|Year : 2019 | Volume
| Issue : 3 | Page : 104-107
Trabeculectomy with Ologen matrix implant versus trabeculectomy with mitomycin-C in primary open-angle glaucoma
Ophthalmology Department, Faculty of Medicine, Mansoura University, Mansoura, Egypt
|Date of Submission||24-Jul-2019|
|Date of Acceptance||01-Aug-2019|
|Date of Web Publication||25-Sep-2019|
MD Tarek Mohsen
Ophthalmology Department, Faculty of Medicine, Mansoura University, Mansoura, 35516
Source of Support: None, Conflict of Interest: None
Background The purpose of this study was to compare the efficacy and the safety of trabeculectomy augmented with Ologen matrix implant versus mitomycin-C (MMC) in cases with primary open-angle glaucoma (POAG).
Patients and methods This retrospective comparative study included patients with POAG who presented to the Ophthalmic Center, Mansoura University, from January 2016 to January 2017. Patients were allocated into two groups: group A patients underwent trabeculectomy with Ologen implant and group B included patients who underwent trabeculectomy with MMC. The primary outcome was the change in the intraocular pressure (IOP), with the recorded complications considered as the secondary outcomes. All the patients were followed up for at least 1 year postoperatively.
Results A total of 30 eyes of 17 patients were included in the study. There was no statistically significant difference between the two groups in the baseline demographic or clinical data. The IOP dropped from 43.07±6.23 to 16.03±4.2 mmHg at the twelfth month in group A (P<0.0001) and from 41.41±5.11 to 15.13±2.75 mmHg in group B (P<0.0001). The mean IOP was continuously higher in group A than in group B along the follow-up points, but the difference was statistically insignificant (P>0.05). Hypotony with thin blebs was statistically higher in the MMC group.
Conclusion Trabeculectomy augmented with Ologen implant seems to provide the same efficacy as MMC, with fewer complications in cases with POAG.
Keywords: mitomycin-C, Ologen, primary open angle glaucoma
|How to cite this article:|
Mohsen T. Trabeculectomy with Ologen matrix implant versus trabeculectomy with mitomycin-C in primary open-angle glaucoma. J Egypt Ophthalmol Soc 2019;112:104-7
|How to cite this URL:|
Mohsen T. Trabeculectomy with Ologen matrix implant versus trabeculectomy with mitomycin-C in primary open-angle glaucoma. J Egypt Ophthalmol Soc [serial online] 2019 [cited 2020 Feb 21];112:104-7. Available from: http://www.jeos.eg.net/text.asp?2019/112/3/104/267826
| Introduction|| |
Surgical success following trabeculectomy varies for most procedures, as it relies mainly on inhibiting the process of wound healing. Additional preoperative and postoperative maneuvers had been advocated to reduce scar formation at the site of the wound .
Since the 1980s, antimetabolites were introduced and widely accepted as an augmentation for trabeculectomy. These agents act mainly by reducing the fibroblast proliferation at the site of their application. Nonetheless, several side effects were reported following their application, which consisted mostly of cystic avascular blebs, hypotony with maculopathy, blebitis, and late-onset endophthalmitis . Other agents such as β-irradiation  and photodynamic therapy  were tried but, unfortunately, have not proven themselves.
A biodegradable collagen matrix implant (Ologen) was intended to be applied during trabeculectomy. Ologen is placed above the posterior end of the trap door. Its main action was to guide the fibroblasts and myofibroblasts into its pores, thus secreting a loose connective tissue that differs from the regular pattern of the scar tissue .
The aim of this study was to compare the efficacy and the safety of trabeculectomy augmented with Ologen matrix implant versus mitomycin-C (MMC) in cases with primary open-angle glaucoma (POAG).
| Patients and methods|| |
This was a retrospective comparative study that included patients with POAG attending the Outpatient Clinic of Ophthalmic Center, Mansoura University, during the period spanning from January 2016 to January 2017. The study was approved by the local ethical committee of Mansoura University and followed the tenets of the Declaration of Helsinki. All the patients had signed an informed written consent after a thorough explanation of the possible consequences of the operations.
Patients were enrolled in the study if they were adults older than 18 years and diagnosed as suffering from POAG with uncontrolled intraocular pressure (IOP) defined as IOP more than 21 mmHg in spite of the administration of maximum tolerated antiglaucomatous medications. Patients were excluded from the study if they had an allergy to procaine collagen, had previous glaucoma surgery, or recent attack of ocular inflammation. Pregnant and breast-feeding female individuals were also excluded from the study.
Patients were allocated randomly (using the simple flip coin method) into two groups. For bilateral cases, one eye was assigned to each group. Group A included patients who had undergone trabeculectomy with Ologen (Version 2-Aeon Astron Europe B.V., The Netherlands) implant, and group B included patients who had undergone trabeculectomy with MMC.
Preoperative demographic and baseline clinical data were retrieved. Age, sex, bilaterality, and number and types of antiglaucomatous medications were recorded. IOP was measured by applanation tonometer.
In both groups, classic subscleral trabeculectomy was performed. After a fornix-based conjunctival flap was fashioned, the sclera was exposed, and a rectangular 2×3 mm scleral flap was prepared. In group A, a 1×1 mm sclerostomy was followed by peripheral iridectomy. The scleral flap was closed with one 10–0 nylon suture. Ologen implant was placed over the scleral flap, and the conjunctiva was closed with two 7–0 vicryl sutures. In group B, 0.2 mg/ml MMC was applied under the scleral flap and in a large area around it for 2 min
Postoperative steroids (dexamethasone 0.1%) and topical antibiotic (tobramycin 0.3%) were given every 2 h for 1 week and then every 6 h for 4 weeks, after which the antibiotic was stopped, and the steroid was tapered according to the requirements. Topical antiglaucomatous medications were stopped and were re-added according to the IOP control. Follow-up visits were scheduled at the first day, first week, and the first, third, sixth, and twelfth month postoperatively. At each visit, IOP was measured; full anterior segment examination was performed using the slit-lamp biomicroscopy; the number of the antiglaucomatous medications was recorded; and any complications were recorded and managed properly.
The primary outcome was the reduction in IOP. Vision-threatening complications were considered as secondary outcomes.
Statistical package of the social sciences was used to analyze the data. Qualitative data were represented in number and percent and compared with χ2-test. Quantitative data were tested for normality using the Shapiro–Wilk test. Parametric data were represented with mean±SD, and they were compared with unpaired t-test between the groups and paired t-test within the same group. For the tests, significant results were obtained whenever P was up to 0.05.
| Results|| |
Thirty eyes of 18 patients were included in the study, 15 eyes in each group. There were 11 patients with bilateral eyes, with each allocated to a different group, and there were eight patients with unilateral affection, four in each group. There was no statistically significant difference between the two groups with regard to the preoperative demographic or baseline clinical data ([Table 1]).
|Table 1 Baseline demographic and clinical data for the included patients|
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The IOP dropped from 43.07±6.23 to 16.03±4.2 mmHg at the twelfth month in group A (P<0.0001) and from 41.41±5.11 to 15.13±2.75 mmHg in group B (P<0.0001). The mean IOP was continuously higher in group A than in group B during the follow-up points; however, this difference was statistically insignificant (P>0.05; [Table 2]).
|Table 2 Postoperative intraocular pressure during the follow-up period in the two groups|
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Postoperative hyphema was the commonest postoperative complication in both groups. Hypotony with thin blebs was statistically higher in the MMC group (P=0.031 and <0.001, respectively). [Table 3] summarizes the postoperative complications encountered in the two groups.
| Discussion|| |
Antimetabolite agents such as MMC had been widely used during the past decades to augment trabeculectomy surgery. These agents reduce fibroblast proliferation around the trap door  and hence impede scar formation . However, some complications were reported related to the toxicity of these agents both early and late ,,.
Ologen is a biodegradable material that differs from the well-known antifibrotic agents. As an alternative of inhibiting the fibroblast proliferation, Ologen allows the fibroblasts to grow randomly in its porous structure, resulting in the random alignment of the collagen fibers that could reduce scar formation effectively. This function is achieved without the complications of antifibrotic agents .
This study was a retrospective comparative study that included patients with uncontrolled POAG with planned trabeculectomy. The patients were allocated into two groups for trabeculectomy with either Ologen matrix implant or MMC applications. The results were recorded and compared with regard to the effect on the IOP and the incidence of complications. All the patients were followed-up for at least 1 year.
In this study, the mean IOP was continuously higher in the Ologen group than in the MMC group along the follow-up points; however, this difference was not statistically significant at any point.
Many published studies had compared between these two methods of augmentation for trabeculectomy. Rosentreter et al.  conducted a prospective study comparing Ologen with MMC in POAG and reported higher IOP at 1 month postoperatively in the Ologen group that was statistically different between the two groups and that continued up to 12 months during the follow-up period. Senthil et al.  reported similar findings at the first and sixth month postoperatively. In contrast, Cillinio et al.  found no difference in the IOP between the two groups during their follow-up period.
A systematic meta-analysis was carried out by He et al.  and enrolled seven studies (277 eyes) comparing Ologen with MMC. They reported that there was no statistically significant difference in IOP reduction between the two groups except at 1 and 12 months after surgery (reduction being higher in the MMC group). No significant differences in the reduction of glaucoma medications or success rates (complete and qualified) were found. The rates of adverse events also did not differ significantly between Ologen and MMC.
In this study, the largest difference in the postoperative IOP was recorded in the first month compared with the other scheduled postoperative visits. This difference may be correlated to the reservoir effect of the Ologen matrix absorbing the aqueous humor, pressing on the scleral flap, thus offering a physical resistance against overfiltration in a valvular manner.
In this study, no specific intraoperative complications related to the Ologen implant itself were noted. Any postoperative complication such as hyphema was transient. Early conjunctival leakage was reported in 30% of the cases in one study . Endophthalmitis with negative growth on cultures was reported in one case in another study .
Hypotony and thin blebs were more common in the MMC group among our patients. On the contrary, Mitra  reported more complications with Ologen than with MMC, with a case of blebitis in the Ologen group, in which the implant was removed.
One of the advantages of Ologen implantation is its shorter operative duration; although we did not compare the actual duration intraoperatively. The main disadvantage of Ologen is its price, which is much more expensive than MMC.
Limitations of this study include the retrospective nature of the study, the small number of operated eyes, and the short duration of follow-up.
| Conclusion|| |
Trabeculectomy augmented with Ologen implant seems to provide the same efficacy as MMC, with fewer complications in cases with POAG.
The author thanks Eman El Hefney, professor of ophthalmology, for her kind assistance in the operative part of the study.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2], [Table 3]