Ophthalmologist offers pearls for use of technology in daily work.
MicroPulse transscleral laser therapy (TLT) allows me to offer a safe, noninvasive treatment for patients at any point on the glaucoma severity spectrum. As a glaucoma and cataract specialist at a busy solo practice, I frequently receive referrals for patients who need surgical intervention. We are fortunate to count on a multitude of minimally invasive surgeries in addition to traditional glaucoma surgeries. To provide the best care suited to my patients’ specific needs, I seek to include many tools in my armamentarium.
One such tool is MicroPulse TLT, performed with the MicroPulse P3 delivery device and the Cyclo G6 Laser System (IRIDEX). I have found MicroPulse TLT to be an extremely versatile procedure. It can be used at any point on the glaucoma severity spectrum and is noninvasive, which eliminates incision risk and the need for extensive follow-up.
MicroPulse technology divides the laser beam into microsecond bursts that are interspersed with longer resting intervals, allowing the tissue to cool between pulses. Like continuous-wave transscleral cyclophotocoagulation (CW-TSCPC), the treatment uses a diode laser; however, the pulsatile on/off manner of MicroPulse technology allows tissue to cool between pulses, which makes the procedure less inflammatory and leads to fewer complications compared with CW-TSCPC.1-4
I use MicroPulse TLT frequently in patients who have glaucoma tubes in place and need further IOP control or a decrease in medication. I also use it in combination with minimally invasive glaucoma surgery (MIGS), with complementary mechanisms of action such as angle-based procedures. In some instances, I use it for patients who feel more comfortable with a noninvasive, safe procedure for a variety of reasons. These reasons might include hesitance toward invasive surgery or the inability to follow a demanding postoperative care course. TLT does not preclude future surgeries or leave a foreign object in the eye.
Most patients referred to my practice expect to have surgery, but some are fearful of surgery or not able to have surgery for health reasons. Others are restricted by the downtime that would be required for recovery because they are working, are the primary caretaker for their spouse, or do not have a support structure for their own care that would allow them to be incapacitated or travel to frequent follow-up visits. In these situations, it is valuable to offer MicroPulse TLT.
MicroPulse TLT has an accepted Current Procedural Terminology code and a good safety profile, and it requires no patient downtime. There is no postoperative pain. My usual follow-up protocol is to see patients the next day and at 3 months.
A 71-year-old man presented to me with high IOP having undergone several nonglaucoma surgeries, including a complex cataract surgery that left him hesitant to have additional surgeries. He had OS IOP of 41 mm Hg, partially as a steroid response, and it was important to reduce his pressure.
Following an ineffective selective laser trabeculoplasty treatment, I performed MicroPulse TLT. After 1 day, his IOP had dropped to 13 mm Hg and he was able to stop oral acetazolamide. His vision improved from 20/400 OS to 20/200 OS, and IOP remained stable for 2 years on 3 topical medications.
Findings from the literature show MicroPulse TLT is successful at lowering IOP approximately 27.8% to 57.2%, with very good safety and efficacy.5 In some of my patients, pressure reduction following the procedure has been significant and has brought them to target IOP, reduced medications, or eliminated the need for additional, more invasive surgery.
However, my patients tend to have advanced glaucoma, and they are often sent to me because they require large pressure reductions. I tend to combine MicroPulse TLT with MIGS procedures because I have found the combination is cumulative and effective. I most commonly combine MicroPulse TLT with canaloplasty and trabeculotomy procedures because they have complementary mechanisms of action.
I sometimes combine MicroPulse TLT with cataract surgery. Phacoemulsification itselfis known to reduce IOP by increasing the outflow facility.5 When combining MicroPulse TLT with other procedures, I perform MicroPulse before the procedures, given that there is no need for a sterile preparation with MicroPulse. Patients will receive a short peribulbar block in the preoperative holding area and are then brought into the operating room, where I treat them with MicroPulse TLT under nonsterile conditions. The operating room nurse then irrigates the eye to wash the viscoelastic from the eye surface and performs proper sterile preparation of the eye for the following surgery.
In my practice, one of the top advantages of MicroPulse TLT is that I am often able to perform the procedure instead of inserting a second tube. I regularly see patients who have had a tube implanted, but their IOP is not at target pressure. If the IOP is at the target pressure, it is due to 2 to 4 topical medications.
Traditionally, when someone has a superior temporal tube implant and needs to reduce pressure further, the next step is an inferior nasal tube. This surgery can be more involved and uncomfortable as well as less cosmetically pleasing than the superotemporal tube.
The second tube is usually a nonvalved glaucoma drainage device, which means the surgeon will use a ripcord technique, tie up the tube, or use both methods to avoid immediate IOP reduction. This measure is taken to avoid early hypotony and bleb encapsulation. Along with patient adherence, the timing of the tube opening is important. If a tube is tied with a resorbable suture and this absorbs (usually at week 6 or 8) while the patient is taking too many IOP drops (if the patient does not stop medications as indicated), hypotony will ensue, with possible choroidals and anterior chamber flattening. Although manageable, these complications could lead to loss of vision. I also think it is advantageous and safer for cornea health to not implant a second tube when possible.
There are also the risks and discomforts that come with incisional surgery as well as an elevated lifetime corneal decompensation risk. All these considerations contribute to significant downtime and lifestyle disruption following the procedure.
Nasal tubes can also be undesirable for patients from a cosmetic perspective. Although superotemporal tubes can be nicely covered by the eyelid, even expert placement of a nasal tube will be visible in some patients because of the location.
The introduction of MicroPulse TLT changed the way I treat these patients by allowing me to avoid the use of a second tube. I can even use the procedure for patients with a damaged cornea. So far, I have not seen problems following MicroPulse TLT in patients who have undergone corneal transplant.
MicroPulse TLT is also a great option for general ophthalmologists. If a patient’s pressure needs further reduction after a tube implant by a glaucoma surgeon or if the patient wishes to decrease the number of glaucoma medications they are using, the ophthalmologist can perform MicroPulse TLT in house.
In my experience, MicroPulse TLT is a versatile tool to lower my patients’ pressure without disrupting their lifestyle or precluding future treatments. I use the procedure following tubes and other surgeries and alongside MIGS treatments. MicroPulse TLT can be used to lower IOP anywhere on the glaucoma severity spectrum and can serve patients who are at target IOP but wish to decrease their medication burden.