DOI:10.18240/ijo.2019.07.27
Citation: Rezkallah A, Mathis T, Denis P, Kodjikian L. XEN gel stent: a total delayed-onset postoperative hyphema. Int J Ophthalmol 2019;12(7):1224-1226
·Letter to the Editor·
XEN gel stent: a total delayed-onset postoperative hyphema
Amina Rezkallah1, Thibaud Mathis1,2, Philippe Denis1, Laurent Kodjikian1,2
1Department of Ophthalmology, Croix-Rousse University Hospital, University of Lyon, Lyon 69004, France
2UMR-CNRS 5510 Matéis, University of Medicine Lyon 1, Lyon 69008, France
Correspondence to: Laurent Kodjikian. Department of Ophthalmology, Croix-Rousse University Hospital, 103, Grande Rue de la Croix-Rousse, Lyon 69004, France. kodjikian.laurent@wanadoo.fr
Received:
DOI:10.18240/ijo.2019.07.27
Citation: Rezkallah A, Mathis T, Denis P, Kodjikian L. XEN gel stent: a total delayed-onset postoperative hyphema. Int J Ophthalmol 2019;12(7):1224-1226
Dear Editor,
Minimally invasive glaucoma surgery (MIGS) is a less-invasive surgical alternative to filtering surgery for reducing intraocular pressure (IOP). This technique has been shown to offer long-term outcomes equivalent to filtering surgery[1]. The XEN gel implant (Allergan Inc., CA, USA) is one of MIGS procedures. This implant consists of a 6-mm tube of collagen-derived gelatin cross-linked with glutaraldehyde, preloaded in an injector. The XEN gel implant is implanted ab interno. It produces a drainage pathway between the anterior chamber and the subconjunctival space. The XEN® gel implant has been developed for the surgical management of refractory glaucoma. This simplified technique leads to less post-surgical complications, such as hypotony and choroidal detachment, than filtering surgery[1]. However, there are very few reports of complications following MIGS procedures, in particular for XEN gel implant[1-2].
Here, we report a total hyphema that occurred after an uncomplicated ab interno XEN gel stent surgery. Consent to publish the case report was not obtained. This report does not contain any personal information that could lead to identification of the patient. This report was performed in compliance with the Declaration of Helsinki.
A
72-year-old male was referred for an evaluation of ocular hypertension. His
past medical history included a Bentall procedure, a graft replacement of the
aortic valve, aortic root and ascending aorta and an atrial fibrillation. He
was treated with acetylsalicylic acid (Kardegic® 75 mg/d), and
fluindione (Previscan®) with a target international normalized ratio
of between 2 and 3. His past ocular history included severe myopia (Figures 1
and 2), open-angle glaucoma, and cataract surgery in both eyes. He was under
local treatment with bimatoprost 0.03% (Allergan, Inc., Irvine, California,
USA) at bedtime, a dorzolamide/timolol combination 0.2%/0.5% (Merck Canada
Inc., Kirkland, Quebec) twice daily in both eyes. On initial examination, the
best corrected visual acuity was 20/
Figure 1 Infrared image of the right and left optic nerve heads showing a dysversion, a peripapillary atrophy and the staphyloma of both optic nerve heads.
Figure 2 Optic coherence tomography of the optic nerve head evaluating the retinal nerve fiber layer The analysis is not reliable because of the optic nerve heads’ conformation.
Figure 3 B-mode ultrasound imaging of right eye two days postoperatively The retina appeared to be attached. Neither choroidal detachment nor choroidal hemorrhage was noted.
The aims of MIGS are to provide an alternative and less invasive surgical treatment for reducing IOP to filtering surgery. The XEN gel stent has the potential to keep the patient off IOP-lowering treatment unlike other MIGS procedures[2-3].
Recently, De Gregorio et al[4] prospectively studied the implantation of XEN gel stents in 41 patients. Intraoperative complications included subconjunctival hemorrhage in 36.5% patients, transient anterior chamber hyphema in 24.3% patients, and stent malpositioning requiring repositioning in 12.2% patients were reported. Schlenker et al[1] performed a retrospective cohort study of 354 patients who underwent XEN gel stent procedure or trabeculectomy. Among the most common complication in the XEN gel stent group, malignant glaucoma (n=4) conjunctival wound leak (n=3), hyphema (n=2), vitreous hemorrhage (n=2), hypotony maculopathy (n=2), choroidal effusion (n=1), stent obstruction (n=1) or exposed stent (n=1), and Dellen formation (n=2) were reported.
In our case,
the surgical procedure was performed with no complications. The immediate
postoperative exam did not reveal any intraocular or subconjunctival bleeding.
Indeed, three hours after surgery, the XEN gel stent was well placed with
effective filtration and no blood in the anterior chamber or the
subconjunctival space. The total hyphema was reported two days after the
surgery. Perhaps a slow trickle intraoperative hyphema would have been observed
if the patient had been examined at day 1. In our case, the time delay might be
explained by the onset of a delayed and transient hypotony[5].
Indeed, hyphema can be produced by postoperative hypotony with inherent
reversal of the pressure gradient between episcleral venous pressure and
intraocular pressure. In MIGS, the physiologic outflow system is restored.
Hence, the hyphema might represent blood refluxed from the episcleral venous
system through the XEN gel stent[6]. However, no
hypotony has been noted. IOP was measured at
The patient was treated with a vitamin K antagonist associated with an antiplatelet therapy that increases the risk of bleeding. Systemic anticoagulation and antiplatelet therapy are widely used for the treatment and prevention of thromboembolic events[8]. Stopping these treatments may increase the risk of life-threatening systemic complications such as cerebrovascular accidents or embolic disease. Ophthalmologists are currently dealing with larger numbers of patients undergoing anticoagulant and antiplatelet treatment and requiring ophthalmic surgery and this trend is set to continue. According to the French Glaucoma Society, no systematic approach can be recommended. Any decision to discontinue or modify an antiplatelet therapy or an anticoagulant treatment before glaucoma surgery must be made after the careful evaluation of the benefits and risks with patients, anesthesiologists and cardiologists. Our patient was considered to have a high risk of thromboembolic events because of a graft replacement of the aortic valve and an atrial fibrillation. Discontinuing his treatment would have been life-threatening[9].
XEN gel stent is generally well tolerated, but not without risks, in particular for patients under antiplatelet or anticoagulant therapy. Although hyphema usually resolves spontaneously, patients must be provided with comprehensive information on the benefits and risks.
ACKNOWLEDGEMENTS
Conflicts of Interest: Rezkallah A, None; Mathis T, None; Denis P is consultant for Alcon, Allergan, Novartis and Théa; Kodjikian L is consultant for Abbvie, Allergan, Alimera, Bayer, Novartis, Roche and Théa.
REFERENCES