Lamina cribrosa morphology, peripapillary vessel density and peripapillary choroidal thickness in primary open angle glaucoma patients and healthy controls.

Abstract

Purpose : Primary open-angle glaucoma (POAG) is one of the leading causes of blindness worldwide. In order to assess the microvasculature and lamina cribrosa morphology changes in glaucoma, we measured the lamina cribrosa thickness (LCT), lamina cribrosa depth (LCD), peripapillary vessel density (pVD) and peripapillary choroidal thickness (pCT) in POAG and healthy individuals.

Methods : All participants underwent a thorough ophthalmological examination. Optical coherence tomography (OCT) measurements were made using enhanced depth imaging (OCT-EDI), followed by OCT-angiography (OCT-A). The parameters assessed were pVD, pCT from a total of 6 regions (3 nasally and 3 temporally), LCT and LCD.

Results : We enrolled 22 patients, 11 POAG patients and 11 controls, testing only one eye of each participant. The mean age was similar between the 2 groups (71.2 ± 7.8 in the POAG group and 65.8 ± 6.1 in the control group; p=0.089). RNFL, and pVD were higher in the control group (p values <0.001, and 0.049, respectively). POAG patients presented with lower LCT (155.7μm ± 19.2 vs 234.9μm ± 14.3; p <0.001), and higher LCD measurements (570.2μm ± 120.1 vs 371.1μm ± 109.9; p<0.001). No difference in pCT was detected between the two groups. A positive correlation trend between LCT and pVD was observed among all patients (r= 0.399; p=0.065).

Conclusions : Our study shows that glaucoma patients present thinning along with deeper anatomical location of the LC, and reduction of the peripapillary vessel density. A prospective study of these parameters in a larger cohort may further enhance our understanding of POAG mechanisms.

This abstract was presented at the 2024 ARVO Imaging in the Eye Conference, held in Seattle, WA, May 4, 2024.

 

Figure: Lamina cribrosa measurements on OCT scan, OCT-EDI, Heidelberg Spectralis.
(a) A 10 × 25-degree rectangle was centered on the optic disc with horizontal B-scan images, using EDI mode.
(b) BMO (Bruch’s membrane opening): distance between the two end points of Bruch’s membrane. LCD: the distance between the BMO and the anterior edge of lamina cribrosa. LCT: the area of high reflectivity, from the anterior to the posterior surface of the ONH.
(c) Peripapillary choroidal thickness measurements on horizontal OCT scan at 500 μm, 1000 μm, and 1500 μm distance from the boundary of optic nerve head in temporal and nasal regions.