|Year : 2020 | Volume
| Issue : 2 | Page : 206-208
Department of Ophthalmology, Government Medical College, Thrissur, Kerala, India
|Date of Submission||14-Jun-2020|
|Date of Acceptance||15-Jun-2020|
|Date of Web Publication||25-Aug-2020|
Dr. P V Geethakumari
Department of Ophthalmology, Government Medical College, Thrissur, Kerala
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Geethakumari P V. Journal Review. Kerala J Ophthalmol 2020;32:206-8
| Intravitreal Dexamethasone Implant Migration Into the Anterior Chamber: A Multicenter Study from the Pan-American Collaborative Retina Study Group|| |
Gonçalves MB, Alves BD, Moura R, Magalhães O Jr., Maia A, Belfort R Jr., et al. Intravitreal dexamethasone implant migration into the anterior chamber: A multicenter study from the Pan-American Collaborative Retina Study Group, Retina 2020:40;825-32.
Macular edema (ME) is an important cause of visual impairment in several ocular conditions. Anti-inflammatory and antiangiogenic properties make corticosteroids an attractive alternative for the treatment of ME. Intravitreal dexamethasone implant (DEX implant; Ozurdex, Allergan Inc.) has been approved for the treatment of ME secondary to retinal vein occlusion (RVO), noninfectious uveitis affecting the posterior segment and diabetic macular edema (DME). The DEX implant is a biodegradable, sustained-release implant containing 0.7 mg dexamethasone in a solid polymer drug delivery system. It is a 0.46–6-mm rod-shaped implant delivered into the vitreous cavity with a 22G needle; after implantation, the polymer matrix degrades into lactic and glycolic acids, releasing dexamethasone slowly for up to 6 months.
These implants can occasionally migrate into the anterior chamber (AC), causing vision-threatening complications such as corneal edema and decompensation. It could be endothelial decompensation either due to chemical toxicity of the implant components or mechanical trauma caused by the rigid polymer. The objective of this study was to establish the prevalence and risk factors for intravitreal DEX implant migration into the AC in eyes with ME and its management options.
This was a retrospective, observational chart review of data collected from patients with ME in one or both eyes treated with one or more injections of DEX implants 0.7 mg at the vitreoretinal disease units of 11 Latin American centers. The presence of distinct retinal diseases associated with ME in one or both eyes that had been treated with at least one DEX implant were included in the study.
A total of 468 patients with 764 injections were included for analysis. From patients with a history of cataract surgery, two patients were aphakic and 348 were pseudophakic. The main indications were DME (46.5%) and ME secondary to RVO (25.4%). In this study, 12 cases had implant migration into the AC, with a prevalence of 1.6% considering the number of injections. Among them, one patient was aphakic and 11 patients were pseudophakic. The analysis identified a significant association between intraocular lens (IOL) status and implant migration. The percentages of implant migration were 50.0% in aphakic group, 3.2% in the pseudophakic group, and 0% in the phakic group. Regarding the IOL type, all pseudophakic patients with implant migration had a posterior chamber IOL. Among these patients, half had a history of posterior capsule rupture during phacoemulsification, and the other half was submitted to Nd:Yag laser posterior capsulotomy after the cataract surgery. A higher rate of implant migration was also observed in vitrectomized eyes (4.8%) compared to patients who did not undergo vitrectomy (1.6%).
Among the 12 cases of implant migration, 11 patients developed corneal edema on average, 17 days after the injection. In eight patients, this complication occurred in the first injection itself. Seven patients also had increased intraocular pressure (IOP). All patients were initially treated with topical steroids and NaCl 5% eye drops. However, four patients with persistent corneal edema underwent surgical treatment with either penetrating or endothelial keratoplasty. In this study, the implants that migrated were removed with forceps with/without viscoelastic expression or with 20G cannula connected to the vitreous cutter machine.
This is the first multicenter study to evaluate the prevalence and risk factors for the DEX implant migration into the AC. The current risk of implant migration in this study was 1.6%.
A major limitation of this study was the retrospective design, and the information collected was limited to those reported in the medical records. Another limitation was that, because of the small number of aphakic patients and implant migrations, the greater risk of migration found in aphakic patients is a result that should be viewed with caution.
In conclusion, it is important to be cautious while using a dexamethasone implant in patients with aphakia, pseudophakia with posterior capsular compromise, or zonular dehiscence and vitrectomized patients. When anterior migration occurs, rapid removal is advised, especially if corneal edema is present.
| Reoperations for Complications Within 90 Days After Glaucoma Surgery|| |
Chu CK, Liebmann JM, Cioffi GA, Blumberg DM, Al-Aswad LA. Reoperations for complications within 90 days after glaucoma surgery. J Glaucoma 2020;29:344-46.
With the expansion of surgical options, selecting the most appropriate glaucoma operation involves balancing the risks of adverse events and the benefit of intraocular pressure (IOP) reduction for an individual patient. Although lower rates of surgical complications have been reported with minimally invasive glaucoma surgeries (MIGS), traditional incisional surgery such as trabeculectomy and tube shunt surgery still remain the most commonly performed glaucoma operations worldwide.
An assessment of surgical procedures requires not only an evaluation of efficacy but also an analysis of the incidence and severity of associated complications. Furthermore, unplanned reoperations have also been proposed as a criterion to evaluate the surgical quality. This study seeks to describe the rate of reoperations in the operating room for unplanned complications encountered within 90 days after glaucoma surgery and surgical indications for these reoperations.
In this retrospective study, electronic medical records of adult patients who had undergone glaucoma surgery including a tube shunt (Baerveldt implant or Ahmed valve implant), trabeculectomy with mitomycin C, trabectome, or transscleral cyclophotocoagulation performed by four glaucoma surgeons at the Edward S. Harkness Eye Institute at Columbia University Medical Center between June 1, 2015, and June 1, 2017, were reviewed. These patients were then examined for postoperative complications that required unplanned reoperations within the first 90 days including revision of the tube shunt, revision of the trabeculectomy, drainage of the choroidal effusion, or placement of a tube shunt. Cyclophotocoagulation or surgery for further IOP lowering was not specifically considered a reoperation for surgical complications.
A total of 622 glaucoma procedures on 600 eyes in 525 patients over a 2-year period were enrolled in the study. Of these, 275 (44%) were trabeculectomy with mitomycin C, 253 (41%) were the placement of a tube shunt, 33 (5%) were cyclophotocoagulation, and 61 (10%) were trabectome procedures. Postoperative complications requiring reoperations within 90 days developed in 15 patients (2.4%) overall including seven patients (2.5%) in the trabeculectomy with mitomycin C group and eight patients (3.1%) in the tube shunt group. The rate of reoperation was similar between the tube group and the trabeculectomy group (P = 0.67, χ2 test). There were no complications requiring reoperations in 90 days for transscleral cyclophotocoagulation or trabectome. The indications for the initial glaucoma surgery were primary open-angle glaucoma (11 patients), uveitic glaucoma (2 patients), traumatic glaucoma (1 patient), and combined-mechanism glaucoma (1 patient).
The indications for reoperation were wound leaks (5 patients), serous choroidal effusion (3 patients), bleb encapsulation (2 patients), and tube-related issues (5 patients), which included tube exposure (3 patients), tube retraction (1 patient), and persistent iritis from the iris touching the tube (1 patient).
This study was the first to report the real-world reoperation rate for trabeculectomy with mitomycin C, tube shunt, trabectome, and transcleral cyclophotocoagulation within the 90-day postoperative period. The reoperation rates are comparable between the trabeculectomy with mitomycin C and tube shunt groups. Common indications for reoperation within 90 days include wound leak and tube-related issues. This shows the importance of surgeon awareness regarding wound closures in trabeculectomy, especially with an antifibrotic agent. Tube shunts are commonly used when there is a higher likelihood of failure with a filtering surgery; it is not surprising that there may be tube-related issues. Such information is useful not only in terms of what to expect or examine closely during postoperative visits but also in terms of discussing expected outcomes with patients. Notably, there was no reported reoperation for complications with trabectome, highlighting the overall safety of MIGS procedures.
There are several limitations to this study. Retrospective case series generally report lower complication rates unless attention is directed specifically toward their detection. Similarly, patients undergoing surgical reoperation with an outside hospital provider would not have been identified by this study. Finally, the shorter follow-up period of 3 months may miss surgical complications that are not necessarily seen in the early postoperative time frame.
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Conflicts of interest
There are no conflicts of interest.