Contrast-to-noise ratio is a useful predictor of early displacement of large submacular hemorrhage by intravitreal SF₆ gas injection

Abstract

[Purpose:] To investigate predictors of early displacement of submacular hemorrhage (SMH) by simple intravitreal SF₆ gas injection. [Methods:] This retrospective study included 16 eyes of 16 consecutive patients (age: 74.5 ± 7.7 years; 15 men) with large SMH treated with simple intravitreal SF₆ gas before inception of subretinal tissue plasminogen activator (tPA) injection at our institution. We graded SMH displacement at 1-week posttreatment as 0, 1, or 2. Central retinal thickness, central choroidal thickness, SMH height, SMH area, disease duration, use of anticoagulant or antiplatelet drugs, and contrast-to-noise ratio (CNR) of SMH on optical coherence tomography (OCT) images were recorded. Correlations between displacement grading and baseline parameter were analyzed. [Results:] Univariable correlation analysis revealed association of the 1-week displacement grading with the CNR (P = 0.004, r = −0.68) and SMH height (P = 0.03, r = −0.55). The CNR was most strongly associated with 1-week displacement on multivariable correlation analysis (P = 0.01, β = −0.60). [Conclusions:] Our findings showed that the CNR of SMH was a useful predictor of early displacement of large SMH after simple intravitreal SF₆ gas injection. When vitrectomy with subretinal injection of tPA is difficult in patients with large SMH, with low CNR on OCT, simple intravitreal SF₆ gas injection may be a treatment option.