The use of intravitreal tissue plasminogen activator in the treatment of experimental subretinal hemorrhage in the pig model

Pneumatic displacement with intravitreal tPA injection versus vitrectomy with sub retinal tPA injection in small and medium sub macular hemorrhages- a multicenter comparative study

PURPOSE

Comparing between the visual outcomes and post operative complications of two surgical treatments for sub macular hemorrhage, pars plana vitrectomy with tissue plasminogen activator (tPA) injection procedure, and pneumatic displacement of submacular hemorrhage with intravitreal tPA injection.

METHODS

A retrospective chart review of patients with sub macular hemorrhage (SMH) was performed. Data was collected from 150 patients with sub macular hemorrhage. Patients were followed up from the day of admission and up to a year post surgery. Evaluation included visual acuity, optical coherence tomography (OCT), fundus examination and rates of complications.

RESULTS

Pars plana vitrectomy procedure has showed a better visual outcome in small SMH. Comparing complications between the two treatment modalities, no significant difference has been found in the study.

CONCLUSIONS

Pars plana vitrectomy and tPA showed a clear advantage with a trend of better visual acuity as well as a significant predictor to better visual acuity for small and medium sub macular hemorrhage.

Functional and structural outcome after vitrectomy combined with subretinal rtPA Injection with or without additional intravitreal Bevacizumab injection for submacular hemorrhages

Background

To analyze the functional and anatomical outcome after vitrectomy with subretinal rtPA (recombinant tissue plasminogen activator) combined with or without an intravitreal Bevacizumab injection.

Patients and methods

Retrospective, consecutive case series of 31 pseudophakic patients with submacular hemorrhage (SMH) due to neovascular age-related macular degeneration (AMD) treated with vitrectomy, subretinal rtPA and pneumatic air displacement with or without an additional intravitreal Bevacizumab injection. The primary endpoints were best-corrected visual acuity (BCVA), and central macular thickness (CMT) measured by SD‑OCT. The secondary endpoint was a displacement of hemorrhage from the subretinal space three months after surgery.

Results

31 eyes of 31 patients were treated with vitrectomy and subretinal rtPA. 17/31 were treated simultaneously with an intravitreal Bevacizumab injection (group +B) and 14/31 without (group -B). The mean visual acuity improved significantly in both groups (from 1.37±0.39 to 1.03±0.57 logMAR in +B and from 1.48±0.48 to 1.01±0.38 logMAR in group –B, p<0.05). The mean CMT decreased in group +B from 607±179 μm to 424±205 μm (p = 0.2) and in group –B from 722±216 μm to 460±202 μm (p<0.05). A central displacement of the hemorrhage could be achieved in 47% in group +B, whereas in group -B displacement could be achieved in 50% (p = 0.44).

Conclusions

Vitrectomy with subretinal rtPA injection and air tamponade with or without simultaneous intravitreal Bevacizumab injection displaces SMH and improves BCVA effectively. In comparison, the postoperative outcome is comparable regardless of whether or not intravitreal bevacizumab is applied simultaneously.

Clinical profile and management outcomes of traumatic submacular hemorrhage

Purpose

To evaluate the anatomical and functional outcome of patients with traumatic submacular hemorrhage (SMH).

Methods

A retrospective, interventional case series of patients presenting between January 2016 and April 2018 was carried out at 4 tertiary eye care centers of India. Medical records of the patients with a history of blunt trauma and SMH were retrospectively reviewed. The intervention done was any one of the following: pneumatic displacement with 0.3 ml of intravitreal gas [100% perfluoropropane (C3F8) gas], pneumatic displacement with intravitreal 0.3 ml of 100% C3F8 gas combined with 100 μg/0.1 ml of recombinant tissue plasminogen activator (r-tpa), pars plana vitrectomy (PPV) with subretinal r-tpa and gas tamponade. The primary outcome measures included change in visual and anatomical status.

Results

Twenty eyes of 20 patients with blunt trauma were analyzed. Thirteen patients had small size SMH, 5 patients had medium size SMH, and 2 patients had massive size SMH. Sixteen patients had a favorable functional outcome, and eighteen patients had favorable anatomical outcome. The size and duration of post-traumatic SMH did not significantly affect the anatomical (P = 0.123) or functional (P = 0.293) outcome in our study. The patients who presented with initial visual acuity of 6/60 or better showed better functional outcome, which was statistically significant (P = 0.007).

Conclusion

Minimally non-invasive procedure including intravitreal r-tpa and gas appear to be effective in the displacement of post-traumatic SMH.

Intravitreal tPA Injection and Pneumatic Displacement for Submacular Hemorrhage in a 10-Year-Old Child

Background. Submacular hemorrhage can occur after blunt trauma to the eye. Intravitreal tissue plasminogen activator (tPA) and gas injection are often used for treatment and are effective for submacular hemorrhage caused by age-related macular degeneration. This report describes the clinical outcome in a child with submacular hemorrhage caused by traumatic choroidal rupture who underwent successful intravitreal tPA injection and pneumatic displacement. Case Presentation. A 10-year-old boy developed sudden decrease of vision and a central scotoma in his right eye after trauma. Submacular hemorrhage was found in the eye. Visual acuity was 20/70 OD. Tissue plasminogen activator (12.5 μg in 0.05 mL) and 0.3 mL of pure sulfur hexafluoride were injected into the vitreous cavity under general anesthesia. After surgery, the patient was instructed to maintain a prone position. Displacement of the submacular hemorrhage from the fovea revealed a choroidal rupture, presumed to be the cause of the hemorrhage. After 4 months of follow-up, visual acuity was restored and final visual acuity is 20/16. Conclusion. Intravitreal tPA and gas injection can be an effective treatment for children with submacular hemorrhage.

The Miniature Swine as a Model in Experimental and Translational Medicine

The use of the miniature swine as a nonrodent species in research has continued to expand for over a decade, and they are becoming routinely used both in experimental pharmacology and as a therapeutic model for human diseases. Miniature swine models are regularly used for studies designed to assess efficacy and safety of new therapeutic compounds given through different routes of exposure and are used as an alternative model to rodents, canines, or nonhuman primates. Translational preclinical swine study data presented here support the current understanding that miniature swine are the animal model of choice for the assessment of drugs targeting endocrine, dermal, and ocular disorders. Because research investigators need to be familiar with some of the important features of the models developed in the miniature swine in order to place clinical and experimental findings in their proper perspective, relevant references and data from these models will be presented, compared, and partially illustrated.

Submacular hemorrhage in neovascular age-related macular degeneration: A synthesis of the literature

Large submacular hemorrhage, an uncommon manifestation of neovascular age-related macular degeneration, may also occur with idiopathic polypoidal choroidal vasculopathy. Submacular hemorrhage damages photoreceptors owing to iron toxicity, fibrin meshwork contraction, and reduced nutrient flux, with subsequent macular scarring. Clinical and experimental studies support prompt treatment, as tissue damage can occur within 24 hours. Without treatment the natural history is poor, with a mean final visual acuity (VA) of 20/1600. Reported treatments include retinal pigment epithelial patch, macular translocation, pneumatic displacement, intravitreal or subretinal tissue plasminogen activator, intravitreal anti-vascular endothelial growth factor (VEGF) drugs, and combinations thereof. In the absence of comparative studies, we combined eligible studies to assess the VA change before and after each treatment option. The greatest improvement occurred after combined pars plana vitrectomy, subretinal tissue plasminogen activator, intravitreal gas, and anti-vascular endothelial growth factor treatment, with VA improving from 20/1000 to 20/400. The best final VA occurred using combined intravitreal tissue plasminogen activator, gas, and anti-vascular endothelial growth factor therapy, with VA improving from 20/200 to 20/100. Both treatments had an acceptable safety profile, but most studies were small, and larger randomized controlled trials are needed to determine both safety and efficacy.

Intravitreal tissue plasminogen activator, perfluoropropane (C3F8), and ranibizumab or photodynamic therapy for submacular hemorrhage secondary to wet age-related macular degeneration

PURPOSE

To report a combined intravitreal treatment for submacular hemorrhage.

METHODS

This retrospective, noncomparative, interventional case series included 7 patients with neovascular age-related macular degeneration and 2 with idiopathic polypoidal choroidal vasculopathy, presenting with fovea-involving submacular hemorrhage ≥ 4 disk areas in size, of <10 days of duration. All patients received a single 0.05-mL intravitreal injection of 50 μg alteplase, 0.3 mL of 100% C3F8, and facedown positioning for 1 week. Patients with newly diagnosed age-related macular degeneration received 3 consecutive monthly intravitreal injections of 0.5 mg ranibizumab, followed by monthly retreatment as needed. Those with idiopathic polypoidal choroidal vasculopathy were treated with photodynamic therapy.

RESULTS

Mean (± SD) logarithm of the minimum angle of resolution visual acuity improved from 0.75 ± 0.35 at presentation to 0.35 ± 0.30 at a mean final follow-up of 15.1 months (P = 0.0078). Median Snellen acuity improved from 20/200 to 20/32. Visual acuity was stable in one case and improved in eight. The average size of submacular hemorrhage was 6.8 disk areas at presentation, reducing to 2.6 within 1 month (P = 0.0039). Subfoveal hemorrhage was displaced in all cases within 9 weeks. The mean pretreatment central retinal thickness of 669 μm reduced to 528 μm (P = 0.0039). One case developed transiently elevated intraocular pressure. Two developed breakthrough vitreous hemorrhage. No adverse events were attributed to tissue plasminogen activator.

CONCLUSION

Tissue plasminogen activator and C3F8, combined with intravitreal ranibizumab or photodynamic therapy, may result in anatomical clearance of submacular hemorrhage and improved visual acuity, in a condition with an otherwise poor visual prognosis.

Treatment of multilevel macular hemorrhage secondary to retinal arterial macroaneurysm with submacular tissue plasminogen activator

Purpose.

To evaluate the efficacy of pars plana vitrectomy (PPV) followed by internal limiting membrane (ILM) removal and injection of subretinal recombinant tissue plasminogen activator (rtPA)–assisted pneumatic displacement in eyes with massive multilevel macular hemorrhage caused by ruptured retinal arterial macroaneurysm (RAMA).

Methods.

Four eyes of 4 patients treated with PPV for recent (≤7 days) macular hemorrhage at both beneath the ILM and subretinal space involving the center of the fovea caused by RAMA were included in the study. In each case, following PPV, ILM removal, subretinal injection of rtPA (12.5 µg/0.1 mL), and fluid-air exchange with postoperative prone positioning was performed. Optical coherence tomography (OCT) examination was performed at the initial and the follow-up visits.

Results.

Duration of symptoms ranged from 3 to 7 days (average, 4.5±1.9 days). Preoperative visual acuity ranged from hand motions to 20/800. Follow-up ranged from 6 to 18 months (average, 13±5.2 months). The postoperative visual acuity improved in all eyes and ranged from 20/100 to 20/30 (mean, 20/50). At the final visit, OCT examination revealed well-preserved foveal structure in all eyes. Mild nuclear sclerosis developed in one eye.

Conclusions.

Pars plana vitrectomy followed by ILM removal and injection of subretinal rtPA-assisted pneumatic displacement appears to be effective in both improving visual acuity and preserving the foveal structure in eyes with recent massive multilevel macular hemorrhage secondary to RAMA.

Treatment for submacular hemorrhage associated with neovascular age-related macular degeneration

Submacular hemorrhage associated with neovascular age-related macular degeneration is a complication known to have potentially devastating effects on visual acuity. Multiple treatment modalities have been suggested including intravitreal anti-vascular endothelial growth factor injections, photodynamic therapy, pneumatic displacement with or without adjuvant intravitreal tissue plasminogen activator, and pars plana vitrectomy with or without adjuvant subretinal tissue plasminogen activator. However, there remains no consensus on optimal treatment, as clinical trials for neovascular age-related macular degeneration have excluded patients with submacular hemorrhage. This manuscript offers guidelines to the management of subretinal hemorrhage based on its size and characteristics, and highlights the need for clinical trials in this area.

Effects of intravitreal gas with or without tissue plasminogen activator on submacular haemorrhage in age-related macular degeneration

PURPOSE

To compare the anatomic and functional outcomes of treating thick submacular haemorrhage with intravitreal gas injection with and without tissue plasminogen activator (t-PA) in patients with age-related macular degeneration.

METHODS

A review of age-related macular degeneration patients with submacular haemorrhage who underwent intravitreal gas injection with and without t-PA at a tertiary referral centre was conducted. Main outcome measures were best and final postoperative visual acuity.

RESULTS

A total of 53 eyes of 53 patients were included, 28 eyes received intravitreal t-PA and gas injection (t-PA and gas group) and 25 eyes received intravitreal gas injection alone (gas-alone group). Incidence of best visual acuity improvement was significantly higher in the t-PA and gas group than in the gas-alone group (60.7 vs 32.0%; P=0.037). However, subgroup analysis demonstrated that the difference was significant only in eyes with haemorrhage duration of more than 14 days (46.2 vs 8.3%; P=0.035). Incidence of final visual acuity improvement was not significantly different between the two groups (42.9 vs 28.0%; P=0.39). The complications of vitreous haemorrhage and endophthalmitis were similar between the two groups. Multiple logistic regression analysis demonstrated that shorter haemorrhage duration (<14 days) was the main factor predictive of best visual acuity improvement (OR=9.02, P=0.015). Whether t-PA was used was of borderline significance (OR=4.96, P=0.046).

CONCLUSIONS

Intravitreal t-PA was valuable for submacular haemorrhage only in eyes with relatively old haemorrhage. For eyes with recent onset of emorrhage, t-PA is suggested only if initial gas injection failed to displace submacular haemorrhage.

Management of submacular hemorrhage with intravitreal injection of tissue plasminogen activator and expansile gas

PURPOSE

To evaluate the clinical outcome of intravitreal tissue plasminogen activator (tPA) and expansile gas injection as a minimally invasive treatment for submacular hemorrhage (SMH).

METHODS

This study was a retrospective clinical case series examining 104 eyes that received an intravitreal injection of 30-100 mcg of tPA and expansile gas (SF6 or C3F8) for SMH. The main outcomes evaluated were visual acuities (VA), anatomic displacement of submacular blood, and surgical complications.

RESULTS

: A total of 85, 77, and 81 eyes were available at 1 week, 3 months, and 12 months follow up, respectively. Postoperatively, > or = 2 Snellen lines improvement were achieved in 43/85 eyes (51%) at 1 week, 49/77 eyes (63%) at 3 months, and 52/81 eyes (64%) at 12 months. Postoperative VA improvement was significantly associated with preoperative VA, submacular blood displacement, and the underlying cause of SMH. Diagnostic postoperative angiogram and clinical examination were possible at 8.2 +/- 7.4 weeks and 9.5 +/- 7.4 weeks, respectively. The observed complications included breakthrough vitreous hemorrhage in 8 eyes (8%) and retinal detachment in 3 eyes (3%).

CONCLUSIONS

In this retrospective series, intravitreal injection of tPA and expansile gas was shown to be a safe and effective technique that can improve VA in most eyes with SMH and assist in the diagnosis of the underlying cause.

Pars plana vitrectomy with peripheral retinotomy after injection of preoperative intravitreal tissue plasminogen activator: a modified procedure to drain massive subretinal haemorrhage

AIMS

To report outcome of a modified procedure for draining massive subretinal haemorrhages (SRHs).

METHODS

The charts of eight consecutive eyes from eight patients with massive SRHs extending to the periphery and involving two or more quadrants with haemorrhagic and bullous retinal detachment were reviewed. Tissue plasminogen activator (tPA) was injected intravitreally 12-24 h preoperatively; vitrectomy was carried out with peripheral retinotomy, drainage of the SRH from the retinotomy using perfluorocarbon liquid and gas tamponade with prone positioning postoperatively.

RESULTS

The preoperative visual acuities ranged from light perception to 20/200. Most of the subretinal haematomas moved postoperatively to the vitreous cavity through the peripheral retinotomy using perfluorocarbon liquid. Residual SRHs were drained from the anterior chamber at the bedside after prone positioning overnight. SRH recurred in one eye 14 months postoperatively and was successfully retreated. No other serious complications developed. The final visual acuity improved in seven eyes (range 20/1000-20/60). Polypoidal lesions in choroidal vasculatures were present in three of seven patients.

CONCLUSIONS

The technique seems safe and effective for treating massive SRH. However, visual recovery is limited by the underlying macular pathology. Polypoidal choroidal vasculopathy, other than age-related macular degeneration, may be another cause of massive SRHs.

Management of subretinal macular haemorrhage by direct administration of tissue plasminogen activator

BACKGROUND/AIMS

Recent studies on the treatment of acute subretinal macular haemorrhage have shown that the volume of the clot and the time to evacuation have strong prognostic factors for visual outcome. A novel technique for surgical evacuation of these lesions involves direct injection of tissue plasminogen activator (t-PA) into the haematoma using pars plana vitrectomy. The aim of this study was to evaluate the clinical outcomes of this recently described procedure.

METHODS

17 consecutive patients with subretinal macular haemorrhages caused by age related macular degeneration were enrolled. Patient demographics, acuities, and fluorescein angiograms were obtained for all evaluations. All patients underwent complete three port pars plana vitrectomy to enable direct cannulation of the subretinal space and injection of 48 mug of t-PA, partial fluid-air exchange, 1 hour face up supine positioning postoperatively, followed by upright positioning overnight.

RESULTS

88% of patients within the study had stabilisation or improvement of visual acuity. Nine patients had total clearing of the macular haemorrhage and eight patients had subtotal clearing. Two patients had recurrence of the haemorrhage after the procedure and one patient underwent repair for retinal detachment. Occult lesions demonstrated similar outcomes to classic or predominately classic lesions. Nine patients required no therapy after the study to treat subfoveal neovascularisation.

CONCLUSIONS

This study represents one of the largest case series to date showing that direct injection of subretinal t-PA with air-fluid exchange only and no intraoperative clot lysis period can have favourable results.

Intravitreous Recombinant Tissue Plasminogen Activator and Gas to Treat Submacular Hemorrhage in Age-Related Macular Degeneration

We evaluated the safety and efficacy of intravitreous recombinant tissue plasminogen activator (rTPA) and gas for the treatment of submacular hemorrhage in age-related macular degeneration (ARMD). From January 2000 to April 2002, we enrolled 15 patients with submacular hemorrhage secondary to ARMD. All patients received 100 microg rTPA and 0.3 mL perfluoropropane intravitreously. Postoperatively, all patients were kept in a supine position for 4 hours followed by a face-down position for 4 days. Anatomic and functional results were evaluated during a follow-up period of 6 to 19 months. Submacular blood was completely displaced in 12 patients (80%) and partially in three (20%). Best postoperative visual acuity improved in all 15 eyes; in seven eyes (47%), the improvement was two or more lines. Final visual acuity improved in 12 eyes, remained stable in two eyes, and worsened in one eye. Onset of hemorrhage within 21 days was associated with better gains of lines in best postoperative (p = 0.0256) and final visual acuity (p = 0.044). Although two patients developed mild breakthrough vitreous hemorrhage within 1 day after treatment, no rTPA-related retinal toxicity was observed. Intravitreous injections of rTPA and gas are safe and effective in improving visual acuity in patients with submacular hemorrhage secondary to ARMD. Although the final visual outcome is often limited by the progression of the disease, significant and stable visual recovery over an extended follow-up period is possible using this easy and convenient technique.

Intravitreous injection of tissue plasminogen activator and gas in the treatment of submacular hemorrhage under various conditions

OBJECTIVE

To investigate the efficacy and safety of treating submacular hemorrhages secondary to age-related macular degeneration (ARMD) with intravitreous recombinant tissue plasminogen activator (rt-PA) and gas under various conditions.

DESIGN

Prospective, noncomparative case series.

PARTICIPANTS

Forty-three consecutive eyes of 42 patients with recent (range, 2-28 days) subfoveal hemorrhage secondary to ARMD were included in this study. The size of subretinal hemorrhage ranged from 0.25 to 30 disc areas.

METHODS

All patients were treated with intravitreous injections of rt-PA (50 microg) and sulfur hexafluoride (0.5 ml). Postoperative prone positioning was maintained for 24 to 72 hours. Patient follow-up ranged from 4 to 18 months (mean, 6 months).

MAIN OUTCOME MEASURES

Best and final postoperative visual acuity in relation to size and onset of hemorrhage, displacement of subretinal blood, and surgical complications.

RESULTS

Best postoperative visual acuity compared with preoperative visual acuity was improved two or more Snellen lines in 19 eyes (44%) and stable in 24 eyes (56%). Final visual acuity was improved two or more lines in 13 eyes (30%), stable in 26 (61%), and two or more lines worse in 4 eyes (9%). Duration of hemorrhage <or=14 days was associated with a better gain of lines of vision (P = 0.0058). Best postoperative acuity was maintained for an average of 4.2 months (range, 0.5-12 months). Overall, complete displacement of blood from under the fovea was achieved in 35 eyes (81%). Nine eyes (21%) developed recurrent hemorrhage, which required repeat treatment. In three patients (7%), a mild breakthrough vitreous hemorrhage was observed.

CONCLUSIONS

Our findings suggest that intravitreous injections of rt-PA and gas are of value for an improved and accelerated visual recovery in ARMD patients with submacular hemorrhage, although final visual outcome is often limited by the progression of the underlying ARMD. Patients with retinal hemorrhages of recent onset (<or=14 days) seem to have the most favorable results. A rapid displacement of submacular blood may reveal discrete choroidal neovascular membranes amenable to further treatment. The complication rate of this minimally invasive technique seems to be low.

Treatment of subretinal hemorrhages with tissue plasminogen activator

Submacular hemorrhages pose a danger to visual acuity. Intervention may help prevent or mitigate severe visual loss. Pneumatic displacement and vitrectomy with direct evacuation are two methods of treating submacular hemorrhages. Tissue plasminogen activator may be an important adjunct to these techniques.

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.

Pneumatic displacement of submacular hemorrhage

Patients with thick submacular hemorrhage complicating age-related macular degeneration and other disorders typically have a poor visual prognosis. A new outpatient procedure, consisting of intravitreal injection of tissue plasminogen activator and gas followed by brief prone positioning, is effective in displacing thick submacular blood and facilitating visual improvement in most patients. Injection of gas alone also appears to be effective in many eyes. The procedure is technically simple and the rate of serious complications appears to be acceptably low. Although the final visual outcome is often limited by progression of age-related macular degeneration, significant and stable visual recovery is possible in selected eyes. Prospective clinical trials are needed to clarify the role for intravitreal tissue plasminogen activator and to provide definitive outcome comparisons with other management approaches.

Tissue plasminogen activator in the treatment of vitreoretinal diseases

Tissue plasminogen activator (tPA) is a thrombolytic agent that activates plasminogen into plasmin almost exclusively in the presence of fibrin. Intraocular injection of tPA has been proposed for the treatment of vitreoretinal diseases, such as vitreous hemorrhage, postvitrectomy fibrin formation, submacular hemorrhage, retinal vascular occlusive disorders, suprachoroidal hemorrhage and endophthalmitis. Currently, intraocular tPA is only used in the treatment of postvitrectomy fibrin formation and submacular hemorrhage. For other indications, tPA has not been shown to be safe or effective. This article reviews the use of tPA in the treatment of vitreoretinal disorders.

A study of the ability of tissue plasminogen activator to diffuse into the subretinal space after intravitreal injection in rabbits

PURPOSE

Intravitreal injections of tissue plasminogen activator have been used to lyse fibrin from blood in the subretinal space, despite the lack of proof that tissue plasminogen activator can diffuse across the retina. We tested whether tissue plasminogen activator injected into the vitreous could penetrate the neural retina and enter the subretinal space.

METHODS

We injected a mixture of 50 microg of tissue plasminogen activator (70 kD) labeled with fluorescein isothiocyanate and rhodamine B isothiocyanate-labeled dextran, which has a lower molecular weight (20 kD), into the midvitreous cavity of one eye in each of 18 rabbits. The eyes were enucleated after 3, 6, and 24 hours, and cryosections were examined with epifluorescent microscopy to determine the distribution of the labeled molecules. We also evaluated tissue plasminogen activator pharmacokinetics in one eye each of 18 rabbits in which a subretinal clot was induced by injecting autologous blood (50 microL) into the subretinal space through the sclera. Fluorescein isothiocyanate-labeled tissue plasminogen activator was injected into the vitreous 2 days after induction of the subretinal clot.

RESULTS

Fluorescein isothiocyanate-labeled tissue plasminogen activator was present at the vitreal surface of the retina in a linear array in all 36 eyes studied, whereas the rhodamine B isothiocyanate-labeled dextran had diffused throughout the neural retina in the same sections. No fluorescein isothiocyanate signal was observed in the neural retina or in the subretinal clot. Vitreous hemorrhage caused by retinal perforation was observed in all eyes with intraretinal hemorrhage in which fluorescein isothiocyanate fluorescence was seen in the neural retina and inside the clot.

CONCLUSION

Intravitreal tissue plasminogen activator did not diffuse through the intact neural retina to reach a subretinal clot. This study demonstrates no scientific rationale for the intravitreal tissue plasminogen activator treatment of submacular hemorrhage without vitreous hemorrhage presumably caused by an overlying retinal break.

Management of submacular hemorrhage with intravitreous tissue plasminogen activator injection and pneumatic displacement

OBJECTIVE

To investigate the efficacy and safety of treating thick submacular hemorrhages with intravitreous tissue plasminogen activator (tPA) and pneumatic displacement.

DESIGN

Retrospective, noncomparative case series.

PARTICIPANTS

From 5 participating centers, 15 eligible patients had acute (<3 weeks) thick subretinal hemorrhage involving the center of the macula in eyes with pre-existing good visual acuity. Hemorrhages were secondary to age-related macular degeneration in 13 eyes and macroaneurysm and trauma in 1 eye each.

METHODS

The authors reviewed the medical records of 15 consecutive patients who received intravitreous injection of commercial tPA solution (25-100 microg in 0.1-0.2 ml) and expansile gas (0.3-0.4 ml of perfluoropropane or sulfur hexafluoride) for thrombolysis and displacement of submacular hemorrhage. After surgery, patients maintained prone positioning for 1 to 5 days (typically, 24 hours).

MAIN OUTCOME MEASURES

Degree of blood displacement from under the fovea, best postoperative visual acuity, final postoperative visual acuity, and surgical complications.

RESULTS

In 15 (100%) of 15 eyes, the procedure resulted in complete displacement of thick submacular hemorrhage out of the foveal area. Best postprocedure visual acuity improved by 2 lines or greater in 14 (93%) of 15 eyes. After a mean follow-up of 10.5 months (range, 4-19 months), final visual acuity improved by 2 lines or greater in 10 (67%) of 15 eyes and measured 20/80 or better in 6 (40%) of 15 eyes. Complications included breakthrough vitreous hemorrhage in three eyes and endophthalmitis in one eye. Four eyes developed recurrent hemorrhage 1 to 3 months after treatment, three of which were retreated with the same procedure.

CONCLUSIONS

Intravitreous injection of tPA and gas followed by brief prone positioning is effective in displacing thick submacular blood and facilitating visual improvement in most patients. The rate of serious complications appears low. Final visual outcomes are limited by progression of the underlying macular disease in many patients.

Pearls in the management of submacular hematoma

Subretinal hemorrhage (SRH), complicated by choroidal neovascularization such as age-related macular degeneration, often reduces central vision in middle-aged patients. Although the visual results of SRH removal by surgery seem to have improved recently, the efficacy has not yet been confirmed in a prospective, controlled fashion. Therefore, it cannot be stated with certainty that surgery for SRH is more beneficial than the natural course of the disease. However, we believe surgery is beneficial in selected patients. Herein, we describe our technique for the surgical removal of SRH. The development of safer, more effective techniques should further improve patient outcomes.

Pathophysiology and management of subretinal hemorrhage

Subretinal hemorrhage can arise from the retinal and/or choroidal circulation. Significant subretinal hemorrhage occurs in several conditions, but most commonly is associated with age-related macular degeneration, presumed ocular histoplasmosis, high myopia, retinal arterial macroaneurysm, and trauma. Released toxins, outer retinal shear forces, and a diffusion barrier created by subretinal hemorrhage all contribute to photoreceptor damage and visual loss. The use of tissue plasminogen activator and improvements in surgical instrumentation have facilitated surgical drainage and have made it a useful option in the management of selected cases. Mechanisms of subretinal hemorrhage formation, underlying etiologies, diagnostic evaluation, and the histopathology of damage are summarized. Published surgical series are reviewed and surgical advances are summarized. The value of surgically removing subretinal hemorrhages to improve visual outcome remains unestablished, because definitive studies have not been performed. Guidelines for selecting candidates for surgical intervention are proposed.