Having Surgery? Would You Like Lower Pressure With That?

Micropulse laser offers glaucoma patients entering the OR a chance to reduce their topical drop burden.

By Ahad Mahootchi, MD

The ever-increasing costs of medicines are problematic for glaucoma patients. In this setting, a fast, noninvasive procedure that reduces intraocular pressure (IOP) and can be performed either alone or in combination with another surgical procedure is of great value to eye professionals and patients. I have found all of these characteristics with micropulse transscleral cyclophotocoagulation (mTSCPC).

Some may think that cyclodestructive procedures are to be reserved for refractory glaucoma patients, but I am here to tell you that mTSCPC it is not the end-stage procedure of years gone by.

TO THE POINT

Micropulse transscleral cyclophotocoagulation, which can be performed as a standalone procedure or in combination with other ophthalmic surgery, could be a solution for glaucoma patients seeking to reduce their drop regimens.

Given its excellent safety profile, mTSCPC is an option for every glaucoma patient. I put mTSCPC on the table early as an option with many patients. In my experience, mTSCPC works better than anything—except trabeculectomy—for lowering IOP. It requires no intraocular maneuvers and does not require the patient to stop use of blood thinners. I have used it to treat primary open-angle glaucoma, chronic angle-closure glaucoma, low pressure glaucoma, and everything from early-stage to end-stage glaucoma.

Nearly every glaucoma patient—whether well-controlled on drops or in need of additional IOP control—would prefer to use fewer drops. If a patient with glaucoma is having surgery for reasons unrelated to his or her glaucoma, I offer to perform mTSCPC during the surgery. This is a win-win: the patient gets what he or she needs, and the physician doesn’t take a big financial hit.

I have combined mTSCPC with cataract surgery—including cataract surgeries that include placement of an iStent (Glaukos) or a Kahook Dual Blade (New World Medical) procedure—blepharoplasty, goniotomy, ectropion repair, and endothelial keratoplasty.

COMBINED PROCEDURES

When combined procedures are performed in the United States, all procedures after the first one are paid at half their normal rate. If we are to be paid only half for a second procedure, we must be careful that we will not lose significant clinical time to complex postoperative care. Eyes treated with the MicroPulse P3 device with the Cyclo G6 Glaucoma Laser System (Iridex) have little visible inflammation and no uveitis, bleeding, periocular swelling or hypotony in the postoperative period.1

For patients without terrible visual field damage, I do not see them until 5 weeks after mTSCPC. I have them stop one glaucoma medication after 1 week and stop their postoperative steroid drop after 2 weeks. Follow-up care is essentially dictated by the accompanying procedure. Cumulative study results show that patients usually have about a 30% reduction in IOP and a reduction of at least one medication from mTSCPC alone.2-4

Watch it Now

Murray Johnstone, MD, demonstrates how mTSCPC induces contraction of the ciliary muscles, causing an inward and posterior movement of the scleral spur that may increase outflow through the trabecular meshwork.

Cyclodestructive procedures have historically been used as a last-ditch strategy in glaucoma, to destroy parts of the ciliary body so that it cannot secrete aqueous humor. However, Murray Johnstone, MD, presented data at the 2017 American Glaucoma Society meeting showing that other mechanisms of action may be at work in mTSCPC.5 His study demonstrated that mTSCPC induced contraction of the ciliary muscles, causing an inward and posterior movement of the scleral spur that may increase outflow through the trabecular meshwork. In the video highlighted in the box on this page, one sees changes in ciliary muscles, exhibiting a pilocarpine-like effect that stretches the trabecular meshwork open. This likely contributes to the resulting decrease in IOP.

THE OPTOMETRIST’S ROLE

Optometrists referring patients for cataract and other surgeries may wish to discuss mTSCPC with their patients ahead of surgical referral. Sharing a description of the procedure in terms the patient can understand and explaining that it works alone or in combination with other procedures places patients and those overseeing their care in an advantageous position. After all, an informed patient can make an informed decision on how to tackle glaucoma in a way that may reduce the treatment burden for the patient.

1. Aquino MC, Barton K, Tan AM, et al. Micropulse versus continuous wave transscleral diode cyclophotocoagulation in refractory glaucoma: a randomized exploratory study. Clin Exp Ophthalmol. 2015;43(1):40-46.

2. Radcliffe N, Vold S, Kammer J, et al. MicroPulse trans-scleral cyclophotocoagulation (mTSCPC) for the treatment of glaucoma using the MicroPulse P3 device. Poster presented at: American Glaucoma Society Annual Meeting; March 2-5, 2017; Coronado, CA.

3. Tan AM, Chockalingam M, Aquino MC, et al. Micropulse transscleral diode laser cyclophotocoagulation in the treatment of refractory glaucoma. Clin Exp Ophthalmol. 2010;38:266-272.

4. Kuchar SD, Moster M, Waisbourd M. Treatment outcomes of micropulse transcleral cyclophotocoagulation in advanced glaucoma. Poster presented at: American Glaucoma Society Annual Meeting; February 27, 2015; San Diego, CA.

5. Johnstone M, Wang R, Padilla S, Wen K. Transcleral laser induces aqueous outflow pathway motion and reorganization. Presented at: American Glaucoma Society Annual Meeting; March 2-5, 2017; Coronado, CA.

Ahad Mahootchi, MD
• CEO, medical director, and surgeon-in-chief, The Eye Clinic of Florida, Zephyrhills, Fla.
• financial disclosure: consultant, Iridex
am@seebetterflorida.com