Comparison of optic disc topographic Heidelberg Retina Tomograph (HRT) parameters between subjects with normal blood pressure (BP) and subjects with systemic hypertension.

Abstract

Abstract: : Purpose: To compare optic disc HRT measurements between subjects with normal BP and subjects with systemic hypertension. Methods: In 94% of 263 (248) consecutive subjects over 60 yrs of age in Thessaloniki Eye Study, we obtained 3 HRT optic disc measurements. 16 subjects were excluded from analysis, 3 (6 eyes) because of poor quality images and 13 (26 eyes) because of glaucoma diagnosis. 1 eye per subject was randomly selected. 193 (83.2%) of 232 eyes had a mean image created from 3 images while 39 eyes (16.8%) had only one image available for analysis. 2 BP measurements were taken. High BP was defined as systolic BP (SBP) ≥140mmHg and/or diastolic BP (DBP) ≥90mmHg. Subjects were classified based on BP measurements in 3 groups: normal BP (n=60), high BP with or without hypertensive treatment (HT) (n=125) and normal BP secondary to HT (n=47). Subjects were also classified in 2 additional ways: only SBP as criterion (normal SBP n=65, high SBP with or without HT n=113 , normal SBP secondary to HT n=54 ) and only DBP as criterion (normal DBP n=77, high DBP with or without HT n=90 , normal DBP secondary to HT n=65 ). Wilcoxon tests were used to compare the HRT parameters between the 3 groups. Regression models adjusted for disc size, gender, cardiovascular disease, diabetes, IOP and height were used to compare HRT parameters among groups. P<0.01 was considered statistically significant. Results: 

Conclusions:In our cohort of non–glaucoma subjects over 60 yrs of age, those with normal DBP secondary to HT had increased cup area, cup volume, C/D ratio and decreased rim area compared to subjects with normal DBP and subjects with high DBP with or without HT. There were no differences with respect to HRT parameters between groups when SBP or both SBP and DBP were used. DBP below 90mmHg in patients receiving HT may be associated with changes in HRT optic disc parameters in non–glaucoma subjects over 60 yrs of age.

Keywords: imaging/image analysis: clinical • optic disc • clinical (human) or epidemiologic studies: prevalence/incidence