Abstract
Purpose: :
To compare the intervisit variability of intraocular pressure (IOP) in normal tension glaucoma (NTG) patients before and after selective laser trabeculoplasty (SLT).We hypothesize that SLT in this population of glaucoma patients decreases the amount of variability of intraocular pressure, inherent to the pathology of NTG, and would therefore help to stabilize the disease.
Methods: :
24 eyes of 12 NTG patients underwent SLT therapy. Retrospective evaluation of intervisit variability of IOP was performed for both preoperative and postoperative visits. Patients with less than 3 visits pre–laser were excluded.
Results: :
Each eye (n=16) had greater IOP variability prior to SLT treatment than after SLT (p<0.05). Each eye had a decrease in variability of IOP post laser with the maximum drop of variability being 9 mm Hg and the average variability decrease being 3 mmHg. There was no difference in decrease of variability between eyes on medications and those on no medications. There was no statistically significant difference between the mean IOP pre and post SLT.
Conclusions: :
NTG patients have high intervisit IOP fluctuations. SLT results in a significant decrease of intervisit IOP fluctuations in NTG patients. Decreased IOP fluctuations may result in a lower risk for continued glaucomatous progression in NTG.
Keywords: laser • intraocular pressure • circadian rhythms