Birefringence imaging of posterior pathologies by Jones matrix optical coherence tomography for posterior eye

Abstract

 

Purpose

 

Various case series of posterior diseases examined by a new type of polarization sensitive optical coherence tomography (PS-OCT), so called Jones matrix (JM-) OCT, is reported. JM-OCT provides standard OCT, polarization sensitive OCT, and OCT angiography by a single scan. The clinical utility of this new system is discussed by showing several cases including exudative macular diseases, pathologic myopia and glaucoma.

 

Methods

 

42 eyes of 27 subjects were enrolled, which include pathologic myopia (17 cases), choroidal neovascularization (CNV, 21 cases) and glaucoma (4 cases). The eyes were scanned by a custom-built clinical prototype of posterior JM-OCT with a probe wavelength of 1060 nm and a probe power of 1.3 mW. The measurement was performed with 512 A-scan x 256 B-scans x 4 frames covering a 6 mm x 6mm with 100,000 A-scan rate in 6.6 second. Scattering OCT and birefringence images obtained by JM-OCT were compared with standard imaging modality.

 

Results

 

Figure. 1 is the example of myopic CNV. The hyperscattering is consistently appeared both in the color fundus (a) and the en-face OCT (b). In the right side of B-scan image of scattering OCT (c), a hyper-scattering mass is observed (white arrow) which indicates fibrosis. Birefringence imaging (d) visualized the complex regional difference in the fibrosis (dark blue to green). Similar result was observed in 10 eyes. In the left side of tomographies (yellow arrow), sclera with uniform hyper-scattering in (c) is clearly visualized with layered structure which has different birefringence among layers in (d). It was found in 20 eyes.<br /> Figure 2 shows an optic nerve head (ONH) of a glaucomatous eye. En-face OCT (b) visualized peripapillary atorophy (PPA) which shows hyperscattering. This is consistent with color fundus (a) as indicated by yellow line. In C-scan slices of birefringence tomography at two different depths [(c) and (d)], sclera in PPA and around ONH showed high birefringence (white arrow). It would be an indicator of high density concentration of collagen. Similar result was found in 11 eyes.

 

Conclusions

 

Pathologic characteristics of macular disease and sclera were visualized by JM-OCT.