Abstract
Purpose
To describe the presentation and management of a patient with epithelial versus fibrous downgrowth following trabeculectomy surgery and review relevant literature regarding this complication after intraocular surgery.
Observations
A 52-year-old monocular African-American woman was referred for management of presumed epithelial versus fibrous downgrowth following trabeculectomy surgery. The patient was initially treated with intracameral injections of 5-fluorouracil (x2) and bevacizumab (x1). Cataract extraction, membranectomy, and a third intracameral 5-fluorouracil injection were performed. Intraocular pressure (IOP) elevation was subsequently managed with a superotemporal Ahmed FP7 glaucoma drainage device in the sulcus, followed by an inferonasal Baerveldt 350 glaucoma drainage device in the sulcus. The downgrowth has not progressed and the intraocular pressure remains controlled at the most recent follow-up.
Conclusions
This case underscores the risk of this complication following trabeculectomy, the role of a combined medical and surgical approach to management, and the possible need for multiple surgical interventions to control IOP. A review of the literature regarding epithelial and fibrous downgrowth after intraocular surgery was conducted, which highlighted the aggressive nature of these conditions and the range of therapeutic approaches that have been described.
1
Introduction
Epithelial downgrowth is a rare complication of intraocular surgery or trauma characterized by invasion of surface epithelial cells into the anterior chamber (AC) of the eye. The membranous spread of these conjunctival or corneal epithelial cells can be difficult to control and lead to devastating consequences including end-stage glaucoma and permanent vision loss. Fibrous downgrowth is a similar but somewhat less aggressive condition characterized by fibrovascular connective tissue invading into the eye. Patients with these conditions can present with decreasing visual acuity, pain, tearing, photophobia, foreign body sensation or flashes of light. Previous reports have described epithelial downgrowth following glaucoma surgery. Herein, we report the medical and surgical management of a case of severe epithelial versus fibrous downgrowth following prior trabeculectomy surgery.
2
Case report
A monocular 52-year-old African American woman with primary open angle glaucoma (POAG) was referred to the anterior segment service for evaluation of a membrane growing into the AC from a superior trabeculectomy site in her only-seeing left eye (OS) performed 10 months prior. Visual acuity (VA) was 20/125 and intraocular pressure (IOP) was 24 mmHg on four topical antihypertensive agents. She was also using prednisolone acetate 1 % and cyclopentolate 0.5 % once daily for low-grade AC inflammation. She had previously undergone selective laser trabeculoplasty (SLT) OS with initial improvement in IOP; however, after being lost to follow-up for 18 months, the IOP had increased to 29 mmHg so she underwent a superior fornix-based ab externo trabeculectomy with subconjunctival injection of mitomycin-C (MMC) (0.1 mL of 0.4mg/mL). Her post-operative course was notable for hypotony with IOP of 7 mmHg, a shallow AC, self-limited choroidal effusions, and persistent low-grade AC inflammation. Five months after surgery, the angle was documented to be synechially closed for 360-degrees.
On slit lamp examination, a membrane covering the anterior lens capsule was noted, originating from the superior trabeculectomy site with neovascularization on the membrane. This was concerning for an inflammatory membrane, fibrous downgrowth, or epithelial downgrowth ( Fig. 2 ). An inflammatory workup for Lyme disease, syphilis, tuberculosis, and sarcoidosis was negative. Diagnostic argon laser applied to the iris surface was consistent with the diagnosis of epithelial downgrowth. Confocal microscopy did not reveal a retro-corneal membrane.
The patient underwent intracameral injection of 0.05mL of 5-Fluorouracil (5-FU) followed by intracameral injection of 0.05mL of bevacizumab two weeks later, and a second intracameral injection of 0.05mL of 5-FU one month later. Her IOP OS increased to 29 mmHg, so topical prednisolone acetate was discontinued due to a concern for steroid response. Over the next eight months, the appearance of the fibrous membrane remained stable, the patient’s VA OS fluctuated between 20/300 and count fingers, and IOP ranged from 15 to 23 mmHg.
The patient subsequently underwent membranectomy, cataract extraction with implantation of a one-piece intraocular lens in the capsular bag, and another intracameral injection of 0.05mL of 5-FU. The membranectomy involved visco-dissection and excision of the membrane using a cystotome and MST scissors. Histopathologic analysis identified the sample as a hypocellular collagenous tissue with small vessels and focal pigment deposition ( Fig. 3 ).
One month after surgery, the patient’s IOP OS was 38 mmHg on four topical antihypertensive medications, and she was referred to a new glaucoma provider (MQ). Steroid response was considered given prolonged use of prednisolone acetate. Gonioscopy revealed 360-degrees of synechial closure with fibrous tissue extending from the trabeculectomy sclerostomy site to the superior aspect of the anterior capsule. Oral acetazolamide 500mg twice a day was started, but IOP remained elevated at 33 mmHg. The patient underwent implantation of a superotemporal Ahmed FP7 glaucoma drainage device (New World Medical, Rancho Cucamonga, CA) with the tube tip in the sulcus, scleral patch graft, and Kenalog 20mg injected intra-tenons over the plate to reduce encapsulation. The following day, IOP was 17 mmHg OS.
By post-operative week five, IOP increased to 25 mmHg on 4 topical antihypertensive medications and oral acetazolamide 250mg four times per day, so the patient underwent implantation of an inferonasal Baerveldt 350 implant (Johnson & Johnson Vision Care Inc., Jacksonville, FL) with the tube tip in the inferonasal sulcus, split thickness half-moon corneal patch graft, and 3-0 Prolene ripcord suture in the tube lumen to prevent hypotony when the ligating suture dissolves, which is this surgeon’s standard protocol for Baerveldt tubes. Concurrent revision of the Ahmed FP7 was also performed by excising the capsule over the plate and injecting Kenalog 20mg to reduce aqueous outflow resistance and future encapsulation. The goal was to achieve early IOP lowering in the first 6 weeks before the Baerveldt opened.
At post-operative week one, the IOP was 12 mmHg; however, one week later, the IOP decreased to 3 mmHg, the ripcord suture was absent although the patient did not recall removing it herself, and there was a robust AC inflammatory reaction with fibrinous material at the tip of the inferonasal tube, not occluding the tube ( Fig. 2 ). The patient was treated medically with frequent topical steroid and atropine. By post-operative week three, the IOP increased to 16 mmHg, and the AC inflammation subsided. Throughout this period, the AC remained deep, and no choroidal effusions or suprachoroidal hemorrhage were seen. By post-operative week six, the ligating suture dissolved, as expected, and the inferonasal Baerveldt tube was fully functioning. By postoperative month seven, the patient’s best-corrected VA was 20/50, and the IOP was 11 mmHg on five topical antihypertensives (brinzolamide/brimonidine 3x per day, Timolol 2x per day, netarsudil/latanoprost at bedtime) and no oral agents. No recurrence of the downgrowth was noted, the fibrinous AC reaction had resolved, and both tube tips were patent in the sulcus ( Fig. 4 ). A new 24-2 Humphrey Visual Field, this time with a size V stimulus, demonstrated that she still retained a central island of vision in this eye ( Fig. 1 ).
