Using Electronic Health Record Data to Determine the Safety of Aqueous Humor Liquid Biopsies for Molecular Analyses

Abstract

Purpose: Knowing the surgical safety of anterior chamber liquid biopsies will support the increased use of proteomics and other molecular analyses to better understand disease mechanisms and therapeutic responses in patients and clinical trials. Manual review of operative notes from different surgeons and procedures in electronic health records (EHRs) is cumbersome, but free-text software tools could facilitate efficient searches.

Design: Retrospective case series.

Participants: A total of 1418 aqueous humor liquid biopsies from patients undergoing intraocular surgery.

Methods: Free-text EHR searches were performed using the Stanford Research Repository cohort discovery tool to identify complications associated with anterior chamber paracentesis and subsequent endophthalmitis. Complications of the surgery unrelated to the biopsy were not reviewed.

Main outcome measures: Biopsy-associated intraoperative complications and endophthalmitis.

Results: A total of 1418 aqueous humor liquid biopsies were performed by 17 experienced surgeons. EHR free-text searches were 100% error-free for surgical complications, >99% for endophthalmitis (<1% false positive), and >93.6% for anesthesia type, requiring manual review for only a limited number of cases. More than 85% of cases were performed under local anesthesia without ocular muscle akinesia. Although the most common indication was cataract (50.1%), other diagnoses included glaucoma, diabetic retinopathy, uveitis, age-related macular degeneration, endophthalmitis, retinitis pigmentosa, and uveal melanoma. A 50- to 100-μL sample was collected in all cases using either a 30-gauge needle or a blunt cannula via a paracentesis. The median follow-up was >7 months. There was only one minor complication (0.07%) identified: a case of a small tear in Descemet membrane without long-term sequelae. No other complications occurred, including other corneal injuries, lens or iris trauma, hyphema, or suprachoroidal hemorrhage. There was no case of postoperative endophthalmitis.

Conclusions: Anterior chamber liquid biopsy during intraocular surgery is a safe procedure and may be considered for large-scale collection of aqueous humor samples for molecular analyses. Free-text EHR searches are an efficient approach to reviewing intraoperative procedures.

Financial disclosures: Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Keywords: Aqueous humor liquid biopsy; Electronic health records; Free-text search; Intraoperative complications; Precision medicine.

Figure 1

Two surgical techniques were applied to collect aqueous humor liquid biopsies during intraocular surgery. A, In technique 1, a 30-gauge needle connected to a 1-mL syringe was inserted perpendicular to the limbus and into the anterior chamber without prior incision. B, C, In technique 2, a 15° blade was used to make a corneal incision perpendicular to the limbus in the superotemporal quadrant (as part of the scheduled surgery), and an angled 30-gauge blunt cannula connected to a 1-mL syringe was inserted into the anterior chamber. In both techniques, 50 to 100 μL of undiluted aqueous humor was manually aspirated using the syringe.

Figure 2

Electronic health record data analysis workflow. Our liquid biopsy biobank database was queried to identify patients that underwent intraocular surgery with aqueous humor liquid biopsy. The STARR tool was used to obtain electronic health records of these patients. We performed a free-text search with manual verification to determine the primary diagnosis and surgical indication, the anesthesia type, and intra- and postoperative complications. MORLI = Mobile Operating Room Lab Interface; REDCap = research electronic data capture; STARR = Stanford Research Repository.