Abstract
Purpose :
Reduction in perfusion of ONH and choroid may contribute to the development and progression of glaucoma. Thus, the relationship between the choroidal circulation or choroidal thickness (CT) and glaucomatous optic neuropathy is of great importance. In present study, we investigated longitudinal changes in CT, mean ocular perfusion pressure (MOPP), axial length (AL), and intraocular pressure (IOP) after glaucoma surgery and evaluate potential association these parameters.
Methods :
This prospective longitudinal study included 85 eyes of 68 patients who had glaucoma surgery. Subfoveal CT (SFCT) and peripapillary CT (PPCT) were measured by enhanced depth imaging-optical coherence tomography (EDI-OCT) at preoperatively, and 1 week, 2, 6, and 12 months postoperatively. PPCT were measured at nasal, temporal, superior and inferior 1500 µm apart from the optic disc center and then average value was calculated. The IOP, MOPP, AL were also analyzed as independent variables. Univariate and multivariate linear regression analysis were used to evaluate possible association between these parameters and changes of CT. For subgroup analysis, the patients were divided into group with IOP reduction less than or equal to 40% of the baseline IOP (A) and more than 40% (B).
Results :
The increase in SFCT and PPCT was observed at postoperative 1 year (P<0.001, P<0.001). MOPP and AL showed statistical significant increment (P<0.001, P=0.008). Pearson correlation analysis showed that SFCT and PPCT correlated with magnitude of IOP reduction (r=0.514, P<0.001, r=0.586, P<0.001), changes of MOPP (r=0.214, P=0.002, r=0.238 P=0.001) during at postoperative 1 year. Univariate analysis demonstrated that baseline IOP, IOP changes, baseline OPP and OPP changes had significant association with CT changes (At 1 year SFCT P<0.001, P<0.001, P<0.001, P=0.002, PPCT P<0.001, P<0.001, P<0.001, P=0.001, respectively). But, multivariate analysis showed only IOP changes had significant association with CT changes (At 1year SFCT P=0.007, PPCT P=0.001). Group B showed greater increment of SFCT and PPCT than group A.
Conclusions :
Changes in IOP, but not MOPP was the only factor to be associated with thickening of PPCT and SFCT. Our results suggest that IOP reduction following glaucoma surgery may cause the increase in SFCT and PPCT correlating with greater IOP reduction.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.