Surgical strategies for the treatment of concomitant cataract and glaucoma require special efforts that, if not approached properly, can result in disputes between the cataract and glaucoma surgeons comanaging these cases. This article presents a combination procedure that accomplishes the respective goals of both specialties—safe cataract surgery and the reduction of intraocular pressure (IOP)—and also creates an avenue for the implantation of premium IOLs to decrease spectacle dependence.
In many cases, modern microinvasive nonpenetrating glaucoma surgery can be performed immediately before phacoemulsification to treat patients with cataract and glaucoma in a single step. In my practice, these combined single-step cataract and glaucoma operations account for approximately 10% to 15% of all my cataract surgeries— about 400 to 600 procedures per year. In patients with cataract and uncontrolled glaucoma, combining cataract and glaucoma surgery is faster, cheaper, and more convenient for the patient as well as for the surgeon. I have found that, when performed before phacoemulsification with IOL implantation, nonpenetrating deep sclerectomy (NPDS) with autodrainage achieves reduction of IOP similar to full-thickness trabeculectomy but with fewer intra- and postoperative complications and changes in refraction and optical performance. Therefore, implantation of modern premium IOLs can be considered in this population.
DISCLOSE POSSIBLE CONSEQUENCES
The presence of glaucoma, even minimal initial glaucomatous changes in visual function, is a relative contraindication to multifocal IOL implantation. Therefore, the surgeon should thoroughly understand a patient’s expectations and his or her job and lifestyle and confirm that alternative options (monovision or accommodating IOLs) to decrease spectacle dependence are inadvisable before suggesting multifocal IOLs. Only in this case can multifocal IOL implantation be considered in glaucoma patients. Possible consequences of this decision, including decreased contrast sensitivity with multifocal IOLs, the possibility of peculiarities due to glaucomatous central visual field loss, changes in pupil function (such as dilation caused by certain antiglaucomatous agents), and possible future glaucoma progression, should be discussed before surgery.
Taking the above into account, the final decision should be a joint effort with the surgeon and patient. Of the more than 1,500 multifocal IOLs implanted in our clinic, not more than 40 have been implanted in glaucoma patients, even though the percentage of glaucoma patients operated on for cataract is 30% to 40% higher than in the general population.
IOLs can be implanted at various stages of glaucoma progression, except in end-stage glaucoma when central vision is no longer preserved. In cases of uncontrolled glaucoma, we typically perform simultaneous cataract surgery and NPDS with autodrainage. In the past year, we have started using the patient’s own anterior lens capsule to enhance drainage into the subchoroidal space. This is explained below in a review of our surgical technique.
Surgery is performed under topical anesthesia. With the patient looking down, the conjunctiva is separated from the limbus in the area where the incision is planned. Following diathermy coagulation, a one-third thickness superficial round scleral flap is created. The base of the superficial flap is dissected 1.5 to 2.0 mm into the limbus and clear cornea (Figure 1). Then a deep, triangular flap is created, exposing Schlemm canal (Figure 2). At the top of this triangle, a window is cut over the ciliary body.
With the patient now asked to look straight ahead, the surgeon can proceed to phacoemulsification. Following creation of a 1.8-mm temporal clear corneal incision and two paracenteses (Figure 3A), the anterior chamber is filled with an ophthalmic viscosurgical device (OVD) and the capsulorrhexis is performed (Figure 3B). The anterior lens capsule is then stained with a drop of methylene blue (Figure 3C), removed, and preserved.
Following hydrodissection and hydrodelineation, the nucleus and cortex are extracted using the dig-and-split technique,1 and the remaining lens fragments are removed using a bimanual I/A system with obligatory posterior capsular polishing. IOL implantation is preceded by injection of OVD into the anterior chamber.
If even a slight posterior capsular opacity is present or development of a secondary opacity is anticipated, we suggest performing a primary posterior capsulorrhexis under the IOL optic using the layered-pie technique.2
At this time, after asking the patient to look down, the scleral flap should be removed, along with the outer wall of Schlemm canal and some corneal tissue, to expose approximately 1.0 to 1.5 mm of Descemet membrane (Figure 4).
The preserved anterior lens capsule is then sutured to the sclera behind the scleral spur with 10-0 nylon. To avoid sutures completely, during my most recent surgeries I have pushed the stained capsule through the scleral window and into the subchoroidal space with a spatula (Figure 5). This allows the capsule itself to act as a collagen drainage device, not only preventing closure of the intraocular fluid outflow tract we have created but also joining the intrascleral outflow tract with the subchoroidal space to stimulate uveal outflow.
If surgery has been performed without microperforations, there is no need to suture the superficial scleral flap, and the procedure is completed with one buried conjunctival suture.
STRINGENT PATIENT SELECTION
This combined procedure allows surgeons to use premium IOLs (ie, toric, multifocal, multifocal toric, and accommodating) when warranted, as it does not induce any optical changes in the eye. In general, the results in our group are positive, and most patients assess their postoperative vision as good or excellent. Unsatisfactory results have occurred in four cases, one with advanced glaucoma, a concentric visual field defect, and a 3-mm rigid pupil; two with developed glaucoma and high myopia; and one with developed glaucoma and isolated scotomas in the central visual field. The high percentage of satisfied patients is largely due to thorough and stringent patient selection.
Glaucoma surgery in pseudophakic eyes does not differ from that in phakic eyes with primary open-angle glaucoma; however, it does for cases of secondary open-angle glaucoma. Exclusions are any intra- or postoperative complications of cataract surgery. In cases with wide open-angle glaucoma, NPDS is my first choice. Even if filtration does not occur on the operating table, laser puncture of the angle and Descemet membrane can be performed several days after surgery, usually resulting in good outcomes. This approach does not lead to changes in refraction or induced astigmatism, which is especially important in combined cases in which a premium IOL is implanted, and the patient’s visual activity and quality of life remain unchanged.3
If antiglaucomatous interventions have been performed in a pseudophakic eye several times already, the best approach must be chosen on a case-by-case basis, beginning with determining the level of intraocular fluid retention and the reasons for recurrent failures before selecting a customized approach to surgery. Possible approaches include NPDS with drainage, fistulizing surgery, implantation of shunts or drainage devices, endo- or transscleral cyclodestructive surgery, and adjunctive use of cytostatic agents.
Kirill Pershin, MD, is an ophthalmic surgeon at the Excimer Clinic in Moscow, Russia. Dr. Pershin states that he has no financial interest in the products or companies mentioned. He may be reached at tel: +7 495 912 14 22; e-mail: firstname.lastname@example.org.
- Pershin K. ‘Dig & split’ phaco technique for hard and challenging cataracts. Video presented at: the 26th Congress of the European Society of Cataract and Refractive Surgeons; September 13-17, 2008; Berlin.
- Pershin K, Solovyeva G, Pashinova N, et al. Posterior capsulorhexis as a method for prevention of secondary cataract. Poster presented at: the 24th Congress of the European Society of Cataract and Refractive Surgeons; September 9-13, 2006; London.
- Pershin K. Combined glaucoma and cataract surgery with AcrySof Restor IOL Implantation. In: Glaucoma— Trends and Technology. Moscow; 2007;79-80.