CASE PRESENTATION
A 62-year-old white male requested a consultation regarding his increased IOP. He had recently seen a local optometrist who diagnosed the elevated pressure. The patient had no significant medical or family history of eye disease. His UCVA measured 20/30 OD and 20/25 OS. Although his anterior segments were normal, including gonioscopy, his IOP measured 32 mm Hg OD and 31 mm Hg OS. The patient had a cup-to-disc ratio of 0.4 OD and 0.6 with thinning of the inferior temporal neuroretinal rim OS.
I described my findings to the patient and recommended he undergo visual field testing as well as optic disc photography. The visual field testing (HVF 30-2; Carl Zeiss Meditec, Dublin, CA) demonstrated constriction and nonspecific decreased sensitivity in his right eye and constriction with an inferior step in his left eye. After discussing the nature of glaucoma with the patient, I set his target IOP at 15 mm Hg OU, and the patient departed my office with a sample of Lumigan (Allergan, Inc., Irvine, CA) prescribed bilaterally q.d. Although I often perform monocular trials of new medications, I did not in this case.
Two weeks later, the patient's IOP had dropped to the mid-twenties in both eyes. I added Timoptic XE (Merck & Co., Inc., West Point, PA) q.a.m. OU to his regimen and asked him to return in a couple of weeks. Two weeks later, the patient's IOP measured 16 mm Hg OU. Although he had achieved the target IOP, the patient was displeased and asked about possible alternatives to his eye drops, which represented to him an “impossible burden,” both financially and personally. After explaining the risks and benefits of glaucoma surgery, I recommended a laser-assisted deep sclerectomy with an AquaFlow Collagen Glaucoma Drainage Device (STAAR Surgical Company, Monrovia, CA), owing to the procedure's advantageous safety profile in a patient with moderate cupping. After discussing surgical alternatives, risks, and benefits, the patient agreed to proceed with surgery on his left eye.
The uneventful procedure yielded a large bleb and a stable IOP of 15 mm Hg without medications at 15 weeks postoperatively. The successful result in the patient's left eye prompted him to proceed with surgery on his right eye. Despite success in the immediate postoperative period, the patient's IOP rose into the 30s at approximately
3 weeks. An Nd:YAG laser goniopuncture did not reduce his right eye's IOP. The patient then underwent a full thickness trabeculectomy and iridectomy. This procedure occurred at the same site as the previous nonpenetrating surgery. I did not repeat the use of an antimetabolite. After surgery, he maintained an IOP of approximately 11 mm Hg and a well-functioning bleb.
The patient's postoperative course was uneventful until 3 months later, when he suddenly developed blurred vision and pain in his right eye. Examination revealed counting fingers acuity, an IOP of 4 mm Hg, a flat anterior chamber, posterior synechiae, and a choroidal effusion. The bleb still functioned with conjunctival microcystic edema. I could not locate a wound leak, although I suspected one existed.
The patient did not respond to topical atropine and Pred Forte (Allergan, Inc.) after 1 week, so I created a paracentesis and re-formed the anterior chamber with Healon5 (Pfizer Inc., New York, NY). The patient returned 3 days afterward with severe pain and an IOP of 50 mm Hg. That day, I sequentially drained as much Healon5 as I could from the paracentesis, and the patient was released with an IOP of 21 mm Hg and samples of QUIXIN (Santen Inc., Napa, CA), Alphagan (Allergan, Inc.), Lumigan, and Cosopt (Merk & Co., Inc.).
The patient returned after 3 days with a very soft eye. This time, however, careful Seidel testing demonstrated a pinpoint wound leak in the far reaches of the lateral canthal conjunctiva. I closed the leak with 8–0 VICRYL sutures (Ethicon Inc., Somerville, NJ).
After surgery, the eye's IOP was 6 mm Hg without medication, and the wound leak had ceased. There was a shallow but formed bleb with 1+ microcysts. Three weeks later, however, the patient complained of blurry vision. His UCVA measured 20/400. Slit lamp examination revealed a clear cornea, mildly shallow chamber, 360º of posterior synechiae with a patent iridectomy, a 3-mm pupil, and a 4+ posterior subcapsular cataract. The hazy view of the fundus suggested a chronic choroidal detachment. The macula appeared normal, without hypotony maculopathy. The optic disc appeared unchanged from earlier examinations. The patient desired better vision and requested long-term control of his IOP without medications, if possible.
HOW WOULD YOU PROCEED?1. How would you manage the pupil during phacoemulsification?
2. Manage the IOP in the perioperative period?
3. Address the challenge of failed trabeculectomies after phacoemulsification?
SURGICAL COURSE
The surgical plan included phacoemulsification and Endoscopic CycloPhotocoagulation (ECP; Medtronic Solan, Jacksonville, FL). I hoped that a mild ECP treatment would allow continued IOP control without medication, even if the trabeculectomy partially or completely failed after phacoemulsification. I preferred this approach to revising the trabeculectomy because of the patient's history of a wound leak that developed spontaneously 3 months after the prior trabeculectomy. The conjunctiva was at last closed, so I was not anxious to reopen it.
The first challenge was the small pupil and shallow chamber, because phacoemulsification in the presence of a small pupil carries an increased risk of complications. Not only did the patient have 360º of posterior synechiae, but his iris looked as if it might become floppy during surgery.
After administering topical anesthesia, I created a paracentesis, instilled nonpreserved lidocaine, and performed viscosynechiolysis with Viscoat (Alcon Laboratories, Inc., Fort Worth, TX) (Figure 1). I prefer to use a dispersive viscoelastic to lyse posterior synechiae because it tends to spread as an advancing wave under the iris. The procedure enlarged this patient's pupil to 5 mm. After lysing the synechiae and deepening the chamber with Provisc (Alcon Laboratories, Inc.), I constructed a 2.9-mm, temporal, clear corneal, single-plane incision with the diamond 3D knife (Rhein Medical, Inc.,Tampa, FL) in order to allow the insertion of the Perfect Pupil pupil expander ring (BD Ophthalmic Systems, Franklin Lakes, NJ). This polyurethane device creates a stable 7-mm pupil while protecting the iris from aspiration. The diameter of its safety arm is 0.4 mm and necessitates the larger corneal incision. This arm remains external, thereby insuring constant control and easy removal of the device.
I chose a pupil expansion device in this case to protect the iris. Stretching the pupil alone can create a floppy iris that tends to stream into the phaco tip or aspiration port. In my experience, using a device that protects the pupil helps ensure a good functional and cosmetic result.
In the presence of a 7-mm pupil, I was able to complete a standard capsulorhexis, hydrodissection, hydrodelineation, and phacoemulsification of the lens (Figure 2). The operation required little ultrasonic power because of the minimal nuclear sclerosis. I used the Fine-Nagahara chopper (Rhein Medical, Inc.) to score and divide the nucleus, and then I aspirated pie-shaped segments with high vacuum. Occasionally, as the eye rotated slightly, the white light reflex inferiorly identified the presence of the chronic choroidal detachment.
I implanted a Tecnis Z9000 lens (Pfizer Inc.) with the Unfolder (Advanced Medical Optics, Inc., Santa Ana, CA). Once the IOL was stable in the capsular bag, I removed the Perfect Pupil with a Sinskey hook and withdrew the device from the eye with McPherson forceps (Katena Products, Inc., Denville, NJ).
Next, I inflated the ciliary sulcus with additional Provisc in preparation for ECP. This 20-gauge device includes a 175-W Xenon light source, 110º endoscope with 480 lines of horizontal resolution, an 810-nm treating diode laser, and a 640-nm diode-aiming beam. I introduced the probe into the anterior chamber under the operating microscope and then switched my view to the endoscope monitor (Figure 3). Starting to the left, I obtained a good view of the ciliary processes and began the ablation. The diode laser produces whitening and shrinkage of the ciliary processes. Histological studies have shown that the treatment selectively ablates the pigmented epithelium, leaving the underlying structures of the ciliary muscle and vasculature intact.1
I generally treat approximately 270º of the ciliary processes for a 35% to 50% reduction in IOP. I have had no cases of postoperative hypotony, and, in fact, the lowest pressure I have ever achieved with ECP has been 9 mm Hg.2
After completing ECP, I thoroughly removed the viscoelastic from the capsular bag, ciliary sulcus, and anterior chamber. In my experience, the most common cause of postoperative pressure spikes after ECP is retained viscoelastic. I sometimes use bimanual I/A to ensure the complete removal of viscoelastic from the sulcus. In this case, I used Carbostat (Novartis Ophthalmics, Inc., Duluth, GA) to help constrict the stretched pupil. I sealed the clear corneal incision with stromal hydration.
OUTCOME
The patient's UCVA measured 20/40 OD 1 week postoperatively, but his IOP measured 29 mm Hg. There was essentially no bleb. The patient was treated with Pred Forte, Ocuflox (Allergan, Inc.), and Acular (Allergan, Inc.), all q.i.d. His pupil had remained approximately 5 mm, slightly larger than the other, so I asked him to use Pilogel 4% (Alcon Laboratories, Inc.) q.h.s. His IOP dropped to 16 mm Hg with this treatment a few weeks later. It seems likely that he will need to use at least one topical medication to achieve continued IOP control unless he undertakes further surgery.
If the patient continues to desire IOP control without medication, my next recommendation for his right eye will be the implantation of a Baerveldt shunt (Pfizer Inc.). If the patient is willing to continue medical therapy but requires improved IOP control (on the basis of continued glaucomatous progression), then selective laser trabeculoplasty will be an option.
Mark Packer, MD, is Clinical Assistant Professor at the Casey Eye Institute, Department of Ophthalmology, Oregon Health, and Science University, and he is in private practice at Drs. Fine, Hoffman & Packer, LLC. He is a consultant for Pharmacia Corporation; he has received honoraria and travel expenses from Medtronic Solan, Alcon Laboratories, Inc., and Carl Zeiss Meditec. Dr. Packer may be reached at (541) 687-2110; mpacker@finemd.com.1. Francis BA, Alvarado JA. Endoscopic cyclophotocoagulation and other cyclodestructive modalities: A histopathologic comparison. Poster presented at: Annual Meeting of the American Academy of Ophthalmology; October 20, 2002; Orlando, Florida.
2. Chen J, Cohn RA, Lin SC, et al. Endoscopic photocoagulation of the ciliary body for treatment of refractory glaucomas. Am J Ophthalmol. 1997;124:787-796.
