Safety and performance assessment of hyaluronic acid-based vitreous substitutes in patients with phthisis bulbi

Purpose: To assess the safety and performance of hyaluronic acid-based vitreous substitutes in phthitic eyes.

Methods: In this retrospective interventional study a total of 21 eyes from 21 patients with phthisis bulbi were treated at the Eye Clinic Sulzbach between August 2011 and June 2021. Patients who underwent a 23G pars plana vitrectomy received a vitreous substitute composed of (I) a non-crosslinked hyaluronic acid (Healon GV), (II) a crosslinked hyaluronic acid-based hydrogel (UVHA), or (III) silicone oil (SO-5000). Main outcome measures were the intraocular pressure (IOP), the visual acuity and the structural integrity of the retina and choroid assessed by optical coherence tomography.

Results: An increase in IOP ≥ 5 mmHg was achieved with SO-5000 in 5/8 eyes (6/10 interventions, 60.0%) for 36.4 ± 39.5 days, with Healon GV in 4/8 eyes (7/11 interventions, 63.6%) for 82.6 ± 92.5 days and with UVHA in 4/5 eyes (5/6 interventions, 83.3%) for 93.6 ± 92.5 days. Visual acuity increased in 5/21 eyes (23.8%), remained constant in 12/21 eyes (57.1%) and decreased in 4/21 eyes (19.0%). No enucleations were required during the mean follow-up time of 192 ± 182 days. The OCT images indicated the preservation of retinal structures, while choroidal folds were only diminished in UVHA eyes.

Conclusions: Hyaluronic acid-based hydrogels are biocompatible vitreous substitutes in humans and can increase and stabilize IOP in patients with phthisis bulbi for about 3 months.