Posters

Correlation between OCT-angiography and photopic negative response in patients with primary open angle glaucoma

Poster Details

First Author: M.Abdelshafy EGYPT

Co Author(s):                        

Abstract Details

Purpose:

To assess the correlation between vascular , structural and functional changes of the peripapillary retinal nerve fiber (RNFL) and ganglion cell complex (GCC) in patients with open angle glaucoma (OAG) using OCT-angiography (OCTA) and photopic negative response (PhNR)

Setting:

A prospective cross-sectional comparative study. A total of 152 eyes of 76 patients were included.72 eyes of 36 patients with OAG with a mean age of 40.2 ± 4.39 as (Glaucoma group) and 80 eyes of 40 healthy subjects with a mean age of 40.5 ± 4.02 as(control group).

Methods:

All participants underwent full ophthalmological examination, optical coherence tomography (OCT), OCTA “using RTVue XR OCT Avanti System AngioVue Version 201.2.0.93 (Optovue, Fremont, CA, USA) “and PhNR measurement “using RETI-port/scan 21(Roland Consult, Brandenburg, Germany) “.RNFL, GCC thicknesses, the amplitude and implicit time of PhNR were recorded. 6mm×6mm macula OCTA scans were used to measure the superficial capillary plexus vessel density (SCP-VD) and the deep capillary plexus vessel density (DCP-VD).4.5mm×4.5mm optic disc head OCTA scans were used to measure the peripapillary vessel density (RPC-VD). Statistical analysis was performed to compare GCC, RNFL thicknesses, OCTA and phNR values between groups.

Results:

GCC and RNFL (median IQR) thicknesses were reduced in OAG versus normal (81.5 µm vs 99 µm, P<0.001; 90 µm vs 108.5, P<0.001 respectively).In the glaucoma group the superior and inferior quadrants of RNFL were significantly thinner. There were significant differences of PhNR amplitude and latency between the two groups (p<0.001). SCP-VD, DCP-VD and RPC-VD were reduced in OAG versus normal (47.85 vs 54.8, P<0.001; 47.57 vs 57.25, P<0.001; 48.15 vs 59.8, P<0.001, respectively), with a trend of worsening with increased OAG severity.Reduced PhNR amplitude and prolonged latency were associated with reduced SCP-VD, DCP-VD and RPC-VD (P<0.001; R2= 0.725,0.904,0.875,-0.854,-0.874.-0.940 respectively)

Conclusions:

The glaucomatous eyes had significant reduction of the macular ganglion cell-inner plexiform layer (GCIPL) and peripapillary RNFL microcirculation.There was a significant association of the vessel parameters with functional and structural measurements. Regarding functional correlations of OCTA vascular parameters, the SCP-VD ,DCP-VD and RPC-VD had significant positive correlation with PhNR amplitude and significant negative correlation with PhNR latency. Vascular dysfunction plays a significant role in glaucoma pathogenesis. The vascular OCTA parameters and PhNR ,as an objective measures of ganglion cell function can supplement the structural OCT measurement if it has limited diagnostic value as in high myopia, for diagnosis and monitoring OAG.

Financial Disclosure:

None