Recombinant tissue plasminogen activator injected into the vitreous cavity may penetrate the retinal veins of a porcine model of vascular occlusion.

AIM: To determine if recombinant tissue plasminogen activator (rtPA) injected into the vitreous cavity can penetrate the retinal vessels of porcine eyes with or without vascular occlusion. METHODS: Eight eyes (group I) of four pigs underwent clamping of the optic nerve flush with the globe for 90 minutes. One hour after reperfusion, one eye of each pig was injected with 75 microg of rtPA, and the fellow eye was injected with balanced salt solution (BSS). Eyes were processed for immunohistochemistry. Four additional eyes (group II) of two pigs were subjected to the same injections, but without optic nerve clamping. RESULTS: After reperfusion, the clinical picture was similar to that of a central retinal vein occlusion. Immunoperoxidase staining showed rtPA only in the retinal veins but not the retinal arteries in all eyes injected with rtPA in both groups I and II. Those eyes also showed intense rtPA staining at the level of the internal limiting membrane (ILM). No staining was seen at the level of the ILM or inside the retinal vessels in the BSS injected eyes. Immunofluorescence staining showed intense staining at the level of the ILM, but not inside the retinal vessels in the rtPA-injected eyes. CONCLUSIONS: rtPA may penetrate the retinal veins, but not the arteries of porcine eyes with and without vascular occlusion. The ILM may play a part in preventing rtPA penetration.

Alveolar rhabdomyosarcoma that metastasized to the orbit.

A 22-year-old woman with a history of hyperthyroidism and a paravaginal alveolar rhabdomyosarcoma developed diplopia 3 months after successful autologous bone marrow transplantation. Results of computed tomographic scan showed apparent enlargement of the right inferior rectus muscle, and thyroid eye disease was suspected. However, results of further evaluation revealed an alveolar rhabdomyosarcoma that metastasized to the orbit.

Laser-induced chorioretinal venous anastomosis for nonischemic central or branch retinal vein occlusion.

OBJECTIVE: To establish a communication between an obstructed retinal vein and the choroid by means of laser in eyes with nonischemic central or branch vein occlusion. METHODS: Retrospective review identified eyes with nonischemic central or branch vein occlusion, and with decreasing or persistently decreased visual acuity of 20/100 or worse for 4 months or more before treatment, that received 1 or more sessions of laser photocoagulation to create a chorioretinal anastomosis. RESULTS: Of 24 eyes with central vein occlusion, an anastomosis formed in 9 (38%) within 2 months after treatment, with visual improvement of 6 or more lines in 2 (8%) of 24 eyes, 1 to 3 lines in 5 (21%), and no improvement in 2 (8%). Of 6 eyes with branch vein occlusion, an anastomosis formed in 3 (50%) within 2 months after treatment, with visual improvement of 1 to 3 lines in 2 (33%) of 6 and no improvement in 1 (16%). No permanent, vision-limiting complications occurred during a mean follow-up of 13 months after the first treatment session or 8 months after the last session. CONCLUSIONS: Laser photocoagulation of a retinal vein and Bruch's membrane may create a chorioretinal anastomosis in some eyes with a nonischemic vein occlusion. Progression to an ischemic status may possibly be prevented with successful anastomosis formation. Marked visual improvement may occur. Treatment techniques to create reliably an anastomosis with subsequent visual improvement, while minimizing potential complications, continue to evolve.

Traumatic hyphema in children: risk factors for complications.

OBJECTIVE: To identify risk factors associated with higher rates of ocular complications in children with traumatic hyphema. METHODS: Consecutive inpatient records from July 1990 through December 1997 were retrospectively reviewed for all children (aged < or = 18 years) who were admitted to the Wilmer Ophthalmological Institute, Baltimore, Md, within 48 hours of a closed-globe injury leading to hyphema. Data obtained included age, sex, race, sickle cell status, initial and final visual acuities, hyphema size and intraocular pressure at presentation, the occurrence of a secondary hemorrhage, subsequent intraocular pressure elevations, and therapeutic interventions. RESULTS: Forty children fulfilled the inclusion criteria: 20 African American, 1 Asian American, and 19 white. Five of the 20 African American children had sickle cell trait, and 1 had sickle cell anemia. The rate of secondary hemorrhage was statistically higher in the African American population (P =.05), but no statistical difference existed between the rate of secondary hemorrhage in patients with and without sickle cell hemoglobinopathy. Sickle cell hemoglobinopathy was associated with a higher intraocular pressure at presentation (P =.03) and during inpatient follow-up (P =.02). CONCLUSIONS: In the setting of traumatic hyphema, African American children appear to be at greater risk for developing a secondary hemorrhage. In our patients, sickle cell hemoglobinopathy increased the risk of intraocular pressure elevation, but did not seem to increase the risk of rebleeding beyond that associated with race. Larger studies are needed to validate these observations.

Hyalocytes synthesize and secrete inhibitors of retinal pigment epithelial cell proliferation in vitro.

BACKGROUND: Retinal pigment epithelial (RPE) cells that enter the vitreous in pathologic conditions, such as retinal detachment, may proliferate and contribute to the formation of epiretinal membranes. OBJECTIVE: To study whether hyalocytes, endogenous vitreous cells, play a role in modulating the proliferation of RPE cells. METHODS: Cell proliferation was measured by tritiated thymidine incorporation in density-arrested human RPE cells after incubation with media that had been conditioned by cultured bovine hyalocytes. Preliminary characterization of inhibitory activity in hyalocyte-conditioned medium was performed, including blocking experiments with a neutralizing antibody to transforming growth factor-beta 2 (TGF-beta) and proliferation assays that used MV-1-Lu mink lung epithelial cells. Northern blots were done to asses hyalocyte expression of TGF-beta messenger RNA. RESULTS: Hyalocyte-conditioned medium inhibited tritiated thymidine incorporation in RPE cells and MV-1-Lu mink lung epithelial cells in the presence or absence of serum or protease inhibitors. A portion of the inhibitory activity was neutralized by an antibody directed against TGF-beta. Northern blots of hyalocyte RNA demonstrated the presence of messenger RNA for TGF-beta 2. These data suggest that TGF-beta is responsible for a portion of the inhibitory activity secreted by hyalocytes. Additional inhibitory activity is attributable to one or more low-molecular-weight molecules distinct from TGF-beta. CONCLUSIONS: Hyalocyte-conditioned medium inhibits RPE cell proliferation in vitro through TGF-beta and at least one other molecule. Production of these factors by hyalocytes in vivo could provide a deterrent for epiretinal membrane formation that may be perturbed under pathologic conditions.

Hypotony caused by scleral buckle erosion in Marfan syndrome.

PURPOSE: To describe hypotony caused by erosion of the conjunctiva and sclera by a silicone scleral buckle. METHODS: Interventional case report. A 33-year-old man with Marfan syndrome presented with hypotony maculopathy and a collapsed globe 17 months after repair of retinal detachment with a silicone sponge and silicone encircling band. RESULTS: Examination in the operating room revealed extrusion of the buckle through the conjunctiva and full-thickness scleral erosion. The silicone buckle was removed, and the scleral defect was closed with interrupted 8-0 nylon sutures. Postoperative glaucoma was treated with cyclophotocoagulation. Eight months after scleral repair, visual acuity was RE: 20/40, intraocular pressure was 10 mm Hg, and the retina was attached. CONCLUSION: Full-thickness scleral erosion secondary to a silicone exoplant causing hypotony is a rare long-term complication in patients with thin sclera.

Acute annular outer retinopathy: report of four cases.

PURPOSE: To describe the clinical findings and course in four patients with acute annular outer retinopathy. METHODS: Four patients were evaluated during the course of acute annular outer retinopathy, and the historical and clinical findings were retrospectively collected. RESULTS: Four healthy patients developed the acute onset of visual field loss associated with a localized, white annular outer retinopathy. All patients were caucasian; two were women, aged 29 and 32 years, and two were men, aged 71 and 79 years. The mean follow-up was 3.9 years (range, 1 to 6 years). On presentation, four eyes had an irregular, incomplete, peripapillary, annular band of gray-white, deep retinal opacification with visual CONCLUSIONS: These four cases of acute annular outer retinopathy expand our knowledge of this disorder. Acute annular outer retinopathy may be a distinct entity or it may represent a variant of acute zonal occult outer retinopathy retinopathy. As more cases are recognized, the characteristic features of the disease spectrum, the etiology, and treatment options may be better elucidated.

Pars plana vitrectomy, subretinal injection of tissue plasminogen activator, and fluid-gas exchange for displacement of thick submacular hemorrhage in age-related macular degeneration.

PURPOSE: To evaluate a new procedure for displacement of large, thick submacular hemorrhage in patients with age-related macular degeneration. METHODS: Retrospective review of 11 eyes of 11 patients with age-related macular degeneration and thick submacular hemorrhage (defined as causing retinal elevation detectable on stereo fundus photographs) treated with vitrectomy, subretinal injection of tissue plasminogen activator (25 or 50 microg), and fluid-gas exchange with postoperative prone positioning. Outcome measures included displacement of hemorrhage from the fovea, best postoperative visual acuity, and final postoperative visual acuity. RESULTS: In the 11 affected eyes of 11 patients (seven men and four women; mean age, 76 years), preoperative visual acuity ranged from 20/200 to hand motions. With surgery, subretinal hemorrhage was displaced from the fovea in all 11 cases. Mean postoperative follow-up was 6.5 months (range, 1 to 15 months). Best postoperative visual acuity varied from 20/30 to 5/200, with improvement in nine (82%) cases and no change in two cases. Eight eyes (73%) measured 20/200 or better, with four of these eyes (36%) 20/80 or better. Final postoperative visual acuity ranged from 20/70 to light perception, with improvement in eight (73%) cases, no change in one case, and worsening in two cases. A statistically significant difference was found between preoperative and best postoperative visual acuity (P =.004) but not between preoperative and final visual acuity (P =.16). Hemorrhage recurred in three (27%) eyes, causing severe visual loss in one eye. CONCLUSIONS: This technique displaces submacular hemorrhage from the fovea and can improve vision in patients with age-related macular degeneration. However, recurrence of hemorrhage occurred in 27% of eyes and caused severe visual loss in one eye. A randomized, prospective clinical trial is necessary to determine the efficacy of this technique in comparison with other proposed treatments.

The effect of arteriovenous sheathotomy on cystoid macular oedema secondary to branch retinal vein occlusion.

BACKGROUND: Arteriovenous (AV) sheathotomy, a potential treatment for branch retinal vein occlusion (BVO), surgically separates retinal vessels at an AV crossing. Relief of the aetiological obstruction, with resolution of cystoid macular oedema (CMO), may result in improved visual acuity. METHODS: A retrospective review of consecutive cases of AV sheathotomy for BVO was undertaken. Eyes were categorised as having resolution (group 1), reduction (group 2), or persistence (group 3) of CMO. Intergroup comparisons were made with regard to preoperative, intraoperative, and postoperative parameters. Preoperative and postoperative visual acuities were compared within each group. RESULTS: Of the 27 eyes identified, eight (29.6%) had resolution, 14 (51.8%) had reduction, and five (18.6%) had persistence of CMO. Median preoperative visual acuity was similar in all groups (1.0, 1.0, 1.3, respectively; p = 0.29). Overall median follow up was 12.0 months (Q1 = 12.0, Q2 = 22.5). Eyes in group 1 had significantly better median postoperative visual acuity than eyes in groups 2 and 3 (0.6, 1.0, 2.0 respectively; p = 0.01). A significantly higher proportion of eyes in group 1 had visual acuity improvement compared with eyes in the other groups (87.5% v 35.7% and 20.0%; p = 0.03). Median postoperative visual acuity was significantly better than median preoperative visual acuity in group 1 eyes only (p = 0.02). A higher percentage of group 1 eyes had evidence of postoperative retinal perfusion (83.0% v 21.43% and 40.0%; p = 0.16). Postoperative retinal detachment occurred in three eyes (11.1%). CONCLUSION: Complete resolution of CMO after AV sheathotomy occurred in one third of patients, and postoperative vision improved significantly in this group. However, in the majority of cases, despite an improvement in CMO, there was no improvement in vision after AV sheathotomy.

Pseudophakic Candida parapsilosis endophthalmitis with a consecutive keratitis.

We describe a case of Candida parapsilosis endophthalmitis with a consecutive keratitis after phacoemulsification and posterior chamber intraocular lens implantation in an otherwise healthy eye. Despite aggressive medical and surgical management during a 2-year period, multiple episodes recurred, with the development of an intracapsular plaque and an infectious nidus on the corneal endothelium 6 months after the initial presentation. After subtotal removal of the culture-positive capsule, intravitreal and topical amphotericin B, and oral fluconazole, the inflammation improved. However, the corneal endothelial plaque persisted with recurrent inflammation 2 months later, prompting debridement of the culture-positive plaque and further removal of the culture-negative capsular remnants and lens implant. The infection was quiescent for the subsequent 12-month period until recurrent intraocular inflammation developed with enlargement of the endothelial plaque. Culture of this plaque was again positive for C. parapsilosis. After debridement and intraocular and topical amphotericin B, the eye has now been quiescent for 13 months. This case demonstrates the development of a secondary keratitis in an eye affected by pseudophakic C. parapsilosis endophthalmitis, with the posterior cornea serving as a sanctuary site for the fungus despite aggressive management leading to recurrent infection 1 year after the clinical disease appeared to be quiescent.

Chorioretinal venous anastomosis for central retinal vein occlusion: transvitreal venipuncture.

The authors describe an eye with a central retinal vein occlusion that developed chorioretinal anastomoses following transvitreal venipuncture, a vitreoretinal surgical technique.

Current concepts in the management of central retinal vein occlusion.

The results of the Central Vein Occlusion Study (CVOS) guide the management of macular edema and neovascularization. This study did not show that grid-pattern laser photocoagulation had a significant beneficial effect for the management of decreased visual acuity caused by perfused macular edema in eyes with central retinal vein occlusion (CRVO). Panretinal laser photocoagulation (PRP) was shown to be beneficial for eyes with at least 2 clock hours of iris neovascularization or any angle neovascularization. PRP has not been advocated as prophylaxis for ischemic eyes before the formation of neovascularization. Although treatment of the ocular consequences of CRVO may be guided by the CVOS data, management of the underlying cause of CRVO-the occluded vein itself-was not addressed in the study. Recently, several reports have suggested restoring venous outflow by 1) creating a laser-induced or surgically induced chorioretinal anastomosis, 2) administering recombinant tissue plasminogen activator (rt-PA), 3) cannulating the retinal vein transvitreally, or 4) transecting the posterior scleral ring.

Are antioxidants or other supplements protective for age-related macular degeneration?

As the number of individuals with age-related macular degeneration increases, the economic and social consequences of this blinding disease rise. No proven preventive measures exist to halt development or progression of this disease. The specific insults that trigger and perpetuate age-related macular degeneration are unknown; however, it may be the result of repetitive oxidative injuries. Several studies suggest a possible protective role for antioxidant micronutrients and other trace minerals, but data for specific antioxidants have been inconsistent between studies. Although promising, the preliminary evidence is limited. Reliable data on whether antioxidant vitamins or trace minerals decrease the development or progression of age-related macular degeneration will emerge from several ongoing large-scale randomized clinical trials. Based on the currently available information, it is not possible to recommend antioxidant micronutrient supplementation to protect against development or retard progression of age-related macular degeneration.

Eye injuries associated with paintball guns.

AIMS: This study identifies the various types of ocular injuries sustained after blunt trauma with a paintball fired from a paintball gun. METHODS: We report two patients who sustained injury to an eye after being shot with a paintball and review similar cases presented in the world literature. The type of injury sustained and the final visual acuity obtained after a paintball hit to the eye are examined. RESULTS: The two boys presented were hit in the eye with a paintball resulting in lens subluxation, hyphema formation, and angle recession. Cataract extraction was required in both cases. One boy also had an optic neuropathy and a choroidal rupture. A review of the literature reveals a variety of injuries occur after a paintball hit to the eye. In some of the cases, the damage to the eye has led to loss of vision and at times loss of the eye. CONCLUSIONS: Paintball guns can cause devastating ocular injuries. Wearing protective eye and face gear during this game is essential. We recommend that an anti-fog face mask with a one-piece polycarbonate eye shield be worn by those participating in paintball games.

The effect of oral 13-cis-retinoic acid on retinal redetachment after surgical repair in eyes with proliferative vitreoretinopathy.

PURPOSE: To determine if postoperative oral 13-cis-retinoic acid alters the rate of recurrent retinal detachment in eyes undergoing surgery for proliferative vitreoretinopathy (PVR). METHODS: Twenty eyes of 20 adult patients with a detachment due to PVR were identified after retrospective review of the patient records of a single vitreoretinal surgeon (EdJ) over an 18-month period (January 1992-August 1993). All 20 eyes underwent surgical repair using similar techniques. Ten patients received 40 mg oral 13-cis-retinoic acid twice daily for 4 weeks postoperatively (study group). The remaining ten patients did not (control group). The main outcome measure was retinal attachment or detachment. RESULTS: No statistically significant differences in preoperative patient characteristics or surgical procedure were present between the groups. Nine of ten eyes in the study group remained attached during a mean follow-up of 8.3 months, whereas four of ten eyes in the control group remained attached (P = 0.061) during a mean follow-up of 9.6 months. The rate of macular pucker was similar between the groups. The one eye in the study group that redetached did not have PVR. Of the six eyes in the control group that detached, four had 6 or more clock hours of PVR. The final visual acuity was better than 20/400 in six study eyes and four control eyes. CONCLUSIONS: Despite the small sample size and retrospective nature, the postoperative administration of oral 13-cis-retinoic acid appears to decrease proliferative vitreoretinopathy and increase the rate of retinal attachment after surgical repair. A prospective, randomized, controlled clinical trial is warranted.

Current concepts in the management of central retinal vein occlusion.

The results of the Central Vein Occlusion Study guide the management of complications of macular edema and neovascularization. Panretinal photocoagulation was shown to be beneficial for eyes with at least 2 hours of iris neovascularization or any angle neovascularization. Grid-pattern laser photocoagulation for perfused macular edema did not show a significant beneficial effect. Recently, several reports have suggested restoring venous outflow by 1) creating a chorioretinal anastomosis, 2) administering recombinant tissue plasminogen activator, 3) cannulating the retinal vein transvitreally, or 4) transecting the posterior scleral ring.

Clinicopathologic correlation of an epiretinal membrane associated with a recurrent macular hole.

PURPOSE: To describe the clinicopathologic features of an epiretinal membrane associated with a recurrent, full-thickness idiopathic macular hole and speculate on the mechanism(s) contributing to its recurrence 1 year after initially successful closure of pars plana vitrectomy and gas tamponade (SF6). METHODS: After fixation of the 2 x 1 mm specimen in a mixture of 1% glutaraldehyde and 4% formaldehyde followed by 2.5% glutaraldehyde, postfixation with osmium tetroxide, and standard dehydration, the specimen was embedded in epoxy resin. Ultrathin sections were stained with uranyl acetate and lead citrate for transmission electron microscopy. RESULTS: Ultrastructural examination disclosed a fibrocellular membrane composed of Müller cells and fibrous astrocytes. Native collagen was entrapped in the matrix in some areas. CONCLUSION: Those cells that may lead to the closure of an idiopathic macular hole may also contribute to its recurrence if the reparative process goes awry.