Precis

A lower baseline corneal hysteresis and a decrease in corneal resistance factor (CRF) over time are associated with higher risk of visual field progression in glaucomatous and glaucoma suspect eyes.

Purpose

The aim was to investigate the longitudinal change in CRF and cornea hysteresis (CH) as risk factors for visual field progression.

Materials and methods

In this prospective observational cohort study, 72 eyes of 48 glaucoma or glaucoma suspect patients were followed for an average of 4.5 years. Baseline and follow-up CH and CRF measurements were performed with the Ocular Response Analyzer (Reichert Ophthalmic Instruments Inc., Depew, N.Y.). Evaluation of rates of visual field change during follow-up was performed using visual field mean deviation. Univariable and multivariable linear mixed models assessed the relationship of visual field progression with baseline CRF and CH as well as with changes in CRF and CH.

Results

The mean baseline CH was 9.0 (95% confidence interval: 8.6-9.4)  mm Hg and the mean baseline CRF was 9.3 (95% confidence interval: 8.8-9.9) mm Hg. There was no statistically significant difference in average CH and CRF measurements over time. In multivariable modeling adjusting for age, race, and mean intraocular pressure during follow-up, each 1 mm Hg lower in baseline CH and 1 mm Hg decrease in CRF over time were associated with a 0.12 (P=0.042) and 0.14 dB/year (P=0.007) faster rate of visual field mean deviation loss, respectively. Similar findings were found in glaucoma eyes but not found in glaucoma suspect eyes.

Conclusion

Visual field progression was associated with a lower baseline CH and a decrease in CRF over time. Assessment of corneal resistance and elasticity at baseline and during follow-up examinations should be considered to identify those eyes at highest risk of visual field progression.

Purpose

To evaluate the thinning of the circumpapillary retinal nerve fiber layer (cpRNFL) and macular ganglion cell-inner plexiform layer (mGCIPL) in primary open-angle glaucoma eyes with and without a history of disc hemorrhage (DH).

Design

Observational cohort study.

Participants

Thirty-nine 39 eyes (34 participants) with DH and 117 eyes (104 participants) without DH from the Diagnostic Innovations in Glaucoma Study and the African Decent and Glaucoma Evaluation Study.

Methods

Participants had at least 1.5 years of follow-up, with a minimum of 3 visits with biannual spectral-domain OCT cpRNFL and mGCIPL thickness measurements and visual fields (VFs). The rates of cpRNFL and mGCIPL thinning were calculated using mixed-effects models. The dynamic range-based normalized rates of cpRNFL and mGCIPL thinning were calculated and compared between the DH and non-DH groups.

Main outcome measures

Rates of cpRNFL and mGCIPL thinning.

Results

The rate of mGCIPL thinning was significantly faster in the DH group compared with the non-DH group (-0.62 μm/year vs. -0.38 μm/year; P = 0.024). The rate of cpRNFL thinning in the DH quadrant and rate of mGCIPL thinning in the inferotemporal sector in the DH group were faster than the corresponding regions in the non-DH group after adjusting for intraocular pressure (-1.33 μm/year vs. -0.58 μm/year; P = 0.053) and race (-0.82 μm/year vs. -0.44 μm/year; P = 0.048). In the DH group, percent rate of loss was significantly faster for the mGCIPL than the cpRNFL (-1.59 %/year vs. -1.31 %/year; P = 0.046). Rates of mGCIPL thinning were associated weakly with mean deviation slope, VF index slope, and guided progression analysis (GPA). The areas under the receiver operating characteristic curve for VF progression were 0.75 for mGCIPL and 0.56 for cpRNFL in the DH group.

Conclusions

The rate of mGCIPL and cpRNFL thinning was faster in DH eyes than non-DH eyes. Compared with cpRNFL, mGCIPL showed higher proportional rates of thinning and greater association with functional progression. In addition to cpRNFL, clinicians should consider incorporating mGCIPL imaging to monitor glaucoma progression, especially in glaucoma eyes with DH.