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.

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.

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.

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.

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.

Clinicopathologic findings in eyes with retained perfluoro-n-octane liquid.

OBJECTIVE: To describe the clinical and histopathologic findings in five eyes with retained perfluoro-n-octane (PFO) liquid after retinal reattachment surgery. DESIGN: Retrospective, noncomparative, clinicopathologic case series. PARTICIPANTS: Surgical specimens from five eyes were studied. METHODS: Surgical specimens from eyes with prior intraoperative PFO use submitted to the W. Richard Green Eye Pathology Laboratory at the Wilmer Ophthalmological Institute were identified and reviewed. MAIN OUTCOME MEASURES: Histopathologic analysis and energy dispersive spectroscopy identified intracellular vacuoles containing PFO. RESULTS: Five cases were identified. Three specimens were obtained at the time of further surgery for recurrent retinal detachment; one at repeat penetrating keratoplasty, and one at removal of retained PFO. Each eye had macroscopic white flake-like material on intraocular structures noted before or during surgery. Histopathologic analysis disclosed an inflammatory response featuring macrophages with intracellular vacuoles containing PFO. Removal of the PFO in all five eyes combined with repeat retinal reattachment surgery in three eyes resulted in resolution of the inflammatory response. CONCLUSIONS: Retention of PFO after surgery elicits an inflammatory response. We suspect that young patients, those with considerable residual vitreous gel, and eyes with larger amounts of retained PFO may be at higher risk for this complication.

Eye pain after vitreoretinal surgery: a prospective study of 185 patients.

PURPOSE: To assess subjective levels of eye pain, nausea, and sedation following vitreoretinal surgery performed with intravenous sedation and retrobulbar anesthesia. METHODS: One hundred eighty-five consecutive patients who underwent vitreoretinal surgery and had access to a standard postoperative analgesic regimen prospectively quantified levels of eye pain, nausea, and sedation 2 hours and 5 hours after surgery by using a standard visual analog scale. Analgesic requests were recorded. Responses were statistically analyzed. RESULTS: Fifty-six percent of patients had some eye pain after vitreoretinal surgery; 48% of patients requested an analgesic within 5 hours after surgery. Twenty-seven percent of patients required narcotic analgesia. There was a significant relationship between the presence of eye pain and surgery duration of >2 hours (P < 0.02). Sixteen percent of patients had postoperative nausea, which more likely occurred in those who received a narcotic analgesic (P < 0.02). Eighty percent of patients had postoperative sedation, which more likely occurred in those who received a narcotic analgesic (P < 0.02). CONCLUSION: One half of individuals undergoing vitreoretinal surgery, especially those who have lengthy procedures (>2 hours), will request pain medication within 5 hours after surgery; one half of these patients will need narcotic analgesia for pain control. Narcotics may result in nausea and sedation.

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 planitis: clinical features and class II HLA associations.

OBJECTIVE: To describe a cohort of patients with pars planitis followed at a single tertiary care institution, determine the frequency of multiple sclerosis and/or optic neuritis in patients with this disorder, and calculate gene frequencies of human leukocyte antigen (HLA) class II alleles in these patients. DESIGN: Fifty-three patients with the diagnosis of pars planitis underwent clinical record review or telephone interview for follow-up or both; 32 of these underwent phlebotomy for analysis of HLA class II alleles. MAIN OUTCOME MEASURES: Outcomes included visual acuity, occurrence of multiple sclerosis and/or optic neuritis, and HLA class II gene frequencies. RESULTS: With a mean follow-up of 2 years, approximately 90% of patients maintained a visual acuity better than 20/40 in at least one eye. The most frequently encountered ophthalmic complications included cystoid macular edema, cataract, and epiretinal membrane formation. Of 37 patients with pars planitis who had medical or neurologic follow-up evaluations, 6 (16.2%) developed multiple sclerosis. The HLA-DR15 allele, coding for one of the two HLA-DR2 subtypes, was associated with pars planitis (odds ratio = 2.86, 95% confidence interval = 1.42-5.78, P = 0.004). CONCLUSIONS: A common immunogenetic predisposition to multiple sclerosis and pars planitis may be associated with the HLA-DR15 allele. This association may represent genetic linkage to the HLA-DR locus or a role for the HLA-DR15 gene product in the pathogenesis of both of these diseases.

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 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.

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.

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.

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.

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.

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.

Natural history of subfoveal subretinal hemorrhage in age-related macular degeneration.

PURPOSE: The authors describe the natural history of subfoveal subretinal hemorrhage (for which laser treatment was not indicated) in age-related macular degeneration. METHODS: A retrospective review of data was performed at a tertiary retinal referral center for 41 eyes from 40 patients with age-related macular degeneration examined during an 18-month period. All patients had at least 3 months of follow-up, as well as subfoveal subretinal hemorrhage that made up more than 50% of a neovascular lesion-as documented by fluorescein angiography-and therefore, did not meet criteria for laser treatment. The number of lines of visual acuity lost or gained in each eye during follow-up was calculated; presenting characteristics were evaluated as predictors of visual outcome. RESULTS: A progressive loss of visual acuity from baseline was observed throughout the 3-year follow-up period in most eyes. At 36 months, a mean of 3.5 lines of visual acuity had been lost in the 16 eyes examined; 44% of eyes had lost 6 or more lines of visual acuity. The percentage of patients who sustained a spontaneous improvement of 3 or more lines of visual acuity decreased from 31% at 12 months to 21% at 36 months of follow-up. Univariate linear regression analysis demonstrated significant relationships of initial size of the hemorrhage, elevation of the retina by the hemorrhage, and size of the entire lesion with visual outcome at the 12-month and 36-month examinations (P < 0.05). CONCLUSIONS: Although this study confirms that some eyes with subfoveal subretinal hemorrhage associated with age-related macular degeneration have poor prognoses, the visual acuity of other eyes did not deteriorate. These findings underscore the importance of evaluating the role of therapeutic interventions such as surgery to remove subretinal hemorrhage in randomized clinical trials.