Indocyanine Green-assisted Internal Limiting Membrane Research Articles

Virtual retinectomy: indocyanine green-assisted internal limiting membrane peeling as a surgical adjunct in repair of recurrent rhegmatogenous retinal detachment due to PVR

BackgroundThe purpose of this study was to describe and evaluate a surgical approach, known as internal limiting membrane (ILM) peeling, as an adjunct to repair of recurrent retinal detachment due to proliferative vitreoretinopathy (PVR).MethodsThis was a retrospective case series. All eyes underwent repair of recurrent PVR-related rhegmatogenous retinal detachment incorporating macular indocyanine green-assisted ILM peeling. Patients with primary detachments, diabetes, staphyloma, or macular holes were excluded. The main outcome measure was the anatomic success of single surgery. The characteristics of the group were studied, including the number and types of previous detachment repair attempts, as well as the subsequent surgeries.ResultsFourteen eyes from 14 patients were included. Anatomic success with single surgery was achieved in 11 of 14 (79%) of the operated eyes using this technique, and eventual success was achieved in all eyes (100%). Among the failed repairs prior to ILM peeling, 8/14 eyes had scleral buckles, 7/14 had silicone oil tamponade, and two had inferior retinectomies. There was no subsequent development of epiretinal membranes after ILM peeling.ConclusionILM peeling in conjunction with vitrectomy and peeling of peripheral membranes is an effective technique with a high anatomic success rate in the challenging scenario of PVR-related recurrent detachments. We describe the technique as an alternative to the traditional retinectomy.

ANALYSIS OF THE NEURONAL MARKER PROTEIN GENE PRODUCT 9.5 IN INTERNAL LIMITING MEMBRANES AFTER INDOCYANINE-GREEN ASSISTED PEELING

Indocyanine green-assisted internal limiting membrane (ILM) peeling was suspected to disrupt the innermost layer of the neural retina. We examined whether surgically excised specimens contain remnants of neuronal tissue. Ten patients with macular hole underwent pars plana vitrectomy and indocyanine green-assisted ILM peeling. A total of 0.1 mL of a 0.5% indocyanine green solution was applied for 15 seconds. The ILM specimens were prepared for immunohistochemistry, using a polyclonal antibody against protein gene product 9.5. Protein gene product 9.5 is a pan-neuronal marker labeling human neuronal cells. Appropriate controls to show selectivity of the antibody were performed on neuronal tissue of donor eyes. One ILM was prepared for electron microscopy. A selective expression of protein gene product 9.5 was found in neuronal fibers of the retina and optic nerve of donor eyes. Only 1 of the 10 surgical ILM specimens showed a minimal focal positivity for protein gene product 9.5. No neuronal tissue was detected on the ILM by electron microscopy. Focal expression of protein gene product 9.5 in only 1 of 10 surgical ILM specimens argues against a general indocyanine green-related disruption of the innermost retinal layers. However, higher concentrations of the dye, longer incubation times or different solvents than used in this study may lead to different results.

Indocyanine green-assisted internal limiting membrane removal in epiretinal membrane surgery: A clinical and histologic study

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.

Visual field defects after uneventful vitrectomy for epiretinal membrane with indocyanine green–assisted internal limiting membrane peeling

Purpose To report visual field defects after vitrectomy for epiretinal membrane with indocyanine green (ICG)–assisted internal limiting membrane (ILM) peeling. Design Interventional consecutive case series. Methods A retrospective review of 16 eyes of 16 patients who underwent vitrectomy for idiopathic epiretinal membrane. Indocyanine green-assisted ILM peeling was performed in 7 of 16 eyes. The main outcome measure was postoperative visual field. Results Four of seven eyes (57%) with ICG-assisted ILM peeling had visual field defects postoperatively. The field defects identified were nasal in three eyes; in the fourth eye, the visual field was constricted to approximately 30 degrees. None of the nine eyes without ICG-assisted ILM peeling had a visual field defect. Conclusions Peripheral visual field defects may occur after vitrectomy with ICG-assisted ILM peeling. Although the cause of the defects is unclear, the potential role of ICG toxicity requires further investigation.