SEARCH · PubMed Health

Results for “Vitrectomy”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 703 records · Page 39Linked to original sources

PubMed1990

[Vitrectomy in the early treatment of extensive penetrating eye injuries. Comparative studies].

Presented are early and late results of treatment of extensive perforating eye injuries treated by vitrectomy immediately after the patient reported for a hospital treatment. For comparison--a similar group of patients with corresponding posttraumatic lesions was selected; they were treated by traditional methods and in some cases also by vitrectomy but performed only for the treatment of late complications. The results obtained confirm the necessity of early vitrectomy as a method of reconstruction of the anatomical conditions after an extensive perforating injury.

Adolescent↗

PubMed1989

Posterior chamber lens implantation following pars plana lensectomy and vitrectomy in severe proliferative diabetic retinopathy.

In two patients secondary cataracts developed after pars plana vitrectomy. In both cases the lens was removed from the pars plana, and the anterior capsule was kept intact. In one patient a posterior chamber lens was placed in the ciliary sulcus 3 months after the lens had been removed, and in the other patient a posterior chamber lens was implanted intraoperatively after pars plana lensectomy and vitrectomy. Improved visual results were obtained in both cases, and there was no evidence of rubeosis or elevated intraocular pressure. In selected cases preservation of the anterior capsule may be important to implant posterior chamber lenses in eyes requiring pars plana lensectomy and vitrectomy. To our knowledge this technique has not previously been reported.

Aged↗

PubMed1989

Endothelial cell counts following pars plana vitrectomy in pseudophakic and aphakic eyes.

In 13 pseudophakic eyes, endothelial cell counts remained stable following pars plana vitrectomy. The posterior chamber pseudophakos apparently had a protective effect on the corneal endothelium, even though the posterior lens capsule was removed during surgery. By contrast, in nine aphakic eyes, a statistically significant (p greater than .05) cell loss of 7.6% occurred after pars plana vitrectomy. We conclude that vitrectomy therefore poses an increased risk to the cornea in aphakic, but not in pseudophakic eyes.

Aged↗

PubMedDate not supplied

Pars plana vitrectomy in the treatment of chronic aphakic cystoid macular edema.

Long-standing cystoid macular edema was evaluated in three groups of aphakic patients: Group A following vitrectomy, Group B without vitrectomy, and group C without vitrectomy but with associated background diabetic retinopathy. After a two-year follow-up period, no significant differences in resolution of cystoid macular edema and visual acuity were found between the three groups.

Aphakia, Postcataract↗

PubMed1982

Regression of diabetic rubeosis iridis following successful surgical reattachment of the retina by vitrectomy.

The relationship between successful surgical reattachment of the retina following diabetic vitrectomy and regression of preoperative rubeosis iridis was investigated. Seventy-nine (9.2%) of 850 diabetic cases undergoing vitrectomy had both preoperative iris rubeosis and retinal detachment. The iris could be adequately evaluated and the retina could be visualized after surgery in 36 cases. Regression of the rubeosis iridis occurred after surgery in 16 (76%) of 21 eyes in which the retina was reattached successfully. Only four (27%) of 15 eyes had regression of rubeosis iridis when the retina was not reattached completely. Retention of the lens also correlated with regression of rubeosis iridis. Regression occurred in 10 (55%) of 18 cases in which the lens was not removed, 13 (28.2%) of 46 eyes in which lensectomy was combined with vitrectomy, and none of eight previously aphakic eyes. Although the combination of preoperative retinal detachment and rubeosis iridis is associated with a worsened prognosis, successful reattachment of the retina and retention of the lens favorably influence later regression of preoperative rubeosis iridis.

Cataract Extraction↗

PubMed1983

Characterization of membranes removed during open-sky vitrectomy.

Membranes removed during open-sky vitrectomy have been characterized by electron microscopy, reaction with anti-human fibrinogen, susceptibility to enzymatic digestion, amino acid analysis, and electrophoresis in sodium dodecyl sulfate. There were significant differences between longstanding and newly formed membranes. Longstanding membranes contained substantial amounts of hydroxyproline, glycine, and hydroxylysine, were capable of digestion by collagenase but not by plasmin, yielded faint positive results with anti-human fibrinogen, and showed fibrils characteristic of collagen by electron microscopy. After digestion with pepsin, electrophoresis revealed bands that migrated the same distance as vitreous collagen chains. This type of membrane is evidently collagenous in nature. A second type of membrane, which developed in the course of vitrectomy, contained no hydroxyproline, only traces of hydroxylysine, and relatively small amounts of glycine, was digested by plasmin, yielded strong positive results with anti-human fibrinogen, and showed fibers that were not characteristic of collagen by electron microscopy. Electrophoresis demonstrated bands similar to authentic fibrin in these newly formed membranes. These data suggest that this second type of membrane is composed largely of fibrin. Prevention of the formation of this second type of membrane during vitrectomy may require the addition of agents that inhibit fibrin formation.

Amino Acids↗

PubMed1984

Comparison of intraocular irrigating solutions used for pars plana vitrectomy and prevention of endothelial cell loss.

We performed a prospective study of corneal endothelial cell loss following pars plana vitrectomy. Two different intraocular irrigating solutions were used, and the anterior capsule of the lens was removed when performing lensectomy. The central corneal endothelium was photographed with a specular microscope before and at three months after vitrectomy. Endothelial cell loss was calculated using a computer-assisted digitizer. In the 16 aphakic eyes, lactated Ringer's solution caused a significantly greater cell loss (31.1%) with resultant corneal edema when compared to BSS Plus (6.9%). All of the 17 phakic eyes showed minimal cell loss (1.0%) as well as corneal changes regardless of the kind of irrigating solution used. The results suggest that the absence of the lens is a salient factor in corneal endothelial damage during vitrectomy, and that the composition of the intraocular solution used is closely related to this endothelial damage.

Acetates↗

PubMed1983

Vitrectomy in children.

A series of 24 consecutive pars plana posterior vitrectomies in children is reported. The postoperative visual acuities improved in 59%, were unchanged in 23%, and worsened in 28%. Trauma was the most common predisposing etiologic factor to vitrectomy and accounted for 59% of cases. Boys in the series outnumbered girls by a ratio of nearly 3:1, a factor most likely attributable to the high incidence of trauma. In no case did visual loss occur as a direct result of vitrectomy.

Adolescent↗

PubMed1995

Effects of local hypothermia on uveal blood flow and postoperative inflammation in vitrectomy.

Effects of local hypothermia on uveal blood flow and postoperative inflammation were evaluated in experimental vitrectomy in albino rabbits. Solutions used for intraocular perfusion were maintained at 9 degrees C, 22 degrees C or 37 degrees C. Following closed vitrectomy, the vitreous cavity was irrigated for 60 minutes. Temperatures at various sites and uveal blood flow were measured before and during the procedure. Aqueous protein concentrations were checked on postoperative days 1, 7 and 14. There was a larger decrease in temperature at the retina than at the choroid or the ciliary body. Blood flow at the ciliary body was reduced to 76.0% and that at the choroid to 77.0% of the preoperative level after 60 minutes of irrigation at 9 degrees C. The decrease was 91.0% and 88.3%, respectively, after 60 minutes of irrigation at 22 degrees C. Aqueous protein concentrations in the 9 degrees C and 22 degrees C groups were significantly lower than those in the 37 degrees C group on the first postoperative day in the eyes irrigated for 60 minutes. In the eyes irrigated for 30 minutes, however, no significant differences were seen. Local hypothermia during prolonged vitrectomy seems to decrease inflammation in the early postoperative stage.

Animals↗

PubMed1994

Intraocular hemocoagulase in human vitrectomy.

A prospective study was performed to establish the effects on the bleeding time and the ocular toxicity of the use of intravitreal hemocoagulase (1 NIH thrombin unit/100 ml in BSS Plus) in patients undergoing vitrectomy. Sixty patients with diabetic retinopathy, penetrating ocular injury or non-diabetic retinal vascular disorder, in whom electroretinograms were recordable, were assigned to a study of Hemocoagulase-BSS Plus versus BSS Plus. The bleeding time was measured after cutting the proliferative attachments to the underlying retina. Intravitreal hemocoagulase significantly reduced the bleeding time, and this reduction of bleeding facilitated the surgery. A washout of hemocoagulase at the completion of the vitrectomy was not carried out. Hemocoagulase in the vitreous cavity assisted in maintaining hemostasis during the first week after diabetic vitrectomy. Postoperative electroretinography data did not show any disadvantage for the hemocoagulase infusate. Clinical study showed no adverse effect on the cornea, lens or visual acuity.

Adolescent↗

PubMed1994

[Hypothermic effects on uveal blood flow and postoperative inflammation in vitrectomy].

Hypothermic effects on uveal blood flow and postoperative inflammation were evaluated in experimental vitrectomy on albino rabbits. Solutions used for intraocular perfusion were maintained at 9 degrees C and 22 degrees C. Following the vitrectomy, the rabbits' intraocular spaces were irrigated for 60 minutes. The temperature at various sites and the uveal blood flow were measured before and during the procedure. Aqueous protein concentrations were checked on postoperative days 1, 7, and 14. Another solution maintained at 37 degrees C was used as a control. There was a larger decrease in temperature at the retina than there was at the choroid and the ciliary body. Blood flow at the ciliary body decreased to 76.0% and 77.0% at the choroid after 60 minutes of irrigation at 9 degrees C. The decrease at 22 degrees C were 91.0% and 88.3%, respectively. Aqueous protein concentrations at both 9 degrees C and 22 degrees C were significantly lower than at 37 degrees C on the first postoperative day in the eyes irrigated for 60 minutes. In the eyes irrigated for 30 minutes, however, no significant differences were seen. Hypothermia during a prolonged vitrectomy operation seems to decrease inflammation in early postoperative stages.

Animals↗

PubMed1993

Efficacy of intravitreal hemocoagulase for control of bleeding in rabbit experimental model of vitrectomy.

Hemorrhage during vitrectomy for diabetic retinopathy or in the recently traumatized eye can complicate the surgical procedures and might cause termination and failure of vitrectomy in some cases. The effect of the hemocoagulase, Botropase, on the hemostasis of intraocular bleeding was evaluated in a rabbit model by cutting central retinal vessels in the medullary ray. Addition of the hemocoagulase (1 NIH unit/100 ml) to BSS Plus significantly reduced bleeding time. Immediately after vitrectomy with the use of this hemocoagulase, the average of the maximum amplitudes of the b-wave in electroretinography was normal, although the sensitivity of the electroretinogram was reduced by 0.1 log unit in the experimental eyes which were infused with hemocoagulase solution. The sensitivity showed no significant difference after the second postoperative day. The experimental eyes showed no abnormal findings histologically. Infusate containing Botropase appeared to be a useful adjunct for the control of intraocular bleeding during vitreous surgery.

Animals↗

PubMed1993

Pars plana vitrectomy in the management of vitreous touch syndrome.

The management of three patients with aphakic bullous keratopathy by means of pars plana vitrectomy is described. The patients had previously undergone uneventful intracapsular cataract extraction with intact vitreous face. Eventual herniation of the vitreous into the anterior chamber with resultant corneal endothelial touch caused the corneal edema in all three cases. Pars plana vitrectomy resulted in resolution of photophobia and irritation. The visual acuity improved from 20/200, 20/200 and 20/70 to 20/70, 20/60 and 20/40 respectively. The central cornea was cleared of edema in all three cases. The final vision was limited in two of the patients by the persistence of preoperative cystoid macular edema. Pars plana vitrectomy may be used in the management of selected cases of aphakic bullous keratopathy from vitreous touch.

Aged↗

PubMed1993

[Diagnostic vitrectomy for chronic uveitis].

Uveitis is diagnosed by ophthalmologic and systemic examination, but it may be difficult to diagnose accurately in some chronic cases. We performed diagnostic and therapeutic vitrectomy for chronic uveitis in 6 eyes of 4 patients, and examined vitreous specimens with immunohistochemical staining. Visual acuity improved in all cases due to clearing up of the vitreous cells. One patient had sarcoidosis, one had B cell malignant lymphoma (ocular reticulum cell sarcoma), and two had reactive lymphoid hyperplasia. Vitrectomy for chronic uveitis is useful for diagnosis and improvement of vision, and we recommend immunohistological staining of vitreous specimens. Particularly, when intraocular lymphoma is suspected, vitrectomy must be performed early.

Aged↗

PubMed1993

Expression of glial fibrillary acidic protein in rabbit Müller cells after lensectomy-vitrectomy.

PURPOSE: To assess retinal response after lensectomy-vitrectomy, the authors analyzed glial fibrillary acidic protein (GFAP), which retinal glial cells express in several pathologic conditions. METHODS: GFAP expression was examined by means of immunohistochemistry, Western blot analysis, and enzyme-linked immunosorbent assay (ELISA) in rabbit retina after lensectomy-vitrectomy. RESULTS: Müller cells had detectable GFAP immunoreactivity in peripheral retina 3 days after surgery. GFAP immunoreactivity was present in both peripheral and posterior regions 7 days, 14 days, and 6 months after surgery. The authors confirmed that anti-GFAP antibody recognized the 51 kDa protein specifically by Western blot analysis. Time-dependent increase of GFAP in peripheral retina was also obtained by ELISA: CONCLUSIONS: Such progressive GFAP accumulation in Müller cells, which are sensitive to microenvironmental changes, may reflect some underlying retinal response after lensectomy-vitrectomy.

Animals↗

PubMed1995

Efficacy of fluid-air exchange during pars plana vitrectomy.

PURPOSE: Vitreous fluid that remains trapped in the peripheral vitreous cavity after vitrectomy with fluid-air exchange can result in a smaller than desired intravitreal gas bubble size. To evaluate the effectiveness of a single fluid-air exchange in dehydrating the vitreous cavity, we measured the rate and volume of posterior vitreous fluid migration after an initial fluid-air exchange. METHODS: Thirty-eight eyes undergoing vitrectomy for macular hole closure had measurements of posterior vitreous fluid accumulation at either 5, 10, 15, or 20 minutes after fluid-air exchange. RESULTS: An average of 0.38 ml of fluid accumulated posteriorly within 10 minutes after the initial fluid-air exchange compared to 0.22 ml that accumulated after 5 minutes (P = 0.0003). A mean of 0.04 ml accumulated during each 5-minute interval between 10 and 20 minutes after the initial fluid-air exchange. CONCLUSION: Fluid composing 10% of the vitreous volume may migrate and accumulate posteriorly within 10 minutes of an apparently complete fluid-air exchange. Fluid aspiration after a 10-minute wait after the initial fluid-air exchange helps maximize vitreous cavity dehydration and should be employed when a large gas bubble is required after vitrectomy.

Adolescent↗

PubMedDate not supplied

[Value of vitrectomy in treatment of lens dislocation into the vitreous].

PURPOSE: To present own experiences in vitrectomy in cases of subluxation or luxation of the lens to the vitreous cavity. MATERIAL AND METHODS: 41 eyes with subluxation (16) and luxation (25) of the lens, operated on between May 1992 and April 1994 were analysed. Before the surgery, secondary glaucoma was observed in 18 eyes, hypotony in 8. The aim of pars plana vitrectomy was to release the lens from the surrounding tissues, then the lens was put into anterior chamber and removed by limbal incision. RESULTS: Visual acuity improvement was achieved in 73% of cases. Intraocular pressure was normalized in 14 eyes. Retinal detachment developed in 2 eyes after the surgery, and in one retina was reattached using silicone oil tamponade. CONCLUSION: Our results indicate that it is possible to remove the dislocated lens using vitrectomy without perfluorocarbon.

Female↗

PubMed1996

[Vitrectomy in Coats' disease].

Four eyes of four patients with Coats' disease underwent vitrectomy because of exudative or tractional detachments involving the macula or premacular fibrosis. All cases had gelatinous vitreous and had no complete posterior vitreous detachment. The exudates decreased and the retina reattached after removing vitreous traction and coagulating abnormal vessels with endodiathermy and not removing subretinal fluid in 3 eyes with retinal detachment. In one eye with tractional detachment, retinal breaks were found beneath the proliferative membrane during the initial vitrectomy procedure. This eye needed multiple operations because of recurrent traction by the remaining peripheral vitreous. Exudation into the vitreous and vitreous traction may cause mutual progression in these eyes, and vitrectomy is an effective treatment, although there are difficulties in removing vitreous traction completely.

Adolescent↗