Strategies for enhancing outcomes in cataract surgery for glaucoma

Real-world data show Omidria is beneficial in high-risk and routine cataract procedures.

Issue: March 25, 2017

In an era in which we are protecting the quality of our patients’ vision over longer periods of time, often for decades, we are more frequently in the position to integrate cataract surgery into the ongoing management of glaucoma.

While the advent of microinvasive glaucoma surgery, performed in conjunction with cataract surgery, opens up new avenues for controlling IOP, conventional lens extraction itself provides a useful tool that should be considered within the expanding range of treatment options for the glaucoma patient.

Savak "Sev" Teymoorian

Understanding the potential benefits of cataract surgery in different types of glaucoma and taking steps to reduce the risk of complications during surgery are essential to optimizing outcomes in this setting.

Faced with an expanding treatment armamentarium, the clinician’s goal is still to intervene as little as possible to obtain the maximum therapeutic benefit. It is in this glaucoma management environment — early, step-wise, risk-benefit balanced — that cataract surgery emerges as a useful tool. Indeed, we can begin to think differently about the timing and therapeutic objectives of cataract surgery — viewing it as one of several surgical approaches that are an integral component of the glaucoma treatment continuum.

Individual approach

Because glaucoma is a multifactorial disease that is not completely understood, each type of glaucoma and each patient must be approached individually. This is certainly true when considering cataract surgery as a therapeutic intervention. The benefits of lens extraction with phacoemulsification for lowering IOP in acute angle-closure glaucoma (AACG) have been well documented, while some reduction has been shown in primary open-angle glaucoma (POAG) depending on the preoperative IOP. However, cataract surgery can play a role in all subtypes of glaucoma, despite varying pathophysiology. Cataract surgery in most patients results in some IOP reduction as a welcome side effect, including those with POAG. For patients who have pseudoexfoliation, early cataract surgery, when zonules are not as weak and cataracts not as dense, decreases the risk of complications. In AACG, there is a growing body of evidence supporting the use of cataract surgery as a treatment once IOP is best medically controlled (or even before this point), rather than performing laser peripheral iridotomy. Even in patients with narrow angles before an episode of AACG, the use of cataract surgery has been shown to deepen the anterior chamber and reduce IOP, preventing a quasi-phacomorphic effect along with the development of peripheral anterior synechiae.

If a patient with any of these subtypes requires gold standard surgery with trabeculectomy or a tube shunt, the removal of a cataract beforehand is also advantageous. Removal of the natural lens makes performing these surgeries easier because it deepens the angle for placement of an Ex-Press glaucoma filtration device (Alcon) during trabeculectomy or the tip of a tube in Seton shunt surgery. It also removes the risk of a traumatic cataract. Performing cataract surgery first eliminates the inevitable need to address an advancing cataract as a result of prior intraocular surgery.

This shift in paradigm, however, is also dependent on achieving good surgical outcomes. This is especially important in patients with glaucoma because they already have visual field deficiencies that can be expected to worsen over time. Complicated cataract surgery can compound the underlying problem and further decrease their quality of vision.

Just as in angle surgery for glaucoma, maintaining a sufficient operating field of view during cataract surgery is critical to reducing complications. It is well documented that proper dilation of the pupil during cataract surgery can make a significant difference in patient outcomes. A decrease in pupil diameter exponentially decreases the surgeon’s view of the operative field, and studies have shown that small pupils are associated with higher rates of surgical complications. Conversely, good visualization through the pupil leads to decreased surgical time, lower complication rates and a reduction in the use of additional tools such as expansion rings.

In the context of glaucoma treatment, any decrease in surgical time that can be achieved with proper dilation ultimately leads to better IOP control because there are fewer complications, including reduced trauma to tissue. This benefit is enhanced if mechanical dilation can be avoided during the procedure.

Minimizing complications

Better mydriatic/anti-miotic control is a priority in every cataract surgery procedure but is particularly important in high-risk patients such as those with pseudoexfoliation glaucoma. Typical issues that complicate cataract surgery in these patients include poor dilation, weak or loose zonules, and a denser lens. Pseudoexfoliation is also associated with a higher risk for intraoperative miosis. In these and other high-risk patients, as well as in our more routine cases, we have found Omidria (Omeros) to be especially useful. Omidria is a combination of phenylephrine 1% and ketorolac 0.3% that is diluted in the irrigating solution. It is the only FDA-approved intraoperative drug for maintaining pupil size and reducing postoperative pain, as well as the only one to contain an NSAID. Well-controlled trials have confirmed that Omidria maintains pupil diameter and prevents constriction significantly better than placebo and significantly better than either phenylephrine or ketorolac alone in patients given standard preoperative mydriatic and anesthetic agents. Real-world data collected after Omidria was on the market have shown reduced complication rates, reduced use of pupil expansion devices and shorter surgical times when compared with epinephrine in both high-risk (eg, intraoperative floppy iris syndrome, pseudoexfoliation) and routine cataract procedures with and without concomitant use of femtosecond laser.

These results mirror my own experience in patients in whom we could compare the use of Omidria in one eye vs. the fellow eye without the drug. In Omidria-treated eyes, peak iris dilation was larger and the length of dilation longer. This in turn led to fewer complications, including tissue manipulation and the use of expansion rings, resulting in shorter surgical times (including the duration of phacoemulsification). Omidria-treated eyes also experienced fewer IOP spikes. Finally, the ability to perform MIGS was not negatively affected by the mydriatic effects of Omidria. This is due in part to shorter surgical times resulting in a clearer cornea to see through when using a gonioprism to visualize the angle.

In patients with glaucoma, the ability to perform cataract surgery with or without the addition of MIGS can make an important contribution in our pursuit of target pressures. The use of Omidria in this patient subset helps surgeons reduce complications and exert more control over outcomes, ultimately contributing to better functional vision and improved quality of life for their patients. – By Savak “Sev” Teymoorian, MD, MBA

References:

Bucci F, et al. A comparison of the frequency of use of the Malyugin ring with and without intracameral phenylephrine and ketorolac 1%/0.3%(phenyl/keto) injection at the time of routine cataract surgery. Paper presented at: ARVO 2016 annual meeting; May 1, 2016; Seattle.

Cataract in the adult eye PPP – 2016. American Academy of Ophthalmology. https://www.aao.org/preferred-practice-pattern/cataract-in-adult-eye-ppp-2016.

Eid TM. Saudi J Ophthalmol. 2011;doi:10.1016/j.sjopt.2011.07.004.

Guzek JP, et al. Ophthalmology. 1987;doi:10.1016/S0161-6420(87)33424-4.

Hovanesian JA, et al. J Cataract Refract Surg. 2015;doi:10.1016/j.jcrs.2015.10.053.

Huang G, et al. Arch Ophthalmol. 2011;doi:10.1001/archophthalmol.2011.272.

Lindstrom RL, et al. Clin Ophthalmol. 2014;doi:10.2147/OPTH.S69710.

Narendran N, et al. Eye (Lond). 2009;doi:10.1038/sj.eye.6703049.

Nonaka A, et al. Ophthalmology. 2006;doi:10.1016/j.ophtha.2005.11.018.

Rosenberg E. Initial experience, visual outcomes, and efficacy of intracameral phenylephrine and ketorolac (1.0%/0.3%) during cataract surgery. Paper presented at: ASCRS/ASOA symposium and congress; May 6-10, 2016; New Orleans.

Shrivastava A, et al. Curr Opin Ophthalmol. 2010;doi:10.1097/ICU.0b013e3283360ac3.

Slabaugh MA, et al. Am J Ophthalmol. 2014;doi:10.1016/j.ajo.2013.08.023.

Tham CC, et al. Ophthalmology. 2013;doi:10.1016/j.ophtha.2012.07.021.

Visco D. Use of iris fixation ring with and without intracameral phenylephrine/ketorolac in patients with poor pupil dilation. Paper presented at: ASCRS/ASOA symposium and congress; May 6-10, 2016; New Orleans.

Vizzeri G, et al. Curr Opin Ophthalmol. 2010;doi:10.1097/ICU.0b013e328332f562.

Walland MJ, et al. Clin Exp Ophthalmol. 2012;doi:10.1111/j.1442-9071.2011.02617.x.

For more information:

Savak “ Sev ” Teymoorian , MD, MBA, can be reached at Harvard Eye Associates, 24401 Calle De La Louisa, Suite 300, Laguna Hills, CA 92653; email: steymoorian@harvardeye.com.

Disclosure: Teymoorian reports he is a consultant for Allergan, Alcon, Glaukos and Omeros.