The acute changes in intraocular pressure during sustained handgrip contraction (2.5 minutes duration) and the Valsalva manoeuvre (15 seconds duration), both standard tests of autonomic nerve function were studied in 14 diabetic patients and 14 similar aged control subjects.
During sustained handgrip contraction, diastolic blood pressure increased by 16.35 ± 1.87 mmHg in the diabetic patients and 21.36 ± 0.66 mmHg for the control group. Mean intraocular pressure decreased by 0.71 ± 0.43 mmHg in the diabetics, p < 0.05="" and="" 0.64="" ±="" 0.27="" mmhg,="" p="">< 0.01)="" in="" the="" control="">
There was no correlation between the blood pressure and the intraocular pressure responses in either group.
On release of handgrip contraction, mean recovery intraocular pressure over 5 minutes was significantly lower than mean baseline values for the two groups; control: baseline 14.78 ± 0.49 to 14.14 ± 0.67, p < 0.001="" and="" diabetic:="" 14.57="" ±="" 0.65="" to="" 13.86="" ±="" 0.72,="" p=""><>
During the Valsalva manoeuvre, there was a significant rise in intraocular pressure in the control (+7.85 ± 0.75mmHg, p < 0.001)="" and="" the="" diabetic="" group="" (+7.93="" ±="" 1.18mmhg,="" p="">< 0.001).="" 5="" minutes="" after="" release="" of="" intrathoracic="" pressure,="" mean="" recovery="" intraocular="" pressure="" remained="" significantly="" below="" baseline="" values="" for="" the="" two="" groups.="" the="" valsalva="" ratios="" were="" in="" the="" normal="" range="" for="" the="" control="" group="" (1.21="" to="" 2.2)="" while="" 2="" diabetics="" had="" abnormal="">
Key words intraocular pressure - sustained isometric exercise - Valsalva manoeuvre - diabetes mellitus