Relationship of change in central corneal thickness to visual field progression in eyes with glaucoma.

BACKGROUND

To assess the relationship between baseline central corneal thickness (CCT) and/or ongoing CCT change over time with subsequent visual field progression.

METHODS

One hundred sixty three eyes of 163 patients with medically treated glaucoma were followed up for 6.8 ± 1.8 years. Exclusion criteria was laser or intraocular surgery. Baseline and follow up CCT, confocal scanning laser tomography and visual fields were performed. CCT and CCT change related to visual field progression using Glaucoma Progress Analysis were assessed. Multivariate logistic regression analysis for predictive factors of glaucoma progression was used to analyze data.

RESULTS

Thinner baseline CCT was associated with more advanced damage at presentation, mean deviation (MD) (r=0.17, p=0.02) and neuroretinal rim area (NRR) (r=0.20, p=0.02). Progressing eyes had significantly thinner (p=0.01) baseline CCT compared to non-progressing eyes. The slope of visual field change was significantly greater (p=0.05) for thinner (<540 μm) as compared to thicker eyes. A small but significant CCT reduction (12.78 ± 13.35 μm, p<0.0001) was noted in all eyes; however, there was no significant difference (p=0.95) in the amount of change between progressing and non-progressing eyes. CCT change did not correlate with MD or NRR change. A thinner CCT (Odds ratio=1.80, p=0.02), but not CCT change (Odds ratio=1.07, p=0.69), was a significant risk factor for glaucoma progression.

CONCLUSIONS

CCT correlates significantly with the amount of glaucomatous damage at presentation. Thinner corneas may be associated with increased risk of visual field progression. CCT reduced slightly over time in eyes with glaucoma; but the magnitude of this change was not related to visual field progression.