Longitudinal ellipsoid zone and subretinal fluid mapping following ocriplasmin injection in the prospective observational ORBIT trial

Background Ocriplasmin is approved for the treatment of symptomatic vitreomacular traction (VMT). However, several retrospective reports have identified ellipsoid zone (EZ) alterations on spectral domain optical coherence tomography (SDOCT) after ocriplasmin injection. This report quantitatively analysed outer retinal changes after intravitreal ocriplasmin. Methods Ocriplasmin Research to Better Inform Treatment is a prospective, observational phase IV clinical study where subjects received a single intravitreal injection of ocriplasmin for symptomatic VMT. Macular cube scans were imported into a semiautomated EZ mapping and fluid feature extraction software for SDOCT analysis. Change in visual acuity, VMT release, macular hole (MH) closure, EZ integrity/volume and subretinal fluid (SRF) volume on SDOCT macular cube scans were recorded and analysed. Results This analysis included 55 participants with 6 months of follow-up. Intravitreal ocriplasmin injection caused VMT release in 67% and MH closure in 82% of participants. Visual acuity improved by 4.5 letters (p<0.05) in the whole cohort and by 6.0 letters (p<0.05) in participants with VMT release. EZ volume was reduced by 23.4% at week 1 (p<0.001) and recovered to baseline by between months 3 and 6. EZ volume loss at week 1 did not correlate with ETDRS acuity at final visit. Conclusion Ocriplasmin treatment resulted in VMT release, MH closure and visual acuity gains in a significant portion of eyes. EZ volume was significantly reduced at week 1, but recovered to baseline levels by final follow-up and was not associated with final visual acuity.