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At least 199 records · Page 11Linked to original sources
PubMed1993

Effects of apraclonidine on intraocular pressure and blood-aqueous barrier permeability after phacoemulsification and intraocular lens implantation.

To evaluate the effect of topical apraclonidine on early postoperative intraocular pressure and blood-aqueous barrier permeability, we conducted a double-masked clinical trial in which 37 patients undergoing uncomplicated phacoemulsification and posterior chamber intraocular lens implantation were randomly assigned to treatment with 1% apraclonidine or its vehicle. One drop of 1% apraclonidine or its vehicle was instilled 1/2 hour preoperatively and immediately postoperatively. In addition to intraocular pressure, aqueous flare intensity was also determined before and after the operation by using a laser flare-cell meter. In the apraclonidine group, intraocular pressure showed no significant postoperative increase, whereas it showed a significant increase at six hours in the vehicle group (P < .01). Difference between intraocular pressure recorded at the end of the operation with the Tono-Pen II and that measured postoperatively was significantly greater in the vehicle group by 3.5 to 7.0 mm Hg (P < .05 to .01). In the apraclonidine group, the aqueous flare intensity was about half that in the vehicle group with significant differences at six (P < .05) and 24 (P < .01) hours.

Adrenergic alpha-Agonists↗
PubMed2001

Intraocular pressure and silicone oil endotamponade.

PURPOSE: To evaluate intraocular pressure after instillation and eventual removal of silicone oil in patients undergoing pars plana vitrectomy combined with silicone oil endotamponade. METHODS: The study included 198 patients who underwent pars plana vitrectomy with silicone oil endotamponade (5,000 centistoke viscosity), in whom silicone oil was removed and in whom follow-up after oil removal was at least 3 months. All patients were operated on by one of two surgeons. RESULTS: After silicone oil instillation, intraocular pressure increased significantly (P < 0.001) from 12.9 +/- 4.4 mm Hg preoperatively to 16.1 +/- 5.5 mm Hg postoperatively. Intraocular pressure was statistically (P > 0.20) independent of the duration of silicone oil tamponade. Twenty percent of the 198 patients had at least one postoperative intraocular pressure measurement that was higher than 21 mm Hg. Main reasons for increased intraocular pressure were closed inferior iridectomy, iris neovascularisation, silicomacrophagocytic open-angle glaucoma secondary to silicone oil emulsification, and preoperative history of glaucoma. Glaucomatous optic nerve damage was detected in 14 (14 of 198, 7.1%) eyes, including 8 eyes with preoperative antiglaucoma treatment. Silicone oil emulsification occurring in 40 (40 of 198, 20.2%) patients did not statistically influence intraocular pressure after oil removal. Ocular hypotony occurred in 10 (10 of 198, 5.1%) patients after oil release leading to intraocular hemorrhages and loss of vision in 3 patients. CONCLUSION: Clinically significant increased intraocular pressure after pars plana vitrectomy with silicone oil endotamponade occurs relatively rarely, can usually be well controlled by topical antiglaucoma medication, and is reversible in most patients after oil removal. In patients with increased intraocular pressure and silicone oil endotamponade, oil removal may be preferred to invasive antiglaucoma surgery to reduce intraocular pressure.

Adolescent↗
PubMed1996

[Intraocular pressure decrease after phacoemulsification-aspiration+ intraocular lens implantation in primary open angle glaucoma eyes].

Phacoemulsification-aspiration and intraocular lens implantation (PEA + IOL) were carried out in 40 primary open angle glaucoma (POAG) eyes without history of surgery and 53 control (cataract only) eyes. Postoperative change in intraocular pressure (IOP) was evaluated over a long period (at least 18 months, average follow-up period 34 months). The postoperative IOP was significantly lower than the preoperative level in every group from 6 months to 3 years. An IOP decrease of 1.5 mmHg was maintained for 3 years in the control group. A decrease of 2.5 mmHg was stable for 3 years in the good POAG group in which preoperative IOP was controlled (< or = 20 mmHg) with medication. IOP decrease in the poor POAG group in which preoperative IOP was over 21 mmHg with medication, was 5.5 mmHg, and was maintained for 3 years. Medication did not differ significantly before or after the operation. These results imply that in POAG an IOP decrease can be expected after PEA + IOL.

Aged↗
PubMed1977

Low-dose methazolamide and intraocular pressure.

Sixteen patients with increased intraocular pressure (over 20 mm Hg) received 25 and 50 mg of oral methazolamide, twice daily, during consecutive weeks and then 500 mg (Sequels) of acetazolamide. The two methazolamide regimens produced significant decreases in intraocular pressure. Acetazolamide treatment resulted in a greater decrease in intraocular pressure but more systemic acidosis and side effects.

Acetazolamide↗
PubMed1987

Decreased intraocular pressure in dogs with one-kidney, one wrapped hypertension.

We examined the relationship of intraocular pressure and the development of one-kidney, one wrapped (perinephritic) hypertension in the dog. Conscious femoral arterial pressure (direct arterial puncture) and intraocular pressure (Schiotz tonometer) were measured weekly before and after the surgical induction of hypertension in 11 healthy male mongrel dogs and before and after unilateral nephrectomy in 15 normotensive control dogs. Preoperative mean arterial pressure (102 +/- 5 vs 99 +/- 8 [SD] mm Hg, hypertensive vs control dogs) and intraocular pressure (18.1 +/- 2.5 vs 17.7 +/- 2.1 mm Hg, hypertensive vs control dogs) were similar in both groups. In normotensive control dogs, mean arterial pressure and intraocular pressure averaged over the postoperative period (4-8 weeks) did not differ significantly from preoperative values. In contrast, during the same period arterial pressure significantly increased and intraocular pressure significantly decreased in hypertensive dogs (arterial pressure, 163 +/- 8 mm Hg; intraocular pressure, 11.9 +/- 4.0 mm Hg; p less than 0.001 for both values compared with corresponding values in control dogs). Intraocular pressure was inversely related to arterial pressure in hypertensive dogs (r = 0.56, p less than 0.01). These observations indicate that intraocular pressure decreases with the development of canine one-kidney, one wrapped hypertension. The mechanism of this decrease may be related to abnormalities in Na+,K+-adenosine triphosphatase activity found in this form of hypertension.

Animals↗
PubMed1985

Atracurium and intraocular pressure.

The effect of atracurium on intraocular pressure was studied by comparing it with pancuronium in a randomised controlled trial. The intraocular pressure was measured in patients undergoing cataract surgery before administration of the muscle relaxant, at 1, 3, and 5 minutes after its administration, and at 1 minute after tracheal intubation. Atracurium was found to decrease intraocular pressure to a significantly greater degree than pancuronium. The intraocular pressure after tracheal intubation was found to be significantly higher than that measured immediately after induction of anaesthesia. The authors conclude that atracurium provides an acceptable alternative to pancuronium for ophthalmic surgery but does not overcome the ocular hypertensive effect of tracheal intubation.

Aged↗
PubMed1991

Intraocular pressure increases with fenoldopam, but not nitroprusside, in hypertensive humans.

Fenoldopam mesylate stimulates adenyl cyclase in porcine ocular trabecular meshwork and raises intraocular pressure in humans. To clarify whether this results from direct activation of the dopamine-1 receptor or indirectly from baroreflex sympathetic stimulation after blood pressure reduction, intraocular pressure was measured in 14 patients with accelerated/malignant hypertension, randomized between intravenous fenoldopam or sodium nitroprusside. Intraocular pressure was measured with a Perkins tonometer, before and at the twentieth minute of each dose increment. In seven patients with a mean blood pressure of 232/131 mm Hg treated with fenoldopam, intraocular pressure increased in a dose-dependent fashion, from 16 +/- 1 to 20 +/- 2 mm Hg (p less than 0.005). In contrast, seven patients with a mean blood pressure of 225/134 mm Hg treated with sodium nitroprusside exhibited no change in intraocular pressure (15 +/- 1 versus 14 +/- 1 mm Hg) despite similar blood pressure reduction. Increases in heart rate were not significantly different. Rates of urinary excretion of norepinephrine plus epinephrine increased significantly relative to baseline (p less than 0.05) but were not different between groups. These data suggest that the increase in intraocular pressure with fenoldopam results from specific activation of the dopamine-1 receptor and is not caused by baroreflex sympathetic stimulation. Because dopamine-1 receptors may modulate intraocular pressure, dopamine-1 receptor blockers might be useful therapy for glaucoma.

2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-ben↗
PubMed1987

Management of increased intraocular pressure after cataract extraction.

We measured the change in intraocular pressure prospectively after extracapsular cataract extraction in 80 eyes after treatment with either pilocarpine gel, pilocarpine 4% solution, timolol 0.5% solution, or placebo. Intraocular pressure, pupil size, and anterior chamber cellular reaction were measured in a masked fashion on the first day after surgery. A significant increase in intraocular pressure was found in all groups postoperatively when compared with baseline values (P less than .001). Eyes treated with pilocarpine gel had an average intraocular pressure increase of 4.2 +/- 2.1 mm Hg (mean +/- 1 S.E.), eyes treated with pilocarpine 4% eyedrops had an average increase of 9.8 +/- 2.8 mm Hg, and eyes treated with timolol demonstrated an intraocular pressure increase of 8.25 +/- 3.19. The intraocular pressure in untreated eyes (controls) increased by an average of 12.9 +/- 2.7 mm Hg. Only the difference in intraocular pressure change between the eyes treated with pilocarpine gel and control eyes was statistically significant (P = .025). Postsurgical intraocular pressure exceeding 25 mm Hg was observed in three of 20 pilocarpine gel treated eyes (15%) and 11 of 20 control eyes (55%). Pilocarpine treatment was not associated with noticeable changes in intraocular inflammatory response, nor were significant ocular or systemic adverse reactions observed. A single administration of pilocarpine gel is effective in reducing increased intraocular pressure for the first 24 hours after extracapsular cataract extraction.

Cataract Extraction↗
PubMed1981

Influence of untreated chronic plastic iridocyclitis on intraocular pressure in leprous patients.

The intraocular pressures of a total of 1015 eyes of leprous patients who never had ophthalmological care or local eye treatment were measured. The patients were categorised according to the type of leprosy they had the eyes were categorised as without or with chronic plastic iridocyclitis. In patients with the tuberculoid and lepromatous types of leprosy the intraocular pressure was significantly lower in eyes with chronic plastic iridocyclitis than in unaffected eyes. It has been shown that chronic plastic iridocyclitis which remains untreated for many years results in significantly lower intraocular pressure.

Adult↗
PubMed1991

Influence of untreated chronic plastic iridocyclitis on intraocular pressure in leprosy patients.

The intraocular pressures of a total of 286 eyes of patients with lepromatous and borderline lepromatous leprosy who never had regular ophthalmological care or local eye treatment were measured. The patients were categorised according to the type of leprosy they had, and the eyes were categorised as without or with chronic plastic iridocyclitis. In patients with lepromatous and borderline lepromatous types of leprosy the intraocular pressure was significantly lower in eyes with chronic plastic iridocylitis 10.1 (3.6) mmHg than in both unaffected eyes 11.0 (3.2) mmHg and control eyes 13.5 (2.5) mmHg. It has been shown that chronic plastic iridocyclitis which remains untreated for years results in a lower intraocular pressure than normal.

Adult↗
PubMed1976

Changes in the facility of aqueous outflow induced by lens depression and intraocular pressure in excised human eyes.

The effects of intraocular pressure on aqueous outflow facility and mechanical tension on the iridocorneal angle were evaluated in 44 excised postmortem human eyes. Mechanical tension on the iridocorneal angle was induced by depression of the crystalline lens posteriorly in a quantitative manner to simulate the effect of cyclotonia on the facility of aqueout outflow. In eyes perfused at constant intraocular pressure but with stepwise increases in lens depression, the increase in facility of outflow produced by the increased tension on the iridocorneal angle was minimal at low levels of intraocular pressure (2.5 and 5 mm Hg) and greatest at higher levels of intraocular pressure (10 to 25 mm Hg). Conversely, in pairs of eyes perfused over a graded series of increasing intraocular pressure, and subjected to maximal lens depression, facility of outflow remained constant until intraocular pressure exceeded 20 mm Hg; in the fellow eyes, perfused without lens depression, facility of outflow diminished linearly with increasing intraocular pressure.

Adult↗
PubMed1994

Using an anterior chamber maintainer to control intraocular pressure during phacoemulsification.

We describe a phacoemulsification technique that uses an anterior chamber maintainer (ACM) to control intraocular pressure. Continuous irrigation through the ACM maintains pressurized intraocular conditions throughout surgery and when the automated system is not activated. Intraocular pressure is stabilized at predetermined levels with minor fluctuations. Viscoelastics can be used in conjunction with the ACM.

Anterior Chamber↗
PubMed1998

Distribution of intraocular pressure in dogs.

Intraocular pressure (IOP) was measured by four different applanation tonometers in normal dogs. By MacKay-Marg tonometry in 391 dogs (772 eyes) the mean +/- SD IOP was 18.8 +/- 5.5 mmHg (range 8-52 mmHg). Using Tono-Pen XL tonometry in 421 dogs (823 eyes) the mean IOP was 19.2 +/- 5.9 mmHg, and the range was 4.42 mmHg. With MMAC-II tonometry in 80 dogs (158 eyes), the mean IOP was 15.7 +/- 2.8 mmHg with a range of 10-30 mmHg. By pneumatonograph tonometry in 135 dogs (255 eyes), the mean IOP was 22.9 +/- 6.1 mmHg and the range was 10-47 mmHg. In this study 53 breeds were represented. Of those breeds with six animals or more, no significant differences were detected in IOP between breeds (P > 0.353) or sex (P > 0.270). There was a significant decline of 2-4 mmHg (P > 0.0001) in IOP as age increased from less than 2 years to greater than 6 years of age. This trend was present with all of the four tonometers. There were no significant differences between the MacKay-Marg and TonoPen-XL tonometers (P > 0.198), but significant differences with the MMAC-II (P > 0.001) and pneumatonograph (P > 0.001) tonometers existed compared to the first two instruments. Based on this study and the literature, the mean IOP for the normal dog is 19.0 mmHg with a range of 11 (5%) and 29 (95%) mmHg.

Journal Article↗
PubMed1995

Age and intraocular pressure: how are they correlated?

BACKGROUND: The relationship between intraocular pressure and age is not fully understood. Intraocular pressure may increase or decrease with age. PURPOSE: Study was planned to determine the effect of aging on intraocular pressure of an apparently healthy population of Karachi. SUBJECTS AND METHODS: Depending upon age, 8036 subjects were divided into seven groups. All were examined according to standard protocols. Measurements were taken by Goldmann applanation tonometer, after a complete rest for at least 15 minutes and always first in the right eye. RESULTS: Mean intraocular pressure increases progressively with age until 60 years. When one age group is compared with its preceding, the increase is non-significant until 40 years but highly significant (P < 0.001) in the age groups of 41-50 and 51-60 years. The data shows non-significant decrease in the age group of 61-70 but an increase in the age group of above 70 years. CONCLUSION: This study supports the conclusion that as age increases, intraocular pressure also increases, with an average of 0.28 mmHg per decade. Knowledge of the normal range of intraocular pressure in various age groups will help glaucoma screeners.

Adolescent↗
PubMed1989

Estimation of pulsatile ocular blood flow from intraocular pressure.

A relationship has been derived between intraocular pressure and pulsatile blood flow in the eye. Measurements of intraocular pressure show a time variation that is associated with the pulsatile component of arterial pressure. Experimental results provide a means of transforming intraocular pressure changes into ocular volume changes. The eye is represented by a chamber with elastic walls, a pulsatile incoming flow of incompressible fluid (blood), and a steady outgoing flow of blood. Under these conditions, the rate of pulsatile blood flow through the eye can be approximated from the instantaneous intraocular pressure measurements. Data from a healthy human eye are used to illustrate the analysis.

Blood Flow Velocity↗
PubMed1983

Intraocular pressure, cardiovascular risk variables, and visual field defects.

This study evaluates the associations of intraocular pressure with cardiovascular risk factors among 2433 participants in the Framingham Eye Study and the Framingham Heart Study. Persons with intraocular pressure greater than 21 mmHg in at least one eye had an increased prevalence of hypertension and diabetes; no association was found with cardiovascular disease. In multiple regression analysis, systolic blood pressure was the variable most related to intraocular pressure; vertical cup/disc ratio, diabetes, and ventricular rate were also independently related to intraocular pressure. About 6% of the variation in intraocular pressure was explained by these variables. Although blood pressure was associated with intraocular pressure in eyes without visual field defects, this association could not be detected in eyes with field defects; interaction tests found significant differences in the blood pressure-intraocular pressure relationships between visual field groups. Ratios of blood pressure to intraocular pressure were lower in eyes with visual field defects than in eyes without field defects.

Blood Pressure↗
PubMed1989

The pressures in the episcleral veins, Schlemm's canal and the trabecular meshwork in monkeys: effects of changes in intraocular pressure.

The pressures in the episcleral veins, Schlemm's canal and the trabecular meshwork were studied with a micropuncture technique using cannulas with tip diameters of less than 5 microns. The pressure in Schlemm's canal, Psc, was 14.3 +/- 1.0 cmH2O at spontaneous intraocular pressure, IOP, 19.2 +/- 0.9 cmH2O. The outflow pressure from the anterior chamber to Schlemm's canal was 4.9 +/- 0.7 cmH2O. The relationship between pressures was IOP = 0.73 Psc + 8.7. When the intraocular pressure was increased stepwise from the spontaneous level to 30 cmH2O there was an increase in pressure in Schlemm's canal of 1.7 +/- 0.6 cmH2O, (P less than 0.05). The total outflow resistance and the resistance between the anterior chamber and Schlemm's canal were 3.27 +/- 0.43 and 2.92 +/- 0.50 cmH2O min microliter-1 respectively for the intraocular pressure interval between the spontaneous pressure and a level 4-11 cmH2O higher. In the intraocular pressure range from 20 to 30 cmH2O the corresponding figures were 2.89 +/- 0.45 and 2.69 +/- 0.42 cmH2O min microliter-1 and for the pressure range 25-35 cmH2O, 2.48 +/- 0.58 and 2.31 +/- 0.59 cmH2O min microliter-1. The difference between the total outflow resistance and that between the anterior chamber and Schlemm's canal was about 10% of the total at intraocular pressures below 35 cmH2O. Stepwise increments in IOP increased the trabecular meshwork pressure by 0.88 cmH2O for each cmH2O increase in IOP in the interval of 30-50 cmH2O. The total outflow resistance and the resistance between the anterior chamber and the tip of the microcannula was 3.91 +/- 1.53 and 1.94 +/- 0.99 cmH2O min microliter-1 respectively for the intraocular pressure interval between the spontaneous pressure and 30 cmH2O. In the interval between 30 and 45 cmH2O the corresponding figures were 2.16 +/- 0.66 and 0.20 +/- 0.13 cmH2O min microliter-1. The episcleral venous pressure at the spontaneous intraocular pressure was 14.1 +/- 1.0 cmH2O in seven animals with minimal trauma, and 12.3 +/- 0.8 cmH2O in animals after cannulation of Schlemm's canal. The outflow pressure from the anterior chamber to the episcleral veins was 4.4 +/- 1.2 cmH2O in animals with minimal trauma and 7.1 +/- 0.8 cmH2O after cannulation of Schlemm's canal. The relationship between pressures was IOP = 0.68EVP + 11.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1999

High intraocular pressure and survival: the Framingham Studies.

PURPOSE: To examine whether high intraocular pressure (greater than or equal to 25 mm Hg) or a history of treatment for glaucoma is associated with decreased survival and, if so, how such ocular markers might be explained. METHODS: Eye examinations, including applanation tonometry, were conducted on members of the Framingham Eye Study cohort from February 1, 1973, to February 1, 1975. Participants who reported a history of treatment for glaucoma were identified. Survival data, including information on the date of death, were available from the time of the Eye Study through March 31, 1990. RESULTS: Of the 1,764 persons under the age of 70 years at the baseline eye examination, 1,421 persons had low intraocular pressure (< or =20 mm Hg), 264 persons had medium intraocular pressure levels (20 to 24 mm Hg), and 79 persons had high intraocular pressure (> or =25 mm Hg) or history of glaucoma treatment. During the follow-up period, 29%, 30%, and 47% died in the groups with low, medium, and high intraocular pressure (or history of glaucoma treatment), respectively. In an age-and-sex adjusted Cox proportional hazards analysis, the death rate ratio for the group with medium intraocular pressure relative to the group with low intraocular pressure was 1.04. The corresponding death rate ratio for the group with high intraocular pressure was 1.56 with a 95% confidence interval of 1.11 to 2.19 (P < .001). After adjustment for age, sex, hypertension, diabetes, cigarette smoking, and body mass index, a positive relationship remained, but at a borderline level of significance (P = .075). CONCLUSIONS: High intraocular pressure or the presence of glaucoma is a marker for decreased life expectancy in the Framingham Eye Study cohort. The relationship is present even after adjustment for risk factors known to be associated with higher mortality such as age, sex, hypertension, diabetes, cigarette smoking, and body mass index. Special attention to the general health status of patients with high intraocular pressure or glaucoma seems warranted.

Aged↗