Multifunctional OCT imaging of macular degeneration for vasculature, RPE and choroid investigation

Abstract

 

Purpose

 

In order to investigate eyes of age-related macular degeneration (AMD) comprehensively, 1-μm Jones-matrix multifunctional optical coherence tomography (JM-OCT) imaging was performed. This study aims at evaluating clinical utility of JM-OCT imaging, based on a descriptive case series of AMD.

 

Methods

 

Eight eyes of 4 AMD cases, including 4 end stage AMD, 1 early stage AMD, 1 drusen, and 2 drusenoid pigment epithelial detachment were imaged with JM-OCT.6 mm × 6 mm areas around the diseased region were scanned with 512 × 1024 A-lines in 6.6 seconds. Intensity OCT, complex decorrelation OCT, birefringence tomography, and degree-of-polarization-uniformity (DOPU) tomography were calculated from a single scan and each tomography represents the structure, vasculature, sub-resolution microstructural property of the tissue, and melanin pigmentation. DOPU and complex decorrelation signals were combined to provide comprehensive angiography.

 

Results

 

Anormality of retinal pigment epithelium (RPE) was imaged with high DOPU (less pigment) in 4 of 4 end stage AMD cases, and it was corresponding to the hypo-fluorescence of short-wavelength autofluorescence (SW-AF) image. In another 4 eyes, SW-AF did not show hypo-fluorescence and their RPE showed low DOPU (pigmented). High birefringence band structure was observed in sclera with less pigment (high DOPU signal) in 3 eyes of end stage AMD.<br /> Figure 1 shows a representative case of AMD. High contrast choroidal vasculature and hypo-fluorescence were observed in the abnormal RPE region from near infrared (NIR) AF (a) and SW-AF (b) images, respectively. And the en face projection (c) of complex decorrelation (g) showed similar appearance with NIR-AF, in addition DOPU B-scan (h) showed depth resolved melanin pigment distribution (arrowheads indicate abnormal RPE). In this region, intensity OCT B-scan (d) showed higher penetration into sclera. Birefringence B-scan (f) showed layered structure in the sclera (dashed circle) as high birefringence at anterior sclera (green) and low birefringence (blue) at posterior. The sclera was appeared with high DOPU (less pigment). DOPU encoded complex decorrelation angiography (d) showed distinguished choroidal vasculature at the region of abnormal RPE and less pigmented choroid.

 

Conclusions

 

The multifunctional imaging with JM-OCT gives comprehensive information about the vasculature, RPE, and choroid with depth resolved imaging.