Ophthalmic Surgery, Lasers and Imaging Retina

Technique 

Optimizing Visualization of Membranes in Macular Surgery With Heads-Up Display

Alline G.R. Melo, MD; Thais F. Conti, MD; Grant L. Hom, BA; Tyler E. Greenlee, DO; Wener P. Cella, PhD; Katherine E. Talcott, MD; Aleksandra Rachitskaya, MD; Alex Yuan, PhD; Arjun Sood, MD; Ronald Milam, MD; Sruthi Arepalli, MD; Thomas Mendel, MD; Felipe P. Muralha, MD; Felipe Pereira, MD; Felipe F. Conti, MD; Marina R. Ciongoli, MD; Thaisa S. Barbosa, MD; Luciana L. Linhares, MD; Rishi P. Singh, MD

Abstract

BACKGROUND AND OBJECTIVE:

To determine which optical parameter profiles (OPPs) can be utilized to improve the visualization of epiretinal membranes (ERMs) and the internal limiting membrane (ILM) using a three-dimensional heads-up microscope during 25-gauge pars plana vitrectomy.

PATIENTS AND METHODS:

Fourteen independent graders were asked to complete a questionnaire comparing each of the OPPs against the unaltered control image for each given surgical case.

RESULTS:

Analysis of the graders' responses indicated that higher values of hue are correlated with better visualization of ERM/ILM before and after dye application. There was overall agreement that OPPs could be used to enhance the visualization of the ERM and ILM during surgery.

CONCLUSIONS:

The use of OPPs to improve the visualization of specific structures is still new and heavily dependent on surgeon preference. The authors' study shows that some OPPs may enhance the visualization of the ERM and ILM during macular surgery.

[Ophthalmic Surg Lasers Imaging Retina. 2020;51:584–587.]

Abstract

BACKGROUND AND OBJECTIVE:

To determine which optical parameter profiles (OPPs) can be utilized to improve the visualization of epiretinal membranes (ERMs) and the internal limiting membrane (ILM) using a three-dimensional heads-up microscope during 25-gauge pars plana vitrectomy.

PATIENTS AND METHODS:

Fourteen independent graders were asked to complete a questionnaire comparing each of the OPPs against the unaltered control image for each given surgical case.

RESULTS:

Analysis of the graders' responses indicated that higher values of hue are correlated with better visualization of ERM/ILM before and after dye application. There was overall agreement that OPPs could be used to enhance the visualization of the ERM and ILM during surgery.

CONCLUSIONS:

The use of OPPs to improve the visualization of specific structures is still new and heavily dependent on surgeon preference. The authors' study shows that some OPPs may enhance the visualization of the ERM and ILM during macular surgery.

[Ophthalmic Surg Lasers Imaging Retina. 2020;51:584–587.]

Introduction

Epiretinal membranes (ERMs) are fibrocellular proliferations that are often asymptomatic and idiopathic. When the vision is affected, pars plana vitrectomy (PPV) with peeling of the ERM is recommended.1 Currently, two platforms can be utilized for posterior pole visualization during surgery: traditional microscope (TM) and three-dimensional (3-D) heads-up display (3DM).2 Several studies highlight the differences between these platforms, describing advantages of the 3DM.3,4 One of these advantages is the ability to intraoperatively modify the digital image by manipulating parameters, which could improve ERM visualization and provide an alternative to the use of dyes that are commonly utilized to identify the ERM tissue. Unfortunately, there are no studies analyzing these settings, only anecdotal experiences that depend substantially on each individual user.

Technique

This observational, survey-based study evaluated preferred parameters among surgeons from multiple centers. Institutional review board approval was obtained to retrospectively evaluate videos of procedures from 10 eyes of 10 patients who were 18 years or older and underwent PPV for ERM between May and August 2019.

All surgical procedures were performed at Cole Eye Institute, Cleveland, Ohio by one surgeon (RPS) using the Constellation Vision System (Alcon Laboratories, Fort Worth, TX) and the 3-D heads-up display surgery platform, Ngenuity (Alcon Laboratories, Fort Worth, TX). Wide-angle fundus visualization was achieved using the panoramic OPMI LUMERA 700 (Carl Zeiss Meditec, Jena, Germany). A macular contact lens was used to visualize the macula during the peeling process. The resulting image was recorded with each optical parameter profile (OPP) applied before and after staining the macular surface with indocyanine green (ICG) vital dye (HUB Pharmaceuticals, Plymouth, MI). The concentration of ICG was done by mixing 1 cc of balanced salt solution in the ICG vial. Then, 9 cc of 5% dextrose is mixed with ICG mixture and injected in 0.1 cc aliquots to stain the internal limiting membrane (ILM) (Figure 1). It is important to note that ICG preferentially stains ILM over ERM creating a negative stain — an indirect way of visualizing ERM.

Intraoperative photographs of each unique optical parameter profile (OPP) during heads-up surgery. (A) Before use of indocyanine green (ICG) dye. (B) After use of ICG dye. (C) Values of the parameters used in each OPP.

Figure 1.

Intraoperative photographs of each unique optical parameter profile (OPP) during heads-up surgery. (A) Before use of indocyanine green (ICG) dye. (B) After use of ICG dye. (C) Values of the parameters used in each OPP.

Brightness, contrast, gamma, hue, and saturation were adjusted in each of the 11 OPPs created. On each OPP, one parameter was increased or decreased, whereas all other parameters were held constant when compared to the values used for profile 1, which represents the standard parameter settings provided out of the box from the manufacturer (Figure 1). White balancing as recommended by the manufacturer was performed in the beginning of each surgery.

Fourteen graders analyzed each recorded video and completed a questionnaire. Graders were asked to compare each of the 11 OPPs against the control image, using a Likert scale, and each profile was graded from 1–7 (1 being the worst and 7 the best). The average grades were calculated, and all graders answered four questions to assess their overall impression of OPPs (Figures 2 and 3). To compare the perception of image improvement between OPPs (defined as receiving a grade of 5 or better), Cochran's Q test was used for dichotomized perceptions to compare all grades considered worse (1 = much worse, 2 = worse, 3 = slightly worse, and 4 = same) versus grades considered better (5 = slightly better, 6 = better, and 7 = much better), and a P value less than .001 was considered statistically significant.

Average grade in each test before and after indocyanine green dye.

Figure 2.

Average grade in each test before and after indocyanine green dye.

(A, top left) Optical parameter profiles (OPPs) tested could improve the visualization of the epiretinal membrane before the dye application. (B, top right) OPPs tested could enhance indocyanine green (ICG) dye for the visualization of the inner limiting membrane (ILM). (C, bottom left) OPPs tested could replace ICG dye for the visualization of the ILM. (D, bottom right) If given the option, would you choose any of the OPPs for your surgeries?

Figure 3.

(A, top left) Optical parameter profiles (OPPs) tested could improve the visualization of the epiretinal membrane before the dye application. (B, top right) OPPs tested could enhance indocyanine green (ICG) dye for the visualization of the inner limiting membrane (ILM). (C, bottom left) OPPs tested could replace ICG dye for the visualization of the ILM. (D, bottom right) If given the option, would you choose any of the OPPs for your surgeries?

Discussion

Though the graders indicated an overall positive impression of the filters, they did not feel that the filters could replace the use of dyes. This is likely due to the proven efficacy and acceptance of the use of dyes for visualization and the general consensus that indocyanine dye related toxicity is not well-established.5 The uncertainty about the deleterious effects of ICG and the possibility of replacing or increasing the effect of ICG on the visualization of ILM is another advantage of using the OPP even though more studies need to be done. Our study compares the use of vital dye using different OPPs during heads-up vitrectomy and because of that, the results achieved may not be used for surgery performed under the traditional microscope. Drawbacks include the inherent subjective nature of grading of the images. Therefore, it is unlikely that one set of parameters will ever be sufficient for all surgeons. This is probably the reason that all OPPs received different grades from each grader, and none of the OPPs equally pleased all the graders. Despite this variation in grades, it was observed that the increase of hue (OPP 10), before and after ICG dye, received the best evaluations from the graders, suggesting that this parameter may be more involved in improving the ERM/ILM visualization. These changes in the optical parameters to improve visualization methods and the overall positive feedback of digital image manipulation provides a promising avenue for future research and development.5,6

References

  1. Baamonde S, de Moura J, Novo J, Charlón P, Ortega M. Automatic identification and characterization of the epiretinal membrane in OCT images. Biomed Opt Express. 2019;10(8):4018–4033. doi:10.1364/BOE.10.004018 [CrossRef] PMID:31452992
  2. Zhang T, Tang W, Xu G. Comparative Analysis of Three-Dimensional Heads-Up Vitrectomy and Traditional Microscopic Vitrectomy for Vitreoretinal Diseases. Curr Eye Res. 2019;44(10):1080–1086. doi:10.1080/02713683.2019.1612443 [CrossRef] PMID:31021174
  3. Talcott KE, Adam MK, Sioufi K, et al. Comparison of a Three-Dimensional Heads-Up Display Surgical Platform with a Standard Operating Microscope for Macular Surgery. Ophthalmol Retina. 2019;3(3):244–251. doi:10.1016/j.oret.2018.10.016 [CrossRef] PMID:31014702
  4. Charles S. Getting Specific About 3-D Visualization: An understanding of the features and benefits of this new technology is necessary to its successful implementation. Retina Today. 2017;November/December:48–49.
  5. Penha FM, Pons M, De Paula Fiod Costa E, et al. Effect of vital dyes on retinal pigmented epithelial cell viability and apoptosis: Implications for chromovitrectomy. Ophthalmologica. 2013;230Suppl 2 (0 2):41–50. doi:10.1159/000354251 [CrossRef] PMID:24022718
  6. Liu Z, Meyer CH, Fimmers R, Stanzel BVInternational Chromovitrectomy Collaboration. Indocyanine green concentrations used in chromovitrectomy cause a reversible functional alteration in the outer blood-retinal barrier. Acta Ophthalmol. 2014;92(2):e147–e155. doi:10.1111/aos.12247 [CrossRef] PMID:
Authors

From Center for Ophthalmic Bioinformatics, Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio (AGRM, TFC, TEG, KET, AR, RPS); Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio (KET, AR, AY, AS, RM, SA, TM, RPS); Case Western Reserve University School of Medicine, Cleveland, Ohio (GLH, RPS); Reference Hospital in Ophthalmology, HRO, São Luis, Maranhão, Brazil (AGRM, WPC); Federal University of São Paulo, São Paulo, Brazil (FPM, FP, FFC); University of São Paulo, São Paulo, Brazil (MRC, TSB); and Federal University of Góias, Goiânia, Brazil (LLL).

Dr. Singh has received personal fees from Genentech/Roche, Alcon/Novartis, Zeiss, Bausch + Lomb, Ophthea, and Regeneron Pharmaceuticals, as well as grants from Apellis and Graybug. The remaining authors report no relevant financial disclosures.

Dr. Singh did not participate in the editorial review of this manuscript.

Address correspondence to Rishi P. Singh, MD, Center for Ophthalmic Bioinformatics, Cole Eye Institute, Cleveland Clinic, 9500 Euclid Avenue, i-32, Cleveland, OH 44195; email: singhr@ccf.org.

Received: April 22, 2020
Accepted: July 09, 2020

10.3928/23258160-20201005-06

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