Dyes for Eyes™: hydrodynamics, biocompatibility and efficacy of 'heavy' (dual) dyes for chromovitrectomy

Intraoperative efficacy and clinical outcomes of two commercial staining solutions used in idiopathic epiretinal membrane surgery

PURPOSE

To compare two commercially available staining solutions (MembraneBlue Dual® by D.O.R.C., Netherlands, and TWIN by AL.CHI.MI.A. S.R.L., Italy), in terms of intraoperative handling, staining efficacy and safety, in eyes undergoing surgery for idiopathic epiretinal membrane (ERM).

METHODS

In this observational cross-sectional study, the performance of the dyes used during the procedure (cohesion, ERM and internal limiting membrane [ILM] staining efficacy) was scored by the surgeon using a customized questionnaire after 10 procedures with each of the two dyes. Best-corrected visual acuity (BCVA), central foveal thickness (CFT), blue-light fundus autofluorescence (BAF), and microperimetry-determined retinal sensitivity were reviewed preoperatively and then at 1 and 3 months after surgery.

RESULTS

ILM staining efficacy with TWIN was scored 2.89 ± 0.33 by the surgeons, which turned out to be higher than with MembraneBlue Dual® (1.90 ± 0.31, P = 0.0002). The cohesion score was 2.70 ± 0.48 for TWIN and resulted significantly higher than with MembraneBlue Dual® (1.60 ± 0.51, P = 0.0010). BCVA, CFT and retinal sensitivity were similar in the two groups, 1 and 3 months postoperatively (P nonsignificant for all).

CONCLUSIONS

Both TWIN and MembraneBlue Dual® dyes showed suitable staining properties and equivalent safety and efficacy profiles, both intra- and postoperatively. The TWIN dye might offer a solution for surgeons who prefer a more cohesive and stable dye.

Outer Retinal Healing After Internal Limiting Membrane Peeling in Diabetic Macular Oedema with Vitreomacular Interface Abnormality Using Three Different Dyes

Purpose: To evaluate the difference in ellipsoid zone and external limiting membrane (EZ/ELM) restoration after vitrectomy with internal limiting membrane (ILM) peeling in diabetic macular oedema with vitreomacular interface abnormalities (VMA DME) patients using 3 different dyes.Methods: Patients with type 2 diabetes mellitus and VMA DME indicated for ILM peelings were included. Disruption of the EZ/ELM was graded and compared among groups (preoperative and 6 months postoperative). Patients were divided into 3 groups according to the dye used: group A: indocyanine green (ICG); group B: trypan blue (TB); and group C: brilliant blue G(BBG).Results: Twenty-six eyes were included in group A, 29 eyes were included in group B, and 28 eyes were included in group C. Improvement in EZ/ELM integrity was observed in 34.6% of group A, 27.6% of group B, and 32.1 % of group C (p = .84). Deterioration of EZ/ELM integrity was observed in 19.2% of group A, 6.9% of group B and 0% of group C (p = .03).Conclusion: ICG resulted in a greater percentage of deteriorated EZ/ELM integrity at 6 months after surgery in cases with pre-treatment ELM interruption. Therefore, ICG should be used with caution in cases with ELM disruption, yet, further studies are recommended.

[Vitrectomy and iOCT-assisted inverted ILM flap technique in patients with full thickness macular holes]

BACKGROUND

In large full thickness macular holes (FTMH) the closure rate after vitrectomy and conventional internal limiting membrane (ILM) peeling is less than 90%. The aim of this study was to examine the visual acuity and anatomical success rate with high-resolution optical coherence tomography (OCT) after transconjunctival sutureless 23-gauge pars plana vitrectomy as well as intraoperative OCT (iOCT) and Brilliant Peel (BP)-assisted ILM peeling using the inverted ILM flap technique in patients with large FTMHs.

METHOD

In this retrospective study 25 eyes of 25 consecutive patients with large FTMH were treated by 23-G vitrectomy with BP and iOCT-assisted ILM peeling using the inverted ILM flap technique followed by gas tamponade. In all patients best corrected visual acuity (BCVA) and the maximum diameter, base and height of the FTMH as well as intraretinal alterations were measured preoperatively using high-resolution spectral domain OCT (SD-OCT, Spectralis, Heidelberg Engineering, Germany). The BCVA was measured after 1, 3, and 6 months. Additionally, the closure rate and the microstructural integrity of the outer retinal layers, e.g. external limiting membrane (ELM), ellipsoid zone und photoreceptor outer segment (OS) were registered in the SD-OCT and correlated with the results of BCVA after macular hole surgery.

RESULTS

In all surgical procedures with the inverted ILM flap technique the application of iOCT enabled a good visualization and a controlled positioning of the ILM flaps. At baseline mean BCVA was 0.2 (0.7 logMAR) and improved significantly after 1, 3 und 6 months to 0.4 (0.4 logMAR), 0.5 (0.3 logMAR) and 0.63 (0.2 logMAR), respectively. The closure rate of the FTMHs was 100%. Microstructural integrity of the outer retinal layers was evaluated semiquantitatively and showed good correlation with BCVA.

CONCLUSION

Vitrectomy with BP and iOCT-assisted ILM peeling using the inverted ILM flap technique in patients with large FTMH is a very controlled and safe microsurgical strategy and shows good functional and anatomical results. The morphology of the FTMH, the ILM flap and the position of the inverted ILM flap under air was well visualized by IOCT. The microstructural integrity of the outer retinal layers is displayed in detail on SD-OCT and represents an important predictive parameter for BCVA after macular hole surgery.

Management of recurrent rhegmatogenous retinal detachment

Rhegmatogenous retinal detachment (RRD) repair is one of the most common vitreoretinal surgeries a surgeon performs. In an ideal scenario, RRD can be repaired with a single surgical intervention; however, despite excellent skill, flawless technique, and the introduction of high-end technology, up to 10% of cases require additional interventions to ultimately repair recurrent detachments. It is thus important to study the outcomes of multiple interventions to understand whether performing repeat vitrectomy on patients with a history of failed surgeries is worthwhile. Thus, recurrent retinal detachment (re-RD) remains a significant challenge for vitreoretinal surgeons as well as the patients considering the economic and the emotional burden of undergoing multiple interventions. The advent of microincision vitrectomy system, perfluorocarbon liquids, and effective intraocular tamponades has opened new doors for managing re-RDs. In this article, we have reviewed and summarized the various causes and approaches for management for optimal anatomical and functional outcomes.

Effect of vital dyes on human corneal endothelium and elasticity of Descemet's membrane

The purpose of this study was to evaluate the effects of vital dyes on human Descemet's membranes (DMs) and endothelia. DMs of 25 human cadaveric corneas with research consent were treated with dyes routinely used in Descemet membrane endothelial keratoplasty (DMEK), 0.05% Trypan blue (TB) or a combination of 0.15% Trypan blue, 0.025% Brilliant blue and 4% Polyethylene glycol (commercial name Membrane Blue Dual; MB). The effects of these two dyes on (i) endothelial cell viability, (ii) DM mechanical properties as assessed by atomic force microscopy, and iii) qualitative DM dye retention were tested for two varying exposure times (one or four minutes). No significant differences in cell toxicity were observed between treatments with TB and MB at the two different exposure times (P = 0.21). Further, both dyes led to a significant increase in DM stiffness: exposure to TB and MB for one minute increased the apparent elastic modulus of the DM by 11.2% (P = 8*10⁻³) and 17.7%, respectively (P = 4*10⁻⁶). A four-minute exposure led to an increase of 8.6% for TB (P = 0.004) and 13.6% for MB (P = 0.03). Finally, at 25 minutes, the dye retention of the DM was considerably better for MB compared to TB. Taken together, a one-minute exposure to MB was found to improve DM visibility compared to TB, with a significant increase in DM stiffness and without detrimental effects on endothelial cell viability. The use of MB could therefore improve (i) visibility of the DM scroll, and (ii) intraoperative unfolding, enhancing the probability of successful DMEK surgery.

Complications of Macular Peeling

Macular peeling refers to the surgical technique for the removal of preretinal tissue or the internal limiting membrane (ILM) in the macula for several retinal disorders, ranging from epiretinal membranes (primary or secondary to diabetic retinopathy, retinal detachment…) to full-thickness macular holes, macular edema, foveal retinoschisis, and others. The technique has evolved in the last two decades, and the different instrumentations and adjuncts have progressively advanced turning into a safer, easier, and more useful tool for the vitreoretinal surgeon. Here, we describe the main milestones of macular peeling, drawing attention to its associated complications.

A review of current management of vitreomacular traction and macular hole

The paper presents a review of the sequence of events of posterior vitreous detachment (PVD), vitreomacular adhesion (VMA), vitreomacular traction (VMT), and macular hole (MH) from their pathophysiological aspects, clinical features, diagnostic implications, and current management strategies. A treatment algorithm to be used in clinical practice in patients with VMA, VMT, and MH based on the presence of symptoms, visual acuity, associated epiretinal membrane, and width of the vitreous attachment is presented. Observation, pharmacologic vitreolysis with ocriplasmin, and surgical treatment are positioned as treatment options in the different steps of the therapeutic algorithm, with clear indications of the paths to be followed according to the initial presenting manifestations and the patient's clinical course.