Complications associated with subpalpebral lavage systems in upper and lower equine eyelids: A prospective, randomised study in 73 cases (2015-2024).

Background: Evidence for optimal location of subpalpebral lavage (SPL) systems is lacking.

Objectives: To compare the rate and types of complications with SPL systems located in central upper- compared with medial lower-eyelid in hospitalised patients.

Study design: Prospective, randomised treatment trial.

Methods: Horses admitted for ophthalmic treatment using an SPL system from February 2015 to January 2024 were included if ocular pathology did not necessitate SPL system placement in a specific location. Coin toss was used to determine location. SPL systems were monitored at least daily, and complications were defined as major (displacement of footplate from the fornix ± corneal ulceration; loss of footplate; eyelid infection/abscess formation) or minor (loss of suture/tape; palpebral swelling; leakage or tube rupture; loss of injection port; subcutaneous swelling/abscess at suture site). Data were analysed using logistic regression.

Results: Seventy-three SPL systems in 68 horses were included, with 38 (52%) located in the upper and 35 (48%) in the lower eyelid, for a median (IQR) duration of 13 (8-16) days. Sixty-nine complications (37 (54%) in upper and 32 (46%) in lower SPL systems) occurred in 44/73 (60%) of all SPL systems. Major complications occurred with 2 lower (2/69; 3%) and 10 upper SPL systems (10/69;14%). The most common major complication was displacement of the lavage footplate from the conjunctival fornix (7/69; 10%). The most common minor complication was loss of suture or butterfly tape (21/69; 30%). Treatment with chloramphenicol (OR = 0.3; 95% CI: 0.09-0.8; p = 0.02) or cross-linked modified hyaluronic acid (OR = 3.9; 95% CI: 1.2-13.3; p = 0.03) was associated with any complication on multivariable analysis. Multivariable analysis showed that upper systems were 5.1 (95% CI: 1.0-25.7; p = 0.05) more likely to have a major complication than lower SPL systems.

Main limitations: Small study size.

Conclusions: SPL system location had no effect on all complications, but major complications were more common in those placed in the upper lid.