Rates of Local Retinal Nerve Fiber Layer Thinning before and after Disc Hemorrhage in Glaucoma

Abstract

To investigate longitudinal temporal and spatial associations between disc hemorrhage (DH) and rates of local retinal nerve fiber layer (RNFL) thinning before and after DHs. Longitudinal, observational cohort study. Forty eyes of 37 participants (23 with glaucoma and 17 with suspect glaucoma at baseline) with DH episodes during follow-up from the Diagnostic Innovations in Glaucoma Study and the African Descent and Glaucoma Evaluation Study. All subjects underwent optic disc photography annually and spectral-domain optical coherence tomography (OCT) RNFL thickness measurements every 6 months. The rates of RNFL thinning were calculated using multivariate linear mixed-effects models before and after DH. Rates of global and local RNFL thinning. Thirty-six eyes of 33 participants with inferior or superior DHs were analyzed. The rates of RNFL thinning were significantly faster in DH quadrants than in non-DH quadrants after DH (-2.25 and-0.69 μm/year; P < 0.001). In the 18 eyes with intensified treatment after DH, the mean rate of RNFL thinning significantly slowed after treatment compared with before treatment in the non-DH quadrants (-2.89 and-0.31 μm/year; P < 0.001), but not in the DH quadrants (-2.64 and-2.12 μm/year; P= 0.19). In 18 eyes with unchanged treatment, the rate of RNFL thinning in the DH quadrant was faster after DH than before DH (P= 0.008). Moreover, compared with eyes without a treatment change, intensification of glaucoma treatment after DH significantly reduced the global, non-DH quadrants, and DH quadrant rates of RNFL thinning after DH compared with before DH (global, P= 0.004; non-DH quadrant, P < 0.001; DH quadrant, P= 0.005). In the multiple linear regression analysis, treatment intensification (β, 1.007; P= 0.005), visual field mean deviation (β, 0.066; P= 0.049), and difference in intraocular pressure before and after DH (β,-0.176; P= 0.034) were associated significantly with the difference of global RNFL slope values before and after DH. Although the rate of RNFL thinning worsened in a DH quadrant after DH, glaucoma treatment intensification may have a beneficial effect in reducing this rate of thinning.