Selective Laser Trabeculoplasty in Glaucoma Treatment – Results during three Years Follow-up

Overview

The authors present results of their own modification of selective laser trabeculoplasty in primary open angle glaucoma and other groups of glaucoma using the laser machine Laserex Tango (wave length 532 nm, Q-switched, Nd-YAG laser, pulse duration 3 ns [nanoseconds], target diameter 400 Ūm, 80 burns, extension ? of the circumference of the anterior chamber angle, power 1.0 mJ). The intraocular pressure was measured by means of the non-contact tonometer Nidek 2000, calibrated according to the current legislation.

In the first group, the changes of the intraocular pressure (IOP) in primary open angle glaucoma in 106 eyes of 75 patients, aged 21 – 80 years, with seven controls during 36 months were followed – up. Remarkable decrease of the IOP from the baseline of 20.7 ± 4.6 mm Hg to 17.5 ± 3.1 mm Hg (one month - M1), 17.8 ± 3.5 mm Hg (3 months - M3), 17.7 ± 3.1 mm Hg (6 months - M6), 17.8 ± 2.7 mm Hg (12 months - M12), 17.9 + 2.6 mm Hg (24 months -M24), and 18.2 + 3.1 mm Hg (36 months - M36) was recorded. The average IOP decrease by 3.2 mm Hg (decrease by 15.5 %) between the baseline and the values after 1 months of treatment was proven to be statistically significant (p-value <0.0001) as well as the average difference of 2.9 mm Hg (decrease by 14.0 %), 3.0 mm Hg (decrease by 14.5 %), 2.9 mm Hg (decrease by 14.0 %), 3.0 mm Hg (decrease by 14.5 %), 2.9 mm Hg (decrease by 14.0 %), 2.8 mm Hg (decrease by 13.5 %), and 2.5 mm Hg (decrease by 12.1 %) among the baseline IOP values and the IOP values measured successively after 3, 6, 12, 24, and 36 months.

In the second group, the IOP and treatment changes were followed-up in patients with the primary open angle glaucoma with 3 controls during 36 months in 420 eyes of 263 patients (age 21 – 84 years). In the end of three years follow-up period, in 234 eyes the simplified monotherapy remained, in 146 eyes the treatment was the same as before the laser surgery, in 40 cases it was necessary to perform re-SLT, and out of this number, in 19 cases the trabeculectomy was consequently performed due to unsatisfactory IOP compensation. It was recorded remarkable IOP values decrease from the baseline 20.8 ± 4.1 mm Hg to 18.0 ± 2.8 mm Hg (12 months - M12), 17.7 ± 2.6 mm Hg (24 months - M24), and 17.7 ± 3.1 mm Hg (36 months - M36). The average IOP lowering by 2.8 mm Hg (decrease by 13.5 %) found between the baseline values and values 12 months after the SLT was found to be statistically significant (p-value < 0.0001), as well as the average difference of 3.1 mm Hg (decrease by 14.9 %) and 3.1 mm Hg (decrease by 14.9 %) among the baseline IOP values and values found consequently after 24 and 36 months.

Pigmentary glaucoma (35 eyes) – significant, but short – term effect of the SLT to the IOP decrease was observed. In two cases, shortly after the laser treatment, it was necessary due to extreme IOP elevation to perform the trabeculectomy. In 12 eyes it was necessary due to the unsatisfactory IOP compensation to repeat during one-year period the SLT procedure.

Pseudoexfoliative glaucoma (37 eyes) – very good and rapidly appearing effect of the SLT to the IOP decrease was found. In 2 eyes, during the one-year follow-up period, it was performed the phacoemulsification of the lens with artificial intraocular lens (IOL) implantation. During further follow-up, the SLT was indicated and performed again in all eyes, and after that, in other 6 eyes of this group the phacoemulsification of the lens with IOL implantation was performed.

The SLT as primary treatment (44 eyes) – all patients, even after 3 years follow-up period, are without the necessity of antiglaucomatous treatment. At the present time, the SLT was already performed in 122 eyes as the primary treatment.

SLT as termination of the treatment (80 eyes) – in the remaining group of 40 patients, there are still 35 patients without treatment after three years, the data from the others are not available.

Selective laser trabeculoplasty is effective and considerate method in the treatment of different groups of glaucoma diseases.

Key words:
selective laser trabeculoplasty, glaucoma, intraocular pressure