Abstract
Purpose :
To describe the largest cohort of eyes to undergo simultaneous XEN gel stent +MMC with the addition of Ologen collagen matrix to promote bleb formation and prevent fibrosis.
Methods :
Surgical: In addition to ab externo, open-conjunctival XEN + MMC, an Ologen collagen matrix circle was cut in half, with one half positioned below and the other above the XEN stent. Standard post-operative care was followed.
Success Criteria: Success was defined as a >20% drop from preoperative IOP at 12-months without the use of drops, additional procedure (eg. needling), an IOP >21mm Hg at two consecutive visits, or catastrophic events (eg. NLP). Qualified successes were IOPs that met the reduction goal of >20% combined with the use of drops.
Statistics: A linear mixed-effects model was used to estimate change in IOP at each follow-up visit. In this model, age and sex were considered and a patient eye random effect was included for within-eye correlation.
Results :
47 eyes were identified, and 6 were excluded due to insufficient follow up/data or significant compounding factors. After controlling for age and gender, we have strong evidence of a non-zero average change in IOP from baseline and estimate a lower average IOP in all four post-baseline periods (Figure 1 and Table 1). The number of eyes meeting the >20% drop criteria was 82.50% (33/40), 87.80% (36/41), 73.53% (25/34), 70.00% (21/30), and 69.23% (18/26) at 1 month, 3 months, 6 months, 9 months, and 12 months post-operative, respectively. Only one eye required any additional procedures, and no patients had a IOP of >21mm Hg for 2 consecutive clinic visits. No patients had experienced catastrophic events during this time frame.
Conclusions :
Some past studies have put the proportion of XEN fibrosis requiring revisions as high as 45%. However, most notably, only 1 eye in this cohort required an additional procedure to control fibrosis. Our numbers also show that the Ologen/XEN gel stent combination resulted in a statistically significant drop in IOP of -7.04 (CI: -9.34, -4.74, p < 0.001) from baseline. Thus, the use of Ologen collagen matrix with the XEN gel stent may help prevent bleb fibrosis and the need for revision without affecting XEN efficacy. Further studies with randomization may be required to help determine the true size of this impact in preventing fibrosis and the need for revision.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.