The effects of temporary intraocular pressure spikes after intravitreal dexamethasone implantation on the retinal nerve fiber layer

Abstract

Background and objective: The dexamethasone (DEX) implant is known to cause temporary intraocular pressure (IOP) spikes after implantation. The purpose of this study is to determine if IOP spikes after DEX implant cause significant thinning in the retinal nerve fiber layer (RNFL).

Study design, patients, and methods: A total of 306 charts were reviewed with 48 and 21 patients meeting inclusion criteria for the cross-sectional and prospective groups, respectively. Cross-sectional inclusion criteria: IOP spike ≥22 mmHg up to 16 weeks after DEX implant, DEX implant in only 1 eye per patient, and spectral-domain optical coherence tomography (OCT) RNFL imaging of both eyes ≥3 months after IOP spike. Prospective inclusion criteria: OCT RNFL performed within 1 year prior to DEX implantation, IOP spike ≥22 mmHg up to 16 weeks after DEX implant, and OCT RNFL performed ≥3 months after IOP spike. The average RNFL thickness in the contralateral eye was used as the control in the cross-sectional group. Institutional review board approval was obtained.

Results: In the cross-sectional group, there was no statistically significant difference in the mean RNFL thicknesses in the treated vs untreated eyes (80.4±15.5 μm and 82.6±15.8 μm, respectively; P=0.33) regardless of treatment diagnosis, magnitude of IOP spike, or history of glaucoma. In the prospective group, mean RNFL thicknesses before and after IOP spikes ≥22 mmHg were similar (78.0±14.8 μm and 75.6±13.6 μm, respectively; P=0.13).

Conclusion and relevance: Temporary elevation of IOP after DEX implantation when treated with topical IOP lowering drops does not appear to lead to a meaningful change in RNFL thickness.

Keywords:

• Ozurdex^®
• dexamethasone
• glaucoma
• intraocular pressure
• retinal nerve fiber layer
• ocular hypertension

Acknowledgments

An abstract of this paper was presented at the annual Association of Research in Vision and Ophthalmology Conference (May 1, 2018) as a poster presentation with interim findings. The poster’s abstract was published in “Poster Abstracts” in the Investigative Ophthalmology & Visual Science Journal (ARVO journal):2018;59:2705. An abstract was also presented at the following meetings: Alamo Day annual meeting, San Antonio, TX, USA, April 7, 2018; Third Coast Retina Club, Austin, TX, USA, April 14, 2018; The Club Jules Gonin annual meeting; July 11–14, 2018; Jersey, Channel Islands (GB); and The American Academy of Ophthalmology annual meeting, Retina Subspecialty Day, 2018; Chicago, IL, USA.

Journal fees were funded by Allergan plc, Dublin, Ireland, through a publication grant. Otherwise, there was no other financial support.

Disclosure

Kendall Wannamaker, Sarah Kenny, Rishi Das, Aaron Mendlovitz, Jordan M Comstock, Edward R Chu, Sepehr Bahadorani, Nathan J Gresores, Kinley D Beck, Chelsey J Krambeer, Daniel S Kermany, Daniel P Nolan, and Jeong­-Hyeon Sohn report no conflicts of interest in this work. Roberto Diaz­-Rohena reports personal fees from Allergan, outside the submitted work. Michael Singer reports grants from Allergan, during the conduct of the study, has been a consultant for Allergan, Genentech, Regeneron, Santen, Clearside Aerpio, and Alimera Speakers Bureau, and has received research support from Allergan, Genentech, Regeneron, Ampio, Optos, Aerpio, Allegro, Diachii, and Clearside. The authors report no other conflicts of interest in this work.