Indian Journal of Ophthalmology

ARTICLES
Year
: 1986  |  Volume : 34  |  Issue : 1  |  Page : 25--28

Intraocular pressure and its postural response in patients of systemic hypertension


AS Kothari, Indu Arora, SR Mehta, Dinesh Mathur 
 Upgraded Department of Medicine and Ophthalmology, S.M.S. Medical College & Hospital, Jaipur, India

Correspondence Address:
A S Kothari
213, II C Road, Sardarpura, Jodhpur, Rajasthan
India




How to cite this article:
Kothari A S, Arora I, Mehta S R, Mathur D. Intraocular pressure and its postural response in patients of systemic hypertension.Indian J Ophthalmol 1986;34:25-28


How to cite this URL:
Kothari A S, Arora I, Mehta S R, Mathur D. Intraocular pressure and its postural response in patients of systemic hypertension. Indian J Ophthalmol [serial online] 1986 [cited 2020 Mar 29 ];34:25-28
Available from: http://www.ijo.in/text.asp?1986/34/1/25/26349


Full Text

The effect of persistent high blood pre­ssure on Intra-ocular pressure (IOP) is still a matter of dispute[1],[2],[3] The effect of posture on IOP in hypertensive persons has not been probably studied till-date. This study was aimed to find out the effect of high blood pressure on TOP and to evaluate the ortho­static effect on IOP in hypertensive patients.

 MATERIAL AND METHODS



This study was conducted on 10 healthy controls (Group 1) and 20 patients of hyper­tension (Group 2). Selection of patients for the latter group was irrespective to the age, sex and etiology of hypertension but all patients had persistent high blood pressure i.e. more than three readings on consecutive days were above 140/90 mmHg. Patients with heart failure, conduction disturbance, diabetes mellitus, refractive errors, and other complications were not included in the study. Detailed history was recorded and all relevant investigations were done.

IOP was measured by Perkin's hand held applanation tonometer[4] first in supine posture (without pillow) and immediately afterwards in sitting posture. Before measuring IOP; a drop of Lignocaine (2%) was instilled twice in each eye at the interval of few minutes to ensure the anaesthesia and then tear film was stained by Fluoresin strips (Fluorets 1 %).

After measuring IOP in both postures liquid paraffin was instilled in each eye to prevent injury of the anaesthetised cornea. Average reading of both the eyes was record­ed as mean IOP in that particular posture.

Blood pressure was also measured first in supine and immediately afterwards, in sitting position by mercury sphygmomanometer.

 OBSERVATIONS



Mean supine lOP in control group was 14.3 mmHg with a postural fall of 1.1 mmHg while changing from supine to sitting posi­tion [Table 1]. In hypertensive group, the mean supine IOP was 16.6 mmHg with a postural fall of 3 mmHg (supine V/s sitting) [Table 2].

 DISCUSSION



Arterial blood pressure as a determinant of lOP has long been known. Transmission of rise in blood pressure to the intra-ocular blood vessels dilates them raising pressure in the eye through the consequent increase in its volume[5]. Relationship of BP and lOP is further evident by studies which show that patients of open angle glaucoma have higher systemic blood pressure[2]. In present study, mean supine TOP in hypertensive persons was (16.6 mmHg) significantly higher as com­pared to control group (14.3 mm Hg). This hike may be attributed to increased aqueous filtration in ciliary body owing to increased perfusion pressure in hypertensive patient[3],[6].

The possibility of common etiopathogenesis of glaucoma and hypertension as suggested by Leighton & Phillips[2] sound less logical as all patients of hypertension do not have glaucoma and vice-versa. However, we agree to their suggestion that relatively high B.P. may play a role in development of glaucoma. In present study, the level of IOP was not directly proportional to the level of blood pressure as evident from the graph.

Postural response of IOP in normal per­sons is controversial. Though, Williams concluded that normal persons maintain a rigid control of IOP in different postures[7] but most other workers believe that IOP rises while changing from sitting to supine, however, the extent varies from study to study[8],[9],[10]. In patients of glaucoma[10],[11] and retinal vein obstruction[7] the postural res­ponse is exaggerated but no study was seem­ingly available regarding the postural response of IOP in hypertensive persons. In our study, the postural fall of IOP (supine V/s sitting) in hypertensive patients was (3 mmHg) significantly higher as compared to controls (1.1 mmHg). This postural res­ponse may be due to change in facility of aqueous outflow with change in posture[9] . The postural fall of IOP was not directly proportional to postural fall of blood pres­sure as evident from [Table 2]. Further studies are required to evaluate the signi­ficance of this postural response of IOP.

 SUMMARY



IOP and its postural response was studied in 20 patients of hypertension. Our study suggest that mean IOP is higher in hyperten­sive patients and hence, these patients are more prone to develop glaucoma. Postural response of IOP is also significantly higher as compared to controls.

When the real difference of mean value is more than the double of standard error of difference, they are statistically significant. So, it can be interpreted that supine IOP and its postural fall is statistically higher in hypertensive patients as compared to con­trols.

The standard error of difference was evaluated by the formula of

[INLINE:1]

Where sigma is standard deviation and n is number.

References

1Weinstein. P., 1935, Arch. Ophthalmol 13 : 181.
2Leighton, D.A. et al., 1972, Brit J. Ophthalmol 56 : 447.
3Bulpitt, C.J., 1975, Brit J. Ophthalmol., 59: 717.
4Perkin's E.S., 1965, Brit J. Ophthalmol , 49:591.
5Duke Elder, S., 1968, Syst. of Ophthalmol., Vol. IV : In traocular pressure, 285
6Macri, F.J., 1967, Arch. Ophthalmol., 78 : 824.
7Williams, B.I., Brit J. Ophthalmol., 69: 688-693.
8Anderson. D., Grant, R and Morton, W., 1973, Invest. Ophthalmol., 12:204.
9Inglima, R., 1966, Rent monthly, 45 (7) : 64-69.
10Krieglstein, G.K. and Largham, M.E., 1975, Ophthalmologice, 171 : 135-145.
11Wutrich, U.W., 1976, Postural change and TOP in glaucomatous eyes : Brit. Ophthalmol 60 : 111.