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.

Acute bilateral ophthalmoplegia in a young woman.

A 34-year-old woman presented with bilateral ophthalmoplegia, ptosis, and mild gait ataxia. Tensilon test, magnetic resonance imaging, and cerebrospinal fluid analysis were normal. She initially denied any alcohol intake but later admitted to significant alcohol and multisubstance abuse. The patient improved dramatically after treatment with thiamine. Wernicke's encephalopathy is discussed, highlighting that it may be present with normal mentation. It should be considered in the differential diagnosis of bilateral ophthalmoplegia even in the absence of altered mental status.

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.

Intraocular pressure trends after supranormal pressurization to aid closure of sutureless cataract wounds.

PURPOSE: To measure intraocular pressure (IOP) immediately and 25 minutes after small sutureless cataract surgery to estimate the duration of any elevation and to evaluate the relationship between supranormal pressurization and an elevated IOP 24 hours postoperatively. SETTING: Routine outpatient cataract surgery at a tertiary referral center. METHODS: Thirty-six consecutive eyes that had uneventful phacoemulsification cataract extraction were studied in a prospective fashion. Supranormal pressurization was attempted in all cases. Surgery was performed through a 3.5 mm scleral wound. RESULTS: Mean IOP dropped from 38.8 mm Hg +/- 11.4 (SD) to 19.8 +/- 5.3 mm Hg 25 minutes after the surgery (P < .0001). A subgroup of patients (n = 6) whose IOP was greater than 24 mm Hg 24 hours postoperatively had a pressure drop from 36.8 +/- 12.3 mm Hg to 23.2 +/- 6.2 mm Hg 25 minutes postoperatively (P = .051). In this subgroup, the mean 24 hour IOP then rose to 30.8 +/- 5.2 mm Hg (P = .043). Another subgroup of patients (n = 7) whose IOP was greater than 24 mm Hg at 25 minutes had a pressure drop from 46.3 +/- 8.5 mm Hg to 27.9 +/- 2.4 mm Hg (P = .0014), falling to 21.7 +/- 6.6 mm Hg at 24 hours (P = .018). CONCLUSION: These findings demonstrate the rapid decline of IOP after supranormal pressurization at the conclusion of cataract surgery. In addition, supranormal pressurization did not seem to contribute to IOP elevation at 24 hours.

The role of ultrasound biomicroscopy in ocular trauma.

PURPOSE: To demonstrate the usefulness of ultrasound biomicroscopy (UBM) in detecting and localizing small ocular foreign bodies. METHODS: This is a retrospective study of the records of 555 consecutive patients evaluated by UBM by the Visual Physiology Unit of the Wills Eye Hospital from August 1994 to November 1997. RESULTS: In 9 patients, a foreign body was identified. In 6 patients, the history suggested the presence of a foreign body, but one could not be detected by clinical examination. In 2 patients, the referring physicians requested UBM to determine whether or how deep a known foreign body had penetrated the globe. In 1 patient, the foreign body was not suspected clinically. In regard to other diagnostic techniques, CT failed to identify the foreign body in 1 patient. In another, contact B-scan ultrasonography failed. In a third, both CT and contact B-scan ultrasonography failed. The foreign body was intracorneal in 2 eyes, subconjunctival in 2, intrascleral in 3, and intraocular in 2. Six were nonmetallic. Two were metallic. In one case, the foreign body was lost and its composition is unknown. In 5 cases, the UBM findings altered the patient's management. CONCLUSIONS: UBM is a valuable adjunct in the evaluation of small, anteriorly located foreign body that may not be detectable by other methods. UBM may be especially useful for finding nonmetallic foreign bodies.

Increased incidence of sterile endophthalmitis following intravitreal preserved triamcinolone acetonide.

AIM: To report an increased incidence of sterile endophthalmitis following intravitreal injection of preserved triamcinolone acetonide (IVTA) from 1 May to 31 July 2006. METHODS: Charts were reviewed for all patients who underwent IVTA injections between 1 January 2005 and 31 July 2006 at the offices of a referral vitreo-retinal practice. Patients were included if they presented post-IVTA with a clinical picture consistent with endophthalmitis. RESULTS: Between 1 January 2005 and 31 July 2006, 554 eyes underwent IVTA. Eleven eyes (1.9%) developed an endophthalmitis. All eleven eyes underwent vitreous tap and intravitreal injection of antibiotics. All cultures and gram stains were negative for bacterial or fungal organisms. From 1 May to 31 July 2006, 97 eyes underwent IVTA. Nine eyes (9.3%) developed sterile endophthalmitis. This represented a statistically significant (p<0.0001) clustering of cases. Triamcinolone acetonide phials from affected lot numbers were analysed and were all found to be negative for bacterial endotoxin (<0.05 EU/ml). CONCLUSION: Over the 19-month period analysed, 11 cases of sterile endophthalmitis occurred following IVTA, and nine of these cases were clustered over a 3-month period. No endotoxin was detected in the phials tested. The aetiology of this increased incidence of sterile endophthalmitis is still unclear.

Treatment of Propionibacterium acnes endophthalmitis.

Propionibacterium acnes is a well-known cause of delayed endophthalmitis following cataract surgery. A white intracapsular plaque, keratic precipitates, and hypopyon may be present. Although there is no consensus on the treatment approach, recent studies have reviewed the outcomes of relatively large numbers of patients. Reasonable treatment options include pars plana vitrectomy and intra-ocular antibiotics with either partial or total capsulectomy/lens exchange. A good visual outcome is possible.

Successful macular translocation with temporary scleral infolding using absorbable sture.

PURPOSE: To describe successful macular translocation with temporary scleral infolding in a series of patients with small subfoveal choroidal neovascularization due to age-related macular degeneration or ocular histoplasmosis syndrome. METHODS: Ten eyes of 10 consecutive patients were studied in a prospective, nonrandomized clinical trial. Macular translocation with scleral infolding (MTSI) was performed. Absorbable polyglactin suture was used to create temporary scleral infolding. Distance and stability of retinal translocation, corneal topography, visual acuity, and rates of complications were measured. RESULTS: The median distance of translocation in the early postoperative period was 1,700 microm (range, 680-3,200) and did not regress after resolution of the scleral infolding. Induced postoperative oblique corneal astigmatism resolved, coinciding with the disappearance of peripheral retinal elevation due to scleral infolding. Three patients gained more than two lines of vision, two patients were within two lines of preoperative vision, and five patients lost more than two lines of vision. Complications were similar to previously published reports. CONCLUSION: Temporary scleral infolding is an effective technique in MTSI. The distance of translocation is comparable to that achieved with nonabsorbable suture or scleral resection, and does not regress after resolution of the scleral infolding. Induced postoperative corneal astigmatism appears to resolve.

Constitutive and inducible mechanisms for synthesis and release of cytokines in immune cell lines.

We found that production and release of two functionally antagonistic cytokines, TGF-beta and TNF-alpha, were regulated differently in the mast cell, T cell, and macrophage cell lines RBL-2H3, MLA-144, and U-937, respectively. TGF-beta was produced and released constitutively in all three cell lines. When, however, the cell lines were stimulated with Ag, LPS, or calcium ionophore plus PMA, acceleration of release and some additional production of TGF-beta were apparent. In contrast, TNF-alpha was produced and released only when these lines were stimulated. Although neither the glucocorticoid, dexamethasone, nor the protein kinase C inhibitor, Ro31-7549, suppressed constitutive production or release of TGF-beta, these agents inhibited TNF-alpha production and the inducible component of TGF-beta production noted above. The release of these cytokines, whether constitutive or inducible, was dependent on Golgi-processing as indicated by inhibition with brefeldin A. Therefore, although both types of cytokines were processed by Golgi, only TNF-alpha and the inducible component of TGF-beta production were protein kinase C or steroid-regulated processes. These findings suggested that constitutive and inducible pathways exist for production and release of cytokines and that the inducible pathways can be selectively suppressed by pharmacologic agents.

Secretion of TNF from a rat mast cell line is a brefeldin A-sensitive and a calcium/protein kinase C-regulated process.

Stimulated mast cells and cognate cultured cell lines produce and secrete a variety of cytokines including TNF. Because the mechanism by which cytokines are delivered to the external milieu is unknown, the release of TNF was studied in a rat mast cell line (RBL-2H3 cells). In these cells, TNF was not constitutively expressed nor incorporated into secretory granules but was generated de novo upon cell stimulation. It was then released by a process analogous to constitutive secretion in that brefeldin A, an agent known to disrupt Golgi membranes in these cells, inhibited this release without inhibiting release of secretory granules. Unlike constitutive secretion, however, the secretion of TNF was highly regulated by Ca2+ and protein kinase C. Studies with various stimulants and inhibitors indicated that simultaneous mobilization of Ca2+ and activation of protein kinase C were sufficient signals for secretion although optimal production of TNF may be dependent on additional synergistic signals. Because suppression of Ca2+ mobilization or inhibition of protein kinase C alone abrogated TNF secretion, the process may be amenable to therapeutic intervention.

Treatment strategies for postoperative Propionibacterium acnes endophthalmitis.

PURPOSE: Propionibacterium acnes endophthalmitis after cataract extraction and posterior chamber intraocular lens (IOL) implantation is characterized by a chronic indolent course, frequently associated with recurrence after standard endophthalmitis treatment. This study was designed to evaluate the efficacy of various therapeutic methods in the treatment of primary and recurrent episodes of postoperative P. acnes endophthalmitis. DESIGN: Retrospective, noncomparative case series. PARTICIPANTS: Twenty-five patients treated at Wills Eye Hospital for P. acnes endophthalmitis. METHODS: The authors retrospectively reviewed the clinical charts and microbiology files of all patients treated at Wills Eye Hospital between January 1991 and April 1998 with culture-proven P. acnes endophthalmitis after cataract extraction and posterior chamber IOL implantation. MAIN OUTCOME MEASURES: Results of cultures and microbiologic examinations, efficacy of various treatment methods in the prevention of recurrent inflammatory episodes, and final visual outcome. RESULTS: Twenty-five patients who met inclusion criteria were identified; initial therapy consisted of 1 of the following: intraocular antibiotic (IOAB) injections alone (2 patients); IOAB combined with pars plana vitrectomy (PPV) (10 patients); IOAB and PPV combined with partial capsulectomy (9 patients); and IOAB, PPV, total capsulectomy, and IOL exchange (4 patients). Nearly half of the patients (10 of 21, or 48%) initially treated with IOAB alone (1 of 2), IOAB and PPV (5 of 10), and IOAB combined with PPV and partial capsulectomy (4 of 9) required further therapeutic interventions for recurrent disease. Retreatment with IOAB alone or combined with PPV and partial capsulectomy in these patients failed to eradicate the infection in three (75%) of four patients. None of the patients (0 of 4) treated initially with total capsulectomy and IOL exchange required additional surgical intervention. Furthermore, none of the patients (0 of 13) who underwent total capsulectomy with IOL removal or exchange or IOL exchange alone as an initial, secondary, or tertiary treatment required further intervention. CONCLUSION: In the authors' series, approximately half of the patients with P. acnes endophthalmitis were treated successfully initially with nonsurgical or limited surgical intervention. All patients treated with total capsulectomy and IOL exchange or removal, either as an initial treatment or for recurrent disease, were cured. Removal of the entire capsular bag and the IOL may be performed as a definitive initial therapy and should be performed for recurrent inflammation.

Ultrasound biomicroscopy as a tool for detecting and localizing occult foreign bodies after ocular trauma.

OBJECTIVE: To show the utility of ultrasound biomicroscopy (UBM) in imaging small ocular foreign bodies of the anterior segment. DESIGN: Retrospective case series. PARTICIPANTS: Twelve eyes of 12 consecutive patients evaluated in the emergency department or referred to specialty services at 1 institution between August 1994 and November 1997 were examined. INTERVENTION: Ocular ultrasound biomicroscopy was performed. MAIN OUTCOME MEASURES: Detection and localization of an ocular foreign body were measured. RESULTS: An intraocular or superficial foreign body was detected by UBM in 9 (75%) of 12 eyes. The foreign body was classified as corneal in two eyes, subconjunctival in two, intrascleral in three, and intraocular in two eyes. The foreign body was not visible by ophthalmic physical examination in seven of the nine eyes with a confirmed ocular foreign body. In the remaining two eyes, UBM was used to determine the depth of a visible foreign body. In three of the eyes with a confirmed foreign body, computed tomography and/or contact B-scan ultrasonography was obtained and failed to show a foreign body. Six of the foreign bodies were nonmetallic. CONCLUSIONS: Clinical detection of ocular foreign bodies after trauma can be hindered by small size, haziness of the optical media, poor patient cooperation, or hidden location. Ultrasound biomicroscopy is a valuable adjunct in the evaluation of suspected ocular foreign bodies, especially in cases involving small, nonmetallic objects.