Post hoc analysis of ellipsoid zone changes beyond the central subfield in symptomatic vitreomacular adhesion patients from the OASIS trial

Abstract

Background/aims: OASIS is a Phase IIIb trial (NCT01429441) assessing long-term outcomes in subjects with symptomatic vitreomacular adhesion (VMA). The purpose of this study is to report on the frequency, severity, location and time course of ellipsoid zone (EZ) alterations in ocriplasmin-treated and sham control eyes in the OASIS study.

Methods: 220 patients (146 ocriplasmin, 74 sham) subjects with VMA were enrolled in this masked post hoc analysis phase IIIb, randomised, sham-controlled double-masked multicentre clinical trial. A masked post hoc analysis of OCT images was performed at the Doheny Image Reading Center from subjects enrolled in the OASIS trial. The status of the EZ band was assessed in three different macular regions: the central subfield (CS) (≤1 mm diameter), the parafoveal area (PAA) (>1 to ≤3 mm) and the perifoveal area (PEA) (>3 to ≤6 mm). The EZ band was rated as normal/intact, full thickness macular hole (FTMH), abnormal but continuous, discontinuous/disrupted or absent at visits from baseline (pretreatment) to week 1 (day 7), month 1 (day 28), month 3, month 6, month 12 and the final follow-up at month 24. EZ band status was compared in both study and control eyes.

Results: A total of 208 patients (138 ocriplasmin, 70 sham) were included in this analysis. At baseline, FTMH was present in 48.6%, 8.0%, 0% and 52.8%, 2.9%, 0% in the CS, PAA and PEA of the ocriplasmin and sham groups, respectively. The EZ was graded to be abnormal but continuous, discontinuous/disrupted or absent at Baseline in 21.0%, 4.3%, 2.8% in the CS, PAA and PEA, respectively, of the ocriplasmin group; and 12.9%, 10.0%, 4.3% in the CS, PAA and PEA of the sham group. For the ocriplasmin group in the PAA, this frequency increased to 6.6% at week 1, was 9.8% at month 1, but improved to 3.8% at month 3, and remained stable to 1.6% at month 24. These differences, however, were not statistically significant.

Conclusions: Ocriplasmin treatment for symptomatic VMA was associated with EZ abnormalities in a small percentage of patients that was best assessed in regions (PEA) relatively unaffected by the VM interface disease at baseline. The EZ abnormalities were apparent by week 1, persisted at month 1, and appeared to resolve in the majority of cases by month 3.

Trial registration number: NCT01429441.

Keywords: Treatment other; clinical trial; retina; vitreous.

Conflict of interest statement

Competing interests: None declared.

© Author(s) (or their employer(s)) 2021. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.

Figures

Figure 1

Grading scale for EZ band classification. Normal/intact and four categories of abnormal EZ: presence of full thickness macular hole; abnormal but continuous; discontinuous/disrupted and absent. EZ, ellipsoid zone.

Figure 2

Percentage of abnormalities of the EZ in the central subfield at baseline, postinjection day 7, day 28, month 3, month 6 and month 24 in both study cohorts. Only the categories of abnormal EZ with the percentages given relative to the entire cohort (including eyes with normal/intact EZ; O-Ocriplasmin cohort, S-Sham cohort). EZ, ellipsoid zone.

Figure 3

Representative SD-OCT image of a patient with disrupted EZ at baseline and with subsequent restoration by month 3 following ocriplasmin injection. CS, central ubfield; EZ, ellipsoid zone; SD, spectral domain.

Figure 4

Percentage of abnormalities of the EZ in the parafoveal area at baseline, post injection day 7, day 28, month 3, month 6 and month 24 in both study cohorts. Only the categories of abnormal EZ with the percentages given relative to the entire cohort (including eyes with normal/intact EZ; O-ocriplasmin cohort, S-Sham cohort). EZ, ellipsoid zone.

Figure 5

Percentage of abnormalities of the EZ in the perifoveal area at baseline, postinjection day 1, day 28, month 3, month 6 and month 24 in both study cohorts. Only the categories of abnormal EZ with the percentages given relative to the entire cohort (including eyes with normal/intact EZ; O-Ocriplasmin cohort, S-Sham cohort). EZ, ellipsoid zone.