Indocyanine Green Staining Research Articles

LONG-TERM EFFECTS OF VITRECTOMY AND INTERNAL LIMITING MEMBRANE PEELING FOR MACULAR EDEMA SECONDARY TO CENTRAL RETINAL VEIN OCCLUSION AND HEMIRETINAL VEIN OCCLUSION

The purpose of this study was to evaluate the long-term effects of vitrectomy and internal limiting membrane peeling for macular edema secondary to central retinal vein occlusion (CRVO) and hemiretinal vein occlusion (HRVO). Best-corrected visual acuity, central foveal thickness by optical coherence tomography, and fluorescein angiography were evaluated retrospectively in 20 patients (20 eyes). The mean follow-up time was 61.2 months. Pars plana vitrectomy and internal limiting membrane peeling using indocyanine green staining were performed in all patients. Preoperative mean central foveal thickness of all 20 eyes decreased significantly by 6 months, and this reduction was maintained until 60 months. The mean central foveal thickness of the group with perfused type CRVO, ischemic type CRVO, and HRVO at 6 months significantly decreased from the preoperative value, and the significant reduction was maintained until 60 months. Best-corrected visual acuity of the perfused CRVO and HRVO groups tended to improve in contrast to the ischemic CRVO group postoperatively. Best-corrected visual acuity of the perfused CRVO group at 24 months or later was significantly improved from preoperative best-corrected visual acuity. Pars plana vitrectomy with internal limiting membrane peeling in eyes with macular edema secondary to CRVO and HRVO produces an anatomical improvement, which persists up to 5 years, and a best-corrected visual acuity improvement, at least in perfused CRVO and HRVO.

Value of internal limiting membrane peeling in surgery for idiopathic macular hole and the correlation between function and retinal morphology

Idiopathic macular hole is characterized by a full thickness anatomic defect in the foveal retina leading to loss of central vision, metamorphopsia and a central scotoma. Classic macular hole surgery consists of vitrectomy, posterior vitreous cortex separation and intraocular gas tamponade, but during the past decade focus has especially been on internal limiting membrane (ILM) peeling as adjuvant therapy for increasing closure rates. With increasing use of ILM peeling and indocyanine green (ICG) staining, which is used for specific visualization of the ILM, concerns about the safety of the procedure have arisen. At present, it is not known whether ICG-assisted ILM peeling potentially reduces the functional outcome after macular hole surgery. The purpose of the present PhD thesis was to examine whether ICG-assisted ILM peeling offers surgical and functional benefit in macular hole surgery. We conducted a randomized clinical trial including 78 pseudophakic patients with idiopathic macular hole stages 2 and 3. Patients were randomly assigned to macular hole surgery consisting of (i) vitrectomy alone without instrumental retinal surface contact (non-peeling), (ii) vitrectomy plus 0.05% isotonic ICG-assisted ILM peeling or (iii) vitrectomy plus 0.15% trypan blue (TB)-assisted ILM peeling. Morphologic and functional outcomes were assessed 3, 6 and 12 months after surgery. The results show that surgery with ILM peeling, for both stages 2 and 3 macular holes, is associated with a significantly higher closure rate than surgery without ILM peeling (95% versus 45%). The overall functional results confirm that surgery for macular hole generally leads to favourable visual results, with two-thirds of eyes regaining reading vision (>or=20/40). Macular hole surgery can be considered a safe procedure with a low incidence of sight-threatening adverse events; the retinal detachment rate was 2.2%. Visual outcomes in eyes with primary hole closure were not significantly different between the intervention groups; however, for the stage 2 subgroup with primary macular hole closure, there was a trend towards a better mean visual acuity in the non-peeling group (78.2 letters) compared to the ICG-peeling group (70.9 letters), p = 0.06. Performing repeated macular hole surgery was associated with a significant reduction in functional outcome indicating that primary focus should be on closing the macular hole in one procedure. Morphological studies of closed macular holes with contrast-enhanced optical coherence tomography (OCT) found thinning and discontinuity of the central photoreceptor layer matrix that were highly specific for predicting the likelihood of an eye having regained reading vision 12 months after macular hole surgery. Additionally, healing after macular hole surgery appeared to begin with the contraction of the inner aspect of the retina, forming a roof over a subfoveal fluid-filled cavity, and to end with a gradual restoration of the anatomy in the outer layers of the retina at the junction of the photoreceptor inner and outer segments. We found the more intact this structure was on contrast-enhanced OCT 3 months after macular hole surgery, the better the visual acuity after 12 months, whereas late rather than early resolution of subfoveal fluid had no impact on final visual outcome. The use ILM peeling and intraoperative dyes did not have any functionally important effects on postoperative macular structure. Based on the above findings, we conclude that ILM peeling should be performed in all cases of full thickness macular hole surgery. The use of 0.05% intraoperative isotonic ICG with short exposure time appears to be a safe alternative in stage 3 macular hole surgery, whereas a slight reduction in functional potential not can be excluded when performing 0.05% isotonic ICG-assisted ILM peeling in stage 2 macular hole surgery.

FUNCTIONAL OUTCOME OF INDOCYANINE GREEN-ASSISTED MACULAR SURGERY

To evaluate the long-term functional results after surgery for macular pucker and macular holes with indocyanine green (ICG) staining of the internal limiting membrane. Long-term functional and anatomical outcomes of 16 eyes of 16 patients were evaluated for 7.3 years after ICG-assisted macular surgery. Examinations performed included best-corrected visual acuity, Goldmann perimetry, Arden color contrast test, optical coherence tomography, and fundus photography. Ten eyes had undergone surgery for macular holes, and 6 eyes had been treated for macular pucker. Indocyanine green with a concentration of 0.05% and an osmolarity of 275 mOsm had been used to stain the internal limiting membrane. Mean follow-up time was 7.3 years. Eighty-eight percent (14) of the eyes had undergone cataract surgery either in a combined intervention primarily (n = 3) or in the years after the ICG-assisted macular surgery (n = 11). One patient was still phakic with a pronounced cataract at last follow-up. Over all patients, best-corrected visual acuity did not increase significantly from 20/200 (median) before macular surgery to the present 20/70 (median). Large visual field defects (VFDs) were found in 10 of 16 patients after internal limiting membrane staining using ICG. In 8 of these 10 eyes, the VFDs had been diagnosed immediately after vitrectomy and remained unchanged throughout the period of review. In 2 eyes, a VFD was noted at the last follow-up visit despite an unremarkable Goldmann perimetry performed at follow-up visits after 3 months and 6 months. Pathologic color testing was found in 15 of 16 patients when comparing the operated and the fellow eye. A nonglaucomatous optic nerve atrophy was found in 11 of 16 eyes. The optical coherence tomography revealed macular hole closure in all 10 patients. Indocyanine green-assisted macular surgery might lead to optic nerve atrophy in the long-term and persistent VFDs. In addition, new VFDs may occur in the postoperative course. An affection of color vision also underlines the potential impact of ICG on visual function. A long-term observation of patients after ICG-assisted vitrectomy seems mandatory to reliably detect functional adverse events.

READING ABILITY AND RETINAL SENSITIVITY AFTER SURGERY FOR MACULAR HOLE AND MACULAR PUCKER

To assess whether reading ability and microperimetry improve as demonstrated for visual acuity after surgery for macular hole and macular pucker. Fifty-nine consecutive patients underwent pars plana vitrectomy for macular pucker (n = 41) or full-thickness macular holes (n = 18). Functional assessment was made at 3, 6, and 12 months after surgery and included far visual acuity (Early Treatment Diabetic Retinopathy Study charts), retinal sensitivity using the microperimeter (MP1, Nidek Technologies, Padova, Italy), and reading ability (MNRead charts). An improvement was recorded both for macular holes and puckers not only for visual acuity, but also for reading acuity and mean central retinal sensitivity (P < 0.01 for the overall comparisons between baseline and follow-up values). Maximum reading speed was already good at baseline both for puckers and holes overall, and a significant mean improvement was recorded only in patients with macular hole at 6 and 12 months (P < 0.01). Although eyes with macular holes had worse baseline visual function compared with puckers (P < 0.01 for all measures of visual function except for reading speed), they recovered to similar levels thanks to greater improvement (P < 0.05 for the difference in improvement during follow-up between puckers and holes for all measures of visual function). No differences were found among indocyanine green or trypan blue staining compared with no staining for internal limiting membrane removal based on all outcome measures (P > 0.05 for the overall difference of visual function improvement during follow-up). The improvement found for visual acuity after vitrectomy for macular hole and pucker also regards retinal sensitivity and reading ability for up to 12 months. This is reassuring concerning the benefits for the patients, and this shows that visual acuity is a valid functional measure for investigating the efficacy of macular surgery.

Macular morphology and visual acuity after macular hole surgery with or without internal limiting membrane peeling

Aim:To examine postoperative macular morphology and visual outcome after 12 months in relation to internal limiting membrane (ILM) peeling versus no peeling, indocyanine green (ICG) staining and re-operation in eyes...

The Use of Vital Dyes in Ocular Surgery

Vital dyes have advanced diagnosis and surgical technique in various specialties, including oncology, gastroenterology, and ophthalmology. In ocular surgery vital dyes are widely used in cataract and vitreoretinal surgery. Worldwide, intra-operative use of trypan blue during cataract surgery has enhanced visualization of the anterior capsule during capsulorrhexis, and patent blue has been recently licensed in Europe for cataract surgery. For chromovitrectomy, the vital dyes indocyanine green, infracyanine green, and brilliant blue stain the internal limiting membrane, and trypan blue and triamcinolone acetonide help visualize epiretinal membranes and vitreous, respectively. Intra-operative vital dyes are finding uses in corneal, glaucoma, orbit, strabismus, and conjunctival surgery. We provide a summary of current knowledge of the use of vital dyes in ocular surgery. We review the properties of dyes, techniques of application, indications, and complications in ocular surgery. Vital dyes represent an expanding area of research, and novel dyes deserve further investigation.

Double Staining with Brilliant Blue G and Double Peeling for Epiretinal Membranes

To compare methods of removing epiretinal membranes (ERM) and evaluate the usefulness of the double brilliant blue G (BBG) staining and double-peeling method. Prospective, interventional case series. We followed 246 consecutive patients who underwent pars plana vitrectomy to remove ERM and for > or =12 months. Of the 246 eyes, 104 underwent single ERM peeling using indocyanine green staining, and 142 underwent ERM peeling by 1 of the 3 following methods: without staining in 46 eyes, triamcinolone acetonide staining in 42, and BBG staining in 54. Peeling of residual internal limiting membrane (ILM) was then conducted using BBG. In the latter group, the ILM that remained after the initial peeling procedure was evaluated macroscopically with BBG staining and also histopathologically. In 6 eyes requiring reoperation owing to ERM recurrence, the peeled ERM was examined histopathologically. Postoperative visual acuity and recurrence of ERM. The ERM recurrence rate was 16.3% (17 eyes) and the reoperation rate was 5.8% (6 eyes) among the 104 eyes that underwent single ERM peeling, compared with 0% in 142 eyes with double ERM and ILM peeling. Although the ERM recurrence rate was significantly lower with double peeling, postoperative visual acuity did not differ between the 2 methods. The 3 ERM peeling methods differed in the rate and extent of residual ILM, and the lowest rate (21/54 eyes; 39%) was achieved with BBG staining (P<0.0001). Histopathologic examination of the ILM remaining after ERM peeling detected remnant ERM cells on the ILM. Histopathologic examination of the peeled ERM in 6 eyes with ERM recurrence showed residual ILM to serve as a scaffold for cell proliferation. This study verified that ERM recurrence arises from remnant ERM components on the ILM, which proliferate using the ILM as a scaffold, and that complete ILM removal seems to reduce the risk of recurrence. Brilliant blue G with good affinity for the ILM facilitates simultaneous ERM and ILM peeling in many cases, and BBG contact with the retina in the second staining has no apparent effect on visual acuity. Double BBG staining and double peeling is useful for ERM treatment.

VITAL DYES FOR MACULAR SURGERY

To analyze and compare the ultrastructure of the retinal cleavage plane of the internal limiting membrane (ILM) removed during dye-assisted macular surgery. Ninety-six surgical specimens of the ILM obtained during trypan blue (TB)-, brilliant blue G (BBG)-, bromphenol blue (BPB)-, Chicago blue (CB)-, and indocyanine green-assisted pars plana vitrectomy for idiopathic macular hole and macular pucker were evaluated using transmission electron microscopy. Specimens removed without dye assistance served as controls. Specimens removed after TB-, BBG-, BPB-, and CB-staining presented with significantly less cellular fragments (in size and quantity) at the retinal side of the ILM than specimens after indocyanine green staining. Large cellular fragments and Müller cell endfeet, which were typically present after indocyanine green staining, were not found after TB, BBG, BPB, and CB staining. Comparing all groups, TB was found with less retinal debris than BBG, BPB, and CB. Specimens removed without intravitreal dye administration showed the least retinal fragments that were solitarily distributed at the ILM. Trypan blue, BBG, BPB, and CB cause significantly less morphologic changes at the retinal cleavage plane than indocyanine green. Further studies are required to elucidate if presence and amount of retinal cell fragments at ILM specimens correlate with functional deficits.

Entoptic Phenomenon Following Pars Plana Vitrectomy Caused by Retained Preretinal Gel

A patient who underwent pars plana vitrectomy for vitreous floaters is described. At the time of surgery, the posterior hyaloid was avulsed and stripped from the posterior retinal surface. Postoperatively, the patient described filamentous and "sea-fan" entoptic phenomena scattered throughout the periaxial vision that were in focus, attached, and "waving" with movement that was counter to the direction of gaze pursuit and demonstrated after movement. The authors believe these structures represent vitreous gel retained at the retinal surface, even though the structures could not be demonstrated by optical coherence tomography or indocyanine green staining at later vitrectomy surgery. This case should raise caution when considering vitrectomy surgery that requires posterior hyaloid stripping in patients with good vision.

Comparison of Macular Hole Surgery without Internal Limiting Membrane Peeling to Eyes with Internal Limiting Membrane Peeling with and without Indocyanine Green Staining

Background: To compare the long-term anatomical closure rates and visual acuity after vitrectomy for macular hole (MH) surgery with and without internal limiting membrane (ILM) peeling and with and without indocyanine green (ICG) staining. Methods: A total of 75 eyes of 71 patients with MH that had undergone vitrectomy were retrospectively studied. Group A consisted of 21 eyes that had vitrectomy without ILM peeling, Group B consisted of 38 eyes that had vitrectomy with ILM peeling without the ICG staining, and Group C consisted of 16 eyes that had vitrectomy with ILM peeling with ICG staining. The main outcome measures were the anatomical closure rates and visual acuities at 1, 2, and 3 years after surgery. Results: MH were closed in all 75 eyes after the initial surgery. The visual acuity improved significantly (p < 0.0005) at 1 year after surgery and did not change significantly at 2 and 3 years after surgery in the 3 groups. Differences in the mean visual acuity in the 3 groups were not significant at 1, 2, and 3 years after surgery. Conclusions: These results suggest that ILM peeling or the use of ICG dye do not significantly affect the MH closure rates and the long-term visual acuities.

Surgical usefulness of indocyanine green as an alternative to India ink for endoscopic marking

India ink has been commonly used for preoperative colonic tattooing, but various complications have been reported. This study aimed to evaluate the usefulness of indocyanine green (ICG) marking as a replacement for India ink. This study enrolled 40 patients who between January 2005 and February 2006 underwent laparoscopic or open surgery for colorectal lesions considered difficult to locate intraoperatively. Because one patient had a history of allergy to iodinated contrast material, metal clipping was used instead of ICG to mark the lesion. Endoscopists injected 5 ml of ICG suspension and saline solution adjacent to the lesion at duplicate locations to evaluate the visibility, duration, and adverse effects of the dye. For 39 patients, the date of the preoperative colonoscopy was not set for examination of the appropriate interval between endoscopic marking and the surgical operation. The median interval between ICG marking and surgery was 4 days (range, 1-73 days). All 29 patients who underwent surgery within 8 days after marking had positive green ICG staining at the time of surgery. After 9 days or more, however, positive staining was seen clearly in only two of the remaining 10 patients. The staining tended to grow weaker and fainter over the time course, eventually dissipating. No perioperative adverse reactions to the dye were observed. This study supports the use of ICG as a safe technique that can be identified reliably during operations performed within 8 days after endoscopic injection.

Meta-Analysis of Chromovitrectomy with Indocyanine Green in Macular Hole Surgery

Purpose: To report a meta-analysis of the literature comparing internal limiting membrane (ILM) peeling with and without indocyanine green (ICG) staining in macular hole (MH) treatment. Methods: A Pubmed search was conducted from January 1999 to June 2004. Manuscripts describing the anatomical and functional outcomes of vitrectomy plus ILM peeling with and without ICG application in MH surgery were reviewed. A statistical meta-analysis was performed including studies which defined anatomical outcomes as closure of the MH and disappearance of the fluid cuff and functional outcomes as improvement of 2 or more Snellen lines. A secondary outcome was to investigate the incidence of retinal pigment epithelium (RPE) alterations with and without ICG staining in MH surgery. Results: Results including all types of MHs in 837 eyes indicated the same anatomical success but worse functional outcomes in the group with ICG application (p = 0.0008; odds ratio = 0.587, 95% confidence interval = 0.427–0.808). A higher incidence of RPE alterations in the ICG injection group was observed. The incidence of RPE alterations was found to be 1.98%, whereas RPE changes were noted in 13.83% of 201 patients with ICG application (odds ratio = 7.998). Conclusion: This meta-analysis of previous reports comparing ILM peeling with and without intravitreal ICG application in the treatment of MHs demonstrated statistically worse functional outcomes when ICG was applied (p = 0.0008). A higher number of RPE alterations were observed in the ICG-stained group.

Traumatic macular hole-related retinal detachment in an emmetropic eye successfully treated with vitrectomy.

The authors report a case of retinal detachment in an emmetropic eye secondary to development of a traumatic macular hole treated by removal of the internal limiting membrane (ILM) with a good visual outcome. A 13-year-old boy was hit in his left eye by a football. The best-corrected visual acuity (BCVA) of the left eye was 20/40. A traumatic macular hole was present without posterior vitreous detachment. A retinal detachment secondary to a traumatic macular hole developed and BCVA decreased to 20/60 6 weeks after the injury Because the retinal detachment became more extensive 3 months after the injury, vitreous surgery was performed with creation of a posterior vitreous separation, followed by removal of the ILM surrounding the macular hole using 0.5% indocyanine green stain. Fluid-air exchange was performed followed by 20% SF6 gas tamponade. The retina was reattached and the traumatic macular hole closed. The VA of the left eye improved to 20/30 1 month postoperatively. No serious complications occurred during follow-up. Vitreous surgery with removal of the ILM appears to be a useful technique for treating traumatic macular holes with retinal detachments in emmetropic eyes and could achieve good visual outcomes in some cases.

MECHANISMS OF INTRAVITREAL TOXICITY OF INDOCYANINE GREEN DYE

Indocyanine green (ICG) dye was shown to improve the visualization of preretinal tissues during chromovitrectomy. However, controversy arose regarding the safety of intravitreal ICG application, because worse functional outcomes and a higher incidence of retinal pigment epithelium (RPE) changes and visual field defects were reported. The mechanisms of ICG-related toxicity and their relevance for chromovitrectomy are reviewed. A literature search was performed from 1998 through 2005 for relevant information related to the mechanisms of intravitreal ICG toxicity. Animal and clinical data on intravitreal ICG-related toxicity were collected to clarify the mechanisms of the risk of intravitreal ICG injection. Over 80 controversial in vitro, ex vivo, and in vivo animal investigations as well as clinical reports on intravitreal ICG staining were found in the literature. The main postulated mechanisms of intravitreal ICG-related toxicity were as follows: biochemical direct injury to the ganglion cells/neuroretinal cells, RPE cells, and superficial retinal vessels; apoptosis and gene expression alterations to either RPE cells or neuroretinal cells; osmolarity effect of ICG solution on the vitreoretinal interface; light-induced injury; and mechanical cleavage effect to the internal limiting membrane/inner retina. Whereas the exact mechanism of intravitreal ICG-related damage remains yet to be determined, most animal experiments proposed that ICG dye has a dose-dependent toxic effect on retinal tissue. This hypothesis was supported by clinical data, because better functional outcomes were obtained when low dye concentrations and short incubation times were reported. Much evidence supports that ICG dye has a dose-dependent toxic effect on the retina. Therefore, the following recommendations to minimize toxic effects on the retina are proposed: dye injection in concentrations as low as possible; avoidance of repeated ICG injections onto bare retina; dye injection far from the macular hole to prevent direct dye contact with the RPE; short incubation time of ICG in the vitreous cavity to diminish the concentration in contact with the retinal tissue; and the light pipe kept far from the retina throughout the whole surgical procedure.

Surgical effects and complications of indocyanine green‐assisted internal limiting membrane peeling for idiopathic macular hole

To compare the surgical outcomes and complications of vitrectomy with internal limiting membrane (ILM) peeling with or without indocyanine green (ICG) staining in eyes with an idiopathic macular hole. This study involved a non-randomized, single-centre, retrospective, interventional case series. Rates of anatomical closure, visual acuities (VAs) and postoperative complications in 35 eyes of 31 patients who underwent ICG-assisted ILM peeling during macular hole surgery (stained group) were compared with those in 18 eyes of 16 patients who underwent the same procedure without ICG staining (non-stained group). Macular holes were closed following the initial surgery in 97% of the stained group and 94% of the non-stained group (p > 0.999). There was no significant difference in mean final VA between the stained and non-stained groups, but there was a lower percentage of eyes with postoperative vision > 20/25 in the stained group (15%) than in the non-stained group (44%) after 2 years (p = 0.036). Posterior retinal pigment epithelium atrophy, retinoschisis and visual field defects were observed only in the stained group. The difference in mean final VA between the two groups was not significant. However, a lower percentage of eyes obtained VA > or = 20/25 and a higher incidence of postoperative complications occurred in the stained group. These results indicate that some consideration should be made before ICG is used in macular hole surgery.

Current and future concepts in macular hole surgery

Since the first report on successful macular hole surgery in 1991, surgical techniques have been refined and have helped to increase anatomical and functional success rates. Macular hole surgery today consists of vitrectomy, internal limiting membrane peeling (especially in larger macular holes) with or without the use of vital dyes, such as indocyanine green, trypan blue or, as very recently suggested, brilliant blue, followed by endotamponade and prone position for a few days. Indocyanine green staining, in particular, has become a controversial subject of discussion as functional success might be diminished due to the phototoxic properties of the dye. Imaging techniques, such as optical coherence tomography, may not only serve as prognostic factors for visual recovery, but may also help to explain unsatisfactory visual recovery despite anatomical hole closure.

Microscopic characterization of collagen modifications induced by low‐temperature diode‐laser welding of corneal tissue

Laser welding of corneal tissue that employs diode lasers (810 nm) at low power densities (12-20 W/cm(2)) in association with Indocyanine Green staining of the wound is a technique proposed as an alternative to conventional suturing procedures. The aim of this study is to evaluate, by means of light (LM) and transmission electron microscopy (TEM) analyses, the structural modifications induced in laser-welded corneal stroma. Experiments were carried out in 20 freshly enucleated pig eyes. A 3.5 mm in length full-thickness cut was produced in the cornea, and was then closed by laser welding. Birefringence modifications in samples stained with picrosirius red dye were analyzed by polarized LM to assess heat damage. TEM analysis was performed on ultra-thin slices, contrasted with uranyl acetate and lead citrate, in order to assess organization and size of type I collagen fibrils after laser welding. LM evidenced bridges of collagen bundles between the wound edges, with a loss of regular lamellar organization at the welded site. Polarized LM indicated that birefringence properties were mostly preserved after laser treatment. TEM examinations revealed the presence of quasi-ordered groups of fibrils across the wound edges preserving their interfibrillar spacing. These fibrils appeared morphologically comparable to those in the control tissue, indicating that type I collagen was not denatured during the diode laser corneal welding. The preservation of substantially intact, undenatured collagen fibrils in laser-welded corneal wounds supported the thermodynamic studies that we carried out recently, which indicated temperatures below 66 degrees C at the weld site under laser irradiation. This observation enabled us to hypothesize that the mechanism, proposed in the literature, of unwinding of collagen triple helixes followed by fibrils "interdigitation" is not likely to occur in the welding process that we set up for the corneal suturing.

Indocyanine Green Staining Facilitates Detection of Bleb Leakage During Trabeculectomy

To report a new technique to visualize bleb leakage using indocyanine green (ICG) staining during trabeculectomy. The ICG solution was widely applied over the filtering bleb including the conjunctival wound before completion of trabeculectomy. This procedure was performed in 48 eyes of 44 consecutive patients undergoing trabeculectomy between December 2004 and October 2005. Without staining, bleb leakage was not identified by the direct observation under the operating microscope. ICG staining clearly visualized aqueous leakage from the bleb in 5 eyes (10.4%). The bleb leakage in these eyes was easily repaired with 10-0 nylon sutures, and no eyes, including these 5 cases, showed bleb leakage after surgery. There were no intraoperative and postoperative complications related to ICG application. The application of ICG during trabeculectomy is a simple and useful technique to facilitate detection and repair of the bleb leakage.

Effect of Indocyanine Green Staining in Peeling of Internal Limiting Membrane for Retinal Detachment Resulting from Macular Hole in Myopic Eyes

To investigate the effect of using indocyanine green (ICG) to stain the internal limiting membrane (ILM) during vitrectomy in eyes with retinal detachment resulting from macular hole (MHRD). Nonrandomized comparative trial. Thirty-two cases of MHRD. The medical records of the cases were reviewed retrospectively. During the initial vitrectomy, the ILM was peeled in 22 eyes with ICG (group A) and in 10 eyes without ICG (group B). Anatomic reattachment, visual acuity, and optical coherence tomography-determined macular hole closure were measured. The initial reattachment rate in group A (86%) was significantly higher than in group B (40%; P = 0.013, Fisher exact test). The postoperative visual acuity at 6 months and the visual improvements at 6 and 12 months in eyes with an initial reattachment were not significantly different between the 2 groups (P = 0.123, Mann-Whitney rank-sum test; P = 0.17, t test; P = 0.237, t test). The postoperative visual acuity at 12 months with an initial reattachment in group A was significantly better than in group B (P = 0.039, t test). The macular hole closure rate with an initial reattachment was 6 of 17 eyes (35%) in group A and 0 of 4 eyes (0%) in group B, and this difference was not significant (P = 0.281, Fisher exact test). These results show that ICG staining improves the initial reattachment rate and is associated with better postoperative visual acuity at 12 months. Therefore, ICG staining should be used during vitrectomy for MHRD because the complete removal of the ILM with ICG ensures the removal of the tangential traction by an epiretinal membrane and the inverse traction by the retina that cannot follow the posterior enlargement of a staphyloma.

Functional Assessment of the Possible Toxicity of Indocyanine Green Dye in Macular Hole Surgery

To evaluate the possible toxicity of indocyanine green (ICG) dye in macular hole surgery by comparing functional results after successful surgeries performed with and without staining. Prospective observational case series. In a study conducted at our department, 30 eyes of 29 patients with idiopathic macular hole underwent pars plana vitrectomy, with peeling of the internal limiting membrane (ILM). In 21 eyes (group A), ICG staining was used to visualize the membrane; in nine eyes (group B), no dye was applied. Pre- and postoperative examinations (at three, six, 12, and 20 months) included visual acuity (VA) (Snellen chart), slit-lamp biomicroscopy, multifocal electroretinography (mfERG), and optical coherence tomography (OCT). For statistical analysis, the Mann-Whitney U test and Newman-Keuls post hoc analysis were used. The macular hole was closed in all patients. At 20 months, VA improvement (logarithm of minimal angle of resolution units) compared with baseline was more pronounced in group B (P < .001) than in group A (P = .022); VA was also better for group B compared directly with group A (P = .048). For mfERG, preoperative responses were subnormal. Postoperatively, responses initially decreased, but at 20 months significant improvement was seen in both groups (P < .001). When data from the groups are compared at 20 months, significantly greater mfERG improvement was found in group B in both central and perimacular areas (P < .001). The significantly better outcomes without staining may suggest dye toxicity. Alternative internal limiting membrane visualization substances with fewer adverse effects (trypan blue, triamcinolone) may be preferable.