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Results for “Vitrectomy”

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At least 163 records · Page 9Linked to original sources

PubMed2001

[Inhibition of lipid peroxidation in retinal tissue during vitrectomy. Effect of intraocular irrigating solution BSS plus].

PURPOSE: Several antioxidant substances have been included in intraocular solutions for vitrectomy in order to reduce oxidative stress. The objective of this work is to evaluate the antioxidant effect of BBS plus(R) (with oxidized glutathione) by means of determining scores of Malondialdehyde (MDA) in retinal tissue at different post vitrectomy time-periods. MATERIAL AND METHODS: Thirty pigmented rabbits distributed in three groups (n=10). Group I: Control (no surgery); group II: Vitrectomy adding BSS plus(R), scoring of malondialdehyde at 3 hours post surgery; group III: Vitrectomy adding BBS plus(R), analysis of malondialdehide at 48 hours after vitrectomy. Retinal samples were used to determine the score of malondialdehyde using ion-pairing high performance liquid chromatography. Statistical analysis was performed using ANOVA-Scheffé test (p<0.05). RESULTS: Scores of free MDA (microgram of retinal tissue) were: group I (n=8): 1.080 S.D. 0.389 microgram group II (n=8): 1.273 S.D. 0.710 microgram and group III (n=10): 0.639 S.D. 0.374 microgram. CONCLUSIONS: BSS plus(R) showed antioxidant effects in retinal tissue which were observed better at a later rather than early stage after a vitrectomy.

Animals↗

PubMed2002

Suppression of post-vitrectomy lens changes in the rabbit by novel benzopyranyl esters and amides.

This study reports for the first time a therapeutic modality for the suppression of posterior subcapsular cataract (PSC) formation in an animal model (rabbit) of vitrectomy. This therapeutic modality may also have the potential to attenuate/prevent the high incidence of loss of vision due to cataract formation in patients that undergo vitrectomy. Unilateral, partial vitrectomy was performed on 2.5 month old Dutch Belted rabbits with vitreous replaced by either commercially available BSS((R)) or BSS PLUS((R)) (n=16). Alternatively, vitreous was replaced with a proprietary, modified BSS PLUS((R)) irrigating solution containing 1.25 microM AL-8417 (n=12), 5.0 microM AL-12615 (n=5) or 5.0 microM AL-17052 (n=9). Age matched, non-operated rabbits were used as controls (n=16). Lenses were analysed by correlative structural (light, scanning electron microscopic and three-dimensional computer-assisted drawings) and optical (low power helium-neon laser scan) quality analysis 6 months following surgery. Results demonstrate that vitreous replacement with an irrigating solution that contains the ester-linked benzopyran, AL-8417, the amide-linked benzopyran pro-drug, AL-17052, or its active metabolite, AL-12615, prevented abnormal post-vitrectomy lens growth, or fiber formation. Focal length variability (FLV) assessments (sharpness of focus) confirmed the beneficial drug effects detected morphologically, with FLV being essentially equal to that of age-matched, non-surgical controls. In contrast, lenses of animals with vitreous replaced solely with BSS((R)) or BSS PLUS((R)) exhibited significantly higher FLV than both age-matched controls and animals that underwent vitrectomy with drug-containing irrigating solutions. The ability of AL-8417, AL-17052 and its active metabolite, AL-12615, to suppress vitrectomy-induced posterior lens fiber changes appears to reside in their unique pharmacological profile, acting as antioxidant, anti-inflammatory and cytostatic agents.

Animals↗

PubMed1990

[Lens opacities after pars plana vitrectomy in diabetic vitreoretinopathy and macular pucker].

The incidence of lens opacities reported after pars plana vitrectomy for various indications for vitrectomy has varied considerably. Comparison of the different indications for vitrectomy is only partially possible because of a lack of comparable studies. In this prospective study the indications for vitrectomy were investigated: macular pucker and diabetic vitreoretinopathy were compared concerning the postoperative incidence of lens opacities. Nearly twice as many cases of lens opacity occurred after vitrectomy for diabetic retinopathy. Also, the fellow eyes of the patients with diabetic vitreoretinopathy developed lens opacity much more frequently after vitrectomy compared with the fellow eyes of the patients with macular pucker.

Aged↗

PubMed1996

[Contamination of intraocular fluid in pars plana vitrectomy].

UNLABELLED: Endophthalmitis after pars plana vitrectomy is rare, with an incidence of 0.05-0.14%. The aim of this study was to evaluate the microbiological situation during pars plana vitrectomy and to ascertain what organisms and how many enter the eye during the operation. PATIENTS AND METHODS: Twenty-five consecutive subjects undergoing primary pars plana vitrectomy were included in the study. Patients were excluded if they had evidence of local or systemic infections or had undergone antibiotic therapy within 3 weeks before surgery. A standard three-port pars plana vitrectomy was performed on each patient. Preoperative smears of the conjunctiva and intraoperative aspirates of the vitreous were taken immediately after sclerotomy, and aspirates of the intraocular fluid at the conclusion of operation. RESULTS: We obtained preoperative smears from the conjunctival sac of all patients, and found that 19 patients (76%) had positive cultures, with coagulase-negative staphylococci as the most commonly isolated organisms, (n = 14; 56%). Vitreous--aspirated immediately after sclerotomy--was sterile in 68% (n = 17). In 32% (n = 8) contamination occurred, the microorganisms isolated being coagulase-negative staphylococci (20%) and Staphylococcus aureus (12%). Five of the samples (20%) of intraocular fluid from the vitreous cavity--aspirated before wound closure--were contaminated, coagulase-negative staphylococci (8%) and Staphylococcus aureus (12%) again being found in culture. In no case did postoperative endophthalmitis develop. CONCLUSIONS: This study demonstrates that bacteria enter the eye during pars plana vitrectomy and that there is a change in the contaminating bacterial species during operation. Even if bacteria remain in the eye after pars plana vitrectomy, postoperative endopthalamitis does not necessarily develop.

Aged↗

PubMed1987

The role of vitrectomy in the treatment of postoperative bacterial endophthalmitis. An experimental study.

While the diagnostic value of vitreous culture in the management of bacterial endophthalmitis is well established, the therapeutic value of vitrectomy in this condition is debated. The present experimental study uses an aphakic model of Staphylococcus aureus endophthalmitis in the rabbit. Animals were treated with the following: (1) intravitreal antibiotics alone; (2) intravitreal antibiotics with vitrectomy; (3) vitrectomy alone; and (4) no treatment. Eyes treated with antibiotics and vitrectomy displayed significantly clearer media at 14 days after therapy compared with eyes treated with antibiotics alone. There was also a greater tendency for eyes treated with antibiotics and vitrectomy to have negative cultures at 14 days, although this difference was not statistically significant. These findings are consistent with beneficial effects of therapeutic vitrectomy as an adjunct to intravitreal antibiotic therapy in an animal model of aphakic bacterial endophthalmitis.

Animals↗

PubMed1979

Pars plana vitrectomy in ocular trauma.

Visual improvement was achieved in 62% of 100 consecutive patients with ocular trauma treated by pars plana vitrectomy. Anterior segment injuries had a better prognosis than posterior segment injuries, and retinal detachment was a poor prognostic sign. Patients undergoing vitrectomy during the two weeks after injury had a better visual prognosis than those who had delayed vitrectomy. Pars plana vitrectomy has increased the recovery rate in traumatized eyes which previously were deemed inoperable and frequently were enucleated. Most such eyes have intraocular fibrocellular proliferations, resulting in traction retinal detachments, cyclitic membranes, and phthisis, as documented in clinicopathological and experimentally produced specimens of penetrating ocular trauma. Vitrectomy can interrupt this sequence, if performed one to 14 days after injury, by removing the vitreous scaffold onto which proliferation occurs, together with the elements of hemorrhage, damaged lens, vitreous, and foreign material which may incite proliferation. We believe four to ten days after injury to be the optimal time for vitrectomy to avoid the hazards of immediate intervention, while removing damaged tissue before serious sequenlae occur.

Adolescent↗

PubMed1982

Pars plana vitrectomy entry sites.

The histological features of vitrectomy entry sites were studied in a group of monkeys following pars plana vitrectomy for experimental posterior penetrating injury. The extent of fibrocellular proliferation and vitreo-retinal complications arising from the vitrectomy wounds were compared to the proliferation from a much larger penetrating trauma site after complete and partial (core) vitrectomies. Although scarring and complications were more severe following core vitrectomy, there was little difference on histological examination between fibrocellular proliferations from the vitrectomy entry sites and from the penetrating wound.

Animals↗

PubMed2004

Lens-sparing vitrectomy for progressive tractional retinal detachments associated with stage 4A retinopathy of prematurity.

OBJECTIVE: To describe the results of lens-sparing vitrectomy in infants with progressive, fovea-threatening, tractional retinal detachments associated with stage 4A retinopathy of prematurity. METHODS: In a retrospective, interventional, consecutive clinical case series, the records of patients with stage 4A retinopathy of prematurity who underwent lens-sparing vitrectomy for progressive retinal detachments were reviewed. Retinal attachment status, reversed or arrested retinal dragging, and visual acuity were assessed after the procedure. RESULTS: Thirty-two eyes of 29 patients underwent lens-sparing vitrectomy at a mean postconceptional age of 43 weeks. Thirty (94%) of 32 eyes had complete retinal reattachment and arrest or reversal of retinal dragging after 1 lens-sparing vitrectomy. Visual acuity of at least central, steady, and unmaintained was observed in 17 (81%) of the 21 eyes in which it was tested and at least central, steady, and maintained vision was measured in 13 (62%) of 21 eyes, with 1 eye achieving 20/40 visual acuity. CONCLUSIONS: Lens-sparing vitrectomy is a safe and effective procedure for the treatment of fovea-threatening retinal detachments in patients with stage 4A retinopathy of prematurity.

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PubMed2005

Effect of plasmin on laminin and fibronectin during plasmin-assisted vitrectomy.

OBJECTIVE: To determine whether plasmin will cleave the laminin and fibronectin located at the vitreoretinal junction during plasmin-assisted vitrectomy. METHODS: Western blot analyses were performed with antilaminin or anti-fibronectin antibodies on the internal limiting membranes collected from patients with macular holes or cystoid macular edema who underwent vitrectomy with or without plasmin. The results were compared with the results of in vitro experiments in which commercially available laminin and fibronectin were exposed to commercially available plasmin. RESULTS: In all eyes treated with plasmin, a posterior vitreous detachment was not present before surgery but was created easily with a minimal suction of less than 100 mm Hg during vitrectomy. Western blot analyses showed that the laminin and fibronectin in the internal limiting membrane exposed to plasmin during vitrectomy were degraded to several fragments of lower molecular weights, including a fragment of approximately 13,000 Da for laminin and a fragment of approximately 30,000 Da for fibronectin. These lower-molecular-weight fragments also appeared in the in vitro experiments. CONCLUSION: The laminin and fibronectin at the vitreoretinal junction are degraded during plasmin-assisted vitrectomy. CLINICAL RELEVANCE: These findings provide evidence for the efficacy of using plasmin to create a posterior vitreous detachment during vitreoretinal surgery.

Basement Membrane↗

PubMed1984

Evaluation of vitrectomy in penetrating ocular trauma. A case-control study.

A case-control retrospective evaluation of vitrectomy in penetrating ocular trauma was performed by matching 89 eyes, managed with vitrectomy, with 89 similar eyes that did not undergo vitrectomy. The cases were matched according to factors previously shown to correlate with the visual outcome, including the following: (1) type of trauma; (2) length and posterior extent of the laceration; (3) type and degree of lens involvement; and (4) type and location of any intraocular foreign body. The groups differed in the distribution of initial visual acuity, which was worse in the vitrectomy group. When the final visual results were compared, no statistical advantage from vitrectomy was found. However, beneficial trends were demonstrated in air rifle and double-penetrating injuries, as well as in other severe injuries in which initial visual acuity was worse than 5/200.

Adolescent↗

PubMed2000

The relationship between rabbit lens optical quality and sutural anatomy after vitrectomy.

This study was conducted first, to characterize structural changes in rabbit lenses after vitrectomy; and second, to assess whether such changes correlate with a quantifiable compromise in optical function. Unilateral, partial vitrectomies were performed on 2.5 month old Dutch Belted rabbits (n = 64). Age matched non-operated rabbits (n = 32) were used as controls. Lenses were analysed by correlative structural (light, scanning electron microscopic and three-dimensional computer-assisted drawings) and optical (low power helium-neon laser scan) analysis at 1.5, 3, 6 and 12 months post-surgery (n = 16 lenses from operated animals and n = 8 lenses from non-operated controls at each time point). Results demonstrate that in rabbits lens growth, or fiber formation, is compromised after vitrectomy. From 1.5 to 12 months after surgery, lenses had progressively more crooked posterior line sutures with sub-branches of increasing size and number in successive growth shells. Quantification of lens optical quality specifically along and/or between these atypical suture branches and sub-branches revealed a significant increase in focal length variability (sharpness of focus) after vitrectomy. A peripheral zone of fibers with abnormal posterior ends was produced surrounding the pre-surgical lens mass. This additional zone of aberrant fibers was associated with a quantifiable degradation in lens optics. Studies on the prevention of post-vitrectomy lens changes in this rabbit model may yield useful information applicable to the human condition.

Animals↗

PubMed1996

Therapeutic pars plana vitrectomy for chronic uveitis: a retrospective study of the long-term results.

BACKGROUND: Pars plana vitrectomy has both diagnostic and therapeutic potential in chronic uveitis. In this paper the therapeutic value of vitrectomy is investigated. METHODS: This is a retrospective study on 25 eyes that underwent pars plana vitrectomy with therapeutic intent. Surgery was considered in patients with severe vitreous clouding or macular pucker and in those who responded poorly or not at all to conventional treatment for uveitis. The mean period of follow up was 4.5 years, varying from 2 to 12 years. RESULTS: Improved vision was observed in 56% of the eyes (14/25). Twenty-four percent of the eyes (6/25) had stable vision. Macular edema disappeared in 40% (10/25) of cases and persisted in 60% (15/25). Two of the nine eyes with persistent macular oedema progressed to a macular hole. Four of the six eyes with macular pucker suffered recurrence, one ended in phythisis, while the pucker was cured in only one patient. Twelve percent of the eyes (3/25) subsequently experienced a recrudescence of uveitis, making systemic treatment necessary. One patient presented, after vitrectomy, a traction retinal detachment with proliferating vitreoretinopathy. No complications or recurrences were seen in 44% of the eyes (11/25). CONCLUSION: Vitrectomy has a definite place in the treatment of chronic uveitis, both on the functional level, with improvement or stabilisation of visual acuity and on the therapeutic level, with possible reduction or cessation of systemic treatment.

Adolescent↗

PubMed1987

Pars plana vitrectomy for retinal detachment with unseen retinal holes.

A study was made of a consecutive series of 47 cases of rhegmatogenous retinal detachment treated by pars plana vitrectomy in which no holes were identified preoperatively. The view of the fundus during preoperative examination varied from being totally clear to completely obscured by media opacities. The role of pars plana vitrectomy in finding retinal holes peroperatively is considered. The incidence of discovering holes and the locations of those found at the time of surgery are presented. The significance of these findings is discussed. Where the preoperative view was good and the extent of proliferative vitreoretinopathy (PVR) did not exceed grade C2, retinal reattachment was achieved in 75% of the cases. A review made of a similar group of patients treated with conventional retinal buckling before the introduction of pars plana vitrectomy revealed that successful retinal reattachment was achieved in 70% of cases. The study concludes that pars plana vitrectomy, while being necessary for cases of rhegmatogenous retinal detachment when the view of the retina is obscured, will not always reveal the presence of a retinal break. If the preoperative view of the retina was good and the extent of PVR did not exceed grade C2, pars plana vitrectomy did not seem to offer obvious advantages over conventional buckling procedures.

Humans↗

PubMed1996

Diagnostic vitrectomy and chronic uveitis.

BACKGROUND: From the introduction of vitrectomy, infectious endophthalmitis was one of the indications for this surgical technique. Vitrectomy was later found to be a valuable method in both diagnostic and therapeutic evaluation of chronic uveitis. METHODS: Twenty-eight eyes of 25 patients were operated on with purely diagnostic intent. These were patients not responding, or no longer responding, to their cortisone treatment and for whom no etiology had been found previously. RESULTS: Vitrectomy itself yielded the diagnosis in nine eyes of eight patients. Three had unexpected infectious pathology (one bacterial, one mycotic, one viral), while five had tumoral pathology four with non-Hodgkin lymphoma and one with a metastasis of a malignant melanoma of the skin. In four other patients, typical fundus lesions were seen during the surgery, providing a clue to the etiology: three cases of retinal necrosis and one case of a pseudotumoral mass suggestive of Toxocara canis. Serologic tests confirmed three cases of herpes simplex infection and one of Toxocara canis. Apart from the fact that a diagnosis could be made in half of the patients, the diagnostic vitrectomy also had a favorable effect upon vision in half the cases. CONCLUSION: In cases of chronic uveitis where no etiology has been found, vitrectomy is able to provide a diagnosis in about one-third of eyes directly. During surgery a typical appearance of the fundus may reveal a supplementary diagnosis, resulting in an overall diagnosis in about half of the cases. Moreover, half of the patients will have improved vision after surgery.

Adolescent↗

PubMed2002

Effect of pars plana vitrectomy for proliferative diabetic vitreoretinopathy on preexisting diabetic maculopathy.

BACKGROUND: Vitrectomy is the treatment of choice for proliferative diabetic vitreoretinopathy with tractions and persistent vitreous hemorrhage. Since vitrectomy has recently been discussed as a possible therapy for diabetic maculopathy as well, we were especially interested in studying the change in diabetic maculopathy following surgery. For that purpose a grading system developed at our clinic was used. METHODS: In a retrospective study we evaluated fundus photographs and fluorescein angiograms of 33 eyes of 30 patients who had undergone vitrectomy for proliferative diabetic vitreoretinopathy at our clinic between 1990 and 1997. In all eyes diabetic maculopathy was present at the time of surgery. The grading was performed using preoperative images and images taken a median of 18 months postoperatively. RESULTS: Best corrected visual acuity increased by 3.7 lines on average. Intraretinal dot and spot hemorrhages, hard exudates, microaneurysms on fundus photos, and leakage and cysts on fluorescein angiograms decreased after surgery. The extent of the foveolar avascular zone and the extent of the perifoveolar ischemic area worsened, however. CONCLUSION: Vitrectomy seems to help diabetic eyes not only by removal of membranes, tractions, and vitreous hemorrhage; it seems to have a positive influence on the course of diabetic maculopathy as well. We suspect that the removal of the posterior vitreous membrane is one of the crucial factors in interrupting the disease process. From these results the indication for vitrectomy in diabetic patients may have to be reconsidered and extended to include diabetic maculopathy prior to the development of ischemia.

Adult↗

PubMed2007

Early vitrectomy for fundus-obscuring dense vitreous haemorrhage from presumptive retinal tears.

BACKGROUND: Published literature on the management of patients with fundus-obscuring dense vitreous haemorrhage due to presumptive retinal tears is sparse and advocates waiting for spontaneous resolution. Surgery is indicated only when a definite retinal tear or retinal detachment is identified. METHODS: A retrospective review of all patients who underwent early vitrectomy for vitreous haemorrhage associated with posterior vitreous detachment was carried out. A comparison of initial visual acuity versus final visual acuity after vitrectomy was performed. The number of eyes that were found to have retinal tears and retinal detachment were documented. Initial and final Snellen acuities were used for statistical analysis. Categorical data were analysed using Fisher's exact test and statistical significance was considered to be p < 0.05. RESULTS: Sixteen eyes were identified and all these patients presented or were referred soon after the onset of vitreous haemorrhage. Associated ocular pathology (choroidal neovascular membrane, retinal branch vein occlu-sion, macroaneurysm) was suspected to be the source of the haemorrhage in 4 eyes. Vitrectomy was carried out in 12 eyes soon after presentation (mean time 6.3 days, range 1-28 days). Nineteen retinal breaks were seen in these eyes and 5 eyes had more than two breaks. None of the eyes were found to have proliferative vitreoretinopathy at the time of surgery. Two eyes needed repeat surgery for new retinal breaks. Excluding the eyes found to have an ocular pathology as the cause of vitreous haemorrhage, the mean visual acuity improved from hand movements to 6/12 (p < 0.001). CONCLUSIONS: Early vitrectomy for spontaneous dense fundus-obscuring vitreous haemorrhage and posterior vitreous detachment is safe. Since the number of patients in this study was small, a prospective randomised controlled study comparing early versus late vitrectomy is needed to see whether early surgery also prevents proliferative vitreoretinopathy formation.

Aged↗

PubMed2001

Primary vitrectomy for the management of rhegmatogenous retinal detachment associated with choroidal detachment.

PURPOSE: To evaluate the role and the results of primary vitrectomy in treating cases with coexisting rhegmatogenous retinal detachment and choroidal detachment. METHODS: Eleven consecutive eyes with coexisting rhegmatogenous retinal detachment and choroidal detachment with proliferative vitreoretinopathy less than grade C were included. Release of traction on the breaks was achieved by vitrectomy and augmented by episcleral buckle if needed. Perfluorocarbon liquids were used to drain the subretinal fluid through the vitrectomy sclerotomies. The breaks were treated by endolaser under perfluorocarbon liquids. Postoperative tamponade was done by C3F8 gas or silicone oil. Cases were followed up for at least 3 months. RESULTS: Retinal reattachment could be achieved and maintained in all cases by one or more surgeries. No recurrence of choroidal detachment has occurred. In each case, choroidal detachment was drained through the sclerotomies and retinal detachment was repaired. CONCLUSION: Primary vitrectomy represents an effective line in the management of rhegmatogenous retinal detachment with coexisting choroidal detachment in phakic or nonphakic eyes. SUMMARY: Primary vitrectomy is recommended for the management of choroidal detachment associated with retinal detachment.

Aged↗

PubMedDate not supplied

Expanded indications for 25-gauge transconjunctival vitrectomy.

PURPOSE: We conducted 25-gauge (25G) transconjunctival vitrectomy to treat patients with various ocular diseases, and examined the possibility of expanding the indications for this system through combined use with 20G devices when needed. METHODS: The records of 167 patients (169 eyes) who underwent vitrectomy in our hospital between April and June 2004 were studied. Vitrectomy had been conducted using the 20G or 25G transconjunctival vitrectomy system. RESULTS: In 7 of the 169 eyes (4%), the 20G system was initially selected. Vitrectomy could be performed using the 25G system alone in 150 eyes (89%), while 20G devices were used in combination with the 25G system in 12 (7%). None of the 25G scleral wounds were sutured, while all the 20G scleral wounds were sutured at the completion of surgery. Low intraocular tension was noted in 15 of 162 eyes (9%), but all these eyes recovered within 2 to 4 days. In two eyes with macular hole, retinal detachment occurred, but reattachment was achieved after reoperation. No extensive vitreoretinal hemorrhage or postoperative infection was observed. CONCLUSIONS: By combining the use of 20G devices, indications for the 25G system can be expanded. However, postoperative low ocular tension must be addressed by carefully considering surgical indications and prevention measures.

Adolescent↗