Preoperative Surgical Site Vessel Density Is Predictive for Secondary Intervention after Preserflo Microshunt
Martin Kallab1, Sarah Hinterberger1, Sophie Schneider1
1Department of Ophthalmology and Optometry, Kepler University Hospital, Johannes Kepler University, Linz, OÖ, Austria.
Purpose:
Conjunctival properties are known to influence the fate of glaucoma filtration surgeries but are hard to quantify in clinical practice. Therefore, the aim of this study was to investigate the predictive potential of anterior segment optical coherence tomography angiography (AS-OCTA) measured preoperative surgical site vessel density (SSVD) for secondary intervention and intraocular pressure (IOP) after Preserflo Microshunt implantation (PMI). Moreover, association of clinical preoperative conjunctival hyperemia grading (HG) with secondary intervention, SSVD and IOP was assessed.
Methods:
In 23 open angle glaucoma patients, preoperative AS-OCTA measured SSVD and slit lamp photography-based HG were assessed. After PMI had been performed, patients were clinically followed for 6 months and secondary interventions as well as topical medications (MEDs) were recorded. The predictive value of SSVD and HG for secondary interventions was assessed using logistic regression modelling and their correlation with each other and with IOP was tested.
Results:
Secondary interventions were performed in 3 of 23 patients. SSVD (p = 0.0339, area under the receiver operating characteristics curve (AUROC): 0.8167) but not HG (p = 0.7719, AUROC: 0.5750) was predictive for secondary interventions until 6 months after primary surgery. No correlations between SSVD/HG and IOP at any timepoint were detected (p > 0.05 for all timepoints). The number and type of preoperative MEDs were not predictive for secondary interventions and were not correlated with SSVD or HG (p > 0.05 for all analyses).
Conclusion:
In this exploratory study preoperative AS-OCTA measured SSVD, but not clinical HG was a promising biomarker with predictive potential for surgical success of PMI. Confirmation of results in large scale studies is necessary and interventional trials are needed to evaluate whether vessel density based clinical decision making enhances clinical outcomes after filtration surgery.
