Primary argon laser trabeculoplasty vs pilocarpine II: Long‐term effects on intraocular pressure and facility of outflow

Abstract

In a prospective study 82 patients recently diagnosed with simple or capsular glaucoma were randomized to receive primary argon laser trabeculoplasty or pilocarpine treatment. A 2-year follow-up showed a better success rate in the laser group, with less need for additional therapy. The average intraocular pressure and peak pressure was lower and the daytime pressure variation was significantly less in the laser group. The better increase in facility of outflow in the laser group was not statistically significant. In capsular glaucoma, laser treatment resulted in a significantly lower average pressure than with medication. In simple glaucoma the effect was about the same in the two treatment groups. Increase in facility of outflow was significantly better in simple glaucoma than in capsular glaucoma. High initial intraocular pressure gave a significantly lower success rate. Primary argon laser trabeculoplasty as a single glaucoma treatment seems advantageous in comparison to medication with pilocarpine for regulating intraocular pressure.

The Glaucoma Guidelines of the Swedish Ophthalmological Society

“…Primary LTP has long been discussed (The glaucoma laser trial (GLT) 1990; Bergeå et al. 1994), and it is definitely an alternative, particularly if there is reason to avoid eye drops, such as in elderly patients who have difficulties applying that type of medication.…”

Effects of Argon Laser Trabeculoplasty in the Early Manifest Glaucoma Trial

“…In Moorefields Primary Treatment Trial, IOP reduction was 14 mmHg after 6 monhts, but from a high average pre-treatment level of 35 mmHg. 16 Other investigators [17][18][19][20][21][22][23][24][25] have published values ranging from 5.9 to 12.1 mmHg. There are three possible explanations for these differences:…”

“…Considering the small number of eyes with exfoliation glaucoma in our material, it is obvious that non-significant findings might be explained by insufficient statistical power regarding exfoliation status. Many studies have shown that IOP reduction is larger in exfoliation glaucoma than in POAG, 2,5,19,22,32,38 even after performing multivariate analyses to correct for differences in pre-ALT IOP between these two types of the disease. 3 There is no agreement as to whether the pressure-lowering effect of ALT is influenced by trabecular pigmentation or pigmentation grade, 3 -5,22,24,37,38 and we found no significant impact of either of those aspects in our investigation.…”

Laser Trabeculoplasty and Aqueous Dynamics

“…In previously untreated POAG patients, a 63.5% increase in tonographic outflow facility was measured with a 33% reduction in IOP [58]. A similar study on patients already on topical therapy showed a comparable 64% increase in outflow facility and 29% reduction in IOP [59].…”