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Updated: May 2, 2026

Use of Rabbit Eyes in Pharmacokinetic Studies of Intraocular Drugs
Published on: July 23, 2016
Treatment with repeat dexamethasone implants results in long-term disease control in eyes with noninfectious uveitis
Oren Tomkins-Netzer1, Simon R J Taylor2, Asaf Bar1
1Uveitis Service, Moorfields Eye Hospital, London, United Kingdom; Institute of Ophthalmology, University College London, London, United Kingdom; Department of Ophthalmology, Royal Surrey County Hospital, Guildford, United Kingdom.
Purpose:
To describe the long-term outcome of eyes with uveitis after repeated treatment with dexamethasone implants (Ozurdex; Allergan, Inc., Irvine, CA).
Design:
Retrospective, observational case series.
Participants:
Thirty-eight eyes of 27 patients with uveitis that were treated with 61 dexamethasone implants.
Methods:
All eyes underwent dexamethasone pellet implantation. Anatomic and functional outcomes, as well as ocular complications, were noted.
Main Outcome Measures:
Best-corrected visual acuity (BCVA), central retinal thickness (CRT), vitreous haze score, and presence of increased intraocular pressure or cataract.
Results:
Average follow-up was 17.3 ± 1.8 months after the first implant (median, 13.3 months; range, 3-54.5 months; 54.65 eye-years), with 14 eyes (36.9%) receiving a single implant and 24 eyes (63.1%) receiving multiple implantations. After the first implantation, average BCVA improved significantly from 0.47 ± 0.05 logarithm of the minimum angle of resolution (logMAR) units (Snellen equivalent, 20/60) to 0.27 ± 0.07 logMAR (Snellen equivalent, 20/37; P<0.001); CRT decreased by 263 ± 44.22 microm (P = 0.003), although macular edema persisted in 50% of eyes, and the percentage of eyes achieving a vitreous haze score of 0 increased from 58% to 83% (P = 0.03). The median duration of therapeutic effect after the first injection was 6 months (range, 2-42 months), with a similar response achieved after each repeat implantation. The accumulated effect of repeat dexamethasone implants resulted in a continued improvement in BCVA (R(2) = 0.91; P<0.0001), with significant improvement and stabilization of CRT. After repeated implantations, 2 eyes had progression of posterior subcapsular opacities, although neither required surgery. There were 7 instances of increased intraocular pressure of more than 21 mmHg at a rate of 0.13 per eye-year, all of which responded to pharmacologic treatment.
Conclusions:
The accumulated effect of repeat dexamethasone pellet implantations improves retinal thickness and resolves ocular inflammation, resulting in restoration of ocular function. Ocular complications were minimal, with no eyes requiring surgery for increased ocular pressure or progression of cataract.
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