Association between Intraocular Pressure and Rates of Retinal Nerve Fiber Layer Loss Measured by Optical Coherence Tomography

Abstract

Purpose To evaluate the relationship between intraocular pressure (IOP) and rates of retinal nerve fiber layer (RNFL) thickness change over time measured by spectral-domain (SD) optical coherence tomography (OCT). Design Observational cohort study. Participants The study involved 547 eyes of 339 patients followed for an average period of 3.9 ± 0.9 years. Three hundred and eight (56.3%) had a diagnosis of glaucoma and 239 (43.7%) were considered glaucoma suspects. Methods All eyes underwent imaging using the Spectralis® SD OCT (Heidelberg Engineering GmbH, Heidelberg, Germany), along with IOP measurements and standard automated perimetry (SAP). Glaucoma progression was defined as a result of “Likely Progression” from the Guided Progression Analysis™ software for SAP. Linear mixed models were used to investigate the relationship between average IOP during follow-up and rates of RNFL thickness change, while taking into account potential confounding factors, such as age, race, corneal thickness, and baseline disease severity. Main Outcome Measures The association between IOP and rates of global and sectorial RNFL thickness loss measured by SD OCT. Results Forty-six eyes (8.4%) showed progression on SAP during follow-up. Rates of global RNFL thickness change in eyes that progressed by SAP were faster than in those that did not progress (−1.02 µm/year versus −0.61 µm/year, respectively; P = 0.002). For progressing eyes, each 1 mmHg higher average IOP during follow-up was associated with an additional average loss of 0.20 µm/year [confidence interval (CI): 0.08 to 0.31 µm/year; P < 0.001] of global RNFL thickness versus only 0.04 µm/year (CI: 0.01 to 0.07 µm/year; P = 0.015) for non-progressing eyes. The largest associations between IOP and rates of RNFL change were seen for measurements from the temporal superior and temporal inferior sectors, whereas the smallest association was seen for measurements from the nasal sector. Conclusions Higher levels of IOP during follow-up were associated with faster rates of RNFL loss over time measured by SD OCT. These findings support the use of SD OCT RNFL thickness measurements as biomarkers for the evaluation of the efficacy of IOP-lowering therapies to slow down the rate of disease progression.

An in vitro pressure model towards studying the response of primary retinal ganglion cells to elevated hydrostatic pressures

“…Our microfluidic chamber model can provide an efficient framework to study the relationship between intraocular pressure and RGC degeneration. That the pressure levels were associated with the total neurite length and axon length of RGCs corroborates findings from clinical studies in glaucoma patients demonstrating that the rate of retinal nerve fiber layer thinning increases with IOP 52 .…”

Age‐related changes in and determinants of macular ganglion cell‐inner plexiform layer thickness in normal Chinese adults

“…12,22 In glaucomatous eyes that showed progression, each mmHg increase in IOP is associated with a reduction in pRNFL thickness of 0.20 μm per year. 23 We found that mean mGCIPL thickness decreased by approximately 0.19 μm for every 1-mmHg increase in IOP. This is contrary to the findings of another study with a smaller sample of 192 normal Chinese eyes that failed to find an association of IOP with either GCC or pRNFL thickness.…”

“…In glaucomatous eyes that showed progression, each mmHg increase in IOP is associated with a reduction in pRNFL thickness of 0.20 μm per year . We found that mean mGCIPL thickness decreased by approximately 0.19 μm for every 1‐mmHg increase in IOP.…”

Long segment 3D double inversion recovery (DIR) hypersignal on MRI in glaucomatous optic neuropathy

“…All patients used 1 to 4 different drugs for IOP control. Glaucoma was diagnosed based on ophthalmologic examinations, on the average intraocular pressure (IOP) with 2–4 pressure measurements performed by applanation tonometry within 1 month before MRI and with a pathologic IOP of more than 21 mmHg, on OCT measurements and on visual field measurements (OCTOPUS perimetry using dynamic strategy G2 program with analysis of mean deficit or Goldman perimetry) [19].…”

“…The damage to the RGCs and axons is confirmed by thinning of the peripapillary retinal nerve fiber layer (RNFL) thickness that is quantitatively measurable by optical coherence tomography (OCT) [15–19].…”