Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: UMLS:C0595921 (intraocular pressure)
11,750 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In vivo perfusion of the anterior chamber of normal rhesus monkeys with pooled rhesus aqueous humor gives an initial total facility of 0.48 +/- 0.08 (+/-S.E.) microliter/min/mm Hg. With continued intermittent perfusion for 2 hr this value increased only slightly to 0.57 +/- 0.10 microliter/min/mm Hg. Perfusion of the paired eyes of the same monkeys with glutathionebicarbonate Ringer's solution gives an initial total facility of 0.55 +/- 0.08 microliter/min/mm Hg. This value increased to 1.21 +/- 0.15 microliter/min/mm Hg with continued intermittent perfusion. Thus aqueous is a satisfactory perfusate for experiments requiring prolonged stability of the eye, but glutathione-bicarbonate Ringer's solution is not a satisfactory substitute perfusate. Neither addition of physiologic amounts of ascorbic acid to the buffered salt solution nor careful modification of the pH of the solution to the physiologic level prevented the increase of total facility it produces when used as a perfusate. A reversible, fast-phased small-magnitude increase in total facility was noted in eyes perfused with either perfusate. It is speculated this is caused by neural mechanisms for intraocular pressure control.
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PMID:Perfusate effects upon resistance to aqueous humor outflow in the rhesus monkey eye. A comparison of glutathione-bicarbonate Ringer's solution to pooled aqueous humor as perfusate. 41 44

Thirty eyes of 15 patients with open-angle glaucoma were followed up for a period of up to 1 year while being treated with Piloplex eye drops containg a new long-acting pilocarpine polymer salt. Average morning intraocular pressure (IOP) values during treatment with pilocarpine hydrochloride administered 4 times daily was 20.5 mmHg. Average morning IOP values during Piloplex medication administered only twice daily were 19.8 to 18.2 mmHg (range of averages on 14 sessions). These findings indicate the lower average pressure during Piloplex medication and show its prolonged hypotensive effect. Both medications contained an equivalent total daily amount of pilocarpine. Throughout the 1-year study period no adverse side effects were reported, and only 1 patient complained of local sensitivity reaction. Visual disturbances characteristic of pilocarpine eye drops were reduced from 3 times a day on pilocarpine hydrochloride 4 times daily to once a day on Piloplex twice daily.
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PMID:Piloplex, a new long-acting pilocarpine polymer salt. A: Long-term study. 57 57

Surgical solutions and drugs are important in ocular surgery. These include irrigating solutions, viscoelastic substances, mydriatics and miotics, and a growing number of other agents designed to enhance intraocular surgery and its outcome. Potential for damage to the corneal endothelium and other tissues is related to the chemical composition, pH, and osmolality of the irrigating solutions that bathe tissues. Quality balanced salt solutions (BSS) are usually safe for use as an intraocular solution in patients with normal corneal endothelium. If prolonged irrigation times are expected, or the patient already has decompensated endothelium, i.e., primary or secondary endotheliopathy, the use of a "complete" BSS solution is indicated to minimize damage. Intraocular sulfite-containing epinephrine may cause severe corneal edema and should be avoided, or if used, be well diluted. Sulfite-free epinephrine solution is now available and does not cause the endothelial toxicity that one may see with sulfite-containing epinephrine solutions. Current formulations of acetylcholine and carbachol used as miotics in surgery have been evaluated in humans and caution is recommended in using acetylcholine solutions intracamerally in patients with already decompensated endothelium. Chondroitin sulfate, hydroxypropyl methylcellulose, and sodium hyaluronate are non-toxic to animal endothelial cells under conditions analogous to cataract extraction in humans but can be toxic to endothelium if there is continued contact with endothelium for hours. Chondroitin sulfate has been shown to have more of a protective effect in mechanical pseudophakos trauma probably because of its cohesiveness and tendency to coat the endothelium. Viscoelastics cause a significant rise in intraocular pressure of > 30 mm Hg in 3-10% of patients. Very high intraocular pressures are often seen postoperatively after viscoelastic use surgically in patients who preoperatively have a history of ocular hypertension or glaucoma.
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PMID:Overview of the corneal toxicity of surgical solutions and drugs: and clinical concepts in corneal edema. 130 90

Prostaglandin F2 alpha (PGF2 alpha) is a powerful ocular hypotensive agent in rabbit, cat, dog, monkey and human. In cynomolgus monkeys, the intraocular pressure (IOP) lowering is due to increased uveoscleral outflow (Fu). Because the anatomy of the rabbit outflow apparatus differs significantly from that of the primate, we sought to determine whether the mechanism of the PGF2 alpha-induced IOP fall was the same. PGF2 alpha tromethamine salt (PGF2 alpha-TS) (50 micrograms) applied to one eye of 14 conscious rabbits produced a significant IOP fall of 7.4 +/- 0.9 mmHg (P less than 0.001). In untreated control eyes, Fu determined from the quantity of intracamerally perfused [125I]albumin found in the ocular and periocular tissues accounted for 5-8% of total aqueous outflow. In 15 unilaterally PGF2 alpha-treated rabbits, after 4-6 hr dosing Fu was 49 +/- 14% higher in the treated than in the contralateral control eyes. Total outflow facility of outflow from the anterior chamber to the general circulation were measured concurrently in 11 rabbits using a two-level constant pressure perfusion and isotope accumulation technique. Both facilities tended to be higher in the treated eyes than in the controls, with a strong correlation between drug-induced changes in total facility and changes in facility of flow to blood (r = 0.85, P less than 0.001). In eight rabbits treated unilaterally with 50 micrograms PGF2 alpha-TS, the fluorophotometrically determined aqueous formation rate was probably not decreased relative to control eyes. Protein levels in the aqueous humor were approximately eight-fold higher in PG-treated vs. control eyes, suggesting a drug-induced compromise of the blood-aqueous barrier.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:The effect of topical PGF2 alpha on uveoscleral outflow and outflow facility in the rabbit eye. 155 55

In this study 150 pig corneas and 20 human corneas were dissected with an automatic rotating microkeratome for lamellar grafting. The cornea thickness varied between 0.507 mm and 0.829 with an average 0.66 mm. The aim of this investigation was to show the influence of corneal thickness, the chosen diameter and spacing on the precision of cutting lenticles. We did ten series: the pig corneas were dissected at three different intervals of 0.15, 0.25, 0.35 mm and diameters of 9 and 6mm. The human corneas were cut at intervals of 0.4 mm and 0.25 mm and with diameter of 9 and 7 mm. Although the pig corneas were fresh, the intraocular pressure was too low. It was raised with an injection of physiological salt solution to a predefined level. The rotating speed of the trephine blade, the speed of blade advancement and lubrication fluid were kept constant. Ultrasound pachymetry was performed on the center of the corneas before cutting had on the lenticles afterward. We showed that a thick corneal diameter had a negative influence, i.e., the greater the diameter, the lesser the precision; the same was true for the corneal thickness. On the other hand, the intervals had just the opposite effect: the closer they were, the better the correlation. The human eye results were different in quantity but not in tendency, with less striking effects. The average variation for pig corneas was 22% and for human eyes 8%. The best results were received with a large interval, a small diameter, and a normal corneal thickness in human eyes.
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PMID:[Precision of lenticular thickness in relation to full stroma corneal thickness. Experimental results with the lamellar microkeratome]. 160 Mar 23

Isobutylmethylxanthine (IBMX) suspended in 0.5% hydroxypropyl methylcellulose has been shown to enhance the reduction in intraocular pressure (IOP) induced by epinephrine and norepinephrine in rabbits and beagles. In the present study, the effects of two soluble forms of IBMX, i.e. the ethylenediamine salt (IBMX-ED) and IBMX bound to cyclodextrin in saline (IBMX-CD), were studied in rabbits. When used alone, 1% IBMX-ED did not affect the IOP, but the hypotensive response to 0.1% epinephrine was enhanced dose-dependently by combination of the catecholamine with IBMX-ED. Although 1% IBMX-CD applied alone also failed to influence the IOP, the hypotensive response to epinephrine, dipivalyl epinephrine and norepinephrine was enhanced by combination of these substances with IBMX-CD. Soluble IBMX-ED as well as soluble IBMX-CD and the IBMX suspension enhanced, to a similar extent and in a dose-dependent manner, the IOP reduction induced by catecholamines. IBMX-CD, which has a neutral pH, may be a suitable form of IBMX for future long-term experiments.
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PMID:Soluble forms of isobutylmethylxanthine enhance the ocular hypotension induced by catecholamines. 172 76

The prolonged in vitro release of pilocarpine (1) from preparations containing polyacrylic acids were represented consecutively . A preparation of polyacrylic acid-F (PAS-F; an acrylic-methacrylic acid copolymer) does not irritate the eyes. According to miotic activity tests in rabbits, the activity is prolonged by PAS-F as well as Carbopol 940 preparations. Differences between the compared preparations are not obtained. In human studies, the 1 action is prolonged and the intensity is increased by PAS-F and Carbopol containing preparations compared with aqueous 1 solution (relative bioavailability about 200%; the duration of the intraocular pressure is 4.5 times in the therapeutical relevant level). A polymeric salt of 1 and PAS-F was particular suitable in this study.
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PMID:[Antiglaucoma ophthalmic agents with prolonged action based on macromolecular excipients. 2. In vivo studies]. 208 Feb 4

Hypotensive and other ocular effects were studied for 24 hr after topical application of prostaglandin F2 alpha as the tromethamine salt (PGF2 alpha) in 45 normotensive human subjects. After baseline intraocular pressure (IOP) measurements, 62.5 micrograms, 125 micrograms and 250 micrograms of PGF2 alpha dissolved in 50 microliter of saline was applied to one eye of 15 subjects for each dose tested. Contralateral control eyes received 50 microliter of saline. As compared with the IOP of the contralateral control eyes, topical application of 62.5 micrograms PGF2 alpha caused a significant IOP reduction at 1-12 hr, with a maximal IOP reduction of 2.2 mm Hg at 2 hr. Treatment with 125 micrograms of PGF2 alpha lowered IOP significantly at 1-21 hr, with a maximal reduction of 3.1 mm Hg at 9 hr. Administration of 250 micrograms PGF2 alpha produced a significant reduction of IOP, which lasted for at least 24 hr. A maximal IOP reduction of 2.9 mm Hg occurred at 7 hr. Pupillary diameter was not altered. Aqueous flare and anterior chamber cellular response were not seen in any of the eyes of the subjects at any time after topical application of 62.5-250 micrograms PGF2 alpha. The drug caused side effects consisting of reddened skin of lower lid, ocular irritation, conjunctival hyperemia and headache.
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PMID:The effect of prostaglandin F2 alpha on intraocular pressure in normotensive human subjects. 317 Jan 19

Single topical applications of prostaglandin F2 alpha (PGF2 alpha) tromethamine salt to living cynomolgus monkey eyes reduced intraocular pressure (IOP). Twice daily topical application was far more effective, so that after the 7th 50 micrograms or 100 micrograms dose on day 4, IOP fell 40-50%, to 8-10 mm Hg. Following twice daily application of 50 or 100 micrograms for greater than 3 days: (1) no increase in total outflow facility could be demonstrated by 2-level constant pressure perfusion or Schiotz tonography; (2) no decrease in aqueous humor formation rate could be demonstrated by fluorophotometry--rather, aqueous flow may have increased; (3) anterior chamber aqueous humor protein concentration was unaltered, but entry of intravenously injected fluorescein into the cornea and anterior chamber tended to increase; (4) there was a weak but sometimes statistically significant miosis of up to approximately 0.5 mm. We conclude that in the cynomolgus monkey: (1) PGF2 alpha is a potent ocular hypotensive agent with only very weak miotic and blood-aqueous barrier-disrupting effects; (2) the ocular hypotensive action of PGF2 alpha is definitely not due to increased conventional outflow facility or decreased aqueous production, but probably to increased uveoscleral drainage of aqueous humor.
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PMID:Effects of topical PGF2 alpha on aqueous humor dynamics in cynomolgus monkeys. 347 75

A clinical comparison of an emulsion containing a new pilocarpine polymer (Polym) compound to that of a traditional pilocarpine salt solution (Plc) on the intraocular pressure (IOP) has been performed in 40 open-angle patients treated with the long acting pilocarpine-complex for 120 days. The treatment protocol was divided into 3 stages: Stage 1 is a single dose treatment where 12 patients were divided randomly into 2 groups of 6 each. The patients of each group were given 1 drop into each eye: 1 drop every 12 hours for Polym, 1 drop every 6 hours for Plc. The patients were observed for a period of 24 hours. After 24 hours without medication, the treatments were crossed over and nycthemeral graph curves were registered for both groups. Stage 2 is a medium term study were the 12 patients used in Stage 1 were added to another 28 patients. All 40 were then assigned to 1 of 2 treatment groups (2 groups of 20 patients each) according to a table of random numbers. Treatments were administered during one month, then cross-overed again during 4 weeks. Stage 3: finally, every patient could choose his treatment (either Polym or Plc) for the rest of the period (2 months). The clinical study shows that the polymer complex (Polym) produced a prolonged therapeutic effect, this being consistant with a slow release pattern and maintained a more effective around-the-clock control than pilocarpine solution. These results were accomplished by two applications per day as compared to the four necessary applications of Plc, on a half daily pilocarpine dose with Polym. The medium term results confirmed the efficacity noted in the short term survey. Most patients preferred Polym to Plc when they were asked. Throughout the 4 months study period, no adverse side effects were reported. Visual disturbances characteristic of pilocarpine eye-drops were reduced from 3 times a day on pilocarpine salt solution to once a day on pilocarpine polymer complex.
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PMID:[Effect on pressure after instillation of a drop of depot-pilocarpine. Clinical results of its medium-term action]. 635 Apr 12


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