Results of vitrectomy for diabetic traction retinal detachments using the en bloc excision technique

En bloc excision is a technique in which fibrovascular diabetic membranes and the posterior hyaloid are separated from the retina as a single unit. In a consecutive series of 69 eyes with diabetic traction retinal detachment treated with this technique, initial retinal reattachment was accomplished in 100% (69/69) of the eyes. With a minimum of 6 months' follow-up, the retina remained completely attached in 83% (57/69) of eyes, while the macula was attached in 88% (61/69) of eyes. Final visual acuity was 5/200 or better in 71% (49/69) of eyes. While current surgical techniques allow a high rate of anatomic success in the repair of diabetic traction retinal detachment, visual results remain limited by irreversible alterations in retinal function.     

Vitreoschisis in Eales' disease: pathogenic role and significance in surgery

PURPOSE: To report the surgical anatomy of vitreoretinal adhesions as observed intraoperatively in patients undergoing vitreous surgery for complications of Eales' disease. METHODS: Eighteen consecutive male patients (18 eyes) undergoing vitrectomy for Eales' disease were studied prospectively. Intraoperative diagnosis was vitreous hemorrhage (VH) in nine cases, traction retinal detachment (TRD) in four, VH and TRD in three, and combined traction-rhegmatogenous retinal detachment in two. Epiretinal membranes (ERMs) obtained during surgery were studied using light microscopy and immunohistochemistry. RESULTS: An incomplete posterior vitreous detachment was observed in all eyes. Multifocal vitreoretinal adhesions were evident in 83.3% of eyes. The proliferation was fibrovascular in 10 eyes and fibrous in eight. A radial traction fold extending from optic disk to periphery was observed in three eyes. A double-layered membrane, probably the result of vitreoschisis, caused tangential traction. ERMs consisted principally of type II collagen and the cellular element was predominantly composed of lymphocytes, glial cells, and macrophage-like cells (probably hyalocytes). CONCLUSIONS: Fibrous and fibrovascular proliferations have multiple areas of adhesions to the posterior vitreous cortex. The presence of type II collagen in the ERM indicates a possible vitreous collagen component to the double-layered membranes (vitreoschisis). Recognition of the double-layered membranes aids in relief of traction during surgery by delamination.     

Management of proliferative diabetic retinopathy

Proliferative diabetic retinopathy is characterized by neovascularization originating from the retina and/or optic disk in patients with diabetes mellitus. The role of vascular endothelial growth factor appears to be central in the pathogenesis of proliferative diabetic retinopathy. Advanced glycation end products are important in the development of vitreous abnormalities in proliferative diabetic retinopathy. The majority of the neovascular membranes are adherent to the posterior vitreous cortex. When the posterior hyaloid exerts traction, the edges of the neovascular complex are pulled forward, resulting in vitreous hemorrhage. Tractional and/or rhegmatogenous retinal detachments can occur. The Diabetic Retinopathy Study demonstrated the ability of panretinal photocoagulation to reduce the rate of severe visual loss by 50% for eyes with high-risk characteristics, defined as neovascularization originating from the optic disk > 1/3 disk diameter, any neovascularization originating from the optic disk with hemorrhage, and neovascularization originating from the retina with vitreous hemorrhage. The Early Treatment Diabetic Retinopathy Study showed that patients with type II diabetes mellitus who were older than 40 with severe nonproliferative diabetic retinopathy (defined as hemorrhages in four quadrants, venous beading in two quadrants, or intraretinal microvascular abnormalities in one quadrant) also benefited from early panretinal photocoagulation. The Diabetic Retinopathy Vitrectomy Study showed that early vitrectomy (within 6 months of onset of vitreous hemorrhage) was associated with better results in type I diabetes mellitus patients only. The goals of vitreous surgery are to remove the vitreous, including the posterior hyaloid, and to relieve traction from fibrovascular tissue. Delamination and segmentation techniques have been used in the excision of fibrovascular growth on the internal limiting membrane and extending into the vitreous. Panretinal photocoagulation is an integral component of vitrectomy for proliferative diabetic retinopathy. Anti-vascular endothelial growth factor agents may be used in addition to laser as an adjunct to reduce the risk of neovascularization. Vitrectomy surgery may have intraoperative and postoperative complications, including cataract, anterior hyaloidal fibrovascular proliferation, fibrovascular ingrowth, retinal detachment, and recurrent vitreous hemorrhage. Visual potential depends on the preoperative and postoperative status of the macula, as well as on retinal perfusion and the health of the optic nerve. With the improvement in instruments, techniques, and drugs, the results of vitrectomy in proliferative diabetic retinopathy are improving.     

Anterior hyaloidal fibrovascular proliferation after diabetic vitrectomy

Vitrectomy was performed to treat 74 consecutive eyes for complications of diabetic retinopathy. Eight (13%) of 61 eyes followed up for an average of 12 months developed anterior hyaloidal fibrovascular proliferation. This was the most common postoperative complication, whose features included recurrent hemorrhages into the vitreous cavity or anterior vitreous, or both; vessels or fibrovascular tissue on the posterior lens capsule; anterior extraretinal vascularization extending toward the lens on the anterior hyaloid; traction detachment of the peripheral retina or ciliary body; and hypotony. Patients who developed this complication tended to be young males with severe retinal neovascularization and extensive retinal ischemia; traction retinal detachment as an indication for surgery; placement of a scleral buckle; postoperative rubeosis iridis, recurrent vitreous hemorrhages, and retinal detachment; and multiple surgeries. Four eyes progressed to atrophia bulbi. Early recognition followed by additional surgery in two patients and extensive additional photocoagulation in two other patients was successful in preserving good visual function.     

Clinicopathologic findings in anterior hyaloidal fibrovascular proliferation after diabetic vitrectomy

Two young patients (27 and 30 years old, respectively) with long-standing diabetes mellitus underwent vitreoretinal surgery for traction retinal detachment and vitreous hemorrhage. The postoperative course in each was characterized by early recurrence of the hemorrhage into the vitreous cavity, hypotony, and severe visual loss. Histopathologic examination of both operated on eyes showed anterior extraretinal fibrovascular proliferation extending along the anterior hyaloid to the posterior lens surface, causing traction detachments of the peripheral retina and ciliary body. The vessels originated from the anterior retina. There was no evidence of excess fibrous tissue at the well-healed sclerotomy wounds.     

Development of macular holes in diabetic retinopathy with fibrovascular proliferation: Report of four cases

There are yet no reports in the literature describing the mechanism of macular hole (MH) formation associated with fibrovascular proliferation in proliferative diabetic retinopathy. We report four cases of MHs in diabetic retinopathy with fibrovascular proliferation; formation of MHs were studied using sequential pre-MH optical coherence tomography (OCT). In Case 1, initial OCT revealed tractional schisis and cysts with fovea detachment. An MH with bowl-shaped detachment was noted within 6 weeks. In Case 2, initial OCT revealed thickened posterior hyaloid membrane with vitreomacular traction. Five and a half years later, OCT showed MH formation with possible vitreomacular separation. Some epiretinal membrane was also noted in the macula area. In Case 3, initial OCT revealed tractional retinal elevation from the superonasal area to the fovea with macular thinning. An MH with detachment developed 7 weeks later. In Case 4, initial OCT revealed macula-involved retinal detachment with traction. An MH was noted 4 weeks later. The analysis of sequential OCT findings in these four cases suggests that strong vitreoretinal adhesion and traction of fibrovascular proliferation may induce an MH without going through the same evolutionary phases as those characteristic of idiopathic MHs.     

Viscodelamination at the vitreoretinal juncture in severe diabetic eye disease.

Injection of 1% methylcellulose or 1% sodium hyaluronate (Healonid) was used to separate attached vitreous cortex and fibrovascular epiretinal membranes from the retina in 40 eyes undergoing closed microsurgery for severe diabetic eye disease. The viscodelamination technique was of great value in elevating vitreous cortex or sparsely vascularised epiretinal membranes, especially in eyes with combined traction and rhegmatogenous retinal detachment. However, bleeding from or tearing of the retina limited the usefulness of this technique in the surgery of highly vascularised and adherent membranes, as in eyes with table-top traction retinal detachment. Recurrent epiretinal membrane proliferation was seen in some eyes postoperatively.     

Retinal Pigment Epithelium Tear after Vitrectomy for Vitreomacular Traction Syndrome in an Eye with Retinal Angiomatous Proliferation

An 87-year-old Japanese man presented with retinal angiomatous proliferation (RAP) and a retinal pigment epithelium (RPE) detachment in his right eye. His decimal best-corrected visual acuity was 0.15 in the right eye, and optical coherence tomography (OCT) showed a vitreomacular adhesion in the right eye as well. After 3 monthly intravitreal injections of ranibizumab, the size and height of the RPE detachment was significantly reduced. The accumulated intra- and subretinal fluid also disappeared, but the vitreomacular traction remained. Pars plana vitrectomy was performed, and the posterior hyaloid was separated from the retina with a vitrectomy cutter without any intraoperative complications. Two months after the surgery, a large RPE tear was observed over the macular area. His visual acuity decreased to 0.06 and remained unchanged thereafter. We suggest that the small tear led to the larger RPE tear because vitreomacular traction was transmitted to the RPE through the fibrovascular tissue of the RAP during the creation of the hyaloid detachment. Because such an RPE tear has not been reported after vitrectomy for vitreomacular traction, surgeons need to pay special attention to this potential complication in eyes with vitreomacular traction and RAP.Key Words: Retinal angiomatous proliferation, Vitreomacular traction syndrome, Vitrectomy, Retinal pigment epithelium tear     

Ultrastructural study of epiretinal membrane stained by trypan blue: 15 case reports

INTRODUCTION: Idiopathic epiretinal membrane results from detachment of the posterior hyaloid and is believed to be related to naturally occurring defects in the internal limiting membrane (ILM) of the retina. Vitrectomy and peeling are the treatment of choice. Trypan blue 0.15% (TB) stains epiretinal membrane and internal limiting membrane. It allows selective and complete removal, facilitating surgery, with less retinal damage. An ultrastructural study was conducted showing ultrastructural features of idiopathic epiretinal membranes (ERM) and those of the internal limiting membrane and its connections with the retinal side. MATERIAL AND METHODS: After pars plana vitrectomy and induction of posterior vitreous detachment, 0.2 ml TB 0.15% was injected over the ERM in an air-filled eye. The stained tissue was peeled with intraocular forceps. Specimens were at once collected in 4% glutaraldehyde for a transmission electron microscopy study. RESULTS: TB may allow complete and easier ERM and ILM peeling. The staining does not present toxic effects. The major cellular contingent is represented by glial cells, participating actively in neocollagen synthesis. Their presence supports the hypothesis of a migratory movement of retinal cells toward the vitreoretinal side. CONCLUSION: The presence of an intact internal limiting membrane, the absence of optical fibers belonging to the under retina, and the absence of any sign of apoptosis make TB a useful staining agent for ERM and ILM peeling.     

An adjustable-tip brush for the induction of posterior hyaloid separation and epiretinal membrane peeling

PURPOSE: To report a new adjustable-tip brush for induction of posterior hyaloid separation and epiretinal membrane peeling. DESIGN: Observational report. METHODS: The adjustable-tip brush made of 10-0 nylon was used during vitrectomy for a variety of vitreoretinal disorders to induce posterior vitreous detachment and to peel internal limiting membrane or epiretinal membranes. RESULTS: The instrument was especially effective in inducing posterior vitreous detachment in eyes with chronic pseudophakic macular edema and diabetic macular edema. It was used successfully to strip thin, immature epiretinal membranes and to unfold rolled edges of giant retinal tears. No complications were associated with the use of the adjustable-tip brush. CONCLUSION: The adjustable-tip brush was useful for posterior hyaloid separation and epiretinal membrane peeling during vitrectomy for a variety of vitreoretinal procedures.     

Terson's syndrome. Clinicopathologic correlations

In seven cases of Terson's syndrome, an elevated, dome-shaped, membrane was detected in the posterior pole by ophthalmoscopy, echography, or during pars plana vitrectomy. Light and electron microscopic examination of two additional eyes obtained postmortem from an acute case of Terson's syndrome revealed that the posterior vitreous face was elevated by blood and that the internal limiting membrane of the retina was intact and in its normal position. In two chronic cases, a dome-shaped epiretinal membrane was excised from the macula during vitrectomy. Light and ultrastructural studies demonstrated that the membranes consisted of glial cells and basement membrane material. The dome-shaped structure observed in eyes with Terson's syndrome is due to the formation of a subhyaloid hemorrhage. The partially detached posterior hyaloid face created by this hemorrhage provides a scaffold for cellular proliferation and the development of an elevated epiretinal membrane in long-standing cases. Echographically, this membrane resembles a retinal detachment in B-scans, but can be clearly distinguished from retina with standardized A-scan.     

A Case of Proliferative Sarcoid Retinopathy with Sarcoid Nodules in Tissue Obtained During Vitrectomy

Background: In previous studies, intraocular proliferative tissues obtained from proliferative sarcoid retinopathy cases during vitrectomy have been examined histopathologically. However, there is no report of identification of sarcoid nodules in examined tissues. We performed vitrectomy for a case of proliferative sarcoid retinopathy with extensive proliferative changes. Histopathologically, sarcoid nodules were identified in the fibrovascular membranes.Case: A 25-year-old man was treated for sarcoid uveitis in the right eye by his local ophthalmologist. Lens aspiration was performed for complicated cataract. He was referred to our hospital with vitreous opacity and traction retinal detachment which occurred after the surgery.Findings: The vitreous opacity was so severe that details of the fundus were not visible. Traction retinal detachment was suspected from findings of B-mode echography. Vitrectomy was performed, and total retinal detachment due to contraction of the fibrovascular membrane around the optic disc and posterior pole was observed. Sarcoid nodules were identified histopathologically in fibrovascular membranes obtained during vitrectomy.Conclusion: In proliferative sarcoid retinopathy cases, sarcoid lesions may be one of the causes of fibrovascular membrane formation.     

A case of proliferative sarcoid retinopathy with sarcoid nodules in tissue obtained during vitrectomy

BACKGROUND: In previous studies, intraocular proliferative tissues obtained from proliferative sarcoid retinopathy cases during vitrectomy have been examined histopathologically. However, there is no report of identification of sarcoid nodules in examined tissues. We performed vitrectomy for a case of proliferative sarcoid retinopathy with extensive proliferative changes. Histopathologically, sarcoid nodules were identified in the fibrovascular membranes. CASE: A 25-year-old man was treated for sarcoid uveitis in the right eye by his local ophthalmologist. Lens aspiration was performed for complicated cataract. He was referred to our hospital with vitreous opacity and traction retinal detachment which occurred after the surgery. FINDINGS: The vitreous opacity was so severe that details of the fundus were not visible. Traction retinal detachment was suspected from findings of B-mode echography. Vitrectomy was performed, and total retinal detachment due to contraction of the fibrovascular membrane around the optic disc and posterior pole was observed. Sarcoid nodules were identified histopathologically in fibrovascular membranes obtained during vitrectomy. CONCLUSION: In proliferative sarcoid retinopathy cases, sarcoid lesions may be one of the causes of fibrovascular membrane formation.     

特发性黄斑裂孔患者玻璃体后脱离的相干光断层成像特征

目的 观察特发性黄斑裂孔患者玻璃体后脱离的相干光断层成像（optical coherence tomography,OCT)特征,探讨裂孔的发生与玻璃体后脱离间的关系。方法 对临床确诊的特发性黄斑裂孔患者193例（223只眼）进行OCT检查,分析其玻璃体后脱离的发生及发展。结果 按Gass分期标准,I-Ⅳ期裂孔分别为21,74,97有31只眼,在Ⅰ,Ⅱ,Ⅲ期裂孔眼中,OCT图像显示玻璃体与视网膜分离者分别有15（71．4％）,38（51．4％）及46只眼（47．4％）。其表现形式有3种：（1）黄斑中心凹周围视网膜与玻璃体发生分离,但中心凹部相连,此处视网膜神经上皮层被牵起,层间出现囊腔;（2）玻璃体附着于未完全游离的视网膜裂孔盖处,使盖膜牵引上翘;（3）玻璃体完全与后极部视网膜分离,表现可见与其平行的玻璃体后介膜。这3种表现形式分别于Ⅰ,Ⅱ,Ⅲ期裂孔。在随诊的部分患眼中,OCT图像显示出I期进展至Ⅲ期裂孔的过程,并见玻璃体后脱离的裂孔自行愈合现象。在组合的OCT图像中,显示黄斑中心凹部与视乳头和颞侧视网膜之间脱离的玻璃体事 于现凹隆圆顶盖样图形。结论 OCT检测结果证实玻璃体与黄斑中心凹发生分离的过程与黄斑裂孔进展的过程相一致,提示黄斑裂孔的形成及发展与玻璃体后脱离的发生密切相关。     

Vitrectomy for diabetic macular traction and edema associated with posterior hyaloidal traction.

Pars plana vitrectomy with separation of the posterior hyaloid was performed in 10 eyes with diabetic macular edema and traction associated with a thickened and taut premacular posterior hyaloid. Nine of the 10 eyes had previous macular photocoagulation. Preoperative fluorescein angiography showed a deep and diffuse pattern of leakage in the macula. Intraoperatively, the attached and thickened posterior hyaloid was lifted and separated from the retina. Postoperatively, vision improved in nine eyes. The macular traction and edema resolved in eight eyes and decreased in two. Complications included a vitreous hemorrhage, a rhegmatogenous retinal detachment, cataract formation, and a mild epimacular membrane, each occurring in one eye. Vitreous surgery can improve the visual prognosis of some eyes with diabetic macular traction and edema associated with a thickened and taut posterior hyaloid.     

玻璃体积血的形态结构与玻璃体后脱离的图像特征

目的探讨玻璃体积血的形态结构和治疗特点.方法对74例(79只眼)增生性糖尿病视网膜病变、视网膜血管炎、视网膜静脉阻塞所致玻璃体积血的临床资料进行比较分析.术前超声检查、术中手术显微镜观察患者的玻璃体形态特点,分析玻璃体与视网膜的关系.结果所有患者均有不同程度的玻璃体后脱离,根据图像的形态特征可归纳为完全后脱离和部分后脱离两种.部分后脱离又分为"V"型、"L"型及后部玻璃体劈裂型,劈裂型多见于视网膜缺血性疾病的增生期.结论了解和掌握玻璃体后脱离及玻璃体劈裂的形态特点,可提高手术治疗的成功率并改善其预后.     

Contribution of posterior hyaloid membrane to pathogenesis and transciliary surgery of proliferative diabetic retinopathy

Results of 276 transcilliary vitrectomies in patients with proliferative diabetic retinopathy are analyzed. The indications for surgery were traditional in 180 patients and early in 98. The object of surgical manipulations in early surgery for proliferative diabetic retinopathy is the posterior hyaloid membrane, which should be detached from the retina and removed at an area as larger as possible. New vessels or fibrovascular tissue are left intact. After removal of the posterior hyaloid membrane they do not proliferate. Early surgery on the posterior hyaloid membrane in patients with proliferative diabetic retinopathy helps attain more stable and better functional results and involves a lesser number of serious intra- and postoperative complications. Fibrovascular proliferation does not progress after removal of the posterior hyaloid membrane at the site of the posterior pole of the eye, and therefore, we did not carry out panretinal laser coagulation during or after surgery. The only exceptions were cases with neovascularization of the iris in the postoperative period.     

黄斑表面膜的分层结构

目的研究孔源性视网膜脱离患者黄斑表面膜(macular pucker,MP )的超微结构，探讨MP的发生机制。方法13例孔源性视网膜脱 离患者的20块MP通过玻璃体手术获取，根据剥膜时所处的上下层位置分为靠近玻璃体一面膜和紧贴视网膜面膜，二个位置膜组织进行对比性透射电镜观察。结果7块近玻璃体的MP以大 量胶原纤维为主，分布的细胞是一些上皮样细胞，胞浆可含有色素颗粒；13块近视网膜面MP 有大量足突细胞，其周围胶原丰富，细胞数量和类型增多，包括典型的成纤维样细胞和神经胶质样细胞。结论视网膜脱离术后MP的组织结构表现层次上差异；玻璃体后界膜积极参与MP的形成；研究提示玻璃体后界膜在黄斑部粘连是发生继发性MP 的一个原因。临床表现，患者通常为不完全性玻璃体后脱离。(中华眼底病杂志,2001,17:52-54)     

Attached posterior hyaloid membrane and the pathogenesis of honeycombed cystoid macular edema in patients with diabetes

PURPOSE: To investigate the pathogenesis of honeycombed cystoid macular edema in patients with diabetes. METHODS: The relationship between the posterior hyaloid membrane and honeycombed cystoid macular edema was examined in 24 eyes of 20 patients with diabetes who underwent vitrectomy for cystoid macular edema. RESULTS: In 19 eyes of 15 patients with diabetes, the posterior hyaloid membrane was attached to the macula, and in five eyes of five patients, the posterior hyaloid membrane was separated from the macula. In 14 (74%) of the 19 eyes with an attached posterior hyaloid membrane, honeycombed cystoid macular edema was detected. Conversely, honeycombed cystoid edema was not detected in any of the five eyes with posterior hyaloid detachment (P = .0059). CONCLUSIONS: These observations demonstrate a strong correlation between an attached posterior hyaloid membrane and the presence of honeycombed cystoid macular edema. We suggest that retinal traction by the posterior hyaloid membrane is involved in the pathogenesis of honeycombed cystoid changes in diabetic patients.     

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.