Abstract
Purpose :
Trabeculectomy is a filtering surgical procedure commonly used to reduce intraocular pressure (IOP). Inflammation after cataract surgery theoretically has a negative impact on bleb survival. The purpose of this study is to explore VisionBlue (trypan blue) as a means of intraoperatively assessing preexisting bleb function during phacoemulsification and predict future bleb failure.
Methods :
Prospective study of participants with a history of trabeculectomy placed for glaucoma undergoing phacoemulsification were enrolled. Participants with any intraocular surgery or laser within 3 months of scheduled cataract surgery, active ocular inflammation, history of tube shunt placement, or allergy to ophthalmic dyes were excluded. 0.5 cc of VisionBlue was injected intraoperatively during cataract surgery and photographs were taken. Bleb staining was graded as mild staining or diffuse staining for final analysis. Decrease in bleb function was defined as a greater than 20% increase in IOP from baseline, need for additional IOP lowering medications, and need for additional surgical intervention.
Results :
11 participants were enrolled into the study and had completed post-operative month 3 data. 6 participants were categorized as mild staining, and 5 were categorized as diffuse staining. Mean baseline IOP was 9.77 ± 2.47 mmHg in the mild staining group and 9.12 ± 3.55 mmHg in the diffuse staining group (p=0.36). IOP at three month post-operatively increased by 0.55 ± 1.56 mmHg and 1.282 ± 3.56 mmHg in the two groups, respectively (p=0.34). The number of glaucoma medications needed was increased by 0.83 ± 0.98 and decreased by 0.2 ± 0.44, respectively (p=0.03). Decreased bleb function occurred in 86% and 40%, respectively (p=0.08).
Conclusions :
Intraoperative VisionBlue during phacoemulsification allows visualization of filtering bleb function. A significantly greater number of glaucoma medications was needed to control IOP in the mild staining group compared to the diffuse staining group. A greater trend towards decreased bleb function was seen in the mild staining group, though it was not statistically significant. Greater bleb staining may predict a significantly decreased need for glaucoma medications and a trend towards decreased risk of early bleb failure after cataract surgery. This potentially allows us to predict the need for concurrent glaucoma procedures such as bleb needling during phacoemuslfication.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.