Abstract
Purpose::
Recently, we demonstrated the polymorphic structures composed of fibrillar materials beneath Bowman’s layer using cornea-specific in vivo laser confocal microscopy (Heidelberg Retina Tomograph 2 Rostock Cornea Module (HRT2-RCM), Heidelberg Engineering GmbH, Heidelberg, Germany), and designated them as "K-structures" (Kobayashi et al. Ophthalmology 2006). We concluded that these structures may correspond to the anterior collagen fiber bundles (ACFBs) running at the posterior surface of Bowman’s layer. The purpose of the current study is to produce a two-dimentional reconstruction map of K-structures /ACFBs using a HRT2-RCM, and to demonstrate their association with the anterior corneal mosaic.
Methods::
HRT2-RCM was performed on three normal eyes of three healthy human subjects. Using the section mode, a mean of 677±211 images of the ACFBs were obtained for each subject. The data were arranged and images were mapped for each subject into sub-confluent montages. In each subject, electric tracing of ACFBs were superimposed with slit-lamp photo presenting anterior corneal mosaic produced by rubbing the eyelid.
Results::
Mean dimensions of the corneal areas mapped were 5.88±0.50 mm horizontally and 3.51±1.37 mm vertically. In all subjects, the ACFBs form a net-like/reticular pattern with a mean area of 0.082±0.051 mm2. In all subjects, the electric tracing of the ACFBs well accorded with the anterior corneal mosaic.
Conclusions::
This is the first study to elucidate the overall distribution of the ACFBs in the healthy, live central to mid-peripheral human cornea by laser scanning in vivo confocal microscopy. The net-like/reticular pattern of the ACFBs corresponded well to the anterior corneal mosaic pattern, indication a strong link between ACFBs and anterior corneal mosaic. These results may lend support the theory that ACFBs are the structural basis of the anterior corneal mosaic formation.
Keywords: cornea: clinical science • microscopy: confocal/tunneling