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Updated: Aug 23, 2026
Characterization of Vascular Morphology of Neovascular Age-Related Macular Degeneration by Indocyanine Green Angiography
Published on: August 11, 2023
Indocyanine green-assisted internal limiting membrane removal in epiretinal membrane surgery: a clinical and
Alvin K H Kwok1, Timothy Y Y Lai, Winnie W Y Li
1Department of Ophthalmology, Hong Kong Sanatorium and Hospital, Hong Kong. alvinkwok@hksh.com
Purpose:
To evaluate the clinical outcome and quantify histologically the amount of microscopic internal limiting membrane (ILM) and epiretinal membrane (ERM) present in ILM and ERM specimens obtained from ERM surgery.
Design:
Interventional consecutive case series.
Methods:
Patients scheduled for ERM surgery were recruited prospectively. Pars plana vitrectomy, removal of ERM, and ILM peeling with indocyanine green (ICG) staining were performed in all patients. Epiretinal membrane and ILM specimens were sent for histologic examination. The amount of ERM present in ILM specimens and the amount of ILM present in ERM specimens were quantified by manual counting. Outcome measures include change in best-corrected visual acuity (BCVA), proportion of cases with 2 or more lines of visual improvement, anatomic outcome, proportions of microscopic ERM within ILM, and microscopic ILM within ERM.
Results:
Eighteen eyes in 18 patients were operated with a mean follow-up of 19.3 months. There were 13 primary ERMs and five secondary ERMs. The mean logMAR BCVA improved from 0.83 preoperatively to 0.49 postoperatively (P <.001). The mean lines of improvement in BCVA was 3.3 lines with 14 patients (77.8%) who had 2 or more lines of BCVA improvement. Histologic evaluation of the specimens showed no significant correlation with the final BCVA of 20/50 or better. Eleven (61.1%) of the ILM specimens showed various amount of microscopic ERM and 16 (88.9%) of the ERM specimens showed various amount of ILM fragments. The mean proportion of ERM within ILM specimens was 4.69% and that of ILM within ERM specimens was 51.5%. No significant recurrence of ERM was found.
Conclusion:
Recurrence of ERM may be minimized by removing residual microscopic ERM present on the ILM. Indocyanine green-assisted ILM peeling in ERM surgery appears to have favorable visual and anatomic outcomes.
Insights
This study found that removing microscopic epiretinal membrane (ERM) fragments during internal limiting membrane (ILM) peeling in ERM surgery may reduce recurrence. Indocyanine green-assisted ILM peeling shows good visual and anatomic outcomes.
Area of Science:
- Ophthalmology
- Retinal Surgery
- Histopathology
Background:
- Epiretinal membrane (ERM) surgery aims to improve vision by removing the membrane from the retinal surface.
- Internal limiting membrane (ILM) peeling is often performed concurrently to prevent recurrence, but residual microscopic fragments may remain.
Purpose of the Study:
- To evaluate the clinical outcomes of ERM surgery.
- To histologically quantify microscopic ILM and ERM in surgical specimens.
- To assess the impact of residual microscopic ERM on ILM specimens.
Main Methods:
- Prospective interventional case series of patients undergoing ERM surgery.
- Pars plana vitrectomy with ERM removal and indocyanine green (ICG)-assisted ILM peeling.
- Histologic examination of ILM and ERM specimens to quantify microscopic ERM on ILM and ILM fragments on ERM.
Main Results:
- Mean best-corrected visual acuity (BCVA) improved significantly postoperatively (0.83 to 0.49 logMAR).
- 77.8% of patients achieved 2 or more lines of BCVA improvement.
- Microscopic ERM was found in 61.1% of ILM specimens, and ILM fragments in 88.9% of ERM specimens.
Conclusions:
- Removing residual microscopic ERM during ILM peeling may minimize ERM recurrence.
- ICG-assisted ILM peeling in ERM surgery demonstrates favorable visual and anatomic outcomes.
- Histological findings of microscopic ERM on ILM did not correlate significantly with final BCVA.