Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0033377 (prolapse)
 11,717 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The selective DA2 agonist, N-0437, produced an acute reduction in intraocular pressure (IOP) and pupil diameter (PD) when applied topically to the eyes of normal monkeys. Ocular hypotension and miosis were primarily unilateral in nature, dose-related and lasted 3 to 5 hours following drug instillation. In normal monkeys, 24 to 48 hours following drug administration, a secondary chronic (greater than 24 hrs) reduction in pressure was observed. Once-a-day topical administration of N-0437 (250 micrograms), to normal monkeys, for 4 days produced a chronic unilateral reduction in IOP that persisted for 18 days. Associated with this reduction in pressure on day 2 through 6 were miosis and ptosis of the treated eye. Although topical administration did not lower IOP in rabbits, intracameral injection of N-0437 significantly depressed IOP for 3 days when compared to control injected eyes. Evaluation of ocular sympathetic innervation in N-0437 treated rabbits indicated that these fibers were not functional. In rabbits, intracameral administration of the active (S,-) and inactive (R,+) enantiomer of N-0437 produced equivalent reductions in pressure. These data provide further support for the hypothesis that DA2 receptor agonists can produce acute reductions in IOP. In addition, N-0437 appears to have a second non-receptor mediated mechanism of action that produces a chronic reduction in IOP. This chronic reduction in pressure appears, in part, to result from an interruption of ocular sympathetic nerves function.
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PMID:Ocular effects of a N,N-disubstituted 5-OH aminotetralin (N-0437): evidence for a dual mechanism of action. 342 80

The major factors controlling intraocular pressure during surgery are the dynamic balance between aqueous humour production in the ciliary body and its elimination via the canal of Schlemm; the auto-regulation and chemical control of choridal blood volume; the extraocular muscle tone and vitreous humour volume. Prior to surgical incision of the anterior chamber in open intraocular procedures, a low-normal intraocular pressure is mandatory to avoid the hazards of iris or lens prolapse and vitreous loss associated with sudden decompression. In general, the central nervous system depressant drugs, hypnotics, narcotics, major tranquillizers, volatile anaesthetic agents are associated with a reduction in intraocular pressure, with the exception of ketamine and possibly trichloroethylene. The mechanism of action of anaesthetic agents in reducing intraocular pressure may involve a direct effect on central diencephalic control centres, reduction of aqueous production, facilitation of aqueous drainage or relaxation of extraocular muscle tone. Succinylcholine administration is associated with a significant rise in intraocular pressure, with a peak increase between two to four minutes following administration and a return to base line values after six minutes. The intraocular hypertensive effect may be due to a tonic contraction of the extraocular muscles, choroidal vascular dilatation or relaxation of orbital smooth muscle. Despite many claims to the contrary, no reported method to date has been shown to consistently prevent the intraocular hypertensive response to intravenous succinylcholine administration. Because the non-depolarizing relaxants are associated with a reduced intraocular pressure, a barbiturate-non-depolarizing relaxant technique utilizing preoxygenation and cricoid pressure has evolved as the most commonly employed induction technique for the emergency repair of a penetrating eye injury. The alternative non-depolarizing relaxant pretreatment-barbiturate-succinylcholine technique may offer the advantages of more rapid onset of relaxation with only minor increases in intraocular pressure and in a carefully controlled rapid sequence induction technique may be the most acceptable method of handling emergency penetrating eye injuries.
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PMID:Intraocular pressure--physiology and implications for anaesthetic management. 351 35

In a chart review of 100 consecutive Nd:YAG laser capsulotomies, six presumed risk factors of the rise in intraocular pressure (IOP) after capsulotomy were identified. A group of 15 patients in which the pressure rose to at least 10 mmHg above baseline postoperatively showed a significant (P less than or equal to 0.01) association with myopia, vitreoretinal disease, and vitreous prolapse into the anterior chamber. The previously known association of high pressures with glaucoma, a large capsular opening, or absence of a posterior chamber lens were also confirmed. There was no correlation between the energy used and IOP. These retrospective findings are suggestively consistent with the concept that injury to a liquefied vitreous may contribute to the IOP rise after capsulotomy.
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PMID:Vitreoretinal changes associated with rise in intraocular pressure after Nd:YAG capsulotomy. 356 34

An ICCE was complicated by iris prolapse. Three years later the eye appeared quiet and intraocular pressure was normal when the patient was admitted for secondary implantation. An uneventful IOL implantation (CILCO MT 4U) was followed by hypertensive uveitis. Local and systemic corticosteroids and antihypertensive treatment were insufficient. Cryocoagulation of the bleb was performed. The inflammation rapidly subsided and intraocular pressure normalized without further therapy.
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PMID:[Cryocoagulation of a prolapsed iris in hypertensive uveitis]. 358 41

We studied five cases of acute choroidal effusion that occurred during intraocular surgery and one case of a localized choroidal hemorrhage. Acute intraoperative choroidal effusion is a poorly recognized surgical complication and may precede expulsive hemorrhage in many cases. The treatment is immediate closure of the wound, after which the intraocular pressure may rise to 80 mm Hg or more. However, the pressure will return to normal after 15 to 30 minutes and the area of effusion will remain localized. Scleral puncture to drain fluid is not indicated if the wound can be closed before there is a prolapse of the iris or other intraocular tissues.
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PMID:Acute intraoperative choroidal effusion. 389 37

This study describes the surgical treatment and eventual outcome of 15 cases of anterior-segment penetrating ocular trauma that would be classically considered as having a poor prognosis. Signs of poor prognosis included: corneal lacerations, complicated by signs of infection ranging from infiltration to necrotic digestion; large scleral lacerations, with ciliary body or choroidal prolapse; and an exaggerated inflammatory response to the trauma. Treatment included careful microsurgical techniques, vitrectomy (when necessary), use of antibiotics and anti-inflammatory agents, and the liberal use of sodium hyaluronate to break fibrin adhesions and maintain the chamber at the close of surgery. Such treatment resulted in no enucleations, an average best corrected visual acuity of 20/80, an average normal angle of 314 degrees, and 13 cases of normal intraocular pressure without medication.
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PMID:Use of sodium hyaluronate in severe penetrating ocular trauma. 395 2

Dural shunts are vascular communications in which blood flows through small meningeal branches of the carotid arteries to enter the venous circulation near the cavernous sinus. The features of 10 patients with dural shunts are described. Most of these patients were postmenopausal women with dilated episcleral vessels, unilateral elevation of intraocular pressure, and exophthalmos. Pain or discomfort was common and ptosis or limited eye movement was usually present. These findings were characteristically more mild than those associated with carotid-cavernous sinus fistulas. CT scans usually showed enlargement of the extraocular muscles and the superior ophthalmic vein. Arteriography visualized partial or complete occlusion of intracranial venous drainage posterior to the cavernous sinus in all patients. Vascular dynamics of dural shunts are reviewed, and it is suggested that many of these communications may be congenital and that the onset of clinical abnormalities may be associated with the occurrence of intracranial venous thrombosis. Most patients eventually had resolution of their clinical abnormalities without treatment, and in some cases this improvement occurred soon after carotid arteriography.
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PMID:The dural shunt syndrome. Pathophysiology and clinical course. 670 19

Over a period of 4 months, 16 of 24 patients (30 of 46 eyes) with either primary open angle glaucoma (POAG) or suspected glaucoma were treated successfully with a maintenance dose of guanethidine (3%) and adrenaline (0.5%) combined in one eyedrop (GA) once daily. In the previous month the medication was given twice daily and at the end of 4 months the decrease in intraocular pressure (IOP) was 8.9 mm Hg (33%) compared to 9.9 mm Hg (37%) with twice-daily application; three of four eyes responded just as well to single-daily application as to twice daily application of GA. Once-daily treatment with GA was not successful when the average IOP in the absence of treatment was over 32 mm Hg. The advantages of once-daily application were less conjunctival hyperemia, less dilation of the pupils, less ptosis and difficulty reading, plus the advantage that the drops needed only to be applied once a day (patient compliance). The recommended regime for GA therapy in patients with an IOP of less than 32 mm Hg is application of GA twice daily for 1 month followed by a decrease in the dosage to once a day. GA can best be applied in the evening before retiring.
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PMID:Maintenance therapy of glaucoma patients with guanethidine (3%) and adrenaline (0.5%) once daily. 690 83

A trial of the efficacy of low-concentration nonmiotic therapy was carried out, the aim being to minimise the side effects produced by 1% adrenaline or pilocarpine. A total of 77 eyes with open-angle glaucoma were studied in both parts of the trial. Thirty-nine eyes had a base-line pressure of over 28 mmHg and 28 eyes a pressure of 30 mmHg or over. In the comparison between Ganda 1.02 and adrenaline 1% (Simplene) the mean lowering of intraocular pressure was 8.6 mmHg with Ganda and 7.69 mmHg with Simplene. In the comparison between Ganda 1.02 and pilocarpine 1% (Sno-Pilo) the mean decrease was 6.34 mmHg with Ganda and 6.13 mmHg with Sno-Pilo. The resulting falls in intraocular pressure were highly significant statistically, but the differences between the effects of the 3 drugs were not significant. No significant side effects were reported with Ganda 1.02, and in particular no ptosis or superficial punctate staining of the cornea was noted.
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PMID:Double-masked cross-over comparison of Ganda 1.02 (guanethidine 1% and adrenaline 0.2% mixture) with gutt. adrenaline 1% (Simplene 1%) and with pilocarpine 1% (Sno-Pilo 1%). 700 78

The closure of 2 or more vortex veins in rabbits' eyes results in a persistent rise in intraocular pressure. In these circumstances a small opening into the anterior chamber at the corneoscleral limbus resulted in an iris prolapse, while a larger limbal wound was immediately followed by a massive choroidal expulsive haemorrhage. It appears from this experimental study that a definite and persistent rise in intraocular pressure could be a sign of impaired venous outflow and that the occurrence of an iris prolapse after small limbal opening into the anterior chamber should prompt us to examine the fundus of the eye and look for a choroidal complication. It is possible that the present set of experiments is relevant to the mechanism of expulsive haemorrhage in man.
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PMID:Expulsive choroidal haemorrhage: an experimental study. 705 42


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