Abstract
Purpose :
ODD can cause retinal nerve fiber defects with progressive visual field (VF) loss. The aim of our study was to measure the vessel density (VD) in ODD with OCT-A and to compare them with a normal population. Another intent was to determine the sensitivity and correlation of this new promising imaging tool in comparison with functional (VF) and structural parameters, such as retinal nerve fiber layer (RNFL), Bruch`s membrane opening minimum rim width (BMO-MRW) and ganglion cell complex (GCC).
Methods :
In this retrospective, single-center, case-control study we analyzed the VD of ODD (n=50 eyes) and an age-matched control population (n=50 eyes) using AngioVue (Optovue, Fremont, CA, USA). We obtained data about RNFL, GCC, BMO-MRW and VF using standard automated perimetry (SAP, SITA 24-2). Low image quality, any systemic and ocular pathologies interfering with the diagnostics were excluded. Parametric data was analyzed using the t-test and nonparametric values using Mann-Whitney test. Linear regression analysis was used to determine correlations using the Pearson-test. Statistical significance was assumed for p values < 0.05. The study was approved by the institutional review board at the department of ophthalmology, university hospital, LMU Munich, Germany.
Results :
VD was highly significant reduced in the ODD in all sectors, with the highest difference between the ODD and control in the peripapillary capillary VD (mean 43,15%, 51,70%). Peripapillary RNFL thickness at circle 3.5mm, 4.1mm and 4.7mm correlated with the peripapillary capillary VD significantly (Pearson r = 0.902, 0.901, 0.866).The superior RNFL hemisphere showed significant reduction in ODD (mean 107µm, 129µm). The GCC was significantly lower in the ODD group (mean 87µm, 98µm). Positive correlation between the VD and the GCC was significant (r = 0.532). A subgroup analysis (n=19) showed a significant negative correlation (r= -0.726) between the VD and the pattern standard deviation (PSD) in the VF.
Conclusions :
This study reveals significant peripapillary microvascular changes in ODD patients, especially in the peripapillary capillary area. Furthermore, the vessel density showed high correlations with the RNFL and GCC.
The correlation of OCT-A in ODD was significantly higher than other structural parameters such as RNFL or GCC. There is a negative correlation between the PSD and the VD.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.