Systemic Oxidative Stress Level as a Pathological and Prognostic Factor in Myopic Choroidal Neovascularization

Abstract

Purpose: To investigate the association of systemic oxidative stress level with myopic choroidal neovascularization (mCNV) and its clinical outcomes.

Design: Retrospective case-control study.

Participants: This retrospective study included 52 eyes of 52 healthy participants (mean age: 62.5 years), 30 eyes of 30 patients (mean age: 59.6 years) with high myopia (HM) but without mCNV, and 23 eyes of 23 patients (mean age: 61.8 years) with HM and mCNV who received intravitreal anti-VEGF antibody injections (IVIs) using a pro re nata regimen during the 6-month follow-up after the first IVI.

Methods: Clinical findings, including oxidative stress parameters, such as diacron reactive oxygen metabolites (dROMs), biological antioxidant potential (BAP), and the BAP/dROM ratio (B/d ratio), were analyzed.

Main outcome measures: Clinical features and oxidative stress parameters.

Results: Both BAP and the B/d ratio were significantly lower in the HM/mCNV group than in the HM/no mCNV group (P = 0.002 and P = 0.012, respectively) and than in the control group (P = 0.001 and P = 0.026, respectively). In a multiple logistic regression analysis, axial length (odds ratio 1.878, P = 0.042) and the B/d ratio (odds ratio 0.470, P = 0.026) were significantly associated with mCNV. Dividing the patients into high and low B/d ratio groups (with a cutoff of 5.2) showed that subfoveal choroidal thickness (SFCT) was lower (P = 0.002) and the number of IVI treatments was higher (P = 0.029) in the low B/d ratio group than in the high B/d ratio group. In multiple regression analyses, only the B/d ratio was significantly associated with SFCT (β = 0.684, P = 0.006).

Conclusions: The oxidative stress level in eyes with HM differed according to mCNV, SFCT, and the number of IVI treatments. Measuring oxidative stress parameters might be useful in eyes with HM both for assessing the risk of developing mCNV and determining disease activity.

Financial disclosures: Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Keywords: High myopia; Intravitreal anti-VEGF antibody injection; Myopic choroidal neovascularization; Subfoveal choroidal thickness; Systemic oxidative stress.

Figure 1

Typical cases of HM with mCNV that have different B/d ratios. The characteristics of each case are indicated in the table (upper center). Case A (A1, 2, 3): an 82-year-old woman with a B/d ratio of 5.1. Her left eye had mCNV, as demonstrated in a color fundus photograph (A1) and an OCT image (A2) at the initial visit. Three IVI treatments were required for the stabilization of the mCNV during the 6MFU. There were no exudative changes, only a small pigment epithelial detachment, as demonstrated in an OCT image after the 6MFU (A3). Case B (B1, 2, 3): a 78-year-old man with a B/d ratio of 5.8. His right eye had mCNV, as demonstrated in a color fundus photograph (B1) and an OCT image (B2) at the initial visit. The mCNV completely regressed after only 1 IVI treatment during the 6MFU. There were no exudative changes or any recurrence, as demonstrated in an OCT image after the 6MFU (B3). 6MFU = 6-month follow-up; BCVA = best-corrected visual acuity; B/d ratio = biological antioxidant potential/diacron reactive oxygen metabolite ratio; CRT = central retinal thickness; HM = high myopia; IVI = intravitreal anti-VEGF antibody injection; logMAR = logarithm of minimum angle of resolution; mCNV = myopic choroidal neovascularization; SFCT = subfoveal choroidal thickness.