Association between Rates of Retinal Nerve Fiber Layer Thinning after Intraocular Pressure-Lowering Procedures and Disc Hemorrhage.

PURPOSE

To compare the rates of retinal nerve fiber layer (RNFL) thinning after intraocular pressure (IOP) lowering procedures in eyes with or without disc hemorrhage (DH) history.

DESIGN

Observational cohort study.

METHODS

A total of 166 primary open angle glaucoma (POAG) eyes and glaucoma suspect eyes (37 eyes with DH history (DH group) and 129 eyes without DH (non-DH group)) were included from the African Decent and Glaucoma Evaluation Study (ADAGES) and the Diagnostic Innovations in Glaucoma Study (DIGS). Subjects underwent stereoscopic optic disc photography annually and spectral-domain optical coherence tomography (OCT) RNFL thickness measurements every 6 months. The rates of RNFL thinning were compared in eyes with and without DH using univariate and multivariable linear mixed effects models.

MAIN OUTCOME MEASURES

The rates of RNFL thinning.

RESULTS

The mean follow-up of DH group and non-DH group was 4.6 years and 4.2 years, respectively. DH group had more procedures (2.4 vs. 1.9, = 0.080) before follow-up, and more medications (1.8 vs. 1.4, = 0.052) and lower mean IOP (12.69 mmHg vs. 14.41 mmHg, = 0.012) during follow-up compared to non-DH group. When mean IOP was adjusted as a covariate in the model, the RNFL thinning rate in the DH group was 2-fold faster than in the non-DH group (-0.61 μm /year vs. -0.33 μm /year, = 0.025). Higher mean IOP during follow-up was associated with a faster rate of RNFL thinning after procedures.

CONCLUSIONS

POAG or glaucoma suspect eyes with a history of DH should be carefully followed after IOP-lowering procedures. Additional IOP-lowering may be needed to slow structural progression of the DH eyes to the same rate as the non-DH eyes.