[Follow-up of trabeculectomy. Complications and therapeutic consequences]. / Nachbetreuung von Trabekulektomien. Komplikationen und therapeutische Konsequenzen.

BACKGROUND: Intensive follow-up after trabeculectomy is important for long-term success. In the postoperative period, complications must be detected early in order to initiate adequate therapeutic measures. PATIENTS AND METHODS: In a retrospective study 113 eyes from 113 consecutive patients were followed-up for a period of 6 months after trabeculectomy with regard to postoperative complications and therapeutic decisions (invasive and conservative). Criteria of success were defined as an intraocular pressure (IOP) < 21 mmHg without antiglaucomatous treatment as well as an IOP reduction > 20% compared to the preoperatively treated IOP. RESULTS: Most of the postoperative complications occurred within the first 3 weeks: scarring of the filtering bleb (47.6%), choroidal detachment (18.6%), shallowing of the anterior chamber (8%), fibrinous reaction (5.3%), overfiltration (4.4%), reduced flow under the scleral flap (4.4%), corneal dellen (3.5%), prolapse of the iris (3.5%), external fistulation (2.7%), increase of the IOP due to steroids (1.8%), detachment of the ciliary body (1.8%) and malignant glaucoma (0.9%). In the postoperative period, 45.1% of the eyes needed further interventions such as 5-fluorouracil (5-FU) injections (28.3%), needling and 5-FU-injections (14.2%), laser suturolysis (6.2%). Repositioning of the iris, YAG-laser iridotomy, laser treatment of the filtering bleb, autologous blood injection and cyclocryoapplication were needed only in rare cases and 36.3% received other conservative treatment (i.e. modification of topical steroids, increase of cycloplegic treatment). After 6 months the success rate without antiglaucoma medication was 88.5%. CONCLUSIONS: An intensive follow-up after trabeculectomy is mandatory to avoid postoperative failure. In about half of the patients postoperative additional therapeutic measures became necessary, particularly if scarring of the filtering bleb occurred. Paying attention to these factors yields in a high success rate after filtering surgery.

Transforming growth factor beta 2 levels in the aqueous humor in different types of glaucoma and the relation to filtering bleb development.

PURPOSE: To investigate the transforming growth factor beta 2 (TGF-beta 2) levels and total protein levels in the aqueous humor of eyes with different types of glaucoma [primary open-angle glaucoma (POAG), pseudoexfoliation glaucoma (PSX), juvenile glaucoma (JG)], and the relation to filtering bleb development after trabeculectomy. METHODS: Aqueous humor was collected at the beginning of surgery from 52 eyes with glaucoma (29 POAG eyes, 17 PSX eyes, 6 JG eyes) and from 29 control eyes that underwent cataract operation. TGF-beta 2 levels (intrinsically activated and total TGF-beta 2) using ELISA methods as well as total protein concentrations of the aqueous humor were determined. All preoperative clinical data of the glaucoma eyes (age, gender, IOP, previous treatment, type of surgery) were compared with the TGF-beta 2 levels. In 40 of these eyes, the postoperative follow-up (filtering bleb development, need for intervention, IOP) was correlated to the preoperatively determined TGF-beta 2 levels. RESULTS: TGF-beta 2 levels were increased in nearly half of the eyes with POAG and in most of the eyes with JG, but in eyes with PSX, TGF-beta 2 levels were within the normal range. No correlation between TGF-beta 2 levels and age, gender, IOP, previous treatment, or type of surgery, or between TGF-beta 2 levels and protein levels in aqueous humor, was found. Correlation between bleb formation and TGF-beta 2 levels revealed that all but two of the POAG eyes with good clinical outcome (type 1 bleb) had normal levels of activated TGF-beta 2. Of the 13 eyes that needed postoperative intervention (type 2 and type 3 bleb), 8 had high and 5 had normal TGF-beta 2 levels. CONCLUSIONS: PSX eyes differ from POAG and JG eyes not only by their clinical or biomicroscopic appearance, but also by their normal TGF-beta 2 levels in aqueous humor. The fact that most of the POAG eyes with favorable bleb development had normal TGF-beta 2 levels indicated that there might be some relationship between bleb formation and TGF-beta 2 levels. On the other hand, the fact that eyes with less favorable bleb development had both low and high TGF-beta 2 levels indicated that other factors are also involved in the scarring of the filtration bleb.

The presence and properties of myocilin in the aqueous humor.

PURPOSE: To determine whether myocilin is present in the aqueous humor (AH) and to examine certain properties of this protein. METHODS: Human AH was obtained at the time of either glaucoma surgery or cataract extraction. Monkey AH was obtained at the time of death, and bovine aqueous was obtained from eyes delivered from an abattoir. Column chromatography was performed on aqueous samples to determine the approximate size of the myocilin present. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and western blot analysis were performed using antibody prepared against a peptide sequence in myocilin. Analysis of the bovine proteins present in AH that were retained by a microporous filter was also performed using western blot analysis. RESULTS: By western blot analysis, myocilin was present in human, monkey, and bovine AH. The apparent molecular size of the myocilin present in the AH were greater than 250,000 Da, when quantified with a gel filtration column. Myocilin appeared to be hydrophobic and was one of the proteins that was retained on microporous filters that were obstructed by AH. CONCLUSIONS: Myocilin is a constituent in the AH. It appears that myocilin is a hydrophobic protein that may exist in an oligomeric state or in association with other proteins. Myocilin is retained by microporous filters and may be involved in the obstruction of these filters that occurs when AH is perfused through them.

Classification of filtering blebs in trabeculectomy: biomicroscopy and functionality.

The long-term success of filtering surgery is not dependent on surgical technique alone. The development of the filtering bleb in the postoperative period, in particular with regard to wound healing and subconjunctival scarring, is equally important. Morphologic changes of the developing filtering bleb after trabeculectomy can predict early failure even if the intraocular pressure is still normal. A basic understanding of wound healing processes and histologic changes of the developing filtering bleb are mandatory to interpret correctly the morphologic appearance of the developing filtering bleb. In clinical practice, follow-up of the filtering bleb according to a standardized morphologic classification may help to predict outcome and provide clues for the necessity and timing of further treatment.

Acetazolamide and CO2: acute effects on cerebral and retrobulbar hemodynamics.

PURPOSE: Acetazolamide and CO2 are cerebral vasodilators whose specific effects in various brain regions have not been carefully defined. We investigated the effects of these agents in both larger cerebral and smaller, retrobulbar arteries, to compare their general cerebral vasodilatory influence with their specific ocular vascular effects. METHODS: Twelve young adults with healthy eyes were studied under normocapnic and hypercapnic (6% CO2, 94% O2 tanked gas) conditions after receiving either placebo or 1,000 mg acetazolamide (3 h before study). Color Doppler imaging was used to measure peak systolic and end-diastolic velocities (PSV and EDV) in the internal carotid, middle cerebral, ophthalmic, and central retinal arteries under each condition. RESULTS: Acetazolamide and CO2 each lowered intraocular pressure; combining the agents provided no additive ocular hypotensive effect. Hypercapnia or acetazolamide per se failed to alter PSV, EDV, or the derived resistance index [RI; (PSV-EDV)/PSV] in the internal carotid or in either orbital artery. However, when hypercapnia was superimposed upon acetazolamide, the resistance index fell in the internal carotid and central retinal arteries (each p < 0.05). In contrast, the middle cerebral artery was responsive to either vasodilator and to their combination: PSV and EDV rose, and RI fell with each experimental treatment. CONCLUSIONS: In the brain, the middle cerebral artery exhibits substantial dependence of flow velocity on the vasodilators CO2 and acetazolamide. In contrast, the ophthalmic and central retinal arteries appear less responsive. Nonetheless, the combination of carbonic anhydrase inhibition (acetazolamide) with CO2 augmentation did lower vascular resistance distal to the central retinal artery, suggesting that this mechanism vasodilates critical ocular tissues.

Clonal analysis of the effect of TGF-beta on the apoptosis-inducing activity of normal cells.

We have recently described induction of apoptosis in transformed fibroblasts by transforming growth factor type beta (TGF-beta)-treated normal fibroblasts, which leads to the specific elimination of transformed cells. Here we investigate whether the ability to eliminate transformed cells is the property of a specialized subpopulation of normal fibroblasts or whether all cells within the population are able to respond to exogenous TGF-beta by induction of elimination of transformed cells. Clonal analysis of the eliminative capacity of normal fibroblasts showed that all cells are able to induce elimination after addition of optimal concentrations of exogenous TGF-beta. In the absence of exogenously added TGF-beta, a minority of clones exhibited complete eliminative activity. Neither the ability nor the inability to perform elimination in the absence of exogenous TGF-beta was a stable characteristic of the respective cell clones. The number of cell clones with the ability to respond to suboptimal concentrations of TGF-beta increased with the passage number of the normal cells, whereas the number of clones inducing apoptosis in the absence of exogenous TGF-beta remained constant.