Abstract
Purpose :
To analyze and report the 3-dimensional (3-D) structure, qualitative and quantitative parameters in Haller’s layer of the choroid in diseased eyes and compare with age-matched healthy eyes.
Methods :
This was a retrospective study and included 3 groups (healthy, age-related macular degeneration (AMD), and central serous chorioretinopathy (CSCR) eyes). Previously validated end-to-end algorithm based on ResUnet, 3D tensor voting and geometrical modeling was used to segment, reconstruct and quantify Haller’s sublayer vasculature in 3D. A heat map showing the relative radius of the blood vessel, vascularity showing the blood flow in the vascular lumen was generated. A histogram showing the distribution pattern of the thickness of Haller's vessel was prepared. Qualitative parameters including symmetricity, arrangement, and branching pattern of vessels, rarefaction of vessel density, hot areas, and focal constriction were analyzed.
Results :
A total of 34 eyes (14 healthy, 9 AMD, 11 CSCR eyes) were analyzed. The mean (±SD) Haller vessel radius in healthy, AMD and CSCR eyes was 86.4 ± 4.4 µm (range, 14.96 to 174.1 µm), 88.8 ± 6.4 µm (range, 14.7 to 179.2 µm) and CSCR: 88.3 ± 6.6 µm (range, 14.6 to 171.5 µm) respectively (Figure 1). However, the percentage of eyes with radius > 100 µm was more in AMD (17.7%) and CSCR eyes (16.8%) compared to healthy eyes (14.2%). Two eyes in CSCR and 3 eyes in the AMD group had an asymmetrical pattern of vessel arrangement whereas all the healthy eyes had a symmetrical pattern. Severe vessel rarefaction was seen in 1 healthy eye compared to 3 and 4 in AMD, and CSCR eyes respectively. Either focal or diffuse hot areas i.e., sites of vascular dilatation were seen in all 3 groups (healthy, focal: 8; diffuse: 2; AMD, focal: 6, diffuse: 2; CSCR, focal: 5, diffuse: 3). Focal constriction in Haller's vessels was seen in 2/14 eyes in healthy subjects compared to 7/9 eyes in AMD and 3/11 eyes in the CSCR group.
Conclusions :
The diameter of Haller's vessels shows a wide range of variation in healthy as well as diseased (AMD, CSCR) eyes. However, both AMD and CSCR eyes showed a higher percentage of vessels with a radius > 100 microns compared to healthy eyes. Moreover, the qualitative analysis showed a higher percentage with symmetrical distribution, relatively fewer eyes with severe vessel rarefaction, and/ or focal constriction in healthy subjects compared to diseased eyes.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.