Association of retinal nerve fiber layer thickness and systemic hypertension

Abstract

Purpose : Structural losses in the retina nerve fiber layer (RNFL) are known to result from glaucoma, and have also been associated with cerebrovascular disease. For this study, we investigated the relationship between systemic hypertension and RNFL thickness.

Methods : After informed consent was obtained, clinic patients were recruited into both hypertensive and non-hypertensive groups, based on known prior diagnosis by their primary care physician. Patients were excluded if they had diabetes, retinal vascular occlusion, or other retinal disorders which could affect retinal vessel diameter. Patients were also excluded if they had known prior glaucoma, ocular hypertension, or cerebrovascular disease. Patients had a baseline interview, during which their medical history was obtained and their blood pressure was measured using automated arm plethysmography (Welch Allyn). For each eye, the RNFL was assessed using optical coherence tomography (OCT) (Spectralis, Heidelberg Engineering) using a standard circle scan.

Results : A total of 64 patients and 126 eyes were analyzed (hypertension 32 patients, 63 eyes; non-hypertension 32 patients, 63 eyes). There were no significant differences in the age, gender or racial composition of the groups. All but one of the patients in the hypertension (HTn) group regularly took antihypertensive medications. Six patients in the non-hypertension (non-HTn) group regularly took an antihypertensive medication or a medication with major antihypertensive properties for other reasons. The average systolic blood pressure as assessed by automated plethysmography was significantly higher in the HTn group (139.0 mmHg) than in the non-HTn group (134.5 mmHg); p=0.03. There was no significant difference in diastolic blood pressure. The RNFL was thinner, both globally and for all sectors in the HTn group, but only the inferonasal sector rose to statistical significance.

Conclusions : Systemic hypertension was associated with decreased thickness of the RNFL, though this was only significant in the inferonasal sector for this study.

This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.

 

Table 1: RNFL thickness assessed by optical coherence tomography in non-glaucomatous eyes of patients with and without systemic hypertension. NS - supranasal; N - nasal; NI - infranasal; TI - infratemporal; T - temporal; TS - supratemporal; G - global.