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[Surgical revision for hypotonia after glaucoma operation with mitomycin C].

PURPOSE: Persistent hypotony with maculopathy is a severe complication of mitomycin C when used during filtration surgery. We wanted to know whether this complication can be controlled by a surgical reintervention yielding tight closure of the initial sclerostomy. METHOD: In our clinic, 52 eyes underwent filtering surgery with intraoperative application of mitomycin C. Seven of them required a reoperation owing to persistent hypotony with maculopathy. During this reoperation, the scleral flap was tightly sutured (5x) or, if necessary, was closed with dehydrated human dura mater (2x). RESULTS: In all cases the intraocular pressure increased immediately (i.e., within less than 24 h) after reoperation. This intraocular pressure increase was accompanied by a simultaneous regression of the maculopathy. Further details: mean intraocular pressure (mmHg): before initial operation with mitomycin C: 38.5 +/- 2.9; after initial operation: 3.7 +/- 0.6; before reoperation (= 8 months after initial operation): 3.3 +/- 0.7; 24 h after reoperation: 22.0 +/- 2.9; 9 months after reoperation: 16.7 +/- 1.7. Mean visual acuity: before initial operation with mitomycin C: 0.72 +/- 0.1; after initial operation: 0.34 +/- 0.1; before reoperation (= 8 months after initial operation): 0.17 +/- 0.05; 24 h after reoperation: 0.28 +/- 0.05; 9 months after reoperation: 0.55 +/- 0.1. CONCLUSIONS: (1) Since the interval between reoperation and intraocular pressure increase was very short in all cases, overfiltration is at least one major reason for hypotony, not only ciliary body failure; (2) in cases of persistent hypotony after filtering surgery with mitomycin C, surgical reintervation can be recommended. During this reoperation, the initial sclerostomy should be closed tightly.

Adult↗

Matrix metalloproteinase gelatinase B (MMP-9) is associated with leaking glaucoma filtering blebs.

The goal of glaucoma filtering surgery is to create a low resistance pathway for aqueous outflow. The result is a blister or 'bleb' on the conjunctiva, from which fluid drains into the vasculature. Filtering surgery results may be compromised if blebs develop leaks, a problem that surfaces more frequently when antimetabolites are used to control the wound healing response. We investigated the role of tissue remodelling enzymes of the Matrix metalloproteinase (MMP) family in the development of bleb leaks. Our design was a case series. We enrolled glaucoma patients with leaking blebs, glaucoma patients with overhanging blebs and normal eyes. Leaking bleb tissues (n=11) and bleb leak fluid were collected from patients undergoing bleb revision surgery. Overhanging bleb tissues (from non-leaking blebs, n=3), normal conjunctiva (n=8), and aqueous humour (n=4) were collected for comparison. Samples were analysed for MMP content and proteinase activity by the methods of zymography, western blotting, immunohistochemistry, and in situ zymography. Our main outcome measures were presence and activity of MMP in sample. Zymography revealed the presence of a high molecular weight caseinase and a 92-kDa gelatinase of a size appropriate for the proenzyme form of gelatinase B (gelB; MMP-9), in extracts from leaking bleb tissue, but not in bleb leak fluid or aqueous humour samples. In contrast, a 65-kDa gelatinase of a size appropriate for gelatinase A (MMP-2) proenzyme was observed in all samples. All proteinases disappeared when 10mm EDTA was added to the development buffer, consistent with their identity as MMPs. Western blotting and immunohistochemical analyses confirmed the identity of the 92kDa proteinase as gelB, and further revealed its absence from extracts of overhanging bleb tissue and normal conjunctiva. In situ zymography demonstrated strong gelatinolytic activity in leaking bleb tissue, but not overhanging bleb tissue or normal conjunctiva. MMP-g may be involved in the mechanism of formation of bleb leaks. Precise description of the cascade of events leading to bleb leakage may allow the design of therapeutic interventions to prevent, stabilize or reverse bleb leakage.

Adult↗

Intraoperative prediction of intraocular pressure for the first postoperative day following glaucoma filtration surgery.

The goal of glaucoma filtering surgery is to achieve adequate control of intraocular pressure (IOP). This prospective study evaluates the authors' accuracy in predicting IOP for the first postoperative day (POD 1) through digital palpation of the globe and evaluation of the achieved leakage at the end of trabeculectomy. Fifty patients underwent trabeculectomy with or without the use of an antimetabolite. At the conclusion of the procedure, an IOP prediction for POD 1 was given by the surgeon. The recorded IOP readings on POD 1 were compared with this prediction. The results were evaluated by linear regression analysis. The IOP predictions were within +/- 3 mm Hg of the forecasted value for 31 patients (62%), within +/- 6 mm Hg for 44 patients (88%) and outside of +/- 6 mm Hg for 6 patients (12%). Short-term postoperative IOP control is reasonably predictable and may be adjusted for individual care.

Aqueous Humor↗

Prevention and management of hypotony after glaucoma surgery.

Postoperative hypotony is a common complication of glaucoma filtering surgery, particularly with adjunctive use of antifibrotic agents. Associated structural sequelae and reduced visual function may occur in some eyes, resulting in the low-pressure syndrome. Precautions may be taken intraoperatively and postoperatively to decrease the likelihood of hypotony. Sometimes, despite these measures, the low-pressure syndrome still can occur, the management of which can be difficult. When simple observation does not result in spontaneous resolution, several noninvasive and invasive techniques are available, targeted at the cause of low IOP.

Anterior Chamber↗

Management of large filtering blebs with the argon laser.

Complications attributable to large conjunctival blebs after glaucoma filtering surgery range from annoying foreign-body sensation to devastating endophthalmitis. We used the argon laser to shrink large complicated blebs in four eyes of four patients who had previously undergone glaucoma filtering surgery. The eye is first anesthetized with a topical agent. The bleb surface is lightly abraded with a sterile cotton swab and then "painted" with a tissue-staining dye. Diffuse laser burns applied over the surface resulted in sufficient shrinkage to allow resolution of the respective symptoms or secondary complications in all four cases. The first two patients developed small leaks that we attribute to delivering laser burns to extremely thin areas of conjunctiva. In both cases the leaks gradually sealed over several weeks. None of the eyes developed increases in intraocular pressure or anterior segment inflammation. In each case, filtering capability was maintained.

Aged↗

Conjunctival impression cytology of the filtering bleb.

Impression cytology was used to evaluate the conjunctival surface change after filtering surgery and its association with bleb type and mitomycin C. Impression cytology were obtained at least ten (mean, 20.4) months after surgery from 22 eyes of 19 patients who had undergone trabeculectomy, and were graded according to a previously described system. Blebs were divided into thin cystic and thick diffuse types. Abnormal impressions, demonstrated as disturbed epithelial and goblet cell morphology and a decrease in the numbers of both cells, were found in nine eyes (40.9%). With regard to the prevalence of abnormal impressions, there were statistically significant differences between bleb type and between the use or non-use of mitomycin C (p = 0.040, 0.013); these related more to the use of mitomycin C than to bleb type. This study reveals that filtering surgery causes long-term damage to the conjunctival epithelium overlying a filtering bleb, especially in a patient with a thin cystic bleb or one has been treated with mitomycin C. This change in the conjunctival surface may lead to the occurrence of late hypotony and bleb-related infection.

Adult↗

[Goniotrepanation combined with sinus surgery as a transitional measure in spontaneous carotid artery-cavernous sinus fistulas].

Two patients with spontaneous, angiographically proven fistulas showed progressive ocular symptoms which precluded waiting for spontaneous occlusion of the fistulas. On the other hand, endovascular therapy of the carotid-cavernous fistulas was not possible because the arterial supply of the fistulas came from both internal carotids. Therefore filtering surgery was performed in the affected eyes. Postoperatively, intraocular pressure decreased to normal values in both patients and the symptoms resolved. The visual acuity increased in one patient and remained the same in the other. In conclusion, filtering surgery is an important therapeutic tool to preserve visual function in eyes with carotid-cavernous fistulas that display progressive ocular symptoms but cannot be treated by embolization.

Aged↗

Progression of glaucomatous field defects despite successful filtration.

It is generally assumed that successful filtering surgery, by maintaining intraocular pressure at a low level, will protect a glaucoma patient's remaining visual field. We present three patients with chronic open angle glaucoma and typical visual field changes. In each case, filtering surgery was performed because of progressive loss of visual filed and inadequate pressure control. Despite excellent pressure levels after operation, field loss continued in the operated eye. Certain genetic and systemic factors may contribute to further loss of visual field in the presence of normal intraocular pressures. We stress the importance of careful and continuous examination of the visual fields in all glaucoma patients regardless of the response of pressure to treatment.

Adult↗

Subconjunctival 5-fluorouracil and herpes simplex keratitis.

We present a case of herpes simplex keratitis that appeared during a period following filtering surgery in which subconjunctival 5-FU was being administered. Although the 5-FU treatment was not halted, 4 days later the keratitis healed. The typical practice of discontinuing 5-FU treatment when these kinds of inflammation occur following filtering surgery may be unwarranted.

Eye Diseases↗

Long-term evaluation of timolol.

Maintenance effect of the topical beta-blocker timolol on intraocular pressure (IOP) was investigated for a mean follow-up of 31.6 months in a group of 155 patients (275 eyes) with glaucoma or ocular hypertension. The mean IOP-value was calculated from 3 readings of the daytime IOP curve, and the mean eye pressure of the right and left eye in the respective individual was used. The medical therapy was carried out with our ranking order of drugs of choice: timolol, timolol combined with adjunctive drug therapy, laser trabeculoplasty and/or filtering surgery. Intraocular pressure was controlled with timolol alone in 98 of 155 patients (63.2%, Group 1). In 36 patients, timolol plus adjunctive medication was required to control IOP (23.2%, Group 2). Twenty-one (13.6%, Group 3) required either laser trabeculoplasty or filtering surgery in addition to timolol. Sufficient IOP-lowering effect was more frequently maintained in patients with ocular hypertension than those with glaucoma simplex or capsular glaucoma. Failures in timolol treatment occurred mostly within 6 months from the start of the therapy and correlated well with higher initial IOP. Transient adverse effects were observed in 11.2% of cases. In three cases (1.9%) local and systemic side effects were serious enough to require discontinuation of the drug therapy. One patient (0.7%) was a non-responder and was withdrawn from the study for that reason. Sixteen patients (10.3%) were lost to follow-up during the 4 year study.

Adult↗

Encapsulated filtering bleb. A selective review--new deductions.

Filtering bleb encapsulation may, in some cases, be a severe complication following filtering surgery. The cause and mechanism of its development are not known. A selective review of data that might shed some light on these dilemmas, is presented. Based on these data, it is suggested that: (a) non-contractile collagen-producing fibroblasts play a major role in the process of bleb encapsulation, while in wound healing following filtering surgery, contractile fibroblasts are the major components; (b) the process of bleb encapsulation is less sensitive to the toxic effect of 5-Fluorouracil than would healing; (c) collagen-producing fibroblasts may be less sensitive to the destructive effect of 5-Fluorouracil than contractile fibroblasts; (d) inflammatory mediators are important triggers of bleb encapsulation.

Animals↗

Surgical outcomes of deep sclerectomy with collagen implant.

We evaulated the effectiveness and adverse effects of deep sclerectomy with collagen implant (DSCI), which is a kind of nonpenetrating filtering surgery. In this retrospective study, DSCI was performed in 15 eyes of 11 glaucoma patients. An trabeculo-Descemet's membrane (TDM) window is created by a deep sclerokeratectomy, and the collagen implant is placed in the sclera bed under a superficial flap (deep sclerectomy with collagen implant). In 3 of 15 eyes the DSCI was intraoperatively converted to conventional filtering surgery for a large perforation of the TDM. These eyes were not included in the results of the surgical outcomes. The mean age of the patients was 50.3 +/- 14.4 years, and the mean follow-up period was 11.1 +/- 5.9 months. A diagnosis of chronic open angle glaucoma was made in 7 eyes and a diagnosis of secondary glaucoma in 5 eyes. The mean preoperative IOP was 25.8 +/- 11.9 mmHg, the immediate postoperative IOP was 6.4 +/- 2.9 mmHg, and at the final follow-up, the IOP was 11.9 +/- 2.5 mmHg. The IOP in 5 eyes was under 6 mmHg temporarily. However, there was no serious complication such as shallow anterior chamber. DSCI is considered to be a good surgical procedure that has similar surgical outcomes to a conventional trabeculectomy without serious complications.

Adult↗

High incidence of sympathetic ophthalmia after contact and noncontact neodymium:YAG cyclotherapy.

BACKGROUND: Two cases of sympathetic ophthalmia occurring after noncontact neodymium:YAG (Nd:YAG) cyclotherapy have previously been reported. In each case, the patient had undergone filtering surgery in the exciting eye. Although in each case Nd:YAG cyclotherapy was the last surgery performed, the inciting event of sympathetic ophthalmia was unclear. METHODS: The authors studied three additional patients who developed sympathetic ophthalmia after Nd:YAG cyclotherapy for glaucoma. RESULTS: Two patients developed sympathetic ophthalmia 4 months after noncontact Nd:YAG cyclotherapy, and 1 patient developed sympathetic ophthalmia 18 months after contact Nd:YAG cyclotherapy. All patients had previous cataract extractions but no filtering surgery in the exciting eye. Clinical features included chronic iridocyclitis, choroidal folds, Dalen-Fuchs nodules, and optic disc edema. Combining these cases with the two previously reported cases, the incidence of sympathetic ophthalmia at our institution thus far is 5.8% (4 of 69) and 0.67% (1 of 150) after noncontact and contact Nd:YAG cyclotherapy, respectively. CONCLUSIONS: The incidence of sympathetic ophthalmia after Nd:YAG cyclotherapy is high compared with other ocular procedures. The clinician should vigilantly monitor patients after Nd:YAG cyclotherapy and report additional cases that may have occurred at other institutions.

Aged↗

Mitomycin C in higher risk trabeculectomy: a prospective comparison of 0.2- to 0.4-mg/cc doses.

PURPOSE: This randomized, masked, prospective study was conducted to compare the outcome of filtering surgery using doses of 0.2 mg/cc or 0.4 mg/cc of mitomycin C (MMC) in eyes that were at higher risk from previous conjunctival incisional surgery. METHODS: Eyes of 50 consecutive patients with primary open-angle, pseudoexfoliation, or pigmentary glaucoma requiring trabeculectomy who had previously undergone either limbal cataract surgery or trabeculectomy were enrolled. Patients received an intraoperative dose of either 0.2 or 0.4 mg/cc MMC for 2 minutes (n = 25 in each study group). Intraocular pressure (IOP), logMAR visual acuity, and complications were monitored at regular intervals for 1 year. Unpaired student t tests were used to compare percent decrease in IOP in both study groups at each interval. RESULTS: The percent decrease in IOP was not significantly different between groups at 1 day, 1 week, 1 month, 3 months, 6 months, or 1 year after surgery. LogMAR visual acuity was not significantly different between groups at 1 month, 6 months, or 1 year. Treatment failure occurred in seven patients in the 0.2 mg/cc group (28%) and seven patients in the 0.4 mg/cc group (29.2%). Postoperative hypotony, choroidal effusions and hemorrhages, and wound leaks occurred in both groups, but occurred more often in the group receiving 0.4 mg/cc MMC. CONCLUSION: Filtering surgery performed on higher risk eyes was as effective using a lower dose (0.2 mg/cc) of MMC as that using a higher dose (0.4 mg/cc). Incidence of complications and treatment failures was slightly higher in the group receiving high-dose MMC.

Adult↗

Use of the argon laser to close filtering bleb leaks.

We attempted to seal 15 consecutive filtering bleb leaks in 11 patients using argon laser energy. Eight leaks were at the conjunctival-corneal interface associated with a fornix-based flap, 4 leaks resulted from suture scissoring of the conjunctiva, and 3 leaks were button-holes in the conjunctiva. Thirteen leaks occurred within 2 weeks after filtering surgery, while 2 were of late onset. Argon laser parameters used were a 500-microns spot size, 0.1-s time interval, and between 500 and 1800 mW of power. Thirteen leaks were sealed after one or two laser sessions, while 2 leaks required other treatment modalities. Complications included conjunctival fenestration and transient corneal stromal opacities. This study suggests that the argon laser can be used to seal filtering bleb leaks in many patients following filtering surgery.

Adult↗

Glaucoma drainage implants.

Glaucoma drainage implants provide a useful option in the management of complicated glaucomas for which the risk of failure of conventional filtering surgery is high. The basic design of these devices is similar; a silicone tube shunts aqueous humor from the anterior chamber to a fibrous capsule surrounding a synthetic plate or band positioned at the equatorial region of the globe. The capsule serves as a reservoir for aqueous drainage. Drainage implants have been used in the treatment of various refractory glaucomas, including those associated with aphakia and pseudophakia, prior unsuccessful filtering surgery, anterior segment neovascularization, trauma, youth, uveitis, epithelial downgrowth, iridocorneal endothelial syndrome, vitreoretinal disorders, and penetrating keratoplasty. Modifications in implant design and surgical technique have been developed to limit the occurrence of postoperative complications such as hypotony and its related sequelae, and strabismus.

Child↗

Clinical experience with the single-plate Molteno implant in complicated glaucomas.

Ninety patients with medically uncontrollable glaucomas and poor surgical prognoses received single-plate Molteno implants (Optomat Supplies, Dunedin, New Zealand) without postoperative adjunctive systemic antifibrosis therapy. Eleven patients had insufficient follow-up for assessment of intraocular pressure (IOP) or visual acuity outcome. The initial Molteno implant procedures in the remaining 79 patients were successful (IOP less than or equal to 21 mmHg with at least 6 months' follow-up) in 26 (63%) of the 41 patients older than 12 years of age with non-neovascular glaucomas in aphakia/pseudophakia; 7 (70%) of the 10 patients older than 12 years of age with non-neovascular glaucomas in phakic eyes after failed filtering surgery; 7 (47%) of the 15 patients with neovascular glaucomas; and 7 (54%) of the 13 patients younger than 13 years of age with non-neovascular glaucomas. The visual acuities remained within one line of their preoperative levels or improved in 31 (76%) of the 41 aphakic or pseudophakic eyes with non-neovascular glaucomas; 3 (30%) of the 10 phakic eyes with non-neovascular glaucomas after failed filtering surgery; 10 (67%) of the 15 eyes with neovascular glaucomas; and 9 (100%) of the 9 eyes with non-neovascular glaucomas in patients younger than 13 years of age on whom Snellen acuity was available.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

A review of surgical alternatives to medical therapy for glaucoma.

Results of four uncontrolled studies, with short-term follow-up, of argon laser trabeculoplasty (ALT) as initial treatment for various open-angle glaucomas indicate short-term success varies from 65 to 90 percent. The success rates are less impressive when the definition of success, usually intraocular pressure 22 mmHg or less, and the short follow-up, usually limited to months, are considered. The ongoing, multicenter, random-assignment, controlled Glaucoma Laser Trial in the United States will provide additional information about short- and long-term follow-up of primary ALT that will clarify the accuracy of the results of these preliminary trials.Results of another study suggest that initial filtering surgery is as effective at controlling intraocular pressure and preserving visual function as medical treatment for newly diagnosed glaucoma. All these clinical studies are difficult to interpret and suffer from the lack of data analysis using the life-table method. The comparatively low rate of long-term success of ALT for open-angle glaucoma performed after failure of medical management, particularly in blacks, cautions that ALT may not be a good substitute for medications or filtering surgery in newly diagnosed glaucoma.

Glaucoma, Open-Angle↗