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 28,634 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In a clinicopathologic study of ten patients, utilizing a modified trabeculectomy technique for acquisition of histologic specimens, a high insertion of the iris was observed in four types of developmental glaucoma. A survey of the literature revealed additional developmental disorders with this abnormality of the anterior chamber angle. The common defect is believed to arise from a developmental arrest during the third trimester of gestation of tissues derived from cranial neural crest cells. The mechanism by which this developmental defect leads to aqueous outflow obstruction may, in some cases, be a paradoxical collapse of the trabecular meshwork and Schlemm's canal in response to contraction of the ciliary musculature, while other patients may have additional developmental abnormalities in the aqueous outflow system as the possible mechanism of glaucoma.
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PMID:A common pathway for developmental glaucomas. 332 16

The effect of sodium hyaluronate (Healon) on the post-operative course 1 week, 1 month and 1 year after trabeculectomy is reported. Forty-six eyes of 38 patients with open-angle glaucoma (16 simple, 16 capsular and 14 secondary glaucomas) were operated with the use of sodium hyaluronate. The study was prospective. For comparison, 46 eyes of 38 age-, sex- and diagnosis-matched patients with glaucoma operated during the pre-Healon period were selected. Patients in the study group were operated by the same surgeon and in the control group by different senior staff members. IOP decrease was essentially the same in both groups. No differences in post-operative pressure level existed between the different types of glaucoma. Extremely shallow or flat chamber occurred more frequently in the control series: 15 versus 9. Statistical analysis could not be applied. The trend in favour of Healon is discussed. Pressure rise greater than or equal to 30 mmHg 2-7 days after the operation was diagnosed in 8 eyes of the Healon group and 13 eyes of the control group. IOP rise was relieved by argon laser treatment of the fistula during the first week post-operatively in 6/8 eyes of the Healon group in order to facilitate aqueous drainage. Sodium hyaluronate facilitated the technical performance and prevented collapse of anterior chamber and AC haemorrhages during the operation. Sodium hyaluronate seems to prevent excessive early filtration and hypotony.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Trabeculectomy with the use of sodium hyaluronate. One year follow-up. 343 37

The effect of sodium hyaluronate (Healon) on the post-operative course and IOP 1 week and 1 month after trabeculectomy is reported. Twenty-nine eyes of 23 patients with open-angle glaucoma (10 simple, 11 capsular and 8 secondary glaucoma) were operated with the use of sodium hyaluronate. The study was prospective. For comparison, 29 eyes of 21 age- and sex-matched patients with glaucoma, operated during the pre-Healon period were selected. Patients in the study group were operated by the same surgeon and in the control group by different senior staff members. The method for trabeculectomy is described. IOP decrease was 56 and 54% in the H- and control group. No differences in post-operative pressure level existed between the different types of glaucoma. Shallow or flat chamber occurred frequently in both groups, but had a greater incidence in the control group. Sodium hyaluronate seems to prevent early excessive filtration. In five eyes of both groups choroidal detachment was simultaneously present. The incidence of choroidal detachment was the same as the overall incidence of this complication in this clinic. Post-operative pressure rise of greater than 30 mmHg after restoration of a flat chamber was more frequent in the control series. Sodium hyaluronate is useful in trabeculectomy. It prevents collapse of the anterior chamber and hyphema during the operation, it stabilizes early post-operative pressure and prevents excessive filtration combined with shallow or flat anterior chamber. It does not prevent choroidal detachment after trabeculectomy.
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PMID:Trabeculectomy with the use of sodium hyaluronate. A prospective study. 377 5

Thirty-four consecutive glaucoma triple procedures with a minimum follow up of six months have been shown to be effective and safe. Satisfactory control of the glaucoma was achieved in each case, and 91% of eyes were returned to an acuity of 6/12 or better. 1% sodium hyaluronate was found to be beneficial by preventing scleral or corneal collapse during surgery and ensuring an even filtration postoperatively without hypotony.
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PMID:Glaucoma triple procedure of extracapsular cataract extraction, posterior chamber lens implantation, and trabeculectomy. 396 4

Laser-induced collapse of the blood-aqueous barrier and the protective effect of different prostaglandin inhibitors were investigated in the animal study reported here. As a parameter of the barrier function, the protein concentration in the aqueous humor was measured using a micromethod. The anterior chamber of 90 eyes (45 rabbits) was tapped only once, 100 min after the laser procedure. The results prove that different prostaglandin inhibitors in a systemic or topical application form can effectively reduce disturbances of the blood-aqueous barrier after laser surgery. This is also of clinical relevance with regard to laser iridotomy or trabeculoplasty in glaucoma.
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PMID:[Collapse of the blood-aqueous humor barrier following laser injury--preventive pharmacotherapy with prostaglandin inhibitors]. 403 55

A historical recall and an attempt to simplify the numerous terms used to designate laser treatments for primary open-angle glaucoma (POAG) are presented. There are two main types of laser treatment for POAG involving two entirely different procedures. The first one, contemporary with the beginning of laser photocoagulation, imitates the action of the scalpel, namely goniotomy ab interno or trabeculotomy ab externo. The goal of this early procedure was to produce a through and through trabecular hole but instead of the cutting edge of the knife, it uses the explosive effect of the laser. This procedure has been given numerous names. Among the most frequent ones, we find: 'laser trabeculopuncture', 'laseropuncture', 'goniopuncture', 'laser trabeculectomy', 'laser trabeculotomy', 'laser trabeculopexy'. We prefer to gather them under an explicit generic term: 'laser trabeculoperforation'. The results of this procedure have been very disappointing until now, particularly with conventional lasers, e.g. continuous-wave argon laser, owing to the predominance of their thermal effect over their explosive effect and also to the great scarring property of the trabecular meshwork. In the second type of glaucoma laser treatment, instead of trying to make a patent hole in the trabecular meshwork, the surgeon seeks to reshape the inner trabecular surface by means of argon laser microscars in order to produce a reversal of the trabecular collapse, which is now considered to be one of the major etiologies of POAG.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Trabeculoperforation? Trabeculoretraction? Trabeculoplasty? Review of the various designations used for laser treatment in primary open-angle glaucoma. 405 61

Model experiments and mathematical analysis of intraocular pressure and blood flow show that as venous pressure is increased there is a rapidly increasing tendency for intraocular veins to collapse. Vein collapse slows blood flow markedly. We propose that the visual field loss in glaucoma secondary to elevated venous pressure is associated with intraocular vein collapse and retardation of intraocular blood flow.
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PMID:Mechanism of glaucoma secondary to increased venous pressure. 406 37

Proton beam irradiation resulted in clinical and/or histopathological regression of large ciliary body and choroidal melanomas in three eyes. Enucleations were performed 6 1/2 weeks, five months, and 11 months after irradiation for angle-closure glaucoma from total retinal detachment, increase in retinal detachment, and neovascular glaucoma, respectively. A direct relationship was found between the length of the interval from irradiation to enucleation and the degree of histologic changes. Vascular changes in the tumors included endothelial cell swelling and decreased lumen size, basement membrane thickening, collapse of sinusoidal vessels, and thrombosis of vessels. Although apparently unaltered tumor cells remained, degenerative changes occurred in some melanoma cells, including lipid vacuoles in cytoplasm, pyknotic nuclei, and balloon cell formation. Patchy areas of necrosis and proteinaceous exudate were present. Pigment-laden macrophages were found near tumor vessels and all had a substantial chronic inflammatory infiltrate. The effect of proton beam irradiation on tumor vessels probably plays an important role in uveal melanoma regression.
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PMID:Ciliary body and choroidal melanomas treated by proton beam irradiation. Histopathologic study of eyes. 631 Nov 46

In this retrospective study the results of trabeculectomy in 21 patients with open-angle glaucoma and no previous eye surgery who were followed up for at least 1 year were analysed. In 10 patients sodium hyaluronate had been injected during the operation to cushion the anterior chamber; the other 11 patients served as controls. The two groups had been comparable preoperatively with respect to characteristics assessed postoperatively. The subjects in the sodium hyaluronate group had better visual acuity and less postoperative hypotony. Although the series was too small to statistically validate the following observations, these subjects had better visual fields, their intraocular pressure was easier to control, and they had fewer complications; in particular, none had collapse of the anterior chamber.
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PMID:Sodium hyaluronate in trabeculectomy: a retrospective study. 652 77

A mathematical model of Schlemm's canal is developed to simulate collapse of the canal and its effect on resistance to flow through the aqueous outflow network. Schlemm's canal is modeled as a porous, compliant channel that is held open by the trabecular meshwork. The trabecular meshwork is modeled as a series of linear springs that allow the inner wall of Schlemm's canal to deform in proportion to the local pressure drop across it. Based on comparisons between the model and results in the literature, the following tentative conclusions are reached: (1) Most of the resistance in the aqueous outflow network occurs in the inner wall of Schlemm's canal. (2) Glaucoma is not caused by a weakening of the trabecular meshwork and a resultant collapse of Schlemm's canal alone. Instead, glaucoma probably results from an increased flow resistance of the inner wall of the canal.
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PMID:The role of Schlemm's canal in aqueous outflow from the human eye. 683 7


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