Abstract
Purpose: :
To determine if the success of Selective Laser Trabeculoplasty (SLT) in the first treated eye, predicts the long term success of SLT in the fellow eye, in patients with Ocular Hypertension (OHT) and Primary Open Angle Glaucoma(POAG).
Methods: :
A retrospective chart review of consecutive patients, who underwent SLT in both eyes, between 2002 and 2005, and completed at least 30 months follow up was performed. Patients were excluded if they required additional glaucoma medications, laser, or ocular surgery during the follow up period. SLT Success was defined as a 20% or greater decrease in IOP from the baseline. Pearson’s correlation analysis was performed to correlate the percentage of IOP reduction in the first treated eye at 3 months, to the percentage of IOP reduction in the fellow eye at 3, 6, 12, 18 and 30 months after SLT.
Results: :
80 eyes of 40 patients were identified. In OHT patients with successful SLT in the first treated eye at 3 months, the success rate in the fellow eye was 100% at 3 months, 80 % at 12 months and 83% at 30 months. While in POAG patients who had successful SLT in the first treated eye at 3 months, the success rate in the fellow eye was 100% at 3 months, 77%, and 75% at the 12 and 30 month visits respectively. For those who had unsuccessful SLT in the first treated eye, the rate of success in the fellow eye was 77% at 12 months in both OHT and POAG patients. For OHT patients, the Pearson's r value between the percentage of IOP reduction in the first treated eye at 3 months, and percentage of IOP reduction in the fellow eye at 3 months was 0.886 (p = 0.0001), and a strong correlation was maintained up to 30 months (r= 0.804, p = 0.001). For POAG patients, r value at 3 months was 0.652 (p = 0.001), was 0.582 (p =0.005) at 6 months, however significance of correlation dropped at 12 months to 0.400 (p = 0.065) at and at 30 months r was 0.336 (p = 0.127).
Conclusions: :
In OHT patients, SLT success in the first treated eye was highly predictive of SLT success in the fellow eye up to 30 months, while in POAG patients, SLT success in the first eye moderately predicted the IOP response in the fellow eye up to 12 months. These findings suggest that, OHT patients who have successful SLT in one eye are likely to have successful SLT in the fellow eye up to 30 months. However, in patients with POAG, success in the first treated eye couldn't predict the success in the fellow eye beyond 12 months. On the other hand, failure of SLT treatment in the first treated eye doesn't necessarily predict failure in the fellow eye in either group.
Keywords: intraocular pressure • outflow: trabecular meshwork