Selective laser trabeculoplasty
Low-energy pulses to the trabecular meshwork increase outflow. It can be used first line or added to drops.
LiGHT 2019Glaucoma Care · Laser
Glaucoma Laser Procedures SLT, laser iridotomy and micropulse cyclophotocoagulation.
Lasers treat glaucoma at three different points: the trabecular meshwork, the iris and the ciliary body. Knowing what each one does, and the evidence behind it, helps you decide when to perform, refer or co-manage.
74.2%of SLT eyes drop-free at 3 years in LiGHT
718patients randomized in the LiGHT trial
889angle-closure suspects in the ZAP trial
14states with optometric laser authority, late 2025
The procedures
Three lasers, three targets
Trabeculoplasty improves outflow, iridotomy opens a path around a narrow angle, and cyclophotocoagulation reduces aqueous production.
Direct SLT
BELKIN Vision's Eagle, cleared by the FDA in December 2023, delivers SLT through the limbus without a gonioscopy lens.
Ophthalmology TimesLaser peripheral iridotomy
A small opening in the peripheral iris relieves pupillary block in angle closure or narrow angles at risk.
ZAP 2019Micropulse cyclophotocoagulation
Iridex's MicroPulse delivery on the Cyclo G6 platform treats the ciliary body through the sclera to lower production.
IridexWhat the evidence says
Two large randomized trials published in 2019 reshaped how laser is used early in care.
- SLT as a first-line option
- LPI is not needed for every suspect
- Laser can reduce drop burden
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LiGHT trial
718 patients with untreated open-angle glaucoma or ocular hypertension were randomized to SLT first or drops first; 74.2% of the SLT group needed no drops at 36 months.
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Pressure control
Eyes were within target at 93.0% of visits after SLT and 91.3% with drops, and no SLT patient needed glaucoma surgery compared with 11 in the drops arm.
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ZAP trial
In 889 bilateral angle-closure suspects, treated eyes progressed at 4.19 per 1,000 eye-years versus 7.97 in untreated eyes.
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What ZAP implies
Because progression was uncommon, the authors suggested prophylactic iridotomy may not be needed for every suspect like those studied.
Co-management
How a laser referral flows
Whether you perform the laser or refer it, the pre- and post-procedure work is the same.
Select
Document the angle, pressure trend, OCT and fields, and why laser is preferred over another drop.
Treat
The laser is performed by an authorized provider. Pressure is commonly checked shortly afterward for a spike.
Follow
Recheck pressure at follow-up to judge the response, then continue the usual testing schedule.
Reference details
Procedure codes
| 65855 | Trabeculoplasty by laser surgery |
|---|---|
| 66761 | Iridotomy or iridectomy by laser surgery |
| 66710 | Ciliary body destruction, cyclophotocoagulation, transscleral |
| Global period | Check each code's global days, since post-op visits within the period are not separately billed |
Scope considerations
- Laser privileges for optometrists depend on state law
- Review of Optometry counted 14 states with laser authority as of November 2025
- Hospital or surgery center credentialing may add requirements
- Co-management agreements should state who provides which post-op visits
Device note
SLT systems are sold by several manufacturers, and BELKIN Vision markets a non-contact direct SLT device. Lasers are purchased from the manufacturer, not through the wholesale catalog.
Questions about glaucoma lasers
Can SLT replace drops entirely?
For many patients. In LiGHT, 74.2% of patients treated with SLT first needed no drops to stay at target at three years.
Can SLT be repeated?
Yes, it is commonly repeated when the effect wears off. Decide based on response and the pressure target.
Does every narrow angle need an iridotomy?
Not necessarily. The ZAP trial found a low rate of progression in angle-closure suspects, so the decision is individualized.
What is micropulse cyclophotocoagulation used for?
Lowering pressure by reducing aqueous production, often in patients who are not good candidates for, or have not responded to, other approaches.
Can optometrists perform these lasers?
In states that authorize it. The number has grown steadily, with West Virginia and Montana added in 2025.
What does the co-managing doctor do?
Typically the pre-procedure evaluation and post-procedure pressure checks, under an agreement with the surgeon.
References
- Gazzard G, et al. Selective laser trabeculoplasty versus eye drops for first-line treatment of ocular hypertension and glaucoma (LiGHT). Lancet. 2019. UCL Discovery
- He M, et al. Zhongshan Angle Closure Prevention (ZAP) trial. Lancet. 2019. Summary by AAO. AAO
- Ophthalmology Times. FDA clears glaucoma laser device from BELKIN Vision, December 12, 2023. Article
- Iridex. CYCLO G6 and MicroPulse P3 device. Iridex
- Review of Optometry. Two scope wins secured in 2025. Review of Optometry
Fit laser into your glaucoma pathway
Use laser to reduce drop burden and improve adherence, and build a referral path for the procedures you do not perform.
Written for licensed eye care professionals. Procedure authority varies by state. Codes and global periods change; confirm current CPT descriptors and payer rules. Device names are trademarks of their manufacturers.