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Aims: This pilot study uses Optical Coherence Tomography (OCT) imaging to compare the difference in foveal architecture after successful retinal detachment (RD) surgery by scleral buckling or pars plana vitrectomy (PPV)., Methods: Prospective recruitment of patients with macular off RDs. Detachment surgery was undertaken by scleral buckling, external drainage, and air injection (group 1) or by PPV (group 2). Postoperatively patients had clinical examinations and OCT at 1, 3, 6, and 12 months. If abnormalities persisted, a further OCT was obtained at 18 months., Results: Retinal reattachment, including clinical macular reattachment, was achieved in all cases within 24 h postoperatively. In group 1 (n=22), postoperative OCT showed persistent foveal detachment in 63% of cases (n=14) at 1 and 3 months. At 6 and 12 months, 36% (n=8) and 9% (n=2) had a persistent foveal detachment, respectively, and at 18 months, foveal detachment eventually. In group 2 (n=21), postoperative OCT showed an attached fovea in all cases; however, foveal thickening suggesting intraretinal oedema was present in all cases. The oedematous appearance of retina on OCT settled in 1-3 months. No foveal abnormality was seen at 6 and 12 months postoperatively., Conclusions: A high proportion of patients with successful retinal reattachment surgery by scleral buckling had foveal detachments postoperatively. No cases who had PPV had foveal detachments; however, transient retinal oedema was evident in all cases. The aetiology of these changes is unknown and warrants further investigation, as there is the potential of a long-term effect on vision.

Objective: To identify an optical coherence tomography (OCT) pattern predictive of visual outcome in patients with diabetic macular edema (DME) who underwent a single dose of intravitreal triamcinolone., Design: Retrospective case analysis with prospective data collection for controls., Participants: Ninety-three cases and 25 controls., Methods: Two independent masked observers retrospectively examined preoperative macular OCTs of 93 eyes of 93 patients who were given a single dose (4 mg in 0.1 ml) of intravitreal triamcinolone for DME and categorized them as belonging to 2 groups: 1, comprised of eyes with high reflectivity (bright colors) from inner retinal layers, and 2, comprised of eyes that had low reflectivity (darker colors) from inner retinal layers. Logarithm of the minimum angle of resolution visual acuity (VA) and macular thickness measured by OCT were assessed preoperatively and postoperatively at 1 and 3 months., Main Outcome Measures: Optical coherence tomographic appearance of inner retinal layers., Results: All patients completed 3 months of follow-up. In group 1, 45 of 51 eyes (88%) experienced visual improvement of > or =2 lines on an Early Treatment Diabetic Retinopathy Study (ETDRS) chart at 1 month of follow-up. Forty-four of 51 patients (86%) experienced visual improvement of > or =2 lines on an ETDRS chart at 3 months of follow-up. In group 2, 18 of 42 patients (43%) experienced visual improvement of > or =1 lines on an ETDRS chart at 1 and 3 months of follow-up. For the remaining patients, VA remained unchanged during the postoperative course of 3 months., Conclusions: Patients in whom OCT demonstrated the high reflectivity of inner retinal layers achieved greater VA though macular thickness decreased significantly after intravitreal triamcinolone in both groups. It may be hypothesized that a lower optical reflectivity of inner retinal layers is related to the atrophy of the inner retinal layers, thus resulting in a failure of VA recovery in these patients. The level of reflectivity from inner retinal layers on OCT may provide objective criteria in predicting the response of DME to intravitreal triamcinolone and help in preoperative counseling of patients with DME.

Purpose: Foveal detachment after apparently successful retinal reattachment surgery for macula-on retinal detachments (RDs) has been previously documented. This pilot study aimed to utilize ocular coherence tomography (OCT) imaging to investigate foveal architecture after routine retinal detachment surgery and correlate this to visual acuity., Methods: Prospective recruitment of patients attending one unit with macula-on RDs. Patients underwent full clinical examination including OCT preoperatively and RD surgery undertaken by scleral buckling, external drainage and air injection. Postoperatively patients had clinical examinations and OCT at 1 week, 1, 3, 6, and 12 months., Results: A total of 12 consecutive patients were recruited into the study. All had macula-on RDs and normal OCTs at onset. There were no operative or postoperative complications. Retinal reattachment was achieved in all cases within 24 h postoperatively. At 1 month six of 12 patients (50%) showed foveal detachment on OCT, which was invisible on clinical examination. At 3 months, the foveal detachment persisted in four (33%) of these patients. In these cases the foveal detachment persisted at 6 months follow-up, however, a reduction in subfoveal fluid was noted. All cases had foveal reattachment by 12 months postoperatively. Visual acuity was closely correlated to the presence of foveal attachment., Discussion: A high proportion of patients with successful retinal reattachment surgery had foveal detachments postoperatively. This phenomenon was associated with reduced visual acuity. The aetiology of this occurrence is unknown and warrants further investigation as there is the potential of a long-term effect on vision.

Purpose: To describe a patient who presented with bilateral retinal vascular occlusion and the use of anti-beta2 glycoprotein 1 (GPI) antibody testing in the diagnosis of antiphospholipid syndrome., Design: Observational case report., Methods: Hematological investigations were performed on a 49-year-old man who presented with rapid onset of bilateral severe central retinal vein occlusion., Results: Lupus anticoagulant and anticardiolipin antibody testing was negative. Markedly raised titers of anti-beta2 GPI antibodies were detected on two separate occasions., Conclusions: The raised titers of anti-beta2 GPI antibodies were considered to strongly suggest an underlying diagnosis of the antiphospholipid syndrome.

Aim: To evaluate the efficacy of intravitreal triamcinolone (IVTA) for the treatment of diffuse diabetic macular oedema (DME) refractory to conventional argon macular laser therapy., Methods: A prospective, consecutive, and noncomparative case series was undertaken involving 38 eyes of 38 patients with refractory DME. Triamcinolone acetonide (4 mg) in 0.1 ml was injected intravitreally. LogMar visual acuity (VA) and macular thickness measured by ocular coherence tomography (OCT) were assessed preoperatively and postoperatively at 1, 3, and 6 months., Results: All patients completed 6 months of follow up. VA (mean+/-SD) improved from 0.905+/-0.23 to 0.605+/-0.28, 0.555+/-0.29, and 0.730+/-0.30 at 1, 3, and 6 months, respectively. Macular thickness baseline (mean+/-SD) on OCT was 418.7+/-104.2 microm and this decreased to 276.9+/-72.6 microm, 250.6+/-53.1 microm, and 308.8+/-87.3 microm at 1, 3, and 6 months, respectively., Conclusions: IVTA may be a potential temporary treatment for refractory DME. It is effective in decreasing macular thickness and improving VA but the effect lasts approximately for 6 months in the majority of patients. Further investigations are required to establish the safety of IVTA for the treatment of DME.

Background/aims: Pseudoexfoliation syndrome (PXF) was recently found to be associated with increased expression of transforming growth factor beta(1) (TGFbeta(1)) in the aqueous humour. As concern has been raised regarding anti-TGFbeta therapy, which can potentially disrupt the maintenance of anterior chamber associated immune deviation, the authors explored the levels of tissue inhibitor of matrix metalloproteinase-1 (TIMP-1), matrix metalloproteinase-9 (MMP-9), and connective tissue growth factor (CTGF) in aqueous humour to determine if these may represent alternative therapeutic targets., Methods: Aqueous humour samples were collected from patients who underwent routine cataract surgery. All patients were categorised into three main groups-PXF, uveitis, and control. The PXF group was further subcategorised into three grades based on the density of the exfoliative material observed on biomicroscopy, as well as the presence or absence of glaucoma. TIMP-1, MMP-9, and CTGF levels were measured using specific enzyme immunoassays (ELISA)., Results: Eyes with PXF had significantly higher aqueous humour TIMP-1 concentration (n = 56, mean (SE), 9.76 (1.10) ng/ml) compared with controls (n = 112, 5.73 (0.43) ng/ml, p<0.01). Similarly, the CTGF level in PXF eyes (n = 36, 4.38 (0.65) ng/ml) was higher than controls (n = 29, 2.35 (0.46) ng/ml, p<0.05). Further, the CTGF concentration in the PXF glaucoma group is significantly higher compared with PXF eyes without glaucoma (6.03 (1.09) ng/ml v 2.73 (0.45) ng/ml, p<0.01). The MMP-9 levels were low and below detection limit in all PXF and control samples with no statistical difference between groups., Conclusion: A raised TIMP-1 level and a low MMP-9 level in aqueous humour of PXF eyes may imply a downregulation in proteolytic activity. The increased CTGF concentration supports the proposed fibrotic pathology of PXF. Regulation of MMP/TIMP expression and anti-CTGF therapy may offer potential therapeutic avenues for controlling PXF associated ocular morbidity.

Purpose: Normal aging is associated with accumulation of lipofuscin pigment in the retinal pigment epithelium (RPE). This may occur as a result of phagocytosis and incomplete degradation of oxidized photoreceptor outer segments (POS). This study was undertaken to determine whether phagocytosis of UV-irradiated POS (artificial lipofuscin) would increase expression in the RPE of various chemotactic and angiogenic cytokines., Methods: ARPE-19 cells were exposed to latex beads (0.76 micro m), naïve bovine POS, and UV-irradiated POS (Ox-POS; 2 x 10(7)/mL), and supernatants were collected at 18 and 36 hours. The supernatants were assayed for IL-8, monocyte chemotactic protein-(MCP)-1, and TNF-alpha by ELISA. Protein synthesis and NFkappaB activity were inhibited by actinomycin D and SN50, respectively. Phagocytosis and generation of intracellular reactive oxygen species were assessed by flow cytometry. Confocal and electron microscopy studies were also performed to verify phagocytosis and cellular integrity., Results: IL-8 and MCP-1 levels were decreased in the naïve POS group (IL-8: 473.76 +/- 66.9 pg/mL, P = 0.0005; MCP-1: 550.1 +/- 21.8 pg/mL, P = 0.0001), but were increased in the Ox-POS group (IL-8: 1348.8 +/- 164.9 pg/mL; MCP-1: 1772.28 +/- 65.19 pg/mL) compared with the control (IL-8: 741.09 +/- 39.8 pg/mL; MCP-1: 1413.47 +/- 38.4 pg/mL) and latex bead groups (data not shown). TNF-alpha levels were not affected. At 12 hours (but not at 6 hours), ROS were increased in the Ox-POS group. The cytokine increases observed were dependent on de novo protein synthesis and were NF-kappaB dependent., Conclusions: Ingestion by RPE of oxidized bovine POS stimulates expression of the chemotactic and angiogenic factors IL-8 and MCP-1 that have the capability to promote angiogenesis directly, or indirectly through the accumulation of immune cells such as macrophages, which themselves may release angiogenic promoters and degrade Bruch's membrane. This may be of significance in the development of exudative AMD.

Background: The beneficial effects of adjuvant treatment with agents such as autologous platelet concentrate (APC) or autologous serum (AS) in the surgical management of macular holes remain uncertain. The purpose of this study was to determine the histological changes induced by these agents compared with control on retinal wound healing in an animal model., Methods: The right eyes of 51 pigmented rabbits were used. Under anaesthesia, full-thickness sensory retinal incisions 2 mm in length were made into avascular retina down to the level of the retinal pigment epithelium using a 23-gauge needle via a superotemporal sclerotomy. APC, AS or sterilised balanced salt solution was placed directly over the wound site. Animals were killed at 3, 7 or 14 days and the wounds examined immunohistologically. Proliferating cell nuclear antigen (PCNA) was used to detect proliferating cells., Results: No difference was observed between serum-treated eyes and control eyes. A greater displacement or migration of cells toward the retinal surface was consistently found in the APC-treated wounds than in control wounds. These cells were of mixed origin but appeared to arise predominantly from the outer nuclear layer. A significantly greater number of PCNA-staining cells was found in the platelet-treated group than in controls at 3 days (P=0.038), 7 days (P=0.039) and 14 days (P=0.038)., Conclusion: We have demonstrated a significantly greater proliferative cellular response in the healing of retinal wounds with the use of platelet concentrate than in control wounds. We consider that this model may be used in further studies on the effects of other agents on retinal wound healing.

Purpose: To determine the efficacy of dacryocystoplasty with balloon dilation in the treatment of acquired obstruction of the nasolacrimal system in adults., Methods: Balloon dacryocystoplasty was performed in 52 eyes of 42 patients under general anaesthetic. A Teflon-coated guidewire was introduced through the canaliculus and manipulated through the nasolacrimal system and out of the nasal aperture. A 4 mm wide 3 cm coronary angioplasty balloon catheter was threaded over the guidewire in a retrograde fashion and dilated at the site of obstruction., Results: There was complete obstruction in 30% of cases and partial obstruction in 70%. The most common site of obstruction was the nasolacrimal duct. The procedure was technically successful in 94% of cases. The overall re-obstruction rate was 29% within 1 year of the procedure. There was an anatomical failure rate of 17% for partial obstruction and 69% for complete obstruction within 1 year., Conclusions: Balloon dacryocystoplasty has a high recurrence rate. There may be a limited role for this procedure in partial obstructions. Further refinements of the procedure are necessary before it can be offered as a comparable alternative to a standard surgical dacryocystorhinostomy.

Background: This study aimed to determine whether, in eyes treated for macular hole by vitrectomy and autologous platelet injection, short-term tamponade with SF6 gas was as effective as longer tamponade with C3F8 gas., Methods: Patients in group 1 (n=31) had vitrectomy, injection of platelet concentrate, and 16% C3F8 gas/air exchange. Patients in group 2 (n=31) were similarly treated, except that 23% SF6 gas was used. Group 1 patients were required to posture prone for 2-4 weeks, group 2 for 6 days., Results: All patients had 3 months' follow-up. Postoperatively, visual acuity improved faster in group 2. However, the final mean improvement in logMAR acuity was similar in both groups. Intraocular pressure (IOP) spikes occurred in 12 patients in group 2 and in 17 patients in group 1. Posterior subcapsular cataract (PSCC) occurred in 55% of cases in group 1 and in just 37% in group 2. The rate of anatomical success in group 1 was 96.7%, and in group 2, 93.5% (P=1.0)., Conclusions: The combination of SF6 gas, platelet concentrate, and short-term prone posturing gave a degree of anatomical and visual success comparable to that of the group which had longer tamponade. Although no differences were statistically significant, several trends did emerge; in group 2, patients recovered visual acuity faster, had fewer IOP spikes, and there were fewer cases of PSCC formation.

Background/aim: The pathogenesis of visual field loss associated with macular hole surgery is uncertain but a number of explanations have been proposed, the most convincing of which is the effect of peeling of the posterior hyaloid, causing either direct damage to the nerve fibre layer or to its blood supply at the optic nerve head. The purpose of this preliminary prospective study was to determine the incidence of visual field defects following macular hole surgery in cases in which peeling of the posterior hyaloid was confined only to the area of the macula., Methods: 102 consecutive eyes that had macular hole surgery had preoperative and postoperative visual field examination using a Humphrey's perimeter. A comparison was made between two groups: I, those treated with vitrectomy with complete posterior cortical vitreous peeling; and II, those treated with a vitrectomy with peeling of the posterior hyaloid in the area of the macula but without attempting a complete posterior vitreous detachment. Specifically, no attempt was made to separate the posterior hyaloid from the optic nerve head. Eyes with stage II or III macular holes were operated. Autologous platelet concentrate and non-expansile gas tamponade was used. Patients were postured prone for 1 week., Results: In group I, 22% of patients were found to have visual field defects. In group II, it was possible to separate the posterior hyaloid from the macula without stripping it from the optic nerve head and in these eyes no pattern of postoperative visual field loss emerged. There were no significant vision threatening complications in this group. The difference in the incidence of visual field loss between group I and group II was significant (p=0.02). The anatomical and visual success rates were comparable between both groups., Conclusion: The results from this preliminary study suggest that the complication of visual field loss after macular surgery may be reduced if peeling of the posterior hyaloid is confined to the area of the macula so that the hyaloid remains attached at the optic nerve head. The postoperative clinical course does not appear to differ from eyes in which a complete posterior vitreous detachment has been effected during surgery.

Background: Vitrectomy and gas tamponade has become a recognised technique for the treatment of macular holes. In an attempt to improve the anatomic and visual success of the procedure, various adjunctive therapies--cytokines, serum, and platelets--have been employed. A consecutive series of 85 eyes which underwent macular hole surgery using gas tamponade alone, or gas tamponade with either the cytokine transforming growth factor beta 2 (TGF-beta 2) or autologous platelet concentrate is reported., Methods: Twenty eyes had vitrectomy and 20% SF6 gas tamponade; 15 had vitrectomy, 20% SF6 gas, and TGF-beta 2; 50 had vitrectomy, 16% C3F8 gas tamponade, and 0.1 ml of autologous platelet concentrate prepared during the procedure., Results: Anatomic success occurred in 86% of eyes, with 96% of the platelet treated group achieving closure of the macular hole. Visual acuity improved by two lines or more in 65% of the SF6 only group, 33% of those treated with TGF-beta 2 and in 74% of the platelet treated group. In the platelet treated group 40% achieved 6/12 or better and 62% achieved 6/18 or better. The best visual results were obtained in stage 2 holes., Conclusion: Vitrectomy for macular holes is often of benefit and patients may recover good visual acuity, especially early in the disease process. The procedure has a number of serious complications, and the postoperative posturing requirement is difficult. Patients need to be informed of such concerns before surgery.

The Eurodiab Insulin Dependent Diabetes (IDDM) Complications Study was a cross-sectional investigation of a stratified random sample of IDDM patients attending 31 clinics in 16 European countries. We compared the findings in the only participating Irish centre (Cork Regional Hospital) with those of the study group as a whole. There were fewer episodes of ketosis but severe hypoglycaemia occurred more frequently in Cork patients, when compared to the full study group. There were no significant differences in the prevalence of background retinopathy, proliferative retinopathy, microalbuminuria, macroalbuminuria or peripheral neuropathy, when the two groups were compared. However, autonomic neuropathy was significantly less common in Cork. The prevalence of cardiovascular disease was slightly lower than the Eurodiab average in Cork patients, and cardiovascular risk factors were more favourable. Waist-hip ratio and total plasma cholesterol were significantly lower than in the full study group. The prevalence of hypertension was similar, but there were fewer smokers in Cork than in most other centres.

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.

We used new applications for a pars plana infusion cannula in three patients with retinal and choroidal detachments. Because the cannula maintained intraocular volume and form, it was helpful in treatment bullous retinal detachment and choroidal detachment.

Serial, bright-flash electroretinograms (ERGs) were recorded from rhesus monkey eyes before and after a standard posterior penetrating ocular injury and injection of 0.5 mL of blood into the vitreous. This procedure resulted in a progressive depression to virtual nonrecordability of the ERG during a period of several weeks, owing to a combined progressive increase in optical density and loss of retinal function. The ERG depression, however, was reversible, showing a remarkable recovery during the subsequent four to eight weeks. These findings suggest that in the presence of a recent, massive vitreous hemorrhage, a nonrecordable bright-flash ERG does not necessarily indicate a permanent loss of retinal function.

The histological findings of the wound, the vitreous, and the retina in the rabbit eye with experimental posterior penetrating injury are described. Wound healing had just begun at 3 days after injury and was well established by 9 to 12 days. It involved proliferation of cells from the episclera and from the choroid. The progression to a fibrous ingrowth from the wound occurred only in eyes with blood in the vitreous. The intravitreal fibroblastic proliferation had begen at 6 days after injury and seemed to be derived from the choroid, the nonpigmented ciliary epithelium and, posteriorly, from the optic nervehead. During the development of retinal detachment the configuration of the peripheral and posterior retina, together with the orientation of vitreous strands, suggested the presence of vitreous traction. We postulate that the presence of contractile fibroblasts (myofibroblasts) in the vitreous may provide the mechanism for vitreous traction. The retinal detachments were also characterised by epiretinal and subretinal membranes, but these were not prominent. The end-stage appearance of a soft, shrunken eye with cyclitic membrane formation and retinal detachment resembles the outcome in many human eyes after severe penetrating injuries.

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.

The overlying retinal blood vessels were abnormal in five cases of congenital hypertrophy of the retinal pigment epithelium. This illustrated the well-recognized association between outer retinal degeneration and obliteration of the overlying retinal vasculature. The proposed pathophysiological mechanisms, however, seem inadequate to explain completely the morphological changes of the retinal blood vessels in the presence of atrophy of the outer retina.

We have developed a reproducible model of traction retinal detachment in the rhesus monkey secondary to a penetrating eye injury. The model is characterized histologically by intravitreal fibroblastic proliferation and by epiretinal and by retroretinal membranes. Cells proliferating within the vitreous and in the epiretinal membranes have the ultrastructural characteristics of myofibroblasts. The presence of these contractile cells suggests that vitreous traction and the contraction of epiretinal membranes may be cell mediated. Our findings suggest that the pathophysiology of traction retinal detachment has many features in common with the normal process of wound healing and in particular with the mechanisms responsible for wound contraction and cicatrization.

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.

Sixty-six patients in whom the macula was detached before surgery were observed for at least 1 year after retinal reattachment. Macular abnormalities were recognised clinically in most patients with severely reduced vision. Failure of retinal receptor regeneration or receptor misalignment may account for visual reduction in a minority of patients but may be less important as a cause of reduced visual acuity than was previously supposed. This study confirms that the visual prognosis is related to the duration of the detachment before surgery, and patients with a macular detachment for 2 months or longer are likely to suffer persistently reduced vision.

A technique has been developed which produces an experimental posterior perforating eye injury, that reproducibly results in traction retinal detachment. 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 is considered useful for further histological, electron microscopic, electrophysiological, and ultrasonic studies of posterior perforating eye injuries. In a controlled experiment, it will be possible to assess whether pars plana vitrectomy can interrupt the sequence of events leading to traction retinal detachment after posterior perforating injury.

Exudative retinal detachment and oedema of the posterior retina are well-recognized clinical entities for which a cause is rarely found. Scleritis may cause both these clinical syndromes by a spread of inflammation from the sclera into the uveal tract. Although treatment may result in a rapid resolution of scleritis, retinal detachment and macular oedema persist and prove extremely resistant, even to high doses of systemic steroids. Recovery may be incomplete and may occur only after weeks or months of treatment.

A sequential study of the macula using biomicroscopy and fluorescein angiography in patients who had undergone successful retinal re-attachment procedures is reported. The purpose of this study is to identify the morphological changes which occur at the macula following retinal re-attachment surgery, and to relate these changes to the post-operative visual function.

Twenty patients with retinal macroaneurysms were examined and observed for at least 9 months. All these patients were elderly and had evidence of hypertension or systemic vascular disease. Nineteen patients presented with loss of central vision and one patient was asymptomatic. Visual loss was due to macular haemorrhage in 13 patients and macular oedema in 6. Whereas the visual prognosis in patients with haemorrhage was good it was considerably poorer in the patients with macular oedema.

We studied the ultrastructural characteristics of an experimental model of traction retinal detachment secondary to a penetrating eye injury in the rhesus monkey. Cells with the characteristics of myofibroblasts were present in the intravitreal fibrous tissue and in epiretinal membranes. These cells were probably derived from many sources, and were capable of contraction through the mechanism of intracytoplasmic contractile proteins such as actin or myosin. The morphologic observations supported our hypothesis that traction retinal detachment is a cell-mediated event analogous to the processes of wound healing and wound contraction. The force of contraction is mediated by cell-to-cell and cell-to-vitreous connections and by glial bridges that connect epiretinal membranes to the retina. These ultrastructural studies, which provide insight into the pathogenesis of traction retinal detachment in the experimental animal model, may well have significant clinical relevance.

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.

A controlled trial of pars plana vitrectomy for posterior penetrating eye injury was done in rhesus monkeys. After standard injury, each eye was allocated randomly into a treatment or control group. Treatment groups (ten eyes each) had vitrectomy at 1, 14, or 70 days after injury. The control group had 15 eyes. The same techniques were employed as in human eyes. Surgical objectives were lensectomy, then complete posterior vitrectomy and excision of the anterior vitreous to within 1 or 2 mm of the surface of the peripheral retina and pars plana. Results from this controlled trial provide strong support for the effectiveness of vitrectomy techniques in managing selected posterior penetrating injuries in human eyes and in preventing the complication of traction retinal detachment.

Twenty-five patients with retinitis pigmentosa and retinal leakage were investigated. Oedema was present in dominant and X-linked inherited disease and is likely to be present in recessive disease as well. We suggest that this might be a general response seen in many types of tapeto-retinal degeneration to actively degenerating photoreceptors or pigment epithelium.

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.

Condensation and contraction of the vitreous have been implicated in the development of vitreoretinal traction and traction retinal detachment after penetrating ocular injury. In this study, using the inorganic dye ruthenium-red, we studied ultrastructural changes in vitreous in the rabbit eye after standard penetrating injury and intravitreal blood injection. In normal rabbit vitreous the collagen fibrils have a regular arrangement. In contrast, after a penetrating injury the collagen fibrils appear focally condensed. While it appears unlikely that such a network could alone produce tractional or directional forces, these alterations along the collagen fibrils could provide a scaffold along which contractile cells migrate into the vitreous.