Retinal perfusion 6 months after trabeculectomy as measured by optical coherence tomography angiography

To investigate potential changes of vessel density (VD) at the optic nerve head (ONH) and the macula 6 months after trabeculectomy (TE).

In a prospective monocentric study, 19 eyes with open-angle glaucoma were treated with TE + MMC (mitomycin C). At four different time points multiple morphological papillary parameters were measured by OCT, and the ONH VD in the radial peripapillary capillary layer and the superficial and deep plexuses of the macula was determined by OCTA (optical coherence tomography angiography, RTVue-XR, Optovue). The mean defect was determined by visual field examination (mode 30-2, Humphrey Field Analyzer). The duration of follow-up was 6 months.

Nineteen eyes, one each from 19 patients (11 females; 8 males) with a mean age of 66.0 (58.07, 70.94) years and a mean intraocular pressure (IOP) of 21.0 mmHg (17.07, 23.87), were included in the study. All showed a significant reduction in IOP at each follow-up after TE (p < 0.0001). There was no significant change in the peripapillary retinal nerve fiber layer thickness (p = 0.88), the ganglion cell complex (p = 0.97), the cup-disk ratio (p = 0.63), the rim area (p = 0.78), or the mean visual field defect (p = 0.82). With regard to VD, no significant difference could be determined in either the ONH or the macular area.

After significant surgical reduction of IOP by TE, there are no significant detectable morphological changes in the ONH or the ganglion cell complex as measured by OCT, nor does the papillary or macular OCTA-determined VD change significantly. Trial registration 2016-409-f-S Avanti-OCT-A. Registered December 1, 2016.