Abstract
Purpose:
To compare the reduction of intraocular pressure (IOP) and number of medications after trabecular meshwork ablation between the trabectome (AIT) and Baerveldt (BGI) glaucoma implants which bypass the conventional drainage system in similar patient populations.
Methods:
This was a retrospective study of outcomes of AIT (n=91) vs BGI (n=64) surgeries. Procedures were performed by the same group of surgeons on comparable patient populations with primary and secondary open angle and chronic angle closure glaucoma. Neovascular glaucoma and cases with less than 6 months of follow-up were excluded. AIT and BGI were matched using propensity-score matching using a genetic algorithm based on age, gender, type of glaucoma, if there was a concurrent phacoemulsification, baseline number of medications, and baseline IOP. Cases of AIT or BGI too different from their counterparts were excluded. Linear regression examined IOP change versus treatment (AIT vs BGI) and baseline IOP.
Results:
Pre-matching the 155 cases resulted in 50 cases with 6 months of follow-up similar enough to match and justifiably compare. The effect of baseline IOP on surgery effect (IOP change) was statistically significant (for every 1 mm Hg increase in baseline IOP, the surgically-induced decrease in IOP was 0.82 ± 0.06 mm Hg), as was the surgery type, since BGI resulted in a 2.4 ± 0.9 mm Hg lower IOP than AIT after 6 months (p<0.02). For both surgical modalities, the reduction in number of medications from baseline was significant. AIT reduced from 2.7 ± 1.8 medications at baseline to 1.9 ± 1.7 medications at 1 year (p=0.002). BGI reduced the number of medications from 2.9 ± 1.2 at baseline to 2.0 ± 1.4 meds at 1 year (p<0.001). The difference in medication change when comparing between AIT and BGI was not significant (p=0.71).
Conclusions:
In this retrospective study of two glaucoma surgeries with well established, highly different profiles of complications, costs and length of procedure, BGI lowered IOP approximately 2.4 mmHg more than AIT in closely matched patient populations with similar reduction of medications.