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Background: Systemic hypertension and degenerative vascular disease are more common in multigravidae than in primigravidae. The present study investigated whether the known ocular hypotensive effect of late pregnancy is influenced by the number of pregnancies., Methods: Intraocular pressure (IOP) was measured in normotensive third-trimester primigravidae and multigravidae along with nulligravida controls by means of the Goldmann applanation tonometer. Depending upon the number of previous pregnancies, multigravidae were divided into four subgroups., Results: The IOP of the pregnant group (primigravidae and multigravidae together) was (mean+/-SEM) 2. 1+/-0.07 mmHg (P<0.001) lower than in the nulligravida control group. The IOP of nulligravidae was 1.7+/-0.06 mmHg (P<0.001) and 2.5+/-0. 01 mmHg (P<0.001) higher than in third-trimester primigravidae and multigravidae, respectively. In all subgroups of multigravidae IOP was significantly lower (P<0.02) than in primigravidae. The differences among different subgroups of multigravidae were statistically insignificant., Conclusions: Gravidity influences IOP and should be taken into account in future research.

The present study investigated whether a correlation between days of the menstrual cycle and variations in intraocular pressure exists or not. The number of days since the beginning of last menses was recorded along with intraocular pressure for 1,459 women. Measurements were taken by Goldmann applanation tonometer. The differences among various days of menstrual cycle were statistically insignificant. The highest mean IOP occurred between 20th and 22nd day and the second peak from 13th to 15th days of the cycle. The lowest mean IOP was found from 16th to 19th days of the cycle. This study concludes that intraocular pressure varies with the various days of the menstrual cycle, but fluctuations are statistically insignificant and cannot affect the diagnoses of glaucoma.

This study was planned to evaluate the effect of pregnancy on diurnal variation of intraocular pressure (IOP) after placing control on all the IOP affecting factors. The IOP was measured with the Goldmann applanation tonometer. Both in the control and 3rd trimester subjects, the peak of mean IOP appeared in the morning when the subjects waked, and the trough of mean IOP happened at 2 am to 4 am. The diurnal intraocular pressure curves revealed that the IOP peaks were 15.4 +/- 0.9 and 12.9 +/- 0.6 mmHg in the control and third trimester pregnant subjects, respectively. Whereas the trough were 13.1 +/- 0.4 and 11.8 +/- 0.3 mmHg, respectively. The mean diurnal variation were 2.3 +/- 0.6 mmHg (P < 0.01), and 1.1 +/- 0.8 mmHg in the control and third trimester subjects, respectively. There are two main findings of present study: first, compared with non-pregnant control subjects, the IOP was significantly lower (P < 0.001) in the third trimester pregnant subjects. Second, in the third trimester of pregnancy, the lower IOP level was associated with the less degree of IOP fluctuations at various hours of the day.

Background: Recently it has been shown that environmental conditions have a significant influence on intraocular pressure (IOP). Due to differences in inherent constitution, diet and environmental conditions, there is a clear need for well collected IOP data in different countries and ethnic groups. The seasonal variation of IOP has never been described in Pakistani subjects., Methods: IOP was measured each month over the course of 12 months with the Goldmann applanation tonometer in normal, ocular hypertensive, and glaucoma male subjects., Results: In all groups, the average intraocular pressures in the winter months were highest, while lowest in summer months. The intraocular pressures of spring and autumn months were nearly the same. The intraocular pressure levels in these seasons were between the IOP levels in summer and winter seasons. The difference between highest and lowest IOP was 1.4 +/- 0.2, 3.1 +/- 1.4, and 2.3 +/- 1.1 mmHg, in normal, ocular hypertensive, and glaucoma subjects, respectively. The ups and downs of intraocular pressure were greater in the ocular hypertensive subjects than in the glaucoma patients., Conclusions: This study confirms that season influences IOP, and concludes that seasonal influence is highest in ocular hypertensive than in normal and glaucoma subjects. As compared to other nations, effect of seasons on IOP seems to be somewhat less pronounced in Pakistan.

Background: Despite some findings to the contrary, it would appear that pharmacological doses of progesterone and estrogen (alone or in combination) can influence intraocular pressure (IOP). The relationship between hormonal changes associated with the menstrual cycle and intraocular pressure is not clearly understood. After elimination of those factors that can affect IOP, the present study investigated whether physiological hormonal changes associated with the menstrual cycle have a correlation with intraocular pressure., Methods: Intraocular pressure and the concentrations of circulating hormones, namely, the luteinizing hormone (LH), follicle-stimulating hormone (FSH), estrone (E1), estradiol (E2), progesterone, and testosterone, of twenty married women of the same age groups were recorded daily throughout a menstrual cycle. None was taking any contraceptives in any form. The intraocular pressure was measured using a Goldmann applanation tonometer., Results: The intraocular pressure values fluctuated in each of the twenty subjects at various times of the cycle; however, they were not definitely correlated with the different phases of the cycle. This study failed to find any correlation between IOP and progesterone or estradiol levels.

Intraocular pressure (IOP) has never been compared between hard working and sedentary subjects. The relationship between physical fitness and IOP is not clearly known. There are only two studies and their results are contradictory. The variability in their results may be due to several factors. Therefore, the present study was planned to investigate the relationship between working style, physical fitness and IOP after taking into account those factors that can affect IOP. One hundred fifty male volunteers of a steel factory were divided equally in two groups. The subjects of group 1 were sedentary worker, whereas group 2 subjects were actively engaged in heavy works requiring exertion. Physical fitness was evaluated by the measurement of maximum oxygen uptake with a Bechman O2 analyzer. IOP was measured with the Goldmann applanation tonometer. As compared to sedentary subjects, maximum oxygen uptake was significantly higher whereas IOP was significantly lower in those who did moderate or severe exertions. The maximum oxygen uptake difference between group 1 and 2 was found to be (mean +/- SD) 5.1 +/- 1.1 ml/kg/min (p < 0.001), whereas, IOP difference was 1.9 +/- 0.7 mmHg (p < 0.001). This study concludes that hard working is associated with physical fitness and physical fitness is associated with reduced resting IOP. It would seem reasonable at present not to discourage subjects who have ocular hypertension from exercise; perhaps, on the contrary, it should be encouraged to increase their physical fitness.

The present study was planned to investigate the relationship between the magnitude of intraocular pressure (IOP) reduction after short-duration exercise and the intensity, duration and quantity of exercise in healthy subjects. Twenty-five healthy, sedentary male of the same age group, performed exercises at the levels of 80%, 60%, and 40% maximum heart rate (HRmax) for 15 minutes, 80% HRmax for 7.5 minutes, 60% HRmax for 10 minutes, and 40% HRmax for 30 minutes. IOP was measured with the Goldmann applanation tonometer. The IOP reduction at 5 minutes after 15 minutes of exercising at 80% HRmax, 60% HRmax, and 40% HRmax were 4.7 +/- 0.9, 3.5 +/- 0.7, and 0.9 +/- 0.4 mmHg, respectively. At five minutes, after exercising 7.5 minutes at 80% HRmax, 10 minutes at 60% HRmax, and 30 minutes at 40% HRmax, IOP reduced by 4.5 +/- 0.7, 3.3 +/- 0.9, and 2.9 +/- 1.1 mmHg, respectively. This study concludes that intensity of exercise seems responsible for the magnitude of the initial IOP decrease after short-term exercise. Furthermore, it seems that other factors such as duration of exercise or quantity of exercise, blood pressures, body mass index are not related to the amount of the initial fall in IOP.

Background: Virtually all the tissues and systems of the human body have been shown to be responsive to programs of exercise. Regarding the relationship between physical fitness and intraocular pressure (IOP), the existing literature is controversial with some associations inconsistent. In one study, IOP values were not dependent upon changes in physical fitness. In contrast to this, another study demonstrated that physical fitness significantly reduces intraocular pressure levels. In recent years it has been noted that intraocular pressure is a dynamic function and is subject to many influences both acutely and over the long term. The variety of results of previous studies may have come from several factors which can affect intraocular pressure. The present study was planned to investigate the effects of physical fitness on intraocular pressure in Chinese medical studies, after elimination of other affecting factors., Methods: Forty medical students were categorized into control and experimental groups, each consisting of 20 subjects. The experimental group took a supervised exercise program for 10 weeks. Physical fitness was evaluated by measurement of maximum oxygen uptake with a Beckman O2 analyzer. Intraocular pressure was measured with the Goldmann applanation tonometer., Results: After exercise training, the experimental group showed a marked increase in physical fitness. The difference of IOP between the control and experimental groups before exercise conditioning was 0.3 +/- 0.1 mmHg (P > 0.05). After 10 weeks, this difference increased to 1.1 +/- 0.4 mmHg (p < 0.05)., Conclusions: This study concludes that physical fitness reduces intraocular pressure. Whether exercise conditioning has a role as a nonpharmacologic approach or as an addition to medical therapy must be left to future investigations.

Background: Systemic blood pressure is positively related to intraocular pressure. During the third trimester of pregnancy decreased intraocular pressure while increased blood pressure has been reported. After taking into account all those factors that can affect intraocular pressure, the present study investigated whether or not the high blood pressure found in late pregnancy influences the known ocular hypotensive effect of late pregnancy., Subjects and Methods: Normotensive subjects in all trimesters of pregnancy and non-pregnant control groups along with third trimester hypertensive subjects were studied. Intraocular pressure was measured with the Goldmann applanation tonometer., Results: In the second and third trimester subjects, the mean intraocular pressure was significantly lower than in the non-pregnant control group. The differences between first and second, first and third, and second and third trimesters of pregnancy were (mean +/- s.d.) -0.5 +/- 1.2 (p < 0.05), -1.5 +/- 1.7 (p < 0.001), and -1.0 +/- 2.1 (p < 0.01) mmHg respectively. The mean difference between third trimester hypertensive and third trimester normotensive pregnant women was 0.53 +/- 1.5 mmHg (p < 0.05)., Conclusions: With advancing pregnancy, intraocular pressure decreases. The mean intraocular pressures of third trimester hypertensive pregnant women were significantly higher from that of third trimester non-hypertensives. Knowledge of the normal level of intraocular pressure in various stages of pregnancy may help glaucoma screeners.

This study evaluated the distribution of Intraocular pressure (IOP) levels in 67 normal and 59 ocular hypertensive (OHT) subjects during the day after placing control on all those factors that can affect IOP. The IOP was measured with the Goldmann applanation tonometer. All the subjects were examined according to standard protocols. Both in the normal and OHT subjects, the peak of mean IOP appeared in the morning when the subjects woke up and the trough of mean IOP occurred between 2 a.m. to 4 a.m. The mean diurnal variation were (mean +/- sem) 2.9 +/- 0.7 and 3.5 +/- 0.7 mmHg in the normal and in OHT subjects, respectively. Ninety-four percent of the normal subjects and sixty-eight percent of the OHT subjects exhibited a similar diurnal behaviour in both eyes. The IOP variation did not correlate with the variations of blood pressure. The diurnal variation of IOP, found in Chinese, is lower than in other nations. The clinical importance of findings that the peaks of IOP occur in the early morning, raised a serious question as to the necessity of extending the diurnal IOP curves beyond the usual working time (JPMA 46:171, 1996).

Studies have been shown that intraocular pressure (IOP) shows a seasonal variation, but amount of change differs from study to study. The variability in their results may be due to negligence of factors that can affect IOP. Due to differences in environmental conditions of China than other countries, we investigated seasonal variations in IOP of 103 healthy male Chinese of Shanghai. IOP was measured each month over the course of fourteen months with the Goldmann applanation tonometer. The average intraocular pressures in the winter months were higher than those in the spring, summer, and autumn months. The IOP difference between winter and summer months was found to be 1.4 +/- 0.7 mmHg. This study confirms that season influences IOP. As compared to other nations, effect of seasons on IOP seems to be somewhat less pronounced in Chinese. The possible mechanisms, responsible for the seasonal variation of intraocular pressure, are also postulated.

Because the course of glaucoma is often an insidious one and most cases remain asymptomatic until the visual field has been clearly diminished, the frequency distribution of intraocular pressure (IOP) is important from both an academic and clinical viewpoint. However, diagnostically, glaucoma is a disease suited to a preventive approach. Due to differences in intrinsic constitution, diet and environmental conditions, there is a clear need for well collected population-based IOP data in different countries. In the present study, after controlling for the factors that can effect IOP, we investigated the distribution of intraocular pressure in 7201 healthy subjects of both sexes of Karachi, Pakistan. In both sexes, distribution of IOP slightly skewed towards the higher values. In males and females, 85.1% and 82.2% individuals ranged from 11 to 18 mmHg, 4.3% and 3.2% ranged from 8 to 10 mmHg, 7.1% and 11.2% ranged from 19 to 21 mmHg, respectively. Ocular hypertension (IOP > 21 mmHg) was found in 3.5% males and 3.7% females. Intraocular pressure increased with age in both eyes of both sexes. The averages per decade increase were 0.3 mmHg and 0.5 mmHg in male and female respectively. This study reports that an average per decade increase, women have 0.4 mmHg higher IOP than men. The male-female difference was not statistically significant until the age groups reached 31-40 years, after which the differences became significant. Right and left eyes IOPs were found to be 14.3 +/- 0.17 and 14.4 +/- 0.12 mmHg in male and 14.6 +/- 0.14 and 14.8 +/- 0.15 mmHg in females respectively. This survey shows that mean IOP of Pakistani population is similar to the IOP found in other epidemiologic investigations; the prevalence of ocular hypertension, however, seems to be slightly higher. Knowledge of the normal level of IOP in various age groups of both sexes will help to screen glaucoma.