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An 88-year-old woman with a history of complicated cataract extraction by phacoemulsification with sulcus intraocular lens (IOL) placement developed pseudophakic pupillary block after reverse implantation of the IOL. In the postoperative period, she had persistently elevated intraocular pressures (IOP) and was diagnosed with chronic angle-closure glaucoma that was treated medically. She presented 5 years later with acute pupillary block. The diagnosis of reverse IOL implantation was confirmed by ultrasound biomicroscopy. An IOL repositioning, anterior synechialysis, and Baerveldt tube shunt placement led to resolution of the pupillary block and a well-controlled IOP.
Pseudophakic pupillary block can occur after anterior chamber intraocular lens (IOL) implantation, as the IOL can act as a valve to occlude aqueous flow through the pupil.1,2 However, it can also occur after posterior chamber IOL implantation and may be related to several factors, including placement of the IOL in the ciliary sulcus resulting in an alteration of the anterior chamber angle,3 disruption of zonular fibers intraoperatively leading to vitreous presentation in the anterior chamber,4 and exacerbation of a preexisting shallow anterior chamber. The onset can occur from a few days to several months postoperatively.2 We present a case of pupillary block secondary to reverse implantation of an IOL in the ciliary sulcus leading to chronic angle-closure glaucoma (ACG) and acute pupillary block.
An 88-year-old woman with a history of chronic ACG and complicated cataract extraction presented to the glaucoma service with intermittent right-sided headache and severe right ocular pain, which had gradually worsened over 2 days. She had been on latanoprost 0.005% daily in both eyes, which she stopped 2 days before presentation. Her presenting corrected distance visual acuity (CDVA) was 20/25 in the affected eye. Goldmann applanation tonometry measured 26 mm Hg in the affected eye and 11 mm Hg in the fellow eye. A shallow anterior chamber with 360 degrees of iris-to-cornea touch was noted. Evaluation of the IOL revealed a slightly tilted and anteriorly displaced 3-piece IOL in the sulcus that appeared to be in a reversed ”S” configuration (Figure 1, A and B). The angle was notably closed on gonioscopy. Humphrey visual field testing showed a dense superior arcuate deficit in the affected eye. Optical coherence tomography (OCT) of the retinal nerve fiber layer revealed diffuse thinning. The unaffected eye had a normal Humphrey visual field and OCT retinal nerve fiber layer. Dilated fundus exam revealed an asymmetric cup-to-disc ratio of 0.9 in the right eye compared to 0.4 in the left eye, and was otherwise unremarkable.
The patient was started on latanoprost 0.005% daily, brimonidine/timolol 0.2%/0.5% twice daily, atropine 1.0% daily, and oral acetazolamide. When she returned to clinic a week later, her IOP was elevated to 32 mm Hg and her CDVA deteriorated to 20/40. Anterior segment ultrasound biomicroscopy (UBM) showed an incorrectly positioned 3-piece sulcus IOL that was vaulted anteriorly, leading to pupillary block (Figure 2, A) with a normal ciliary body position. Due to advanced glaucoma, high IOP, and extensive peripheral anterior synechiae, incisional surgery was recommended. An experienced anterior segment surgeon (O.S.) performed an uncomplicated IOL repositioning, goniosynechialysis, and Baerveldt 350 tube shunt with corneal patch graft placement (Figure 3). This was achieved by first placing a 4-0 polypropylene (Prolene) suture in the lumen of the Baerveldt tube shunt, then placing the Baerveldt tube shunt and securing it underneath the superior and medial rectus muscles, then tying off the tube before proceeding to the IOL repositioning. A clear corneal incision was made, and an ophthalmic viscosurgical device (OVD) was used to deepen the anterior chamber. Iris hooks were used to further expand the pupil. The IOL was noted to be in the sulcus and mobile. An OVD cannula was placed underneath the IOL and OVD was injected to push the temporal aspect of the IOL anteriorly to flip the IOL on its vertical axis with the aid of a Sinskey hook. After the haptics were positioned appropriately in the sulcus, an anterior synechialysis was performed. The tube shunt was subsequently placed into the eye and tied off. A corneal patch graft was placed and conjunctiva was reapproximated.
Postoperatively, there was significant improvement in her eye pain, and the anterior chamber deepened (Figure 1, C). The IOP ranged from 6 to 33 mm Hg after surgery prior to removal of the intubating suture (“rip cord”). After the suture was pulled at postoperative month 2, the IOP stabilized and ranged between 9 and 13 mm Hg on brimonidine 0.2% and timolol 0.5% twice daily; the CDVA measured 20/30. Repeat anterior segment UBM 4 months postoperatively revealed a posteriorly-vaulted IOL (Figure 2, B). ImageJ software was used to measure the anterior chamber depth (ACD), angle opening distance at 500um , and the trabecular–iris angle in both the preoperative and postoperative anterior segment UBM images. The ACD was found to increase from 1.74 mm to 2.83 mm. The angle opening distance at 500umincreased from 0.36 mm to 0.65 mm nasally and 0.24 mm to 0.91 mm temporally. The trabecular–iris angle was found to increase from 19 to 36 degrees nasally and 29 to 46 degrees temporally.
Five years prior to presentation, the patient’s cataract surgery had been complicated by a large posterior capsular tear, necessitating anterior vitrectomy and implantation of the 3-piece IOL in the ciliary sulcus. On the first postoperative day after the surgery, she was noted to have an IOP of 54 mm Hg in her righteye with subluxation of the IOL haptic into the anterior chamber, which was repositioned at the slit lamp with a 30-gauge needle. There had been no evidence of glaucoma prior to this surgery, and she was started postoperatively on apraclonidine 0.5%, brinzolamide 1.0%, oral acetazolamide, and prednisolone acetate. Her elevated IOP persisted despite discontinuing prednisolone acetate 1.0% eyedrops. Gonioscopy of the right eye had revealed narrow anterior chamber angles, and she was diagnosed with chronic ACG, for which she was treated with chronic latanoprost therapy.
Pupillary block is an infrequent complication of posterior chamber IOL implantation. It can be caused by 360-degrees of posterior synechiae between the IOL and iris, or if the IOL is placed in the ciliary sulcus, alteration of the anatomy of the anterior chamber angle.4 In the case of reversed IOL orientation in the sulcus, the anterior vault of a 3-piece IOL can cause the optic to become apposed to the posterior surface of the iris, leading to pupillary block. Whereas accidental reversal of the IOL is not a commonly reported cause of pseudophakic pupillary block, incorrect positioning of the IOL in the sulcus has been noted to occur with a frequency of 1.3% even in experienced hands.5 All of these situations can result in anterior chamber shallowing, IOP elevation, and subsequent ACG.
Our patient is unique in that she presented with acute on chronic pupillary block glaucoma 5.5 years after the initial sulcus IOL placement. Similar to previous reports of pseudophakic pupillary block after sulcus IOL reversal, anterior displacement of the IOL optic was noted in the early postoperative period, which was relieved by repositioning at the slitlamp. Although this technique has been reported previously,6 our case shows that in the long term, this may not reduce the risk for chronic and acute-on-chronic glaucomatous damage. Laser peripheral iridotomy has also been attempted in this setting, but particularly given the anterior segment ultrasound, we determined that the vaulted IOL would continue to push the iris diaphragm anteriorly and cause further peripheral anterior synechiae. To this end, we recommend surgical repositioning of the IOL in the ciliary sulcus as soon as possible after reverse IOL implantation is recognized.
Anterior segment UBM is useful in evaluation of pupillary block, plateau iris, IOL positioning, ocular trauma, and other ocular diseases involving the anterior segment.7 This technique has been used to determine IOL positioning in the past and to elucidate the cause of reverse pupillary block.8–10 In a case study by Sathish et al.,10 anterior segment UBM helped to diagnose iris bombe as the cause of pseudophakic pupillary block glaucoma 3 years after implantation of a 3-piece IOL in the bag8. In our case, while the configuration of the haptic provided a clue as to the etiology of pupillary block, anterior segment UBM confirmed that the IOL was causing anterior bowing of the iris and helped to exclude other causes such as aqueous misdirection syndrome,11 bilateral ring cysts of the ciliary body,8 late-onset secondary pigmentary glaucoma,9 a thick Soemmerring ring, and anterior displacement of the ciliary body.12
Aydin et al.13 described a case in which reverse implantation of a vaulted IOL into the ciliary sulcus led to pupillary block, the sequelae of which were resolved with neodymium:YAG laser peripheral iridotomy. Harsum et al.6 reported a case of a patient who developed pupillary block after being dilated on postoperative week 4 of a reversed IOL, which was resolved with repositioning of the IOL at the slitlamp. Prior case reports have not shown the long term follow up of patients with such temporizing measures.
Our patient required a low pressure to manage her advanced glaucoma and required placement of a Baerveldt 350 tube shunt placement with corneal patch graft, in addition to goniosynechialysis and IOL repositioning. This treatment resolved the pupillary block and successfully controlled the patient’s IOP. All anterior segment UBM measurements, especially ACD, angle opening distance at 500um, and trabecular–iris angle, revealed significant improvement postoperatively. In normal subjects, average anterior segment UBM measurements for ACD is 3.13 mm ± .37 (SD).14 Whereas our patient had an ACD that was below the range of normal during her episode of pupillary block at 1.74 mm, her ACD increased to 2.83 mm following the procedure. Her trabecular–iris angle also revealed an opening of 17 degrees both nasally and temporally. Thus we can conclude that the reverse implantation of the IOL led to both chronic ACG and acute pupillary block.
The aim of our case report is to remind providers to assess the position of the IOL when faced with pseudophakic pupillary block, or when there are persistently high IOPs postoperatively. Furthermore, anterior segment UBM serves as a reliable method to assess IOL positioning in such cases. Temporizing measures may resolve acute pupillary block in such cases, but may still lead to chronic glaucomatous changes. Early repositioning of the IOL could prevent progression of ACG and prevent pupillary block.
Financial Disclosure: None of the authors has a financial or proprietary interest in any material or method mentioned.