PubMed Health⌕ Search

Biomedical subjects

G A Peyman

Publications and source records attributed to G A Peyman.

At least 19 recordsLinked to original sources

Prophylaxis of acute posttraumatic bacterial endophthalmitis with or without combined intraocular antibiotics: a prospective, double-masked randomized pilot study.

PURPOSE: The effectiveness of an intraocular injection of combined gentamicin and clindamycin in the prevention of acute posttraumatic bacterial endophthalmitis following penetrating ocular injuries was evaluated in a prospective, double-masked, randomized pilot study. METHODS: Sixty eyes of 60 patients with penetrating ocular injuries were treated at a tertiary care hospital. Following primary repair, the eyes were randomized in two groups. Group 1, the antibiotic injection group (cases), was given an intracameral or intravitreal injection of 0.1 mL antibiotic (40 microg gentamicin and 45 microg clindamycin). Group 2 (balanced saline solution [BSS] injection group [controls]) received intracameral or intravitreal injection of 0.1 mL BSS. All patients received standard prophylactic antibiotic therapy (systemic, subconjunctival, and topical). RESULT: Although the overall incidence of acute posttraumatic bacterial endophthalmitis was 6.6% (4 eyes), the results of three cultures were negative. All endophthalmitis cases occurred in the BSS injection group; however, there was no statistically significant difference between case and control groups (p = 0.11). The incidence rate for those with retained intraocular foreign bodies was 13.3% and for those without foreign bodies was 4.4%. No retinal toxicity was detected. CONCLUSION: Intraocular injection of gentamicin and clindamycin in addition to the other methods of prophylaxis may be an effective modality in the prevention of posttraumatic endophthalmitis. Early results suggest that these antibiotics may have a role as adjunct therapy to primary repair of injured globes without significant side effects at the dosage used.

Adolescent↗

Retreatment effect of NPe6 photodynamic therapy on the normal primate macula.

PURPOSE: To evaluate the safety and efficacy of repeated photodynamic therapy (PDT) with mono-L-aspartyl chlorin e6 (NPe6) on normal primate fovea and choroid. METHODS: Macaca fuscata monkeys were used as experimental subjects. Mono-L-aspartyl chlorin e6 at a dose of 2 mg/kg was administered by intravenous infusion. Laser irradiation was applied within 5 minutes using a 664-nm diode laser at a power output of 5.9 mW (750 mW/cm2), spot size of 1,000 microm, and time of 10 seconds. This resulted in a fluence of 7.5 J/cm2. Three consecutive PDT treatments at 2-week intervals were applied over the center of the fovea and posterior fundus near the arcade vessels of each eye. The animals were killed and the eyes were enucleated for histologic study 2 weeks after the last treatment. RESULTS: Limited changes could be observed in the sensory retina under light microscopy. Photoreceptor cells and outer segments were not damaged, even after repeated PDT. Proliferation and duplication of the retinal pigment epithelial cells were common findings. A plaque of fibrous tissue was present, interwoven with retinal pigment epithelial cells in eyes that received repeated PDT. The retinal vessels remained patent even after three sessions of PDT. However, occlusion of the choriocapillaris and the large choroidal vessels was observed after repeated PDT treatment. CONCLUSION: Repeated PDT of healthy nonhuman primate fundi using a hydrophilic photosensitizer (NPe6) shows preservation of the neurosensory retina components and architecture with damage confined to the retinal pigment epithelium and choriocapillaris.

Animals↗

Photodynamic therapy of experimental choroidal neovascularization with a hydrophilic photosensitizer: mono-L-aspartyl chlorin e6.

PURPOSE: To demonstrate the selective localization of the hydrophilic photosensitizer mono-L-aspartyl chlorin e6 (NPe6) in experimental choroidal neovascularization in nonhuman primate eyes. METHODS: Sixty-seven experimental choroidal neovascular lesions (CNV) were created in the fundi of Macaca monkeys using the modified Ryan's model and documented by fluorescein and indocyanine green angiography. To determine the biodistribution of NPe6 and the optimal timing of laser irradiation after dye administration, NPe6 angiography and fluorescence microscopy with NPe6 were performed. Photodynamic therapy (PDT) was performed at various dye doses (0.5-10.0 mg/kg) and laser fluences (7.5-225.0 J/cm2) on the CNV and on 10 areas of normal retina and choroid. Treatment outcomes were assessed by fluorescein and indocyanine green angiography and confirmed by light and electron microscopy. RESULTS: NPe6 fluorescence microscopy demonstrated intense fluorescence of CNV and retinal pigment epithelial cells. Choroidal vessel walls and outer retina adjacent to CNV fluoresced moderately; retinal vessel walls and microcapillaries had trace fluorescence. The fluorescence of CNV lesions on fluorescein angiography became stronger than that of retinal vessels 20-60 minutes after dye injection. Choroidal neovascular lesion closure was achieved with NPe6 PDT without significant damage to the sensory retina. Histology demonstrated necrosis of CNV endothelial cells with minimal damage to surrounding tissues. CONCLUSIONS: NPe6 PDT selectively localizes to experimental CNV in nonhuman primates, resulting in occlusion of CNV with sparing of the neurosensory retina.

Animals↗

Implantation of silicon chip microphotodiode arrays into the cat subretinal space.

There are currently no therapies to restore vision to patients blinded by photoreceptor degeneration. This project concerns an experimental approach toward a semiconductor-based subretinal prosthetic designed to electrically stimulate the retina. The present study describes surgical techniques for implanting a silicon microphotodiode array in the cat subretinal space and subsequent studies of implant biocompatibility and durability. Using a single-port vitreoretinal approach, implants were placed into the subretinal space of the right eye of normal cats. Implanted retinas were evaluated post-operatively over a 10 to 27 month period using indirect ophthalmoscopy, fundus photography, electroretinography, and histology. Infrared stimulation was used to isolate the electrical response of the implant from that of the normal retina. Although implants continued to generate electrical current in response to light, the amplitude of the implant response decreased gradually due to dissolution of the implant's gold electrode. Electroretinograms recorded from implanted eyes had normal waveforms but were typically 10-15% smaller in amplitude than those in unimplanted left eyes. The nonpermeable silicon disks blocked choroidal nourishment to the retina, producing degeneration of the photoreceptors. The laminar structure of the inner retinal layers was preserved. Retinal areas located away from the implantation site appeared normal in all respects. These results demonstrate that silicon-chip microphotodiode-based implants can be successfully placed into the subretinal space. Gold electrode-based subretinal implants, however, appear to be unsuitable for long-term use due to electrode dissolution and subsequent decreased electrical activity.

Animals↗

Problems with and pitfalls of photodynamic therapy.

OBJECTIVE: To delineate the various factors that may influence the outcome of photodynamic therapy of the retina and choroid. DESIGN: Experimental animal study. ANIMALS: Pigmented and nonpigmented rabbits; rhesus monkeys. INTERVENTION: The hydrophilic photosensitizer, mono-L-aspartyl chlorin e6, which is maximally activated at 664 nm, was studied after intravenous injection into pigmented and nonpigmented rabbits and rhesus monkeys. Laser light was supplied by a red diode laser coupled to a modified slit-lamp biomicroscope and delivered to the ocular fundus after passing through a standard fundus contact lens. Standard photodynamic parameters were used. The effects of fundus pigmentation, intraocular pressure, spot focus and defocus, region of fundus treated, equivalent fluence, and retreatment were observed in the different animal species. MAIN OUTCOME MEASURES: Slit-lamp biomicroscopy, fluorescein angiography, light and transmission electron microscopy. RESULTS: Fundus pigmentation appeared to be a factor only at the lowest fluence level tested, where only 4 of 12 lesions attempted in pigmented fundi were noted on fluorescein angiography, compared with 12 of 12 lesions in albino rabbits. At normal intraocular pressures and a given fluence, 10 of 10 lesions were fully manifested on fluorescein angiography, compared with 4 of 10 at 30 mmHg and 0 of 10 at pressures sufficient to blanch the optic nerve (>60 mmHg). For laser spots either focused or defocused, there were 6 of 6 lesions that were fully manifested on fluorescein angiography for each of the parameters. Lesions treated in the fovea resulted in larger spots on fluorescein angiography. The fluence of 5 mW for 10 seconds resulted in a larger lesion on angiography than the equivalent fluence of 10 mW for 5 seconds. Areas of retreatment in rabbits demonstrated more thinning of the neurosensory retina and loss of photoreceptor outer segments and nuclei than corresponding areas receiving one treatment. CONCLUSIONS: Photodynamic therapy results varied, depending on intraocular pressure, region of fundus treated, ocular pigmentation, and the total time of exposure to the photosensitizer. Retreatment resulted in progressive thinning of the neurosensory retina with loss of photoreceptor outer segments and nuclei in the rabbit eye.

Animals↗

The efficacy of plasminogen-urokinase combination in inducing posterior vitreous detachment.

PURPOSE: To investigate the toxicity of intravitreal plasminogen, urokinase, and their combination, and to evaluate their efficacy in the production of posterior vitreous detachment (PVD) in the rabbit eye. METHODS: Fifty-six albino New Zealand rabbits were examined before and after injection using the indirect ophthalmoscope, slit-lamp biomicroscopy, and electroretinography. Various concentrations of urokinase or recombinant plasminogen or a combination were injected intravitreally into the right eyes of four rabbits for each concentration. The left eyes of the animals served as controls and received 0.1 mL balanced salt solution. Group 1 was injected with pure urokinase (1,000, 5,000, or 10,000 IU); Group 2 with recombinant plasminogen (0.1, 0.4, 1.0, 2.0, 4.0, 8.0, or 16.0 caseinolytic units [CU]); and Group 3 with a combination of 1,000 IU urokinase (highest nontoxic dose) and nontoxic concentrations of plasminogen (0.1, 0.4, 1.0, or 2.0 CU). The animals were killed and the eyes enucleated 15 days after injection. Electron and light microscopy were performed. RESULTS: A concentration of 1,000 IU of urokinase was found to be nontoxic to the retina. Plasminogen concentrations of 2.0 CU or less did not produce retinal toxicity, whereas 4.0, 8.0, and 16.0 CU of plasminogen caused minimal-to-severe inflammatory response in the vitreous without histologic or electroretinographic changes. Neither plasminogen nor urokinase alone was successful in producing PVD. The combination of 1,000 IU of urokinase and 1.0 to 2.0 CU of plasminogen was effective without causing retinal toxicity. CONCLUSION: Posterior vitreous detachment can be produced in the rabbit eye using a combination of plasminogen and urokinase.

Animals↗

Angiographic and histologic effects of fundus photodynamic therapy with a hydrophilic sensitizer (mono-L-aspartyl chlorin e6).

PURPOSE: To demonstrate the efficacy of the photosensitizer mono-L-aspartyl chlorin e6 (NPe6) in closing choroidal vessels at low energy levels, that tissue uptake and clearance are rapid, and that low concentrations of drug are needed to achieve clinical effects. DESIGN: Experimental animal study. ANIMALS: Pigmented rabbits and Japanese monkeys were used in this study. METHODS: Using a modified 664-nm diode laser, the fundi of pigmented rabbits and Japanese monkeys were irradiated after intravenous administration of NPe6 (2-100 mg/kg). Time from injection to irradiation varied from 5 to 15 minutes, and duration of exposure varied from 1 to 10 seconds. Power output at the corneal surface was either 3.6 or 5.9 mW. Animals were examined by indirect ophthalmoscopy and fluorescein angiography at 2 hours and 7 days after treatment. After enucleation 7 days after treatment, specimens were prepared for light and electron microscopy. MAIN OUTCOME MEASURES: Angiographic evidence of occlusion and histopathologic evidence of retinal damage. RESULTS: Both clinical and histopathologic examination demonstrated effects on the choroidal vasculature and the retinal pigment epithelium, including necrosis of endothelial cells and occlusion in choroidal vessels, particularly within the choriocapillaris, at low energy levels. Overlying neurosensory retina was minimally affected. Fluorescein angiography of lesions treated with 2 mg/kg and laser fluence of 2.3 to 7.5 J/cm2 showed a normal appearance 2 hours after treatment, which changed to early hypofluorescent and later hyperfluorescent lesions 7 days after treatment. In contrast, those animals receiving the 10-mg/kg dose and laser fluence of 0.46 to 0.75 J/cm2 showed marked hypofluorescence of choroidal lesions and occlusion of retinal vessels 7 days after treatment. CONCLUSIONS: Effective occlusion of normal choroidal vessels was achieved at 2 mg/kg using 2.3 to 7.5 J/cm2 or at 10 mg/kg using 0.46 to 0.75 J/cm2 with minimal injury to overlying neurosensory retina.

Animals↗

Experimental prophylaxis of Staphylococcus aureus endophthalmitis after vitrectomy: the use of antibiotics in irrigating solution.

PURPOSE: To test the efficacy of clindamycin and gentamicin in irrigating solution during vitrectomy to prevent experimental Staphylococcus aureus endophthalmitis. MATERIALS AND METHODS: Thirty-six New Zealand white rabbits were divided into six groups. Vitrectomy using two different irrigating solutions was followed by intravitreal injection of S. aureus: Group 1, balanced salt solution (BSS) followed by 1,000 colony-forming units (CFU) S. aureus; Group 2, BSS fortified with clindamycin, 10 microg/mL, and gentamicin, 8 microg/mL (CGBSS), followed by intravitreal injection of 1,000 CFU S. aureus; Group 3, BSS followed by 2,000 CFU S. aureus; Group 4, CGBSS followed by 2,000 CFU S. aureus; Group 5, BSS followed by 4,000 CFU S. aureus; and Group 6, CGBSS followed by 4,000 CFU S. aureus. The eyes were examined clinically after surgery. Vitreous samples were cultured and histologic studies were performed. RESULTS: Severe endophthalmitis developed in all eyes in Groups 1, 3, and 5 (not given antibiotics). No endophthalmitis developed in Group 2. In Group 4, five of the six eyes were normal and one eye had endophthalmitis. In Group 6, one eye had clear vitreous and fundus, three eyes had moderate vitreous haze, and the other four eyes demonstrated severe endophthalmitis. Bacterial growth in Groups 1, 2, 3, 4, 5, and 6 were 4/4, 0/4, 6/6, 1/6, 4/6, and 2/8 eyes, respectively. CONCLUSION: When 1,000 to 2,000 CFU S. aureus were injected after vitrectomy, clindamycin and gentamicin in the irrigating solution significantly diminished the intraocular inflammation and the rate of positive bacterial culture. Clindamycin and gentamicin in the irrigating solution were not significantly effective when 4,000 CFU bacteria was injected; however, the degree of inflammation was less severe than in the control group.

Acetates↗

Tolerance of extended-term vitreous replacement with perfluoro-n-octane and perfluoroperhydrophenanthrene mixture (phenoctane).

PURPOSE: To improve the surface visibility of perfluoroperhydrophenanthrene, we added various percentages of perfluoro-n-octane. METHODS: Twenty New Zealand white rabbit eyes underwent gas vitrectomy. One milliliter of balanced salt solution was injected into each Group 1 eye as control. Perfluoro-n-octane was added to perfluoroperhydrophenanthrene in ratios of 15:85, 25:75, and 50:50; 1 mL of each mixture was injected into the vitreous cavities of Groups 2, 3, and 4, respectively. Eyes were examined clinically and electroretinograms were performed before and 4 and 8 weeks after injection, when the rabbits were killed. Eyes were processed for light and transmission electron microscopy (TEM). RESULTS: The indices of refraction of the 15:85, 25:75, and 50:50 mixtures were 1.3275, 1.3191, and 1.3026, respectively, and the mixtures were visible in the vitreous cavity. Emulsification and mild-to-moderate dust-like opacities were observed in eyes from Groups 2 through 4; vitreous strands formed in four of the Group 4 eyes. The retinae were attached. Electroretinographic responses were normal, except in one eye with cataract. Light microscopy showed normal retinal architecture, with some macrophages with intracytoplasmic vacuoles on the surface of the inferior retina or in the vitreous cavity. Fingerprint disfigurement of photoreceptor outer segments was seen in some Group 3 and 4 eyes under TEM. CONCLUSIONS: Minimal changes were induced by the 15:85 mixture in the rabbit eye. The mixtures of 25:75 and 50:50 produced some ultrastructural changes of the retina. The mixtures were visible under water.

Animals↗

Ocular toxicity of intravitreal clarithromycin.

OBJECTIVE: To investigate the ocular toxicity and clearance of intravitreal clarithromycin lactobionate (Klaricid) and to determine the highest nontoxic dose. MATERIALS AND METHODS: To evaluate toxicity, 24 New Zealand white rabbits were divided into six groups (four rabbits each). Rabbits were examined preoperatively and electroretinography (ERG) was performed. The left eyes of the animals served as controls and received intravitreal injection of 0.1 mL sterile water. Klaricid (0.1 mL) was injected into the midvitreous cavity of the right eyes at concentrations of 25 microg, 250 microg, 500 microg, 1.0 mg, 2.0 mg, and 4.0 mg/0.1 mL. The animals were followed up to 15 days postinjection by clinical examination and ERG. The animals were killed and the eyes were enucleated and processed for light microscopy. Ten New Zealand rabbits were used for the vitreous clearance study as drug test rabbits and two additional rabbits were used to generate control retina and vitreous. The highest nontoxic dose (1 mg) was injected into the vitreous and the concentration of clarithromycin in the vitreous was determined using high-performance liquid chromatography at various time intervals after injection. RESULTS: Cataract occurred after intravitreal doses of 2.0 and 4.0 mg. Electroretinography showed decreasing b-wave amplitude with both dark- and light-adapted stimulus in the 4.0-mg group; it was normal in other groups. Histopathologic sections showed localized retinal necrosis and disorganization with the 2.0 and 4.0 mg dosage. No histologic changes were found in the other groups. The half-life of intravitreal clarithromycin was found to be 2 hours. No metabolites of clarithromycin were observed in the vitreous samples. CONCLUSION: Intravitreal clarithromycin lactobionate is nontoxic to rabbit eyes up to a dose of 1.0 mg. Because of its broad-spectrum antibiotic effect and appropriate half-life in the vitreous, it may be a good choice for intravitreal treatment of susceptible organisms.

Animals↗

Evaluation of toxicity of intravitreal ceftazidime, vancomycin, and ganciclovir in a silicone oil-filled eye.

PURPOSE: To evaluate the toxicity of intravitreal drugs in an eye filled with silicone oil for prolonged internal retinal tamponade. METHODS: Vitrectomy was performed in 21 rabbit eyes, and the vitreous was replaced with silicone oil. Different concentrations of various drugs (ceftazidime, vancomycin, and ganciclovir) were injected intravitreally. RESULTS: Silicone oil increased the toxicity of these drugs, which were injected in previously determined nontoxic doses, possibly because of a reduction of the preretinal space. Injecting one quarter of the known nontoxic dose failed to show any toxicity. CONCLUSIONS: Nontoxic concentrations of intravitreal drugs can cause toxicity in a silicone-filled eye.

Animals↗

Fluorescent labeling of blood cells for evaluation of retinal and choroidal circulation.

BACKGROUND AND OBJECTIVE: To develop a method of staining and tracking cells in vivo with a scanning laser ophthalmoscope (SLO) to evaluate the retinal and choroidal circulations. MATERIALS AND METHODS: Twelve pigmented male rats were used. Staining of leukocytes. Two commercially available nucleic acid stains SYTO 16 and SYTO 59 (Molecular Probes, Eugene, OR) were used to stain leukocytes. Blood (0.5 mL) was withdrawn from the subject animal and placed in a heparinized tube to which phosphate buffered solution was added (1.0 mL buffer/0.5 mL blood). Ten microliters of solution of SYTO 16 or SYTO 59 in alcohol (5 mM) was added. Staining of Erythrocytes. The lipophilic carbocyanine dye indocarbocyanine (D-307, Molecular Probes) was used to stain erythrocytes. Blood (0.1 mL) was withdrawn from the subject and handled as above; plasma and leukocytes were removed with a pipette. HEPES buffer was added to the remaining erythrocytes (1.4 mL buffer added to 0.1 mL blood). Ten microliters of D-307 in alcohol (5 mM) was added to the 1.5 mL buffered blood. The final concentration of dyes in the buffered blood mixtures was 0.03 mM. The stained cells were injected intravenously in the subject animal. The eyes were observed with SLO; the resident helium-neon laser was used to excite the SYTO 59 and the resident argon laser for SYTO 16. The He-Ne laser was used to excite the D-307-stained erythrocytes. RESULTS: The movement of the leukocytes and erythrocytes in the retinal and choroidal vessels was clearly distinguishable from the surrounding tissue. CONCLUSION: By selecting different dyes for staining leukocytes or erythrocytes and choosing appropriate laser wavelengths, the hemodynamics of blood cells can be observed and evaluated in the retina and choroid.

Affinity Labels↗

Intravitreal tPA and SF6 promote clearing of premacular subhyaloid hemorrhages in shaken and battered baby syndrome.

BACKGROUND AND OBJECTIVE: Child abuse is a serious problem in many cultures. The ocular signs of shaken baby include intraretinal, subretinal, and preretinal hemorrhages. The hemorrhages may be unilateral or bilateral and are seen in 50% to 80% of patients. Previous treatment was limited to observation or vitrectomy, but some observed eyes develop amblyopia, and pediatric vitrectomy has many complications. PATIENTS: We report 4 eyes in 2 children with shaken baby syndrome in whom we administered intravitreal tissue plasminogen activator (tPA) in an attempt to resolve preretinal hemorrhages earlier than observation alone without the complications of vitrectomy. The tPA dose ranged from 12.5-25 microg per injection. Eyes were injected once weekly for 3 consecutive weeks. Each time 0.25 cc of sulfur hexafluoride gas was also injected. RESULTS: Within 1 week following the last tPA administration, complete resolution of the preretinal hemorrhage was seen. There were no associated ophthalmic complications. CONCLUSION: Intravitreal tPA with an expansive gas is an alternative method to observation or vitrectomy for resolution of preretinal hemorrhages in battered babies and may allow faster resolution of hemorrhages without the complications of vitrectomy.

Battered Child Syndrome↗

Intraoperative complications of perfluoroperhydrophenanthrene: subretinal perfluorocarbon, retinal slippage and residual perfluorocarbon. Vitreon Study Group.

BACKGROUND: An earlier analysis of postoperative complications of the perfluorocarbon liquid perfluoroperhydrophenanthrene (Vitreon) showed a low overall rate of posterior segment complications. A study was conducted to determine the incidence of specific intraoperative complications in a wide variety of vitreoretinal procedures performed by many different surgeons using Vitreon. METHODS: The records of consecutive patients enrolled in the Vitreon Collaborative Study were reviewed to determine the incidence of subretinal Vitreon, retinal slippage and residual Vitreon. A total of 1867 vitreoretinal procedures performed between Nov. 16, 1989, and Dec. 14, 1994, at 35 participating centres were studied. Vitreon was used as a surgical tool at the surgeon's discretion after informed consent was obtained. The incidence of intraoperative complications was determined, and preoperative, intraoperative and postoperative characteristics were tabulated. RESULTS: Subretinal Vitreon was observed in 24 patients (1.3%), retinal slippage in 20 patients (1.1%) (15 [6.9%] of the 216 patients with giant retinal tears) and residual Vitreon in 68 patients (3.6%). INTERPRETATION: Vitreon can be used as a surgical tool in a wide variety of vitreoretinal procedures with a low incidence of intraoperative complications.

Adolescent↗

Management of submacular hemorrhage with intravitreal sulfur hexafluoride: a pilot study.

BACKGROUND: Some success has been reported with the intravitreal use of tissue plasminogen activator (tPA) and perfluoropropane gas in the management of large submacular hemorrhages. However, the dosage of tPA that has been used (100 micrograms) has a narrow margin of safety, and it remains to be shown that intravitreal tPA can cross the retina and effect subretinal clot lysis. We carried out a pilot study to evaluate the efficacy of intravitreally administered sulfur hexafluoride (SF6) gas alone in the management of large submacular hemorrhages secondary to age-related macular degeneration (AMD). METHODS: Three patients with large submacular hemorrhages secondary to AMD seen at a university-affiliated teaching hospital in Ottawa were treated with an intravitreal injection of 0.6 mL of SF6 gas. They were instructed to assume a prone position for 7 to 10 days. The patients were followed 3, 7, 14 and 28 days after the procedure and monthly thereafter for at least 6 months. Colour photography and fluorescein and indocyanine green angiography were performed immediately before and 2 weeks after the procedure and, thereafter, at the discretion of the treating ophthalmologist. RESULTS: In all three cases significant inferior displacement of the submacular blood was observed. Two patients showed an improvement of vision from counting fingers to 20/70 and to 20/200. In one case the submacular blood was displaced such that laser photocoagulation of a juxtafoveal choroidal neovascular membrane became possible. INTERPRETATION: The results suggest that intravitreally administered SF6 alone may have a role in the management of selected cases of neovascular AMD complicated by significant submacular hemorrhage. These results call into question the utility of adjunctive intravitreal tPA in such cases.

Fluorescein Angiography↗