Research Article: Choroidal vascular index in patients with open angle glaucoma and preperimetric glaucoma

Date Published: March 20, 2019

Publisher: Public Library of Science

Author(s): Yuli Park, Kyong Jin Cho, Akram Belghith.

http://doi.org/10.1371/journal.pone.0213336

Abstract

To evaluate choroidal structural changes in glaucoma using choroidal vascularity index (CVI) compared to healthy subjects.

This retrospective study included 56 patients with open angle glaucoma (OAG), 50 patients with preperimetric glaucoma (PPG) and 50 age-matched healthy eyes. Choroidal images were binarized into luminal area (LA) and stromal area. CVI was defined as the ratio of LA to total circumscribed choroid area (TCA). Mean choroidal thickness (CT) and mean CVI between glaucoma patients and healthy subjects were compared.

OAG and PPG eyes showed smaller LA (0.45 ± 0.13 ㎟ vs. 0.47 ± 0.11 ㎟, p = 0.04). In multivariate regression analysis, CVI of both OAG (64.34±0.19%, p = 0.001) and PPG (65.37±0.15%, p = 0.001) were significantly lower than healthy eyes (68.81±0.14%).

Eyes with glaucoma demonstrated reduced CVI compared with healthy eyes. CVI may be a potential noninvasive tool for studying vascular dysfunction in glaucoma.

Partial Text

Glaucoma is a progressive optic neuropathy that can cause irreversible blindness [1]. Early diagnosis aims to slow disease progression to prevent functional vision loss. Although the exact mechanism of glaucoma is unknown, increased intraocular pressure (IOP) is the main risk factor for glaucoma [2]. Considering that glaucomatous optic neuropathy can develop and progress in untreated eyes with statistically normal IOP, or in eyes with an IOP lowered by medical or surgical treatment, the pathogenesis of glaucoma progression is not solely dependent on IOP.

This retrospective, comparative study evaluated patients with OAG, PPG, and normal eyes from October 2015 to September 2018. Our study adhered to the tenets of the Declaration of Helsinki for research involving human subjects and followed all guidelines for investigation in human subjects required and approved by the Institutional Review Board of Yeouido St. Mary’s Hospital (IRB#SC12RISI0037). Written Consent was not obtained since this is retrospective study. Participating in the study were 56 eyes affected by OAG, 50 eyes of PPG, and 50 eyes of age-matched normal eyes.

Our study evaluated 56 eyes affected by OAG, 50 eyes of PPG, and 50 eyes of age-matched normal eyes. The mean age of the OAG, PPG, and healthy subjects were 69.4 ± 9.3, 64.9 ± 8.7, 67.3 ± 9.1 years respectively. There was not a statistically significant difference between groups in age, gender, BCVA, IOP, and CCT (p > 0.05). The mean number of glaucoma medications used during the study was 2 eye drops in OAG group and none used in PPG and healthy eyes. The demographic and clinical characteristics of subjects, stratified by diagnostic category, are summarized in Table 1.

In the very early stages of glaucoma, the diagnosis is difficult because structural damage and functional losses may not be apparent. Since RGCs are concentrated at the macula [12], macular thickness or subfoveal choroidal vascularity can be valuable parameters for the detection of glaucoma. Therefore, we evaluated choroidal vascularity in the eyes of patients with OAG, PPG, and compared with healthy eyes.

 

Source:

http://doi.org/10.1371/journal.pone.0213336

 

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