Peripapillary capillary vessel density progression in advanced glaucoma: a case report

BACKGROUND: We report a case of advanced juvenile open-angle glaucoma (JOAG) in which peripapillary capillary vessel density (PcVD) in the inferior retina showed significant progression while the spatially corresponding retinal nerve fiber layer thickness (RNFLT) and visual field cluster defect values had reached their minimal detectable values, and showed no change during the follow-up (floor effect). CASE PRESENTATION: A 45-year old white female patient with very advanced under treatment JOAG in the left eye was prospectively investigated with the AngioVue OCT (Optovue Inc., Fremont, USA) for RNFLT and PcVD, and Octopus Normal G2 visual field testing, at 6-month intervals for 2.5 years (6 visits). Images quality was high (8/10 in 5 visits and 7/10 in one visit), and the optical media were clear. For the superior and inferior retina the baseline RNFLT and PcVD values were 48 and 43 μm, and 28.9 and 36.5%, respectively. Using the instrument’s linear regression analysis significant progression (P < 0.05) was seen only for the hemifield with greater baseline RNFLT (superior RNFLT: − 0.5 μm/year) and the hemifield with greater baseline PcVD (inferior PcVD: − 2.4%/year). All inferior visual field cluster defect values progressed significantly (2.0 to 5.1 dB/year) while in the superior clusters no progression was measurable due to software indicated floor effect. CONCLUSION: Our case shows that PcVD progression can be measured in advanced glaucoma, that PcVD can show floor effect, and that it may indicate glaucomatous progression when the spatially corresponding RNFLT and visual field cluster defect do not show progression due to floor effect.