Method of production and natural history of experimental posterior penetrating eye injury in the rhesus monkey.

We developed an experimental model for a posterior penetrating eye injury that resulted in traction retinal detachment in 21 rhesus monkey eyes. The standard injury was an incision through the pars plana with vitreous prolapse and incarceration; the wound was then carefully closed with microsurgical techniques. At one to two weeks after injury, detachment of the posterior vitreous occurred and detachment of the retina occurred between seven and 11 weeks. The development of retinal detachment was related to traction on the peripheral retina over the vitreous base; and to the contraction of epiretinal membranes on the peripheral and equatorial retina. Our study supports clinical observations on the importance of blood in the vitreous in the development of vitreous traction and traction retinal detachment after a posterior penetrating injury.     

Experimental posterior penetrating eye injury in the rabbit. I. Method of production and natural history.

A technique has been developed which produces an experimental posterior penetrating eye injury that reproducibly results in traction retinal detachment in rabbit eyes. The standard injury is an incision through the pars plana with vitreous prolapse and incarceration; the wound is then carefully closed with microsurgical techniques. It appears that blood in the vitreous is an essential factor in the development of vitreous traction and of traction retinal detachment. The model, which has been successfully transferred to Rhesus monkey eyes, is considered useful for further histological, electromicroscopical, electrophysiological, and ultrasound studies of posterior penetrating injuries of the eye. Our immediate goal is to assess in a controlled experiment whether pars plana vitrectomy can interrupt the sequence of events leading to traction retinal detachment after a posterior penetrating injury.     

Histology of wound, vitreous, and retina in experimental posterior penetrating eye injury in the rhesus monkey.

We performed a histologic study to support our clinical observations on the mechanisms responsible for traction retinal detachment after a penetrating injury in the rhesus monkey eye. The monkey eyes (40 eyes; 40 monkeys) were characterized by intraocular fibrosis with the formation of a cyclitic membrane and epiretinal and subretinal membranes. The progression to a fibrous ingrowth from the wound occurred only in eyes with blood in the vitreous. The intravitreal fibroblastic proliferation had its origin mainly from the stroma of the ciliary body and choroid at the wound but probably also from the nonpigmented ciliary epithelium. A fibroblastic response was present within the vitreous as early as four days after injury, and had progressed to form a cyclitic membrane by six weeks. Epiretinal membranes were identified as early as four weeks after injury. They were most prominent over the peripheral retina anterior to the equator. It is likely that they are derived from multiple cellular sources including the fibrous ingrowth from the wound but they were also connected to the surface of the retina by bridges of tissue indicating a glial origin. The subretinal membranes appeared to be derived from both retinal pigment epithelium cells and glial cells.     

Combined posterior contusion and penetrating injury in the pig eye. II. Histological features.

The main histological features observed after an experimental posterior contusion injury in the pig eye were haemorrhage from the choroidal vessels into the subretinal space and into the vitreous, uveal vessel dilatation, and an inflammatory reaction. These changes resolved during the first 2 weeks, and the subretinal haemorrhage was replaced by a fibrocellular membrane. The addition of a posterior penetrating injury resulted in fibrocellular proliferation at the wound site 6 days after injury and in formation of vitreoretinal traction membranes and subsequent traction retinal detachment. Posterior vitreous separation did not occur.     

The role of scleral buckle in experimental posterior penetrating eye injury.

PURPOSE: Although episcleral buckles are frequently placed as an additional procedure to vitreoretinal surgery, little is known about their independent effect after ocular trauma. The authors created a posterior penetrating ocular injury model to evaluate the isolated role of primary episcleral buckle placement. METHODS: Twenty eyes underwent surgery. The penetrating injury consisted of two 5-mm circumferential incisions placed five clock hours apart and 8 mm behind the limbus. A segmental episcleral buckle was placed over a randomly chosen injury site after wound closure. The degrees of fibrous proliferation, traction, and the presence of retinal detachment were evaluated on follow-up examinations. After enucleation and initial fixation, tissue sectioning was performed, and the greatest dimension of the fibrous proliferation at both wound sites was measured with a caliper. RESULTS: Two eyes were excluded from the study. Three eyes developed a retinal detachment; the remaining 15 eyes showed varying degrees of proliferation and traction on the retina. The greatest dimension of the fibrous proliferation at the buckle site (1.22 +/- 1 mm) was significantly different from that at the nonbuckle site (2 +/- 1.45 mm, P = 0.01). CONCLUSIONS: Primary episcleral buckle placement at the time of surgical repair reduces vitreous traction from the buckle site and decreases the degree of fibrovascular proliferation.     

Experimental traction retinal detachment in the cat

We developed a reproducible model of traction retinal detachment (TRD) in the cat eye by creating a serous retinal detachment and then injecting 2.5 × 10⁵ kitten dermal fibroblasts into the vitreous cavity at the site of a retinal wound. Serous detachments were produced by exposing an area of retina to focused light after intravenous injection of rose bengal (a photosensitizing dye). TRD developed rapidly within the first 2 weeks after fibroblast injection, accompanied by the formation of vitreoretinal strands and, to a lesser degree, epiretinal and/or subretinal proliferation. Histopathology demonstrated fibroblasts within the vitreous or along the posterior hyaloid face. Focal deposits of fibroblasts were occasionally found on the inner surface of the retina and/or in the subretinal space. Fibroblast proliferation was confirmed by uptake of radiolabeled thymidine. Deposition of collagen was noted at as early as 3 days after fibroblast injection. Neovascularization was not observed. Control eyes that did not receive fibroblasts showed resolution of serous detachment without retinal traction. In all eyes, retinal degeneration and thinning were seen in the area of previous photodynamic treatment. In this model of TRD, anteroposterior traction (due to vitreous strands) predominates, as is observed in experimental posterior penetrating ocular injury induced by intravitreal blood injection, which also results in vitreous strand formation. Our model, however, enables clinical assessment of TRD in the cat without the media opacification produced by vitreous blood. Offprint requests to: D.L. HatchellSupported by VA medical research funds, NIH research grant EY02903, core grant EY05722, the Helena Rubinstein Foundation, New York, and Research to Prevent Blindness, Inc., New York. Dr. D.L. Hatchell is a Research to Prevent Blindness, Inc., Senior Scientific Investigator. The authors have no commercial or proprietary interest in the chemicals, drugs, or devices used in this study     

Penetrating eye injuries: a histopathological review.

This study reports the histological findings in human eyes after severe penetrating trauma. The findings confirm the high incidence of retinal detachment in eyes with severe penetrating injuries. The retina was detached in 32 out of the 34 eyes examined, with 27 having evidence of traction on the retina. These eyes were characterized histologically by intraocular cellular proliferation producing cyclitic, epiretinal, and retroretinal membranes. Intraocular cellular proliferation was discernible or established within 1 week of injury and typically resulted in a cyclitic membrane at about 6 weeks. Epiretinal and retroretinal membranes were found between 1 and 2 weeks after injury in eyes with a detached retina. The results indicate that a damaged lens, the admixture of lens material and vitreous, and the presence of vitreous haemorrhage were all factors promoting intravitreal fibroblastic proliferation. Vitreous surgery may be a rational method of treatment for these severely injured eyes by removing the stimulus and vitreous scaffold for intravitreal fibroblastic proliferation. From this series it would appear that vitrectomy should not be delayed beyond the second week of injury, by which time massive cellular ingrowth may already be under way.     

Experimental posterior penetrating eye injury in the rhesus monkey: vitreous-lens admixture.

A standardised experimental posterior penetrating eye injury in the rhesus monkey with the vitreous-lens admixture resulted in limited fibrous ingrowth from the wound and minimal traction on the peripheral retina. Microscopically inflammation was noted in the iris, ciliary body, and as a perivascular infiltrate of the inner retina. Periretinal membranes did not occur, and cellular proliferation within the vitreous was less marked than observed after an identical wound and simulated vitreous haemorrhage in previously reported studies. The lens may be a less important stimulus to intravitreal fibroblastic proliferation than previously assumed.     

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.     

Morphological study of epiretinal membrane following posterior penetrating injury in the monkey eye

Posterior vitreous detachment (PVD) and epiretinal membranes occur in a number of vitreoretinal diseases. We have developed an experimental model in which we can provide the morphologic correlation of these dynamic processes. The method provides the opportunity to study epiretinal membrane formation with the scanning electron microscope (SEM); with SEM, some epiretinal membranes that could not be readily detected either clinically or by routine light microscopy can now be identified and studied in detail. We performed an experimental posterior penetrating injury with injection of autologous whole blood or blood and lens material into the vitreous. Five eyes with posterior vitreous detachment but no retinal detachment were selected for SEM. A reduction in the cortical vitreous filaments and the presence of epiretinal membranes was apparent with SEM. In most areas the epiretinal membranes were separated from the internal limiting membrane by a narrow cleft; however, limited attachment sites between the epiretinal membranes and retina were observed in areas overlying retinal blood vessels. In two eyes we observed microscopic retinal folds beneath the membranes, demonstrating a possible morphologic correlation between epiretinal cellular contraction and traction on the retina.     

外伤性增殖性玻璃体视网膜病变发病机理

增殖性玻璃体视网膜病变是眼后段穿破伤视力丧失的主要原因,临床所见轻则为黄斑区视网膜前膜,重则可引起视网膜全脱离,眼球萎缩,为了探讨其发病机理,作者用灵长类为动物模型进行了形态学的观察,并用13只患者摘除的眼球进行粘连蛋白免疫抗体组织化学研究,结果表明,此病变为组织对视网膜损害的过度反应.发生在视网膜内界膜水平的玻璃体后脱离是诱发因素。病变过程中脉络膜粘连蛋白持续升高,这不但是由于血管通透性改变血浆外渗引起,而是脉络膜自身产生细胞型粘连蛋白.粘连蛋白巳知对组织损伤的愈合有促进作用,故此也可能是增殖性玻璃体视网膜病变发病的重要因素.     

玻璃体切除在巩膜破裂伤手术中的应用

目的探讨玻璃体切除技术在巩膜破裂伤中的应用。方法对28例(28眼)巩膜裂伤采用前段玻璃体切除器,边暴露边切除边缝合巩膜伤口,伤后2周内再行闭合式玻璃体切除术,重建眼后段结构。结果28眼巩膜裂伤中出现牵拉性网脱16眼、单纯性玻璃体浑浊12眼。术后视网膜复位14眼,视网膜脱离复发2眼。视功能提高者18眼,不变者8眼,下降者2眼。视网膜复位与巩膜裂伤的位置、长短及手术时间有关。结论前段玻璃体切除在巩膜裂伤修补中,有效地防止了视网膜或脉络膜的嵌顿,为进一步重建眼后段结构创造了基础。     

Potential applications of optical coherence tomography in posterior segment trauma.

BACKGROUND AND OBJECTIVE: To describe potential clinical applications of optical coherence tomography (OCT) in diagnosis and surgical timing in eyes with posterior segment trauma. PATIENTS AND METHODS: In a noncomparative study, 7 consecutive patients who had open-globe or closed-globe injury and were found to have posterior abnormality that could also be detected by OCT are described. RESULTS: All patients had documented OCT abnormalities in the posterior segment. In one patient with a penetrating injury, two metal foreign bodies were located in the posterior segment, one in the vitreous compartment coupled with inflammatory reaction and localized posterior vitreous detachment and the other embedded in the retina. In a second patient with a penetrating injury, OCT revealed the appearance of posterior vitreous detachment 5 days after injury. A closed-globe injury in one patient resulted in anterior optic neuropathy, manifested as disc edema and thickening of the circumpapillary retinal nerve fiber layer. The other patients had received blunt trauma and were found to have either full-thickness macular holes (2 patients), retinal pigment epithelium detachment at the papillomacular bundle site (1 patient), or macular edema (1 patient). CONCLUSIONS: OCT may serve as an important adjunct imaging device in evaluation of injuries to the posterior segment, qualitatively and quantitatively. It has potential in diagnosing subtle key abnormalities and in follow-up of these injuries.     

后房型人工晶体缝线固定术后视网膜脱离原因分析

目的报告后房型人工晶体缝线固定术后视网膜脱离的临床特征。方法观察后房型人工晶体缝线固定术后视网膜脱离14例14[的患者背景、术中所见及术后观察。结果患者术后视网膜脱离发生在20～204日(平均96.5日),初次手术6[施行了巩膜环扎术,8[玻璃体手术。经玻璃体手术者视网膜全部解剖复位,3[巩膜外手术复位失败,后经玻璃体手术视网膜复位。视网膜脱离发生的原因是睫状沟缝合时医源性裂孔3[,前部玻璃体牵拉性网膜裂孔11[。术后视力提高的5[,不变者6[,3[视力下降。结论后房型人工晶体缝线固定术后前部玻璃体的牵拉是视网膜脱离的主要原因,玻璃体手术是有效的。另外,由于血—[屏障的破坏易发生前部增生性玻璃体病变,早期的玻璃体手术是重要的。     

Retinal detachment in highly myopic eyes due to macular holes and epiretinal traction

We operated on four highly myopic eyes with recurrent retinal detachment due to macular holes. A thin layer of epiretinal tissue was present over the posterior retina in each eye, probably causing tangential traction on the retina and accounting for the recurrent detachment. Biopsy of the tissue from one case showed mainly acellular material resembling cortical vitreous. Recognizing this clinical condition may permit successful treatment of certain cases with recurrent retinal detachment in highly myopic eyes with macular holes.     

Experimental retinal detachment in the rabbit. Penetrating ocular injury with retinal laceration

Retinal detachment was studied in a rabbit model of penetrating ocular injury with retinal laceration. The injury was an 8 mm perforation through the sclera, choroid, and retina with vitreous loss and incarceration. When the injury was located at the equator of the globe, the rate of retinal detachment was 16%, but if located at the ora serrata, the rate was 78%. The higher rate of retinal detachment following injuries located at the ora serrata is probably due to the involvement of the vitreous base.     

Pars plana vitrectomy for severe penetrating injury with posterior segment involvement

We studied 50 consecutive cases of severe penetrating ocular trauma with posterior segment involvement for which vitreous surgery and scleral buckling were performed as secondary reparative procedures. Eyes with a better prognosis, such as those with anterior segment injuries alone and intraocular foreign bodies, were excluded. Of 50 eyes, 31 (62%) had a successful outcome. There was a significant difference in visual outcome between those eyes that had received blunt and sharp penetrating trauma. Visual acuity of 20/50 or better was more frequently attained in eyes with sharp penetrating trauma (P = .002). Thirty-three eyes had initial retinal detachment; 17 (52%) were successfully repaired. Blunt penetrating trauma produced retinal detachment more frequently than sharp penetrating trauma (22 of 29 vs 11 of 21). Retinal detachment was more often successfully repaired after sharp penetrating trauma (8 of 11 vs 9 of 22). Contusive damage to the choroid and retina limited final visual and anatomic results after blunt rupture of the globe.     

Management of anterior and posterior proliferative vitreoretinopathy. XLV. Edward Jackson memorial lecture

Proliferative vitreoretinopathy is a composite of anterior and posterior proliferation producing multidirectional tractional forces and resultant complex management problems. In a series of 98 consecutive cases of nondiabetic, nontraumatic proliferative vitreoretinopathy, anterior proliferation caused retinal detachment in 58 patients. Relaxation of circumferential traction created by anterior proliferation in the vitreous base and its contiguous surfaces is achieved by multiple radial incisions in the vitreous base and associated anterior retina is eliminated by incision of the displaced anterior and posterior hyaloid surfaces. The subsequent release of posterior traction and determination of residual traction by sequential fluid-air exchange before final tamponade with longer acting gas or silicone oil is described. Total retinal reattachment was achieved in 23 of 33 eyes (70%) with only posterior proliferation compared to 27 of 47 eyes (57%) with significant anterior proliferation. Retinal attachment posterior to the scleral buckle was achieved in 27 of 33 eyes (82%) and 37 of 47 eyes (79%), respectively. Although the success rate was less in eyes with anterior proliferation, the retinal reattachment rates in the two groups approached comparability as experience and understanding of the clinical significance increased.     

手术治疗先天性视网膜劈裂症眼后段并发症

目的评价玻璃体视网膜手术治疗先天性视网膜劈裂症眼后段并发症的效果。方法回顾性分析伴有眼后段并发症的先天性视网膜劈裂症7例（10眼）玻璃体视网膜手术的效果。其中玻璃体积血5眼，玻璃体积血合并牵引性视网膜脱离1眼，原发性（孔源性）视网膜脱离2眼，周边劈裂腔进展累及黄斑2眼。所有病例均有周边视网膜劈裂及黄斑中心凹劈裂。1眼孔源性视网膜脱离行巩膜扣带术，其余9眼行玻璃体手术。结果随访12～51月，平均38月，玻璃体积血者术后屈光间质透明，视网膜脱离者术后视网膜复位良好，所有病例术后视力较术前均有不同程度提高，而且视网膜劈裂无明显进展。无严重并发症出现。结论玻璃体视网膜手术用于治疗先天性视网膜劈裂症眼后段并发症，不仅可以清除浑浊的屈光间质，而且可以解除玻璃体牵引，阻止劈裂腔进一步发展，有助于改善和稳定视功能。     

Tomographic features and surgical outcomes of vitreomacular traction syndrome

PURPOSE: To study the relation between preoperative macular changes and surgical outcomes in vitreomacular traction syndrome. DESIGN: Prospective study. METHODS: We prospectively examined 14 eyes of 13 patients (aged 48 to 82 years; mean 66.1) with vitreomacular traction syndrome using optical coherence tomography (OCT) before and after vitreous surgery. RESULTS: OCT demonstrated two types of partial posterior vitreous detachment: incomplete V-shaped detachment in 10 eyes (group 1) and partial detachment temporal to the fovea but attached nasally in 4 eyes (group 2). Preoperative OCT showed foveal retinal detachment in all eyes in group 1; the detached retina was intact in 2 eyes and edematous with (6 eyes) or without (2 eyes) cystic changes. After surgery, these 10 eyes had a normal foveal configuration accompanied by visual improvement. In group 2, 3 of the 4 eyes had prominent cystoid macular edema (CME) without foveal retinal detachment before surgery. After surgery, 2 eyes developed a full-thickness macular hole, 1 had persistent CME, and 1 developed macular atrophy. The visual acuity decreased in 2 eyes and remained the same in 2 eyes. CONCLUSIONS: Two types of vitreous traction develop in vitreomacular traction syndrome: an incomplete V-shaped posterior vitreous detachment that leads to foveal retinal detachment, the surgical outcome of which is favorable, and partial posterior vitreous detachment temporal to the fovea in which prominent CME developed, which may result in a macular hole or macular atrophy postoperatively.