Prospective Study on the Effect of Selective Laser Trabeculoplasty in Normal Tension Glaucoma

Purpose: Compare the effect of selective laser trabeculoplasty (SLT) in normal tension glaucoma (NTG) patients with its effect in primary open angle and ocular hypertension patients (POAG/OHT), considering both evolution of intraocular pressure (IOP) and mean number of medication. Method: Prospective trial of 130 patients on glaucoma medication. Patients were offered SLT as a means to diminish medication use. Both eyes of the patient underwent SLT. Laser was performed over 360°, 100 spots, 3nsec, 400 μm. IOP and medication were recorded at 1 hour, 1 week, 1, 3, 6, 12 and 18 months. Results were compared with a control group of patients that remained on medication. Results: IOP changed little after SLT, as the groups were controlled under medication. Nevertheless, SLT was able to achieve additional IOP reduction: 9% and 6% respectively after 12 and 18 months in the NTG group and 19% and 2% respectively in the POAG/OHT group. The use of medication lowered significantly: from a mean of 1.20 in the NTG group to 0.19 and from 1.71 to 0.31 in the POAG/OHT group. This was a significant change compared to the control groups. Mean reduction of medication after SLT was comparable between the NTG and the POAG/OHT group at 1 week, 1 month, 3, 6 and 12 months. Conclusions: The efficacy of SLT is not inferior in NTG patients compared to POAG or OHT patients.