Structural and Functional Progression in Open-Angle Glaucoma with Unilateral Peripapillary Intrachoroidal Cavitation

<b>Background/Objectives</b>: The aim of this study was to investigate the longitudinal visual field (VF) and circumpapillary retinal nerve fiber layer thickness (cpRNFLT) changes in open-angle glaucomatous (OAG) participants with unilateral peripapillary intrachoroidal cavitation (PICC) and to identify factors associated with VF progression. <b>Methods</b>: Sixty eyes of 30 OAG patients with unilateral PICC were included in this retrospective longitudinal observational study. Humphrey 24-2 VF testing and optical coherence tomography scanning were performed in all eyes over a period exceeding 5 years. VF progression was assessed using mean deviation (MD) and superior and inferior total deviation (TD) slopes. Structural progression was evaluated using global, superior, and inferior cpRNFLT thinning rates. Longitudinal changes were compared between PICC eyes and their contralateral non-PICC eyes. Factors associated with superior or inferior TD slopes were analyzed using linear mixed-effects models. The following variables were included as explanatory variables: age, sex, intraocular pressure, axial length, Bruch's membrane opening (BMO) and scleral flange opening (SFO) area, SFO/BMO offset magnitude, disk tilt, disk rotation, baseline superior or inferior TD, baseline corresponding cpRNFLT, and the presence of PICC. <b>Results</b>: MD slope was -0.24 ± 0.35 dB/year in PICC eyes and -0.35 ± 0.53 dB/year in contralateral eyes. There was no significant difference in MD slope, superior and inferior TD slope, or the rate of cpRNFLT thinning (all <i>p</i> > 0.05). In multivariable analysis, the presence of PICC was associated with slower progression in the corresponding superior VF (<i>p</i> = 0.037), whereas greater SFO/BMO offset magnitude was associated with faster progression (<i>p</i> = 0.047). <b>Conclusions</b>: OAG eyes with PICC exhibited modest functional and structural progression over 5 years, comparable to that of contralateral non-PICC eyes. The presence of PICC was associated with slower corresponding superior VF progression, whereas greater myopia-associated structural change was related to faster progression. Our findings characterize the clinical course of eyes with pronounced myopic ONH deformation, highlighting the importance of detailed ONH structural assessment in the management of myopic glaucoma.