• Association of Nocturnal BP Dips and Optic Disc Hemorrhage in NTG Patients

    Written By: Lynda Seminara and selected by Richard K. Parrish II, MD

    Journal Highlights

    American Journal of Ophthalmology, April 2017

    Download PDF

    Kwon et al. performed a case-control study of patients with normal-tension glaucoma (NTG) to assess whether there is an association between noctur­nal dips in blood pressure (BP) and optic disc hemorrhage (OHD). They also evaluated the possible linkage between ODH and visual field progres­sion (VFP). They found that “overdip­ping” is a significant risk factor for ODH and that the presence of ODH is a strong predictor of VFP.

    The study included 349 Korean adults with NTG (698 eyes) who underwent 24-hour monitoring of intraocu­lar pressure (IOP) and ambulatory BP. All patients were examined by optic disc photography every 4-6 months and completed at least 5 reliable visual field tests during follow-up (minimum, 3 years).

    The researchers noted that a reduc­tion of nocturnal BP in the range of 10%-20% relative to daytime BP levels is usually observed in normotensive subjects and in the majority of hyper­tensive patients. For this study, subjects within that range were classified as physiologic dippers; nonphysiologic dippers were defined as overdippers (>20% reduction in nocturnal BP) and nondippers (<10% reduction).

    Among all eyes, ODH was detected in 15.3% and VFP in 8.6%. The fre­quency of ODH was significantly greater among overdippers than either nondippers or physiologic dippers. Throughout follow-up, overdipping remained a significant and independent risk factor for ODH. The rate of VFP was 6% for physiologic dippers, 7% for nondippers, and 24% for overdip­pers. The cumulative probability of VFP was significantly greater in eyes with 1 episode of ODH than in eyes without ODH, and eyes with recurrent ODH (≥2 episodes) had significantly greater cumulative probability of VFP compared with those that had only 1 episode of ODH.

    The researchers concluded that nocturnal overdipping is a risk factor for the occurrence of ODHs during follow-up in NTG eyes. Further, they found that ODH is a potent prognos­tic factor for glaucomatous VFP. They noted that their findings support the idea that occurrence of ODH may be associated with IOP-independent risk factors and that vascular mechanisms may play an important role in the pathogenesis of OHD.

    The original article can be found here.