Abstract
Purpose :
To evaluate the role of intraocular pressure, its fluctuations and other risk factors on glaucoma development and progression in patients with ocular hypertension and normal tension glaucoma.
Methods :
Between 2010 and 2014, data from 137 eyes of 75 normal tension glaucoma (NTG) patients and 61 eyes of 43 patients with ocular hypertension (OH) were analyzed. Inclusion criteria were at least two 48h IOP profiles including nighttime IOP measurements in supine position, (>2) visual field examinations, (>2) HRT analysis and (>2) optic disc photographs. A total of 742 IOP profiles, 1548 visual field examinations, 912 HRT analysis and 877 optic disc photographs were included. The associations between IOP, IOP fluctuation, refraction, central corneal thickness, visual field mean defect (MD), HRT stereometric parameters, gender and progression were assessed using chi2-test. Survival analyses were enrolled to identify progression-free survival time, and regression analysis to illuminate risk factors for NTG and OH.
Results :
Progression was registered in 23% of OH- and 34% of NTG-patients during follow up. Progression was detected by visual field (36% (OH) versus 79% (NTG)) and HRT (64% (OH) versus 21% (NTG)). In both groups women were more often affected by progression. The mean follow-up period was 37 months (+/- 20), the mean age was 60 (+/-12) years. In both glaucoma groups the fluctuations and the mean intraocular pressure did not show an association with progression. Risk factor analysis pointed out myopia (SE <-3 dpt.) as a strong risk factor for progression in OH (chi2test). Survival analysis revealed a cumulative progress-free-survival-ratio of 59% in both glaucoma groups. The progression-free-mean-time was estimated 82 months (95%CI: [74; 90 months]) in OH and 60 months (95%CI: [60; 65 months]) in NTG (p=0.02). For NTG multivariate cox-regression analysis revealed a significant association of mean defect height with higher intraocular pressure means.
Conclusions :
IOP fluctuation does not influence development and progression of glaucoma in OH and NTG patients. Progression rate in NTG patients is significantly higher compared to OH (p=0,180). Progression free time was long in both groups. Structural changes were seen in OH patients, mostly without visual field defects. Therefore, treatment of OH patients seems to be adequate in our study group.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.