Abstract
Purpose: :
To evaluate the potential of intra operative light filters to enhance perceivable contrast following intra-operative Brilliant Blue G (BBG) staining of the internal limiting membrane (ILM).
Methods: :
In a prospective, nonrandomized clinical case-series we included 59 consecutive chromovitrectomy interventions in 59 patients operated by two surgeons (CV, CL). Indications for chromovitrectomy included macular holes (MH), epiretinal fibrosis (ERF), vitreoretinal traction syndromes (VRTS) or persistent macular edema (PME). For intraoperative staining of the ILM, a heavier than water 0,25mg/ml BBG solution was applied (Brilliant Peel®, Geuder AG, Heidelberg, Germany) followed by immediate washout. Subsequent to peeling of the ILM, 5 different illumination modes were applied consecutively using a Stellaris PC surgical platform (Bausch & Lomb surgical, Aliso Viejo, CA/USA): Photon, Photon/Mercury and Xenon without filters or with amber, green or yellow filter, respectively. Main outcome measure was the chromaticity difference between the stained ILM and the unstained underlying retina, measured by means of an objective and quantitative, video-based analysis method to describe color contrast strengths as they are perceived by the human eye.
Results: :
In 36 individuals all 5 illumination modes could be evaluated, while in 11 patients, technical quality allowed the analysis of 4 of the 5 illumination modes. Twelve subjects were excluded due to low video quality in more than one illumination mode. Mean chromaticity scores were similar for all light sources with Photon (7.97) and Photon/Mercury (7.96) being almost identical (p=0.99) and Xenon white (7.41) minimally inferior to Photon (p=0.56). The use of filters did not significantly alter contrast recognizability compared to white Xenon light, although a tendency towards improved contrasts was observed for the amber filter (9.38; p= 0.13) while green (6.63) and yellow (7.02) filters produced slightly inferior contrasts (p=0.37 and 0.64, respectively). Contrasts recognizability was better when using the amber compared to the green filter (p=0.04).
Conclusions: :
Contrasts between the ILM and the underlying retina during BBG assisted Chromovitrectomy are similar with the use of Photon, Xenon or Photon/Mercury light sources. The use of filters does not significantly change contrast recognizability. Among several commercially available filters, best results where achieved using the amber filter. The use of the amber filter is recommended during BBG chromovitrectomy, as it allows a significant reduction in retinal light toxicity without compromising contrast recognizability.
Clinical Trial: :
http://www.clinicaltrials.gov ilm-amf2
Keywords: macula/fovea • vitreoretinal surgery