Association Between Peribulbar Anesthesia Followed By

1. Association Between Peribulbar Anesthesia Followed By Ocular Compression Before Cataract Surgery and Optic Nerve Changes on RNFL OCT Tarek El-Sawy, MD PhD, Eric Wolf, MD, Lynda Kleiman, MD Harkness Eye Institute, Columbia Universty and New York Presbyterian Medical Center. New York, NY No financial relationship or conflict of interest

2. Background and Purpose • Known complications of peribulbar anethesia: • Globe trauma • Injection into subarachnoid space • Diplopia • Ischemic optic neuropathy • Question: • Does OCT imaging of optic nerve and RNFL • demonstrate more subtle changes following standard • peribulbar anesthesia and ocular compression?

3. Study Design • Retrospective chart review from 7/2007 – 3/2009 • Five resident surgeons all with attending support • All surgeries performed at the Harkness Eye Institute • Inclusion Criteria: • Elective surgery for visual significant cataract • Exclusion Criteria: • History of glaucoma, optic neuropathy, optic neuritis • History of clinically significant macular edema • Complicated surgery including but not limited to capsule rupture and lens loss • Poor quality imaging

4. Materials and Methods • Thirteen patients included in study • Nine patients received peribulbar anesthesia and ocular compression • Four patients received topical anesthesia only • RNFL-OCT performed between 1 week and 2 months prior to surgery • RNFL-OCT repeated between 1 month and 3 months following surgery • RNFL thickness was compared within and between groups • The fellow eye was used as an internal control

5. RNFL Thickness by OCT - Example Pre-Operative RNFL Thickness Post-Operative RNFL Thickness

6. Analysis of Overall Optic Nerve Thickness Peribulbar and Compression Topical Only Pre-Operative RNFL Thickness Operative Eye Average: 99.7 Fellow Eye Average: 95.0 Pre-Operative RNFL Thickness Operative Eye Average: 90.1 Fellow Eye Average: 87.8 Post-Operative RNFL Thickness Operative Eye Average: 94.9 Fellow Eye Average: 93.7 Post-Operative RNFL Thickness Operative Eye Average: 84.6 Fellow Eye Average: 88.1

7. Analysis of Overall Optic Nerve Thickness RNFL Thickness Pre and Post-Operatively

8. Percent Change Pre to Post-Operative Peribulbar and Compression Topical Only Percent Change Operative Eye: -6.6% Fellow Eye: -1.6% Percent Change Operative Eye: -6.4% Fellow Eye: 0.7% Result pattern was equivalent when optic nerve was analyzed by quandrant in all four groups (data not shown)

9. Conclusions • Mild and equivalent RNFL thinning by OCT in both peribulbar and topical anesthesia only groups • Essentially no change in RNFL thickness in fellow eyes • However, the range of percent change was large • Peribulbar group: -33.7% to +7.6% • Topical Group: -13.5% to +6.5%

10. Conclusions • Unclear how to interpret data: • Large range of percent change in all groups • Differences in operative technique • Unknown susceptibility to compression • Undiagnosed optic nerve disease (glaucoma, other neuropathies) • Reliability of imaging technique despite reports to the contrary

11. Conclusions No clear difference between peribulbar and topical anesthesia to suggest significant concern in standard cataract surgery with peribulbar anesthesia and ocular compression To address the limitations of this study, additional patients will be recruited particularly in the topical anesthesia only group and followed for longer time points.

12. Thank You Mentors: Lynda Kleiman, MD Eric Wolf, MD Resident Surgeons: Irena Tsui, MD Suzanna Airiani, MD Loh-Shan Leung, MD Michael Weisberg, MD Joseph Tseng, MD