Residual Vitreous Cortex Research Articles

Vitreous Hydro-dissection with a Flute Needle for Inducing Posterior Vitreous Detachment in Pediatric Retinopathies.

To present a novel intraoperative technique using a flute needle to induce posterior vitreous detachment (PVD) in pediatric retinal cases. Following 23-gauge pars plana vitrectomy in pediatric eyes with complex vitreoretinal disease, triamcinolone is applied for staining, and vitreous hydro-dissection is performed. A flute needle containing basic salt solution (BSS) is introduced to separate the thin residual posterior vitreous cortex from the retina near the vascular arcades. Gentle taps allow balanced salt solution (BSS) to enter the vitreous crevice, with controlled oscillation facilitating separation. PVD is then induced, and the vitrector is used to lift and complete the detachment. Vitreous hydro-dissection with a flute needle was effective in inducing PVD in pediatric eyes with complex vitreoretinal disease. We report no intraoperative or postoperative complications. This adjuvant vitreous hydro-dissection technique facilitates PVD induction and may reduce the associated risk of iatrogenic retinal damage.

Injectable in situ cross-linking hyaluronan hydrogel for easier removal of posterior vitreous cortex in vitrectomy.

Removing transparent vitreous tissues, such as a residual vitreous cortex (VC) or proliferative membrane, without damaging the retina is often problematic in vitrectomy. We examined the feasibility of an injectable in situ cross-linking hyaluronan hydrogel (XL-HA) for vitrectomy. Experiments using ex vivo and in vivo animal models. HA-dibenzocyclooctyne and HA-azidoethylamine solutions were mixed to form XL-HA, which then gradually formed a hydrogel. We tested the function of XL-HA in ex vivo porcine eyes. We then examined the performance of XL-HA in in vivo rabbit models of posterior vitreous detachment, posterior VC removal, and proliferative vitreoretinopathy. The ex vivo study showed that XL-HA rapidly embedded triamcinolone acetonide, mimicking VC attached to the retina, and became hard enough to be pinched with tweezers within 3 minutes, allowing us to remove only the triamcinolone acetonide without impairing the internal limiting membrane. In the in vivo rabbit models, XL-HA injection improved posterior vitreous detachment, and the thin and fragile posterior VC or fibrous proliferative membrane was readily peeled off without any damage to the underlying retina as compared with untreated controls. A short-term intraocular biocompatibility test demonstrated that the intraocular pressure remained normal with XL-HA injected into the eye. In addition, transmission electron microscopy showed no obvious abnormalities in the cornea or in the inner and outer retina. The results indicate that XL-HA is a potential adjunctive device to help make vitrectomy safe, effective, and successful.

Development of in situ crosslinked hyaluronan as an adjunct to vitrectomy surgery

Ophthalmologists have used hyaluronan (HA) products as adjuncts to ocular surgery since the 1970s. However, HA products are not always functional in surgeries of the posterior eye segment due to their lack of biomechanical strength. In this study, we developed an in situ crosslinked HA (XL-HA) and evaluated its potential as an adjunct to vitrectomy surgery in an in vitro model with a triamcinolone acetonide (TA) layer used as a pseudo residual vitreous cortex (RVC). Within a few minutes at concentrations over 0.9%, XL-HA, generated by the click chemistry of HA-dibenzocyclooctyne and HA-azidoethylamine, formed a hydrogel with the appropriate hardness for tweezers peeling. XL-HA (concentration, 0.76–1.73%) without dispersion successfully entered the TA layer and removed more than 45% of the total TA. Dynamic viscoelasticity helps to explain the rheological behavior of hydrogels, and the assessment results for XL-HA indicated that suitable concentrations were between 0.97% and 1.30%. For example, 1.30% XL-HA hydrogel reached sufficient hardness at 3 min for tweezers peeling, and the TA removal ability exceeded 70%. These results demonstrated that XL-HA was a potential adjunct to successful vitrectomy.Graphical

A simple new technique for the induction of residual posterior vitreous cortex removal and membrane peeling.

To describe a quick, cost-effective alternative to using a scraper to remove the residual posterior vitreous cortex and create an inner limiting membrane (ILM) flap during vitrectomy. The surgical technique and a retrospective interventional single-center series of cases were described. A hook was made on the tip of a conventional syringe needle (outer diameter, 0.6 mm; 23 gauge) by bending the needle against a plate. We used this hook to remove the residual posterior vitreous cortex and create an ILM flap during vitrectomy. The efficacy and safety of using this instrument in ophthalmological procedures for a variety of vitreoretinal disorders were evaluated. The hook was effective for removing focal or diffuse residual posterior vitreous cortex in eyes with rhegmatogenous retinal detachment, proliferative diabetic retinopathy, and pathological myopia. It was also successfully used to make a free edge of the ILM and help strip the epiretinal membrane. There were no serious complications associated with using the hook in delicate ophthalmological procedures. The hook, made by bending a conventional needle, is a simple and cost-effective instrument for removing residual posterior vitreous vortex and to create epiretinal and ILM flaps during vitrectomy in eyes with various vitreoretinal diseases.

Risk Factors for Residual Vitreous Cortex at the Fovea after Posterior Vitreous Detachment during Vitrectomy in Ocular Trauma

Purpose To investigate the frequency and patterns of the residual vitreous cortex (RVC) at the fovea after posterior vitreous detachment (PVD) during vitrectomy after ocular trauma and the risk factors associated with its occurrence. Methods A cross-sectional, multicenter, and observational study was conducted in 72 consecutive patients who underwent pars plana vitrectomy after ocular trauma. In patients with PVD after vitrectomy, RVC patterns were visualized using triamcinolone acetonide staining and were classified as diffuse or focal. A multivariate logistic regression analysis was performed to evaluate the association between RVC and various factors, such as the patient's age, preoperative visual acuity, days after injury, the existence of spontaneous PVD, and the type of injury prior to vitrectomy. Results Of the 72 eyes with trauma, 35 eyes (48.6%) showed RVC on the macula, of which 19 (54.3%) were of the diffuse type and 16 (45.7%) were of the focal type. A multivariate logistic regression analysis showed that age (OR = 0.933, P=0.025) and days after injury (OR = 0.862, P=0.013) had a significant impact on RVC. Conclusions RVC at the fovea is very common after spontaneous or surgical PVD during vitrectomy. Younger patients are more likely to show RVC if vitrectomy is performed soon after injury.

Utility of microscope-integrated optical coherence tomography (MIOCT) in the treatment of myopic macular hole retinal detachment

Macular hole-associated retinal detachment in high myopia is described as a final stage in progression of myopic traction maculopathy (MTM).1–3 Shimada et al4 described the progressive stages of MTM from...

Diffractive multifocal intraocular lens interferes with intraoperative view

We report an unusual finding during vitreous surgery in an eye implanted with a diffractive multifocal intraocular lens (IOL). A 70-year-old woman reported gradual visual deterioration to 20/40 in the left eye two and a half years after uneventful cataract surgery with implantation of a diffractive multifocal IOL. Funduscopic examination showed an epiretinal membrane (ERM) in the left eye. Increased macular traction was believed to cause the visual deterioration. Vitreous surgery with removal of the ERM was performed and triamcinolone acetonide (TA) was injected intravitreally to visualize the residual vitreous cortex. Although the ERM was peeled successfully, the ability to focus on the vitreoretinal interface through the IOL required great effort with decreased contrast sensitivity and ghost images of the intravitreal TA crystals. The vision improved to 20/25 4 months postoperatively. Macular surgery can be performed in an eye with a diffractive multifocal IOL; however, decreased contrast sensitivity and ghost images may interfere with the intraoperative view through the diffractive IOL in complicated cases.

Comparison of surgical procedures for vitreous surgery in diabetic macular edema

Results of vitreous surgery alone in patients with diabetic macular edema (Vit group) were compared with results of surgery combined with peeling of the internal limiting membrane (ILM group), and surgery combined with removal of the residual vitreous cortex after its visualization using triamcinolone acetonide (TA) and a postoperative intravitreal TA injection (TA group). Visual acuities after the operation, degree of improvement in visual acuity (VA), and intra- and postoperative complications were evaluated. The study included 141 consecutive patients (168 eyes) who could be followed up for at least 12 months after the operation. The Vit group consisted of 66 eyes, the ILM group of 62 eyes, and the TA group of 40 eyes. Patient background factors, and visual acuities 6 and 12 months after operation were evaluated first, and at the final examination, the degree of improvement in VA, the incidences of intra- and postoperative complications, and the incidence of intraocular pressure > or =25 mmHg were studied. Preoperative VA was compared with the 6- and 12-month postoperative VA and the VA at the final examination. The preoperative to 6 months postoperative improvements and those between the 12-month postoperative and final examination did not differ among the three groups. However, the degree of improvement in VA between 6 and 12 months after the operation was significantly smaller in the TA group than in the other two groups. The incidences of intra- and postoperative complications did not differ among the three groups, but the incidence of intraocular pressure >/=25 mmHg was slightly higher in the TA group. Surgical results did not differ among the three operative techniques examined in this study.

Role of residual vitreous cortex removal in prevention of postoperative vitreous hemorrhage in diabetic vitrectomy

To evaluate whether residual vitreous cortex removal has a role in the prevention of postoperative vitreous hemorrhage in diabetic vitrectomy. Retrospective, comparative, nonrandomized study on a consecutive series of patients who underwent vitrectomy for diabetic eye disease. Recurrence of postoperative vitreous hemorrhage was compared in patients following surgery with and without residual vitreous cortex removal. During the study period, 59 patients had vitrectomy for diabetic disease. In 31 patients (group 1), the residual vitreous cortex was not removed and in 28 patients (group 2) the residual vitreous cortex was removed during surgery. Both groups were matched for number of patients, age, sex, duration of follow-up, and diagnosis. Recurrent postoperative vitreous hemorrhage (RVH) was noted in ten patients in group 1 (10/31, 32.25%) and in two patients in group 2 (2/28, 7.14%). The difference in postoperative vitreous hemorrhage between the two groups was statistically significant (P = 0.017). Logistic regression analysis showed that residual vitreous cortex removal and presence of intravitreal gas tamponade were associated with reduced risk of postoperative vitreous hemorrhage. However, only residual vitreous cortex removal was statistically significant factor in reducing risk of postoperative vitreous hemorrhage [odds ratio = 0.174; confidence interval (CI) = 0.0331-0.919; P = 0.040]. Residual vitreous cortex removal may be beneficial in reducing recurrence of postoperative vitreous hemorrhage following diabetic vitrectomy. Further randomized studies should be performed to evaluate the potential of this surgical technique in preventing postoperative recurrent vitreous hemorrhage following diabetic vitrectomy.

Resolution of Tractional Macular Edema Following Spontaneous Detachment of Residual Vitreous Cortex in a Vitrectomized Eye

A 15-year-old boy underwent pars plana vitrectomy and lensectomy following blunt closed-globe injury. Postoperatively, he had visual distortion and a decline in visual acuity attributable to tractional macular edema caused by clinically apparent residual vitreous cortex. One month later, macular edema resolved and visual acuity improved following spontaneous vitreous separation. This case illustrates what has been termed the posterior bursa macularis and emphasizes its pathoetiologic role in vitreomacular disease.

Reoperation for Persistent Myopic Foveoschisis After Primary Vitrectomy

We performed vitrectomy on two eyes for persistent myopic foveoschisis (MF) after primary surgery that did not include internal limiting membrane (ILM) peeling. Interventional case reports. Two highly myopic eyes of two patients with persistent MF after primary vitrectomy and gas tamponade but without ILM peeling were treated with pars plana vitrectomy, residual vitreous cortex removal, ILM peeling, and long-term gas tamponade. Total foveal reattachment was achieved and best-corrected visual acuity (BCVA) improved in both eyes. Reoperation including complete vitreous cortex removal and ILM peeling could be beneficial for patients with persistent MF after primary surgery, indicating that vitreous cortex removal and ILM peeling are critical in treating MF.

VITREOMACULAR ADHESION AND THE DEFECT IN POSTERIOR VITREOUS CORTEX VISUALIZED BY TRIAMCINOLONE-ASSISTED VITRECTOMY

To study the vitreomacular adhesion and the contractile force of posterior hyaloid, which are shown in triamcinolone acetonide (TA)-assisted pars plana vitrectomy (PPV). Interventional case series. Twenty-eight eyes with diabetic macular edema (DME) without posterior vitreous detachment (PVD) received TA-assisted PPV. Surgical PVD was performed by an aspiration of vitrectomy probe, and the dynamic changes of posterior vitreous cortex and residual vitreous cortex were evaluated. A premacular defect was formed in the detached posterior vitreous cortex during surgical PVD in 27 of 28 eyes. Immediately thereafter, the small defect expanded into a large hole in the detached posterior vitreous cortex in all cases. A residual vitreous cortex was left on the macula in 22 eyes. These observations demonstrate a firm vitreoretinal adhesion in the central macula and suggest that the enlargement of the defect of posterior vitreous cortex may be extrusion of vitreous out through the premacular dehiscence into the preretinal space, or a tangentially contractile force may exist in the posterior vitreous cortex. Both macular adhesion and the traction of vitreous cortex might contribute to the pathogenesis of DME and other vitreomacular disease.

Double Visualization Using Triamcinolone Acetonide and Trypan Blue during Stage 3 Macular Hole Surgery

Purpose: To study the usefulness of intravitreal injection of triamcinolone acetonide and trypan blue for facilitating visualization and dissection of the posterior vitreous cortex and internal limiting membrane (ILM) during vitrectomy in idiopathic stage 3 macular holes. Methods: Pars plana vitrectomy was performed in 10 eyes of 10 patientswith idiopathic stage 3 macular holes. After core vitrectomy had been performed, triamcinolone acetonide was injected over the posterior pole. After separation of the visualized posterior vitreous cortex, trypan blue was injected over the macular area. Excised specimens were examined by electron microscopy. Results: Upon injection of triamcinolone acetonide, the posterior vitreous cortex and residual vitreous cortex could be visualized in all patients. The posterior vitreous cortex and residual vitreous cortex were completely removed. The ILM of the retina was stained faint blue and was successfully removed in all patients. Electron microscopy revealed that the triamcinolone-acetonide-visualized layer and the trypan-blue-stained layer had different histological features. No complications related to the use of triamcinolone acetonide and trypan blue were encountered. Conclusion: Double visualization of the posterior vitreous cortex and ILM using triamcinolone acetonide and trypan blue during vitrectomy may facilitate separation of the posterior vitreous cortex from the retina and removal of the ILM around the macular hole in patients withidiopathic stage 3 macular holes.

Triamcinolone Acetonide Facilitates Removal of the Epiretinal Membrane and Separation of the Residual Vitreous Cortex in Highly Myopic Eyes with Retinal Detachment due to a Macular Hole

Purpose: To study the usefulness of intravitreal triamcinolone acetonide injection during vitrectomy in highly myopic eyes with retinal detachment due to a macular hole. Methods: Pars plana vitrectomy was performed in 6 patients with retinal detachment resulting from a highly myopic eye with a macular hole. After separation of the posterior hyaloid and removal of any visible epiretinal membrane, triamcinolone acetonide was injected over the posterior pole. Excised specimens were evaluated by transmission electron microscopy. Results: Upon injection of triamcinolone acetonide, the entire epiretinal membrane and residual vitreous cortex could be visualized in all patients. The epiretinal membrane and residual posterior vitreous cortex were completely removed. Successful reattachment was performed without retinal damage in all cases. Electron microscopy revealed a cellular epiretinal membrane within a collagenous matrix lining the smooth internal surface of the internal limiting membrane. No complications related to the use of triamcinolone acetonide were encountered. Conclusion: Intraoperative visualization of the epiretinal membrane and residual posterior vitreous cortex with triamcinolone acetonide was found to be a useful adjunct to vitrectomy. Using triamcinolone acetonide during vitrectomy may facilitate both removal of the epiretinal membrane around the macular hole and separation of the residual vitreous cortex from the retina in highly myopic eyes with retinal detachment.

Residual vitreous cortex after surgical posterior vitreous separation visualized by intravitreous triamcinolone acetonide

Objective To visualize the residual vitreous cortex (VC) on the retinal surface after surgical posterior vitreous separation (PVS) during a pars plana vitrectomy (PPV), especially in patients with diabetic retinopathy. Design Case–control study. Participants Patients with proliferative diabetic retinopathy (PDR), diabetic macular edema (DME), branch retinal vein occlusion (BRVO), and rhegmatogenous retinal detachment (RRD). Methods A triamcinolone acetonide (TA)–assisted vitrectomy was performed on patients with the following diseases: PDR (40 eyes), DME (26 eyes), BRVO (11 eyes), and RRD (17 eyes). Eyes with no apparent preoperative posterior vitreous detachment were enrolled in this study. After performance of surgical PVS, the residual VC was visualized as a white gel highlighted by TA. Based on this finding, the residual VC pattern was then divided into 3 groups: (1) diffuse type (VC was diffusely present in the temporal vascular arcade), (2) focal type (a small island of VC was left), and (3) no residual VC. A multivariate analysis using analysis of variance was performed regarding the residual VC pattern, disease type, age, and the 3 different surgeons. Main outcome measures Each surgeon determined the type of residual VC during the operation, and the results were confirmed by a postoperative review of the videotape records judged by the other 2 surgeons. Results Eighty percent of the PDR eyes demonstrated the diffuse type; 10%, the focal type; and 10%, no residual VC. Fifty-eight percent of the eyes with DME demonstrated the diffuse type; 19%, the focal type; and 23%, no residual VC. Eighteen percent of the BRVO eyes showed the diffuse type; 24%, the focal type; and 59%, no residual VC. Thirty percent of the RRD eyes showed the diffuse type; 30%, the focal type; and 40%, no residual VC. A multivariate logistic regression analysis showed that PDR was a predictor of the diffuse type of residual VC in comparison to RRD (odds ratio = 8.42, 95% confidence interval = 2.07–34.3). Neither age nor the surgeon was a significant factor for a specific type of residual VC. Conclusions Diabetic eyes more often demonstrated the diffuse type of residual VC, even after surgical PVS. This information may be valuable for surgeons performing a PPV on patients with diabetic retinopathy.

Perifoveal Traction Retinal Detachment Following Successful Optic Disc Pit Surgery

A 25-year-old male presented 8 years after a successful vitreoretinal operation for a left optic disc pit (ODP). On presentation his visual acuity had reduced from 6/5 (20/15) to 6/12 (20/40) in his operated eye. On examination an annular serous retinal detachment possibly secondary to tangential traction by either the internal limiting membrane (ILM) or residual lamellar vitreous cortex or both around the peripheral macular area was seen. The central fovea was flat. Following an uncomplicated vitrectomy and ILM peel, visual acuity improved to 6/6 (20/20) postoperatively. The author suggests that traction forces are responsible for the development of the serous detachment in eyes with ODP. Epiretinal membranes together with the ILM should be removed in all patients undergoing therapy for a retinal detachment associated with ODP in an effort to initially achieve a further relief of all forces and to try to avoid the late retinal detachment associated with epiretinal membrane or ILM contraction.

Indocyanine green selectively stains the internal limiting membrane

PURPOSE: To demonstrate whether indocyanine green stains the inner limiting membrane of the retina or residual vitreous cortex. METHODS: We report on the intraoperative staining patterns of the vitreomacular interface in 10 eyes of 10 consecutive patients who underwent vitrectomy with indocyanine green staining for macular hole formation and diffuse diabetic macular edema. RESULTS: In five eyes of five patients with macular holes, indocyanine green staining of the macula after posterior vitreous detachment resulted in an immediate visibility of a discernable membrane that was not previously seen. In five eyes of five patients with diffuse diabetic macular edema and adherent cortical vitreous, indocyanine green failed to stain the vitreomacular interface. After peeling off the residual vitreous cortex, however, a discernable membrane could be identified using indocyanine green dye again. Light and transmission electron microscopy revealed the inner limiting membrane as the membrane that had been stained and removed in all specimens. CONCLUSION: Indocyanine green selectively stains the inner limiting membrane. Staining of the vitreomacular interface using indocyanine green as a vital dye enables the surgeon to distinguish between the residual vitreous cortex and the inner limiting membrane, and it allows safer and easier removal of the inner limiting membrane.

Diamond-dusted Silicone Cannula for Epiretinal Membrane Separation During Vitreous Surgery

To report a diamond-dusted silicone cannula as a tool for membrane separation during vitreous surgery. A diamond-dusted silicone cannula was fashioned from flexible silicone tubing with a beveled tip and coated with diamond fragments for use during vitreous surgery. The instrument was used successfully in seven eyes with idiopathic macular hole and was found to be particularly useful for removing residual vitreous cortex and epiretinal membranes from around the hole. It was also effective in removing "immature membranes" in three eyes with proliferative vitreoretinopathy. The diamond-dusted silicone cannula is a useful tool for removing thin epiretinal membranes and vitreous cortex that may be difficult or nearly impossible to remove safely using other techniques.