Abstract
Purpose :
There is little research on the predictive factors of SLT success in a veteran population. Given this is a specific population, a retrospective, observational study was completed to determine what factors predict success of SLT in veteran patients.
Methods :
This study was performed with 311 eyes that underwent SLT from Jan 2001 to Dec 2015 in a veteran ophthalmology clinic. Success was defined as an IOP decrease of ≥ 20% from baseline, 12 months after SLT treatment without requiring additional interventions. Preop characteristics and IOP and postoperative IOP measurements were collected. Data was then analyzed to determine if certain prognostic factors can predict success, and the Student’s T test employed to determine statistical significance.
Results :
Overall 52.6% of 311 eyes had success post SLT. Those with higher preoperative IOP had a better response. Preop IOP <15 only had 34.78% success rate while Preop IOP >25 had 75% success rate (p<0.01). Age <60 showed a better response with average IOP decrease of 31.31% (SD 13.84). Of glaucoma types, the highest rate of success was pseudoexfoliative glaucoma, followed by ocular hypertension/glaucoma suspect, primary open angle glaucoma, normal tension glaucoma, and multiple mechanism glaucoma (75%, 50%, 46.59%, 30%, 22.22% respectively). Phakic eyes had higher success rate and average IOP percentage decrease than pseudophakic eyes (46.82% vs. 39.54% and 17.61% vs. 14.00%, respectively). The amount of laser energy between 80-99 mJ had greater success (56.76%) than less or more energy independent of the amount of trabecular meshwork pigmentation.
Conclusions :
A recent study found that patients with lower preop IOP had greater IOP reduction post SLT, contradicting the findings of previous studies. We showed in a veteran population that higher preop IOP was a strong predictive factor of success. In addition, the amount of energy associated with higher success rate was between 80-99 mJ in one session. This represents a significantly higher amount of energy than what was used in prior studies, but did not lead to increased number of complications. Interestingly, phakic eyes responded more favorably than pseudophakic eyes which is in contrast to what was reported before. These differences in our findings may be explained by the large number of procedures, unique patient population, and lower preop IOP.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.