Deterioration of filtering bleb morphology and function after phacoemulsification

Abstract

BackgroundTrabeculectomy remains the most efficient method of lowering he IOP applied for the treatment of glaucoma refractory to pharmacological treatment. Cataract is concerned as the most frequent late complication of trabeculectomy. The aim of the study was to analyse the effect of phacoemulsification with posterior chamber lens implantation on the morphology and function of filtering bleb in patients after previous successful trabeculectomy.MethodsThe retrospective study included 122 eyes treated for primary open angle glaucoma, 50 eyes (study group) in which, after a successful trabeculectomy with5-Fluorouracil, phacoemulsification with posterior chamber lens implantation was performed, and 72 eyes (control group), in which only a successful trabeculectomy was conducted. The surgical success of the trabeculectomy was expressed as IOP < 17 mmHg.ResultsIn the group of patients subjected to both trabeculectomy and phacoemulsification, mean IOP was significantly higher than in the group of patients who underwent trabeculectomy after 6 months (p = 0.003), 12 months (p = 0.01) and 18 months (p = 0.007) of observation. The filtering blebs after phacoemulsification in the study group were characterized by a greater reduction, compared to those in the control group. Cox regression survival success was 75% (SE = 5.9; 95% CI: 63.4 – 86.6), 75% (SE = 5.9; 95% CI: 63.4 – 86.6), 71% (SE = 5.4; 95% CI: 60.4 – 81.6) in study group and 92% (SE = 1.8; 95% CI: 91.5 – 98.5), 92% (SE = 1.9; 95% CI: 88.3 – 95.7), 91% (SE = 2.0; 95% CI: 87.1 – 94.9) in control group after 6, 12 and 18 months, respectively.ConclusionsPhacoemulsification causes a significant elevation of IOP in the eyes after previous successful trabeculectomy and deterioration of filtering bleb morphology.

The impact of cataract surgery on glaucoma care

“…For patients in the 14-9 mmHg group (n ¼ 198), the mean IOP at the final examination was 0.2 mmHg (0.1%) higher than the baseline. In another analysis, IOP reductions of up to 8.5 mmHg (34%) were noted in the high IOP group (23)(24)(25)(26)(27)(28)(29), and a 1.5 mmHg (15%) increase was found in patients with preoperative IOP less than 14 mmHg [9]. In a retrospective analysis of 1122 pseudoexfoliative eyes, Shingleton et al [10] similarly demonstrated…”

“…The fact that performing cataract surgery earlier rather than later following trabeculectomy leads to a higher failure rate may be secondary to the introduction of inflammatory mediators after surgery into a relatively immature bleb. Sałaga-Pylak et al [27] retrospectively analyzed 122 eyes that had successful trabeculectomy surgery defined as IOP less than 17 mmHg, of which 50 underwent subsequent cataract extraction. Morphological deterioration of the filtering blebs in the cataract surgery group was noted, and the cataract surgery arm furthermore had an approximately 20% lower success rate when compared with the group that did not undergo cataract surgery at 6, 12, and 18 months postoperatively.…”

Revision of trabeculectomy filtering blebs with mitomycin C: Long term results

“…A deterioration of filtering bleb morphology and a reduction of bleb function after phacoemulsification have been observed in eyes with previously successful trabeculectomy. [819] In our study, it was easier to re-establish a patent fistula in pseudophakic eyes than in phakic eyes because of deeper anterior chambers in pseudophakic group. In phakic group, surgeon should also pay attention and more caution to the lens, and the natural lens is thicker than artificial one.…”

“…[41619] An IOP >30.0 mmHg and an IOP >10.0 mmHg immediately after this procedure were found to be the significant risk factors for failure. [5] Our results support the significance of low IOP just after the surgery for the success of the final outcome.…”

Operieren wir die Glaukome zu spät?

“…Hauptkomplikation der filtrierenden Operation ist ja dann auch noch die Kataraktentwicklung, die beim phaken Patienten zwangsläufig früher oder später zu einer weiteren Operation führt. Dieser Eingriff trägt dann auch noch zusätzlich das Risiko, dass bei einem nicht zu vernachlässigenden Anteil der Patienten die initial gute Druckeinstellung verloren gehen kann [39][40][41][42][43][44] und damit wieder eine drucksenkende Therapie und/oder sogar ein erneuter Eingriff nötig werden. Die während der Kataraktoperation durchgeführte Gabe von 5-Fluorouracil subkonjunktival kann zwar das Risiko der Druckentgleisung mindern, aber nicht ganz verhindern [44,45].…”