CASE PRESENTATION
A 32-year-old white female presented to her community ER with an 8-week complaint of pain in her left eye, headache, and subsequent nausea. Her IOP measured 50 mm Hg OS, and the visual acuity in that eye was hand motions.
The patient was referred to an outside ophthalmologist, who diagnosed acute angle-closure glaucoma (ACG) and anterior uveitis. Her condition was managed with a topical steroid, a systemic steroid, a topical beta-blocker, systemic Diamox (acetazolamide; Duramed Pharmaceuticals, Inc., Pomona, NY), and Valtrex (GlaxoSmithKline, Research Triangle, NC), as it was initially thought that there was a viral etiology to the uveitis. Attempts to taper the medications caused a rebound IOP spike. The patient's past medical history was significant for non-insulin-dependent diabetes mellitus of 1 year's duration, which was controlled by diet. She also had hypercholesterolemia and illdefined psychosocial issues. Her systemic medication included alprazolam. The patient was referred to me for further evaluation and management.
She presented to me 2 days after her diagnosis with complaints of nausea, vomiting, diarrhea, and photophobia. Subjectively, she felt that her headache and vision had improved. Her BCVA was 20/30 OD and 20/150 OS. Her IOP measured 18 mm Hg OD and 9 mm Hg OS with Goldmann applanation tonometry. The patient's right pupil was round and reactive to light, whereas the left pupil was middilated at 7 mm and minimally reactive. A slit-lamp examination of her left eye revealed ciliary flush with 1+ Descemet's folds. The anterior chamber was diffusely shallow with temporal iris atrophy and central glaukomflecken of the lens. Gonioscopy revealed an appositionally closed angle of 270º in her right eye and no visible angle structures in her left eye despite goniocompression. Funduscopy revealed physiological cupping of 0.25 bilaterally (Figure 1).
My working diagnosis was acute ACG. I discontinued the Valtrex, and the patient was scheduled for a prophylactic laser peripheral iridotomy (LPI) in her right eye and a trabeculectomy with mitomycin C in her left eye. Both procedures were uncomplicated. The angle in the right eye deepened to the level of midtrabecular meshwork following the LPI. After the trabeculectomy, her visual acuity improved to 20/40 OS, the IOP by applanation tonometry was 8 mm Hg, and the posterior bleb was diffuse. Once stable, she continued her follow-up care with her original ophthalmologist.
The patient was referred back to me 14 months later for progressive narrowing of the angle in her right eye, without an increase in IOP. Her BCVA (+4.75 –1.00 X 180) was 20/30 OD and (+4.25 –0.75 X 180) 20/50 OS. IOP by Goldmann applanation tonometry measured 18 mm Hg OD and 9 mm Hg OS. The iridotomy was patent by slitlamp examination, but gonioscopy revealed appositional closure inferonasally, with 1 clock hour of peripheral anterior synechiae (PAS) nasally to anterior midtrabecular meshwork. Corneal horizontal diameters measured 10 mm OU. The lens was clear and not intumescent in the patient's right eye. Corneal pachymetry measured 569 μm OD and 567 μm OS. A SITA-standard 24-2 Humphrey visual field test (Carl Zeiss Meditec, Inc., Dublin, CA) revealed a full visual field in her right eye and superonasal depression in her left eye (Figure 2).
HOW WOULD YOU PROCEED IN THE
PATIENT'S RIGHT EYE?
1. Would you begin miotic therapy?
2. Would you perform a gonioplasty?
3. Would you extract the lens and implant an IOL?
SURGICAL COURSE
I started the patient on low-dose pilocarpine 0.5% b.i.d. while arrangements were made for an iridoplasty. The brief course of pilocarpine therapy significantly relieved the iridotrabecular apposition as seen by gonioscopy, and subsequent ultrasound biomicroscopy (UBM) revealed an open angle with evidence of plateau iris configuration (Figure 3A). The thickness of the posterior sclera could not be assessed. Given the crowded anterior segment, I performed optical biometry using the IOLMaster (Carl Zeiss Meditec, Inc.), which measured an axial length of 19.79 mm OD and 19.61 mm OS and an anterior chamber depth of 2.05 mm OD and 2.16 mm OS (Table 1).
I performed an iridoplasty 360º and lysis of the small area of PAS. Postoperatively, she was started on prednisolone acetate 1% q.i.d.
OUTCOME
Three weeks postoperatively, the anterior chamber remained shallow, although the angle in the patient's right eye remained open without pilocarpine. Repeat UBM imaging demonstrated a continued narrow but open angle (Figure 3B). Her IOP measured 12 mm Hg OD by applanation, and the anterior segment was quiet on biomicroscopy.
Because she was able to maintain her angle depth off of pilocarpine, I deferred lens extraction in favor of close observation.
DISCUSSION
As people age, the depth and volume of the anterior chamber decreases as the crystalline lens thickens and assumes a more anterior position.1 The incidence of primary angle closure (PAC) therefore increases with age, reaching a peak between 55 and 70 years.2 PAC rarely occurs in adults as young as this patient.
The major mechanism of PAC in older adults is pupillary block3 versus plateau iris in younger adults.2 Other conditions such as iridociliary cysts, trauma, uveal effusion, and nanophthalmos should also be considered in younger patients.
In this case, gonioscopy and UBM ruled out relative pupillary block, trauma, iridociliary cysts, and uveal effusions. Nanopthalmos is characterized by a small eye, hyperopia, small corneal diameters, shallow anterior chambers,4 high lens/eye volume, and thickened sclera.5 The condition is quite rare and usually bilateral.4 Although the patient in this case possessed several of the aforementioned features of nanophthalmos, they are also typical risk factors seen in patients with PAC.3 Although the characteristic double-hump sign—as seen on gonioscopy—was absent, UBM confirmed anteriorly rotated iris processes. I made the diagnosis of plateau iris syndrome incomplete 2 based on continued appositional closure, despite the iridotomy's confirmed patency without elevated IOP. A crowded anterior segment only exacerbates the shallow anterior chamber, which I suspect contributed to the initial presentation of acute angle closure in the patient's left eye.
The options for surgical management include LPI, argon laser peripheral iridoplasty, trabeculectomy, and lens extraction. Psychosocial issues may have delayed this patient's initial presentation to the ER. By the time of my evaluation, the angle of her left eye revealed synechial closure, without evidence of pupillary block. I felt a primary trabeculectomy with antimetabolites would afford her the best long-term IOP control. Although others have advocated argon laser peripheral iridoplasty in chronic angle closure, it has been reported that more than 36% of study patients required trabeculectomy by 3 months after the procedure.6 An alternative approach could have been initial argon laser peripheral iridoplasty followed by cataract extraction and goniosynechialysis for residual PAS, as described by Ritch et al.7
Koybayashi et al demonstrated by UBM that pilocarpine widens the iridotrabecular angle in patients with narrow angles8 and may have a temporary role in managing these patients. In this case, pilocarpine was used until argon laser peripheral iridoplasty could be performed. During this time, UBM confirmed deepening of the angle.
The role of the crystalline lens in acute ACG has been described. Tarongoy et al explained that, despite a patent LPI, lens/angle crowding as seen in plateau iris syndrome can result in acute or chronic angle closure, which necessitates cataract extraction for definitive management.1 Certainly, over time, this procedure may become necessary in this case. Despite cataract extraction and IOL implantation, however, iridociliary apposition is not eliminated in these eyes, as described by Tran et al.9
Regardless of one's surgical approach, the ultimate goal is to prevent trabecular dysfunction from chronic angle closure and the development of glaucomatous optic neuropathy. A well-planned, systematic approach can be achieved with close observation of the patient, including compression gonioscopy, which is essential in monitoring the development of any new PAS.
Fred Kapetansky, MD, provided assistance in acquiring the UBM scans used in this case. Sarah Johanson, COA, provided photographic assistance with this article.
Gloria P. Fleming, MD, is an assistant professor of ophthalmology at The Ohio State University in Columbus, Ohio. She acknowledged no financial interest in the products or companies mentioned herein. Dr. Fleming may be reached at (614) 293-8119; gloria.fleming@osumc.edu.
