Binarization of enhanced depth imaging optical coherence tomographic images of an eye with Wyburn-Mason syndrome: a case report

Abstract

BackgroundTo report a thicker choroid and larger choroidal luminal area in an eye with Wyburn-Mason syndrome. To the best of our knowledge, this is the first report demonstrating an increase in the choroidal thickness and the luminal area in a case of Wyburn-Mason syndrome. In addition, we report the changing appearance of retinal arteriovenous malformations over a 16-year period.Case presentationA 27-year-old woman, who was diagnosed with Wyburn-Mason syndrome at age 11 years, visited our clinic. Her best-corrected visual acuity was 20/12.5 in the right eye and light perception in the left eye. Severely dilated, tortuous vascular loops were distributed from the optic disc over all four quadrants of the left fundus. The vascular loops in some areas were more dilated and tortuous than 16 years earlier. Optical coherence tomography (OCT) showed retinal edema with cystic changes and enlarged choroidal vessel lumens in the left eye. The subfoveal choroidal thickness was manually measured by the caliper function in the enhanced depth imaging OCT (EDI-OCT) images. Binarization of the EDI-OCT images was performed with publicly accessible ImageJ software. The examined area of the subfoveal choroid was 1,500 μm wide, and the dark areas representing the luminal areas were traced by the Niblack method. After determining the distance of each pixel, the luminal area was automatically calculated. The subfoveal choroidal thickness was 250 μm in the right eye and 462 μm in the left eye. The luminal area of the 1,500-μm-wide subfoveal choroid was computed to be 307,165.6 μm2 in the right eye and 545,780.7 μm2 in the left eye.ConclusionsThe EDI-OCT images showed a thicker choroid, and binarization of the EDI-OCT images showed that the luminal areas were significantly larger in the affected eye, suggesting a dilatation of the choroidal vessels. The results demonstrated that conversion of EDI-OCT images to binary images was a useful method to quantify the choroidal structure.

Regional Differences of Choroidal Structure Determined by Wide-Field Optical Coherence Tomography

“…We have analyzed the structure of the choroid in the macular zone and the perimacular zone using the binarized image processing technique on high-penetration OCT images. 10,11,[21][22][23][24][25][26][27][28][29]31 The results showed that the total choroidal area and the luminal ratios were significantly larger in the macular zone than in the perimacular zone. This confirms the results of an earlier study that reported that the macular choroid was thicker than the peripheral choroid.…”

“…10,11 Subsequently, many researchers have used this technique and have reported that specific structural changes can be associated with the progression of various ocular diseases. [10][11][12][21][22][23][24][25][26][27][28][29][30][31] Recently, there have been several reports on the choroidal structure in OCT images. Branchini et al 32 reported that the choroidal luminal area was larger than the stromal area.…”

Choroidal vascularity index as a measure of vascular status of the choroid: Measurements in healthy eyes from a population-based study

“…The advent of enhanced depth imaging (EDI) optical coherence tomography (OCT) has allowed more precise non-invasive quantitative assessment of the choroid 28 . Using EDI OCT, there have been attempts to assess the choroidal stromal and vascular structures 13 29 30 31 32 . Recently Sonoda et al described a method for computing luminal and interstitial areas in the choroid as a means to quantify vascular status of the choroid 30 31 .…”

A clinically oriented computer model for radiofrequency ablation of hepatic tissue with internally cooled wet electrode

“…As the images from the first and second infusion of the same set were seen to have an almost identically shaped and sized distribution (see Results section for further details), they were overlapped to create a "generic distribution" for each set. The margins of the infused areas were then segmented by thresholding each 8-bit greyscale image [21], preceded by the background subtraction operation for increased effectiveness. The segmented margins were then merged with the original images, converted into binary format and mounted together to create one greyscale image in which each image made up 16.6% of the total greyscale intensity, so that 67% greyscale was considered as the "generic pattern" of saline infusion and hence was used to build the computer model.…”