The fluctuation of diastolic blood pressure, diurnal IOP and the presence of a disc hemorrhage are significantly associated with progression of the disease in patients with normal tension glaucoma, according to the study published in the British Journal of Ophthalmology.
Previous researchers have linked normal tension glaucoma (NTG) progression and vascular insufficiency in the lower IOP setting. This study aimed to assess the other factors that may be involved in the progression of NTG.
Researchers divided 102 eyes of 102 patients with NTG and accompanying IOP of 12 mm Hg or less into progressor and non-progressor groups based on visual field progression as associated with change of optic disc or retinal nerve fiber layer defect.
They used baseline diurnal IOP as well as 24-hour blood pressure measurements and demographics to compare the two groups prior to using the Cox proportional hazards model to identify risk factors for NTG progression.
Thirty-six subjects were classified as progressors, and 66 were considered non-progressors.
According to the study, no significant differences were found in follow-up, baseline visual field mean deviation or pretreatment IOP between the two groups.
However, researchers stated that the Cox proportional hazards model indicated risk factors for glaucoma progression that included increased diurnal IOP at baseline, increased fluctuation of diastolic BP and presence of optic disc hemorrhage during follow-up. They concluded that in patients with NTG and pretreatment IOP in the low teens, factors in addition to baseline-IOP may contribute to the risk of disease progression.
The authors said the study was limited by not considering the status of the patients’ fellow eyes and by not including patients who had undergone glaucoma surgery. – by Scott Buzby
Disclosure: The authors report no relevant financial disclosures.