Abstract
Purpose :
ICG is commonly used intraoperatively to stain internal limiting membrane (ILM) during MH surgery in the US. It can be detected post-operatively with a fundus camera using an ICG filter. We hypothesized that ICG-F can serve as a marker to assess the duration of MH repair at a cellular level. This study evaluated the duration of ICG-F after MH repair and correlated with MH size and vision outcomes.
Methods :
Retrospective case series of patients who underwent vitrectomy with ICG-assisted ILM peel and were subsequently followed with ICG-F imaging using an 810 nm ICG filter and optical coherence tomography (OCT). OCT images were graded for MH size and the continuity of ellipsoid zone (EZ) and external limiting membrane (ELM) at foveal center. ICG-F images were graded for presence of fluorescence at the fovea. Best corrected visual acuity (BCVA) was assessed on a standard Snellen chart. The main outcome measure was ICG-F persistence at the fovea and its association with MH size, pre-op BCVA, final post-op BCVA and change in BCVA after surgery. Categorical variables were assessed using Chi square test or Fishers exact test, numerical variables were assessed using the Student’s T, Mann–Whitney U, ANOVA or Kruskal–Wallis tests.
Results :
Forty-five patients, (mean age 68.1 years, 73% female) were included with a mean follow up of 587 days (range 124-1790). MH closure rate was 100 percent. The percentage of patients with persistent ICG-F at 1, 6, 12, 18, 24 and 36 months was 100, 80.5, 68.8, 44.4, 21.7 and 4.5, respectively. After month 1, a higher percentage of ICG-F persistence was present in large vs medium vs small holes at every time point (statistically significant at Months 18 and 24 (p=0.03, p=0.01)). Persistence of ICG-F at 6, 12 and 18 months was associated with larger macular hole size (p=0.02, 0.006, 0.002) and worse preop BCVA (p=0.02, 0.006, 0.002), while persistence at 18 months was associated with worse final postop VA. Restoration of EZ continuity was associated with smaller MH size (p=0.01), better final BCVA (p=0.009) and absence of ICG-F at 6 months (<0.005).
Conclusions :
After MH repair, ICG-F was detected in over half of eyes at 1 year and even at 3 years in some cases. This suggests that ICG, presumably up taken by retinal pigment epithelial cells, can persist for long time, especially in larger holes. Therefore, MH repair may take a long time at a cellular level and correlates with MH size.
This is a 2020 ARVO Annual Meeting abstract.