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, P= 0.080) before follow-up, and more medications (1.8 vs. 1.4, P= 0.052) and lower mean IOP (12.69 mmHg vs. 14.41 mmHg, P= 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, P= 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.