Abstract
Purpose :
Glaucoma is a multifactorial disease comprised of intraocular pressure (IOP) and ocular hemodynamics. Today, the ocular retinal blood flow can be evaluated easily and noninvasively by use of optic coherence tomography angiography (OCTA). The purpose of this present study was to examine via longitudinal OCTA the structure and function at the macular region in regard to retinal blood flow.
Methods :
This retrospective observational study involved 14 eyes of 9 primary open-angle glaucoma (POAG) patients (5 males and 4 females; mean age: 52.7±10.7 years). Inclusion criteria were patients who 1) were examined twice via standard ophthalmic testing including OCT at the macula region and static perimetry at the Oike-Ikeda Eye Clinic, Kyoto, Japan, and in whom 2) clear images could be obtained twice via OCTA (RS-3000 Advance; Nidek), and whose 3) second examinations (exams) were obtained 2 to 3 years after the first exams. The images of the OCTA macula map at the surface layer of the retina were used. We calculated the macular vessel density divided into four areas by means of the image of the 8-bit value and binarization using Image J software. Each quartered macular region was categorized into three groups [i.e., normal structure (condition A)(conA), worsened structural anomaly (conB), and others] according to the GC chart of macula OCT and also categorized into another three groups [i.e., normal function (conC), worsened functional aberration (conD), and others] according to the four center points of 30-2 static perimetry. The vessel densities of conA or C were compared between first and second exam using paired t test. The vessel density ratios (second/first exam) were then compared between conA and B or between conC and D using non-paired t test.
Results :
The number of conA, B, C, and D were 19, 7, 43 and 6, respectively. The first or second exam of mean vessel density of conA was 0.67 and 0.63, of conC was 0.67 and 0.59, respectively (p>0.05, p<0.01). The vessel density ratios of conA and B were 0.96, and 0.83 (p<0.05), and that of conC and D were 0.89 and 0.84 (p>0.05).
Conclusions :
The findings of this study revealed that the retinal vessel densities at the surface layer in normal structure macular region show no decrease, whereas those in the worsened structural anomaly macular region are possibly decreased at 2 to 3 years observation period in POAG patients.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.