Abstract
Purpose: :
To assess whether baseline thickness of macular ganglion cell complex (mGCC) is associated with the progression of visual field loss in patients with normal-tension glaucoma (NTG).
Methods: :
Thirty-one patients with newly diagnosed NTG were included in the study. Before starting medical treatment, baseline thickness of mGCC was measured by a spectral-domain optical coherence tomography (RTvue-100, Optovue, Fremont, CA). All subjects were followed up more than 2 years (mean follow-up, 29.9±5.9 months) with at least 5 reliable visual field tests performed by the Humphrey Field Analyzer (30-2 SITA standard strategy). The subjects were divided into two groups according to the slope of mean deviation (MD); MD slope<-0.4 dB/y (progression of visual field loss) and MD slope≥-0.4 dB/y (no progression of visual field loss). Factors compared between the groups were: age, baseline intraocular pressure (IOP), mean IOP during the follow-up, refraction, baseline MD, pattern standard deviation (PSD), mean thickness of mGCC, global loss volume (GLV) and focal loss volume (FLV).
Results: :
There were 6 patients with progression (mean age; 54.8±11.3 years, baseline MD;-4.3±3.8 dB) and 25 with no progression (mean age; 54.4±11.9 years, baseline MD;-3.7±3.7 dB). There were no significant differences between two groups in age, baseline IOP, mean IOP, refraction, baseline MD or PSD. GLV, a parameter of mGCC, showed significantly higher rate in patients with progression than in patients with no progression(25.53±10.4% versus 17.3±7.8%, p = 0.038). The mean thickness of mGCC in patients with progression was thinner than that in patients with no progression, although the difference was not statistically significant(73.3±11.4μm versus 81.1±8.8μm, p= 0.076).
Conclusions: :
GLV could be a prognostic factor to predict progression of visual field loss in patients with newly diagnosed NTG.
Keywords: imaging/image analysis: clinical • visual fields