Chromovitrectomy: Update

The basic concept for the application of vital dyes during vitreoretinal surgery is to assist in highlighting preretinal membranes and tissues which are very thin and semitransparent and thus difficult to detect. The vital dyes may be classified according to different criteria, where the most commonly applied includes chemical classification. In ophthalmic surgery, vital dyes are widely used in cataract and vitreoretinal surgery. The vital dyes, indocyanine green, infracyanine green, and brilliant blue stain the internal limiting membrane, and trypan blue and triamcinolone acetonide help to visualize epiretinal membranes and vitreous, respectively. This review exhibits the current literature regarding the properties of vital dyes, techniques of application, indications, and toxicities during vitreoretinal surgery and, also suggests that the field of chromovitrectomy represents an expanding area of research.     

生物活性染色剂在白色白内障撕囊术中的应用

目的 评价生物活性染色剂在白色白内障超声乳化手术中显现晶状体前囊的可行性和安全性等。方法 55例白色白内障随机编人台盼蓝和吲哚青绿前囊染色组。采用气泡下染色技术完成连续环形撕囊。结果 台盼蓝和吲哚青绿均可充分着染前囊。染色辅助撕囊的总成功率为98．2％。吲哚青绿组和台盼蓝组分别为96．7％、100％。尚未观察到术后染色剂残存于眼组织或人工晶状体异色。术后矫正视力0．5～1．2。结论 生物活性染色剂可显著提高白色白内障超声乳化手术的安全性。     

Does the use of trypan blue during phacoemulsification affect the intraocular pressure?

Objective: The purpose of the study was to evaluate the effect of trypan blue on intraocular pressure (IOP) after small-incision cataract surgery.Design: Prospective, randomized study.Participants: Fifteen patients (30 eyes) with bilateral, dense, age-related cataracts.Methods: Patients with glaucoma, ocular hypertension, exfoliation, pigment dispersion syndrome, history of uveitis, recent use of topical or systemic steroids, and previous ocular surgery were excluded. The patients were randomly assigned to receive trypan blue during cataract surgery for enhancing capsulorrhexis in 1 of their eyes, while in the other eye, trypan blue was not used. Cataract surgery was performed in an identical fashion in both eyes, with a sutureless posterior limbal incision, phacoemulsification, and implantation of a foldable intraocular lens. The same viscoelastic (sodium hyaluronate) was used in all cases and was thoroughly aspirated at the end of the procedure. All patients received a single dose of 250 mg acetazolamide 8 hours after surgery. No other antiglaucomatous agent was used during surgery or postoperatively. The intraocular pressure (IOP) was measured preoperatively and at 24 hours, 1 week, 1 month, and 3 months postoperatively.Results: IOP values were similar in both groups at all 4 postoperative measurements. There was no statistically significant difference in postoperative IOP values between the eyes in which trypan blue was used and the control eyes.Conclusions: The use of trypan blue during small-incision cataract surgery does not have any effect on IOP during the immediate and early postoperative period.     

The use of vital dyes in corneal disease

Vital dyes such as fluorescein, rose bengal, and lissamine green B, among others, have been an important tool in clinical ophthalmology in diagnosis and evaluation of various ocular surface disorders. Each dye, having a unique chemical structure, has distinct characteristics that allows its preferential use in different ocular pathologies. In this article, history of vital dyes and the use of popular current vital dyes in corneal disease are reviewed.     

Vital dyes for chromovitrectomy

PURPOSE OF REVIEW: The aim of this article is to present the current state-of-the-art in regard to the application of vital dyes during vitreoretinal surgery, 'chromovitrectomy', as well as to overview the current literature regarding the properties of dyes, techniques of application, indications, and complications in chromovitrectomy. RECENT FINDINGS: A large body of published research has recently addressed the toxicity profile of indocyanine green for chromovitrectomy. Experimental data demonstrate dose-dependent toxicity of indocyanine green to various retinal cells. Newer generation vital dyes for chromovitrectomy include trypan blue, patent blue, triamcinolone acetonide, infracyanine green, sodium fluorescein, bromophenol blue, fluorometholone acetate and brilliant blue. Novel instruments may enable a selective painting of preretinal tissues during chromovitrectomy. SUMMARY: This review suggests that the field of chromovitrectomy represents an expanding area of research. The first line agents for internal limiting membrane staining in chromovitrectomy are indocyanine green, infracyanine green, and brilliant blue. Patent blue, bromophenol blue and trypan blue arose as outstanding biostains for visualization of epiretinal membranes. Novel dyes available for chromovitrectomy deserve further investigation.     

Biokompatibilität von Farbstoffen für die vitreoretinale Chirurgie

For the last 8 years vital dyes have been used to visualize preretinal semitransparent structures in the eye during vitroretinal surgery. However, indocyanine green (ICG), which was the first commonly used dye, proved to be partly toxic to retinal cells and the retinal pigment epithelium in various in vitro and in vivo studies. Therefore, an intensive search for new and safer dyes was started. At present three dyes, trypan blue, patent blue and brilliant blue are predominantly used for vitreoretinal surgery, in addition to ICG. In this article an overview of preclinical biocompatibility studies for common vital dyes is presented. Additionally, a systematic approach for testing of new candidate dyes for vitreoretinal surgery will be proposed.     

Staining the Anterior Capsule with Indocyanine Green or Trypan Blue for Capsulorhexis in Eyes with White Cataract

Aim: To assess the efficacy and safety of indocyanine green (ICG) 0.5% and trypan blue 0.1% for anterior capsule staining in cases of white cataract. Methods: This prospective study comprised 55 eyes of 55 patients with white cataract that had phacoemulsification with foldable intraocular lens implantation. ICG in 30 eyes and trypan blue in 25 eyes were used under air to stain the anterior lens capsule. The staining patterns and the ease of creating a continuous curvilinear capsulorhexis (CCC) were assessed; the intraoperative and postoperative complications were noted. The mean follow-up was 17.68±1.65 months. Result: Either ICG or trypan blue stained the anterior capsule uniformly. However, the staining provided by trypan blue was slightly superior. A CCC was successfully achieved in 25 eyes (100%) with trypan blue, and 29 eyes (96.7%) with ICG, respectively. There was no significant postoperative reaction in any eye. Conclusion: The use of vital dyes such as ICG and trypan blue guarantees a complete CCC and makes it possible to deliver the benefits of phacoemulsification in the patients with white cataract.     

Traumatic cataract surgery assisted by trypan blue.

The advantages of trypan blue use in anterior segment surgery have been well recognized, but few reports of its use in traumatic cataract surgery have been published. The authors describe three cases of traumatic cataract in which the role of trypan blue in performing safe and successful cataract surgery is demonstrated. Selective staining of the anterior lens capsule using trypan blue enabled the surgeon to identify the extent of structural damage and plan the surgery accordingly. In all three cases, the cataract was removed and the intraocular lens was implanted successfully without complications. Trypan blue is a safe and helpful aid in traumatic cataract surgery.     

白内障手术中苔盼蓝晶状体囊染色的作用及安全性

目的观察苔盼蓝作晶状体囊染色在超声乳化术中应用的有效性和安全性。方法回顾分析使用晶状体苔盼蓝染色剂Vision Bule前后两个时期的晶状体全浑浊的白内障手术186例（212眼）。其中96例（118眼）使用了染色剂。对术中操作和术后效果进行了对比。结果晶状体囊苔盼蓝染色剂Vision Blue对晶状体前囊有较好的染色效果,可使手术操作变得安全易行,术中术后无不良反应。结论晶状体囊染色剂Vision Blue在超声乳化术中对晶状体前囊染色的应用是有效的和安全的。     

Brilliant blue G-assisted peeling of the internal limiting membrane in macular hole surgery

Dye-assisted internal limiting membrane (ILM) peeling and gas tamponade is the surgery of choice for idiopathic macular holes. Indocyanine green and trypan blue have been extensively used to stain the ILM. However, the retinal toxicity of indocyanine green and non-uniform staining with trypan blue has necessitated development of newer vital dyes. Brilliant blue G has recently been introduced as one such dye with adequate ILM staining and no reported retinal toxicity. We performed a 23-gauge pars plana vitrectomy with brilliant blue G-assisted ILM peeling in six patients with idiopathic macular holes, to assess the staining characteristics and short-term adverse effects of this dye. Adequate staining assisted in the complete removal of ILM and closure of macular holes in all cases. There was no evidence of intraoperative or postoperative dye-related toxicity. Brilliant blue G appears to be safe dye for ILM staining in macular hole surgery.     

染色剂在玻璃体视网膜手术中的应用

玻璃体手术联合视网膜前膜（epiretinal membrane,ERM）、内界膜（internal limiting membrane,ILM）剥除术,是黄斑区相关手术中普遍使用的主流术式.近年来新兴的生物染色剂辅助下ERM/ILM剥除术可降低手术相关操作的难度和风险.目前应用较多的ERM/ILM染色剂有吲哚青绿、台盼蓝、亮蓝、曲安奈德等几种.但所有生物染色剂都对视网膜存在潜在的毒性和副作用,同时,某些染色剂对ILM/ERM的染色也不尽人意.     

Inadvertent corneal stromal staining by trypan blue during cataract surgery

We report a case in which the corneal stroma was inadvertently stained with trypan blue during cataract surgery.     

Results of surgery on white cataract using trypan blue capsule staining to visualize capsulorrhexis

PURPOSE: To evaluate surgery on white cataracts using trypan blue capsule staining. METHODS: A retrospective study comprised 64 eyes of 60 patients with white cataract that had surgery with trypan blue capsule staining. The average age was 62.4 years and progress observation periods were 5.6 months. The rate of successful continuous curvilinear capsulorrhexis(CCC), complications, visual acuity, intraocular pressure(IOP), flare value, and corneal endothelial cell loss were studied. RESULTS: The CCC was completed uneventfully in 93.8% eyes. Posterior capsule rupture occurred in 2 eyes, and early perforation in 1 eye. Accidental vitreous staining and endothelial staining with trypan blue were observed in 1 eye each. There were no postoperative complications associated with trypan blue. Forty-five eyes had a best corrected visual acuity of 0.8 or better at the last visit. Twelve eyes had some ocular pathology resulting in visual loss, and a reliable visual acuity test could not be performed in 6 eyes. The mean postoperative IOP was within the normal range. The mean postoperative flare returned to within normal range 1 month after surgery. The mean corneal endothelial loss was 13.7%, and that of eyes with nucleus of grade 2 or softer was only 2.9%. CONCLUSIONS: Cataract surgery using trypan blue was safe and effective in managing white cataracts.     

Time course of lens capsule staining using trypan blue and indocyanine green: in vitro study in porcine eyes

PURPOSE: To determine whether staining of the lens capsule with trypan blue 0.1% and indocyanine green (ICG) 0.5% diminishes with time and whether it differs between the anterior and posterior capsules. SETTING: Department of Ophthalmology, Keio University School of Medicine, Tokyo, Japan. METHODS: Crystalline lenses removed from porcine eyes were stained for 10 seconds with 0.1 mL of trypan blue 0.1% or indocyanine green 0.5%. They were then placed in distilled water and observed for the persistence of staining over time. In a second experiment, the anterior chamber and internal aspects of the anterior capsule and internal and vitreous aspects of the posterior capsule were gently irrigated with 0.1 mL of trypan blue 0.1% or ICG 0.5%. After 10 seconds, the capsules were irrigated with distilled water and the staining intensities were compared. RESULTS: Staining was not diminished 30 seconds, 5 minutes, or 1 hour after application of either dye. No difference was evident in staining intensity or diminution with time between the anterior and posterior capsules, but the external aspects were stained more than the internal aspects with both dyes. Trypan blue produced more intense staining than ICG. CONCLUSIONS: Since the intensity of capsule staining in the intact lens did not change during a 1-hour immersion in water, capsule dyes may not dissipate fully during cataract surgery. As possible long-term adverse effects have not been ruled out, capsule dyes should be used in a low concentration for a short exposure time.     

Färbetechniken in der Makulachirurgie

Over recent years, evolving surgical experience and the development of techniques in surgery for macular hole, macular pucker and other vitreoretinal diseases have improved anatomic and functional success rates. Today, there is common agreement by many surgeons that removal of the internal limiting membrane (ILM) is an effective and safe treatment option for conditions that involve the vitreoretinal interface.However, the ILM is a delicate and barely visible structure and its removal represents a challenge to the vitreoretinal surgeon. The introduction of vital dyes for ILM staining has led to better visibility of the ILM and epiretinal membranes, potentially making ILM peeling more controllable, easier and safer. It has opened the door, especially for the less experienced surgeon, to follow the principle of ILM removal in macular surgery. While the use of trypan blue and triamcinolone during such surgery seems to be safe, questions of the potential toxicity of indocyanine green (ICG) are currently being discussed. However, the underlying pathomechanisms are not yet completely understood. Whether the observations made on ICG-related toxicity will be sufficient to call ICG a "toxic adjunct" is currently under investigation. Further studies are required to better understand the safety margins of ICG and to investigate other vital dyes offering equal staining characteristics and a better safety profile.     

台盼蓝在全白或过熟期白内障手术连续环形撕囊前的应用观察

目的:探讨台盼蓝在全白或过熟期白内障手术连续环形撕囊前的应用观察.方法:选取近3a在我院眼科住院手术的全白或过熟期白内障患者42例42眼,术中均于前房内注入0.6mg/mL台盼蓝约0.2mL,使前囊膜着色成淡淡的蓝色,后进行连续环形撕囊.记录术前,术后1wk,1mo不同时段角膜内皮细胞密度及角膜内皮六角形细胞比例,并对其进行重复测定方差分析.结果:台盼蓝染色后,所有术眼均顺利完成连续环形撕囊,为下一步手术鉴定了成功的基础.术前,术后lwk,1 mo不同时段记录的角膜内皮细胞密度和角膜内皮六角形细胞比例差异无统计学意义.结论:对于过熟期及全白等难度较大的白内障手术,用台盼蓝染色前囊膜后,连续环形撕囊更易行、更安全.     

Staining characteristics of preserved human amniotic membrane

PURPOSE: Amniotic membrane is an ultra-thin cellophane-like membrane that is used in ocular surface reconstruction. We evaluated the staining characteristics of commonly available dyes on preserved human amniotic membrane to aid in handling of amniotic membrane during transplantation. METHODS: Five dyes, indocyanine green (2.5%, 1.0%, and 0.5%), fluorescein (0.25%), rose bengal (1%), lissamine green B (1%), and trypan blue (0.5%), were used to stain amniotic membrane. After staining, the specimens were observed under a dissecting microscope to evaluate for the uptake of the stains. Positively stained membranes were evaluated for the persistence of staining by placing them in 2 to 3 mL of balanced saline solution that was changed every 30 minutes over 6 hours. RESULTS: Preserved human amniotic membrane is stained by indocyanine green, rose bengal, lissamine green B, and trypan blue. Of these four dyes, only the membrane stained with 1% lissamine green B was free of stain after 120 minutes. Indocyanine green, rose bengal, and trypan blue continued to strongly stain the membrane after 24 hours. CONCLUSIONS: Indocyanine green, rose bengal, trypan blue, and lissamine green B all stain amniotic membrane. Lissamine green B appears to have advantages over the other dyes in that it will stain the membrane well, and in our model, dissipate in 120 minutes. Intraoperative staining with lissamine green B may be a simple and effective way to assist surgeons in the proper handling of amniotic membrane.     

Unintentional staining of the posterior lens capsule with trypan blue dye during phacoemulsification: case report

We report a complication related to the use of trypan blue during capsular staining of the anterior lens capsule during phacoemulsification surgery. In phacoemulsification surgery of the left eye, trypan blue was injected using an air bubble technique. Unintentionally, trypan blue was administered under high pressure, dispersing the dye through the zonules leading to staining of the posterior capsule. This caused a temporary disturbance of visual acuity during the postoperative period.     

Evaluation of the safety of anterior capsule staining with trypan blue under air: a retrospective analysis

AIM: To evaluate the safety of using 0.03% trypan blue under air for anterior capsule staining in cataract surgery. METHODS: The current study involved a retrospective analysis of the medical records of 86 patients with vitreous hemorrhage, who underwent pars plana vitrectomy and cataract surgery. The patients were classified into two groups. The trypan blue group (n=45) comprised patients who underwent anterior capsule staining with 0.03% trypan blue under an air bubble. The control group (n=41) comprised of patients who underwent intracameral illuminator-assisted capsulorhexis. The status of endothelial cell density (ECD) in both the groups was analyzed. RESULTS: The trypan blue group displayed significant decline in ECD at 1mo (7.91% loss, P<0.001) and 3mo (9.65% loss, P<0.001) after the surgery, whereas no significant changes were observed in the control group. Moreover, the number of patients who did not display a postoperative decline in ECD was significantly higher in the control group (43.9%; 18 patients) than in the trypan blue group (17.1%; 7 patients, P=0.004). CONCLUSION: Anterior capsule staining with trypan blue under the air bubble would not be as safe as the intracameral illuminator. The ECD loss might be attributed to the air bubble rather than to the deleterious effects of 0.03% trypan blue. Further studies are required to clarify this.     

Anterior and posterior capsulorhexis in pediatric cataract surgery with or without trypan blue dye: randomized prospective clinical study

PURPOSE: To evaluate the clinical efficacy of trypan blue 0.1% dye (Blurhex) in creating a complete anterior and posterior capsulorhexis during pediatric cataract surgery. SETTING: Tertiary eyecare center, Postgraduate Institute of Medical Education and Research, Chandigarh, India. METHODS: In a prospective randomized study, an anterior (ACCC) and posterior (PCCC) continuous curvilinear capsulorhexis were performed in pediatric patients. In Group 1 (n = 19), the ACCC and PCCC were created without use of trypan blue dye. In Group 2 (n = 23), intracameral trypan blue dye was used to stain the anterior and posterior capsules. RESULTS: In Group 1, 14 eyes (73.6%) had a complete ACCC and 10 (52.6%) had a complete PCCC. In Group 2, 21 eyes (91.3%) had a complete ACCC and 19 (82.6%) had a complete PCCC. CONCLUSION: In cases of pediatric cataract, staining the anterior and posterior capsules with trypan blue 0.1% allowed recognition of capsule flaps and facilitated the creation of complete ACCCs and PCCCs.