assessment, more investigation is needed to have a comprehensive understanding of the effect of the laser beam on the cornea.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.