Techniques and Preferences for Nonvalved Aqueous Shunts

Purpose

To assess practice patterns and opinions of glaucoma specialists regarding indications, surgical technique, and postoperative management for nonvalved aqueous shunts.

Design

Anonymous online survey study.

Participants

American Glaucoma Society (AGS) members.

Methods

An anonymous online survey was distributed to glaucoma specialists via the AGS forum from June to August 2022.

Main Outcome Measures

Survey questions and responses were assessed in 4 sections: (1) general demographics and practice patterns; (2) nonvalved tubes vs. trabeculectomy; (3) nonvalved tubes vs. valved tubes; and (4) nonvalved tube techniques.

Results

There were 132 respondents; nonvalved tubes were reported to be performed more often than trabeculectomy by 61% of respondents within 5 years of completing training and 23% of respondents with more than 15 years since completing training. The most frequently preferred types of nonvalved tubes were Baerveldt-350 (41%), Baerveldt-250 (27%), and ClearPath-250 (18%). In patients with lower target intraocular pressure (IOP), 92% of respondents preferred trabeculectomy over nonvalved tube; 33% cited a cutoff of < 12 mmHg, and 31% cited a cutoff of < 15 mmHg. In patients with higher preoperative IOP, 50% of respondents preferred valved over nonvalved tubes; 29% cited a cutoff of > 40 mmHg, and 38% cited a cutoff of > 30 mmHg. The most frequently used ligature was 7-0 Vicryl (69%). The most frequently used strategies for early IOP lowering were fenestrations without wicks (70%) and with wicks (22%), with one 10-0 Nylon being the most used wick technique (22%). Overall, 37% of respondents use a ripcord; among ripcord users, 55% use it for hypotony prevention (3-0 Prolene most common for this purpose at 35%), and 40% use it for optional early IOP lowering (4-0 Nylon most common for this purpose at 21%). If IOP is too high at postoperative week 4, 38% of respondents do not open the tube early.

Conclusions

We demonstrate significant heterogeneity regarding specific indications, surgical technique, and postoperative management for nonvalved tubes. Future work is needed to identify and develop standardized guidelines alongside best practices.

Financial Disclosure(s)

The author(s) have no proprietary or commercial interest in any materials discussed in this article.