Repeat Laser Trabeculoplasty Can Restore Intraocular Pressure Control

By Lorraine L. Janeczko

February 17, 2016

NEW YORK (Reuters Health) - In eyes with open-angle glaucoma that have already had successful initial selective laser trabeculoplasty (SLT), repeat SLT can restore intraocular pressure (IOP) control, new research suggests.

Repeat SLT achieved the same absolute level of IOP control as did the initial SLT, investigators reported online February 1 in the British Journal of Ophthalmology.

"Repeat selective laser trabeculoplasty treatment is a safe and effective method of restoring IOP control in open-angle glaucoma patients," corresponding author Dr. Julia Polat of the University of Pittsburgh School of Medicine in Pennsylvania told Reuters Health by email.

"While laser trabeculoplasty is an established treatment modality for glaucoma, repeat SLT is still controversial. Although this is a small retrospective study, it clearly shows that repeat SLT is able to reestablish the same degree of IOP control as the first SLT treatment," she said.

"These findings will hopefully encourage ophthalmologists to try repeating SLT in patients who need further IOP control before they add additional IOP-lowering medications or proceed to glaucoma surgery," Dr. Polat said.

Dr. Polat and colleagues reviewed data on 38 eyes of 19 male and 19 female patients, age 62.7 on average, with medically uncontrolled open-angle glaucoma.

The patients had had two successive 360-degree SLT treatments. The first SLT was successful through at least six months of follow-up.

The mean IOP at one, three, six, 12, 18, and 24 months postoperative was compared with baseline using paired t-tests. IOP changes after the initial and repeat SLT were evaluated separately.

The mean baseline IOP before the initial SLT was 21.6 mmHg. The mean IOP after the initial SLT was significantly below baseline at all time points over the 24-month follow-up, ranging from 15.9 to 18.6 mmHg.

The mean baseline IOP before repeat SLT was 19.1 mmHg, with a significant drop in IOP from baseline through 24 months, with the mean ranging from 14.7 to 17.0 mmHg.

The mean drop in IOP for initial and repeat SLT ranged from 2.9 to 5.7 mmHg and from 2.3 to 4.4 mmHg, respectively.

Using the real-world definition of success (no further IOP-lowering interventions), the median Kaplan-Meier survival time was 570 days (19 months) after initial SLT and 1,054 days (35 months) after repeat SLT.

With success defined as a 20% or greater drop in IOP from baseline, the Kaplan-Meier survival analysis showed a median survival time of 270 days (9 months) and 360 days (12 months) for initial and repeat SLT, respectively.

No patients developed a postlaser IOP spike higher than 10 mmHg or had post-SLT inflammation requiring intervention.

Dr. Lili Farrokh-Siar, a glaucoma specialist at the University of Chicago, told Reuters Health by email, "This study further confirms our clinical findings that repeat SLT treatments may have increased efficacy. In our daily clinical practice with glaucoma patients, we perform repeat SLT treatments with good success, as opposed to argon laser trabeculoplasty, which can be done only once or twice."

"Further compliance is the main reason why many glaucoma patients lose vision over time. We see many elderly patients who have difficulty applying the drops into their eyes," said Dr. Farrokh-Siar, who was not involved in the study.

"The only remaining option for them would be surgery, which has its own risks. Repeat SLT offers them an additional option that may alleviate the compliance issue without surgery," she added.

The authors reported no funding or relevant disclosures.


Br J Ophthalmol 2016.