Change of Retinal Vessel Density After Lowering Intraocular Pressure in Ocular Hypertension

Abstract

Purpose: To investigate the relationship between retinal microvasculature changes and intraocular pressure (IOP) for ocular hypertension (OHT) patients and further assess the factors associated with retinal microcirculation changes.Methods: This was a single-center prospective study designed for OHT patients, which consisted of two visits. After collecting baseline data of those who met the eligibility criteria, these patients were treated with latanoprost 0.005% ophthalmic solution for 4 weeks. Peripapillary vessel density (VD) of radial peripapillary capillaries (RPC) layer, macular VD in both superficial and deep layers, and foveal avascular zone (FAZ) area were measured by optical coherence tomography angiography (OCTA) before and after the treatment. We compared the changes in IOP and VD among the two visits by paired-sample t-test. Bonferroni correction was applied. Factors associated with VD changes were analyzed by linear regression analysis.Results: Thirty-four eyes of thirty-four patients were included. The mean IOP decreased by 6.5 ± 2.2 mmHg (p < 0.001). The peripapillary RPC VD increased significantly from 51.8 ± 2.5 to 53.0 ± 3.1% (Adjusted-p = 0.012). We found no significant difference in detailed sectors of the peripapillary region after correction. In the macular area, both the superficial and deep layers in foveal (superficial: 0.2 ± 1.9%, p = 0.523; deep: 0.0 ± 2.3%, p = 0.969) and parafoveal (superficial: 0.3 ± 3.0%, p = 0.565; deep: 0.5 ± 3.1%, p = 0.423) VD remained unchanged. The decrease of the mean FAZ area was insignificant (p = 0.295). The percentage of IOP reduction (β = 0.330, p = 0.031) and the baseline RNFL thickness (β = 0.450, p = 0.004) significantly correlated with the percentage of peripapillary RPC VD improvement in the multivariate linear regression analysis.Conclusion: The peripapillary VD in OHT patients increased after the reduction of IOP. The mild change of IOP did not alter the microcirculation in the macula. In addition, the percentage of IOP change and the baseline RNFL thickness were independent factors for the peripapillary RPC VD improvement.

Peripapillary Vascular Density in Compressive Optic Neuropathy and Normal-Tension Glaucoma: A Severity-Controlled Comparison

“…However, the effect of the IOP on VD outcomes is unclear. Although Chen et al 37 reported that, in patients with ocular hypertension, a reduction in IOP by 6.5 mmHg could led to an 1.2% increase in peripapillary VD, the IOP difference was smaller (2.0 mmHg) in our study and the VD difference was larger (3.5%). The multivariate analysis also did not reveal a significant effect of IOP.…”

Axons of retinal ganglion cells on the optic nerve disc following vessel density correction at different IOP values

“…IOP is a major risk factor for the development of glaucoma and its progression (9,10). After an increase in IOP, the ganglion cells of the retina are altered, which is demonstrated by studies of different animal models of glaucoma revealing a higher sensitivity (compared with other parvocellular ganglion cells) to IOP in magnocellular ganglion cells (19)(20)(21).…”

“…Chen et al ( 9 ) previously investigated the effect of latanoprost (a drug that lowers IOP) on VD. This study found statistically significant increases of VD in the IT, TS, ST, SN, NI and IN segments.…”

A comparison of peripapillary vessel density between subjects with normal-tension glaucoma and primary open-angle glaucoma with similar extents of glaucomatous damage

“…This result could be partially explained by the IOP-induced deterioration of blood flow autoregulation. Chen et al 23 reported that the peripapillary VD of ocular hypertension patients increased after IOP reduction. Choi et al 24 found a decrease in VD around the optic nerve head in the vitrectomized eyes of pigs with high IOP.…”