Abstract
Purpose :
OASIS is a Phase IIIb trial (NCT01429441) assessing long-term outcomes in subjects with VMA. The pre-specified OCT analysis in OASIS only evaluated the ellipsoid zone (EZ) in the central 1mm, but this region was affected by VMA and/or macular hole (MH) in most subjects at baseline. The purpose of this post-hoc analysis is to evaluate the EZ over time outside the central 1mm.
Methods :
A masked post-hoc analysis of OCT images was performed at the Doheny Image Reading Center from subjects enrolled in the MP-1 and ERG substudies of the OASIS trial. The status of the EZ band was assessed in 3 different macular regions: the CS (≤ 1mm diameter, covering the same region previously analysed), the Parafoveal Area (PAA) (> 1mm - ≤ 3mm) and the Perifoveal Area (PEA) (> 3mm - ≤ 6mm). The EZ band was rated as normal/intact, abnormal but continuous, discontinuous/disrupted, or absent at all available visits from baseline (BL) (pre-treatment) to final follow-up.
Results :
In the ocriplasmin group, at BL 28.8% (17/59) of subjects had a normal EZ in CS, 96.6% (57/59) in PAA, and 98.3% (58/59) in PEA, compared to 31.0% (9/29), 89.7% (26/29), and 100.0%, respectively in the sham group. The disruption of the EZ in the CS corresponded to vitreomacular interface (VMI) abnormalities in this region (e.g. MH). At Day 7, the proportion of subjects with normal EZ in the ocriplasmin group were 20.3% (12/59), 86.4% (51/59), and 89.8% (53/59) for CS, PAA and PEA, and in the sham group were 32.1% (9/28), 89.3% (25/28) and 100% (28/28), respectively. These EZ alterations in the ocriplasmin group appeared to normalize by Month 3. At Month 24, the proportion of subjects with normal EZ in the ocriplasmin group were 82.8% (24/29), 93.1% (27/29), and 93.1% (27/29) for CS, PAA and PEA, and in the sham group were 40.0% (2/5), 80.0% (4/5) and 100.0%, respectively.
Conclusions :
The pattern of EZ alteration appears to depend on the retinal region. While the status of the EZ in the CS correlated with VMI disease, the more peripheral EZ (especially the PEA) was less influenced by VMI abnormalities, allowing assessment of a likely direct drug effect. Although transient disruption of PAA and PEA EZ was observed at Day 7, there was recovery over subsequent follow-up, mirroring the previously reported microperimetric and electrophysiologic findings.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.