Trypan blue-assisted iris cyst excision

Abstract

Purpose

To describe a novel surgical technique using trypan blue assistance for iris cyst excision.

Methods

With viscoelastic in the anterior chamber, the cyst contents are aspirated with a 27G needle. Trypan blue is then injected into the residual cyst cavity to stain its walls. Forceps and anterior vitrectomy are utilized to ensure complete removal of the cyst wall with a safe margin of surrounding iris tissue.

Results

The trypan blue-assisted technique facilitates cyst visualization, enabling precise and complete cyst removal.

Conclusions

Trypan blue-assisted excision provides an effective approach for iris stromal cyst removal, minimizing recurrence risk and enhancing surgical precision.

1. Introduction

Secondary iris cysts are usually benign and typically arise in adults following surgical or nonsurgical ocular trauma.¹ Iris cysts can obstruct the visual axis, lead to lens subluxation, pigment dispersion and uveitis, or result in secondary glaucoma and corneal endothelial decompensation.²

Traditional management options for iris cysts include observation, en-bloc excision, surgical or Nd:YAG laser cystotomy, laser photocoagulation, and fine-needle aspiration with or without absolute alcohol irrigation.³ Many experts advocate a sequential approach in the management of iris cysts, prioritizing less invasive interventions before considering surgical removal when appropriate.^2,4

In this context, we present a refined surgical technique designed to enhance visualization and achieve complete removal of the cyst.

2. Surgical technique

After creating two corneal tunnels with a 1.1 mm MVR blade, cohesive viscoelastic (Healon GV, Johnson & Johnson Surgical Vision, Inc., USA) is injected into the anterior chamber. A blunt Rycroft cannula is then used to help the viscodissection of the iris cyst from the iris stroma, facing the iris plane (Fig. 1A). Subsequently, using a 27G needle connected to a 3-port system, the contents of the cyst are aspirated. Then, Trypan blue (Vision Blue, 0.06 %, DORC International) is injected into the residual cyst cavity through the same needle and left for 40 seconds to stain the inner and outer walls of the cyst (Fig. 1B), which will aid in their visualization and removal. Then, the dye is aspirated from the cyst cavity. Following this, after injecting cohesive viscoelastic in the anterior chamber, forceps and a 23-gauge vitrectomy system connected to a phacoemulsification machine (Centurion Vision System, Alcon Laboratories, USA) are used to completely remove the cyst (Fig. 1C). The viscoelastic material is aspirated from the anterior chamber using the irrigation/aspiration function of the vitrectomy system. The two corneal incisions are closed by wound hydration. The surgical procedure is shown in Video 1. Postoperative care includes topical therapy with antibiotic and corticoidsteroid drops. Pre- and postoperative slit-lamp and anterior segment OCT images of an eye which underwent Trypan blue-assisted iris cyst excision are shown in Fig. 2.

Video 1. A 27-gauge needle connected to a three-way port is inserted in the cyst cavity to inject Trypan blue. After 40 seconds of staining, the Trypan blue and the cysts contents are aspirated through the same needle. Viscoelastic is injected in the anterior chamber to viscodissect the iris wall from the corneal endothelium and iridocorneal angle. Microforceps are used to grasp the stained walls of the iris cysts and peel them off the iris surface. An anterior vitrectomy probe is used to cut and aspirate residual cyst wall material. Sutureless closure of the corneal wounds is performed with hydration.

Fig. 1.

A: Following viscodissection of the cyst from the iris plane using a blunt viscoelastic cannula, the cyst contents are aspirated using a 27G needle; B: Trypan blue solution is then injected into the remaining cyst cavity and allowed to stain the walls of the cyst for 40 seconds, then the dye is aspirated from the cyst. C: The cyst is then completely removed using forceps and a 23-gauge anterior vitrectomy. (For interpretation of the references to colour in this figure legend, the reader is referred to the Web version of this article.)

Fig. 2.

A. Anterior segment slit-lamp photo displaying a hazy inferonasal cornea covering approximately 40 % of its extent, caused by an iris cyst touching the corneal endothelium and partially involving the visual axis. B. Postoperative anterior segment slit-lamp photo of the same eye taken 7 days after Trypan blue-assisted excision of the iris cyst. The cornea appears clearer with no signs of surrounding anatomical structure damage. C. Anterior Segment OCT (AS-OCT) scan of the same eye before surgery, revealing the iris cyst wall touching the corneal endothelium and deforming the iridocorneal angle. D. AS-OCT scan of the same eye after surgery, showing a less edematous cornea with no signs of surrounding anatomical structure damage and a more physiological iridocorneal angle morphology. (For interpretation of the references to colour in this figure legend, the reader is referred to the Web version of this article.)

3. Discussion

Primary iris cysts are typically small, stable, and asymptomatic, whereas secondary iris cysts, resulting from the seeding of epithelial cells in the AC due to previous ocular trauma or surgery, may gradually enlarge, potentially leading to complications such as angle-closure glaucoma and corneal endothelial decompensation.²

Various treatment modalities have been proposed, including surgical iridectomy or injection of absolute alcohol into the cyst lumen.^1,3 However, the latter technique, involving alcohol-induced sclerosis, carries the risk of leakage or reflux into the surrounding anterior chamber structures, which can result in complications such as cataract formation, tissue necrosis, epithelial downgrowth, treatment-related glaucoma, corneal edema, posterior segment toxic effects, or even necessitate enucleation. Incidentally, the spillover of Trypan blue dye that can be visualized at the start of the surgical video of our technique also poses questions about the safety of intralesional injection of sclerosing agents, which like Trypan blue dye can easily extravasate through the thin walls of the cyst and spillover in the anterior chamber.

Laser treatments, including Nd:YAG, ab-interno and ab-externo diode, and argon photocoagulation, have been previously investigated for the treatment of iris cysts.² Unlike en-bloc cyst excision, laser treatments targeted at the cyst wall may offer tissue preservation and potentially require less surgical expertise but are associated with an increased risk of recurrence.⁴

Secondary iris cysts possess distinctive histological characteristics. The outer cyst wall comprises iris stromal fibers, melanocytes, and blood vessels, followed by one or two layers of epithelial cells, either pigmented or non-pigmented. Cysts are filled by a watery fluid, potentially containing suspended pigment or cellular debris.

Trypan blue 0.06 % serves as a vital stain with the ability to selectively identify dead tissues and cells or denuded membranes, while leaving viable cells untouched.⁵ This staining technique finds widespread application in ophthalmic surgeries, notably for cataract surgery, where it enhances visibility of the anterior lens capsule, and for Descemet membrane endothelial keratoplasty, to enable visualization of the endothelial graft. Inclusion cysts of the iris often result from the implantation of iris epithelium beneath the stroma due to injury or ocular surgery.² Trypan blue may be used to stain these cysts because it selectively dyes dead or damaged cells, a process facilitated by the compromised integrity of the cell membranes in the cystic wall.⁵ This allows the dye to penetrate and stain the cells, thereby highlighting areas of compromised cell integrity and aiding in the visualization of the cyst, facilitating the surgical removal process.

There remains potential for the development of alternative or improved dyes tailored specifically to enhance surgical guidance in such cases.

In addition, the adoption of Trypan Blue-assisted excision enables the attainment of minimal postoperative anterior chamber inflammation, thereby reducing the risk of damage to other intraocular structures and potentially further lowering the risk of cyst recurrence.

4. Conclusions

The utilization of the Trypan blue-assisted excision technique offers a secure and efficient technique for the removal of iris cysts. This method enables precise dissection and thorough excision of the cyst, consequently lowering the chances of recurrence and minimizing the risk of damaging other intraocular structures. Such a novel approach holds promise as a valuable addition to the range of surgical options for managing iris cysts.

CRediT authorship contribution statement

Alfredo Borgia: Writing – original draft, Methodology, Conceptualization. Matteo Airaldi: Writing – original draft, Methodology, Conceptualization. Francesco Semeraro: Writing – review & editing, Conceptualization. Sanjay V. Patel: Writing – review & editing, Conceptualization. Vito Romano: Writing – review & editing, Conceptualization.

Patient Consent

Consent to publish this case report has been obtained from the patient in writing.

Funding sources/financial disclosure

AB, MA, FS, VR: None related to the topic. SVP: Dr. Patel is a consultant to Santen Inc., Design Therapeutics, Inc., Iris Medicine, Inc., Invirsa, Inc., and Emmecell; Dr. Patel developed the V-FUCHS questionnaire, which Mayo Clinic licenses to Santen Inc., Design Therapeutics, Inc., Iris Medicine, Inc., Trefoil Therapeutics, Inc., and Kowa Research Institute. All are unrelated to the current topic.

Authorship

All authors attest that they meet the current ICMJE criteria for Authorship.

Funding

No funding or grant support.

Declaration of competing interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Appendix A. Supplementary data

The following is the supplementary data related to this article: