Susan G. Elner

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.

CYTOKINES IN PROLIFERATIVE DIABETIC RETINOPATHY AND PROLIFERATIVE VITREORETINOPATHY

We determined whether interleukin-8, monocyte chemotactic protein-1, and macrophage-colony stimulating factor are present in the vitreous of patients with proliferative diabetic retinopathy (PDR) or proliferative vitreoretinopathy (PVR). The levels of these cytokines were measured by specific enzyme-linked immunoassays in vitreous from 30 patients with PDR, 13 patients with PVR, and 26 control individuals, including 10 cadaver eyes and 16 patients with idiopathic macular holes, idiopathic macular puckers, vitreous hemorrhages, or uncomplicated retinal detachments. Detectable levels of interleukin-8 were found in 90% of vitreous samples of patients with PDR, 85% with PVR, and 58% of control samples. IL-8 was significantly increased in PDR (mean +/- SEM; 25.0 +/- 5.3 ng/ml; p = 0.01), but not in PVR (11.9 +/- 3.9 ng/ml; p = 0.50) compared to control human vitreous (8.5 +/- 2.5 2.5 ng/ml). MCP-1 was detected in 90% of vitreous samples of patients with PDR, 92% with PVR, and 81% of control samples. MCP-1 was significantly increased in PDR (6.2 +/- 0.9 ng/ml, p = 0.001) and PVR (7.7 +/- 2.5 ng/ml, p = 0.001) over the levels in control vitreous (1.2 +/- 0.2 ng/ml). M-CSF was detected in 94% of vitreous samples of patients with PDR, 88% with PVR, and 92% from control vitreous. M-CSF was significantly elevated in PDR (32.3 +/- 8.3 ng/ml, p = 0.03), but not in PVR (23.6 +/- 12.8 ng/ml, p = 0.4) compared to control (10.7 +/- 3.5 ng/ml). Our results suggest that IL-8, MCP-1, and M-CSF participate in the pathogenesis of PDR and PVR.

Cystoid macular edema associated with latanoprost therapy in a case series of patients with glaucoma and ocular hypertension.

OBJECTIVE To identify coexisting ocular diagnoses in a case series of eyes that developed cystoid macular edema (CME) associated with latanoprost therapy. DESIGN Retrospective observational case series. PARTICIPANTS Seven eyes of seven patients who developed CME possibly associated with latanoprost treatment were studied. INTERVENTION When these patients, all of whom were treated with latanoprost in addition to other glaucoma medications, described blurred vision or eye irritation, ocular examination revealed CME, which was confirmed by fluorescein angiography. Latanoprost was discontinued, and in three cases topical corticosteroids and nonsteroidal anti-inflammatory agents were used to treat the CME. MAIN OUTCOME MEASURES Visual acuity and intraocular pressure were determined before latanoprost use began, during therapy, and after latanoprost use ceased. In these cases, resolution of CME was documented clinically after discontinuing latanoprost. RESULTS Clinically significant CME developed after 1 to 11 months of latanoprost treatment, with an average decrease of 3 lines in Snellen visual acuity. Intraocular pressure decreased an average of 27.9% during treatment. Cystoid macular edema was confirmed in all cases by fluorescein angiography. In these seven patients, the following coexisting ocular conditions may have placed these eyes at risk for prostaglandin-mediated blood-retinal barrier vascular insufficiency: history of dipivefrin-associated CME, epiretinal membrane, complicated cataract surgery, history of macular edema associated with branch retinal vein occlusion, history of anterior uveitis, and diabetes mellitus. In all cases, the macular edema resolved following discontinuation of latanoprost, in some instances with concomitant use of steroidal and nonsteroidal anti-inflammatory agents. CONCLUSIONS In this case series of pseudophakic, aphakic, or phakic eyes, the temporal relationships between the use of latanoprost and developing CME, and the resolution of CME following cessation of the drug, suggest an association between latanoprost and CME. In all cases, coexisting ocular conditions associated with an altered blood-retinal barrier were present.

Age-related macular degeneration: a high-resolution genome scan for susceptibility loci in a population enriched for late-stage disease.

Age-related macular degeneration (AMD) is a complex multifactorial disease that affects the central region of the retina. AMD is clinically heterogeneous, leading to geographic atrophy (GA) and/or choroidal neovascularization (CNV) at advanced stages. Considerable data exists in support of a genetic predisposition for AMD. Recent linkage studies have provided evidence in favor of several AMD susceptibility loci. We have performed a high-resolution (5-cM) genome scan of 412 affected relative pairs that were enriched for late-stage disease (GA and/or CNV). Nonparametric linkage analysis was performed using two different diagnostic criteria and also by dividing the affected individuals according to GA or CNV phenotype. Our results demonstrate evidence of linkage in regions that were suggested in at least one previous study at chromosomes 1q (236–240 cM in the Marshfield genetic map), 5p (40–50 cM), and 9q (111 cM). Multipoint analysis of affected relatives with CNV provided evidence of additional susceptibility loci on chromosomes 2p (10 cM) and 22q (25 cM). A recently identified Gln5345Arg change in HEMICENTIN-1 on chromosome 1q25 was not detected in 274 affected members in the restricted group with AMD, 346 additional patients with AMD, and 237 unaffected controls. Our results consolidate the chromosomal locations of several AMD susceptibility loci and, together with previous reports, should facilitate the search for disease-associated sequence variants.

Role of MCP‐1 and MIP‐1α in retinal neovascularization during postischemic inflammation in a mouse model of retinal neovascularization

Macrophages are important participants in neovascularization. This study was designed to examine the role of the monocyte/macrophage chemotactic proteins, monocyte chemotactic protein‐1 (MCP‐1), and macrophage inflammatory protein‐1α (MIP‐1α) in a mouse model of oxygen‐induced ischemic retinopathy and to determine whether the morphology and distribution of macrophages/microglia are concomitantly altered. The MCP‐1, MIP‐1α mRNA levels increased at 3 h after ischemia. MCP‐1, MIP‐1α, and vascular endothelial growth factor protein levels were also increased markedly and were maximal on days 1,0.5, and 1, respectively, after ischemia. In situ hybridization showed that MCP‐1 and MIP‐1α were localized in the hypoxic inner retina. Immunostaining demonstrated that the macrophages/microglia in the retina had morphological changes with enlarged processes, and some were closely associated with neovascular tufts at postnatal day 17. Coadministration of the neutralizing antibodies against MCP‐1 and MIP‐1α inhibited retinal neovascularization by 30%. Our data suggest that MCP‐1 and MIP‐1α are involved in the induction of retinal neovascularization and play a role in the inflammation induced by the ischemic retinopathy, possibly by modulating or attracting macrophages/microglia.

Endophthalmitis after Pars Plana Vitrectomy

Purpose: To describe the clinical course and incidence of culture-proven Postvitrectomy endophthalmitis in 18 patients from five academic centers and three private practices. Methods: Patients undergoing pars plana vitrectomy for recent trauma or endophthalmitis were excluded. The average age was 58 years (range, 21–85 year). Sixty-one percent of the patients (11/18) had diabetes mellitus. The indication for initial vitrectomy was vitreous hemorrhage (n = 10), macular epiretinal membrane (n = 3), recurrent retinal detachment with proliferative vitreoretinopathy (n = 2), retinal detachment with retinoschisis (n =1), proliferative diabetic retinopathy with tractional retinal detachment (n =1), and dislocated intraocular lens (n =1). None of these eyes received prophylactic intraocular antibiotics during the vitrectomy. Results: All eyes were treated with intraocular antibiotics after the diagnosis of Postvitrectomy endophthalmitis was made. Final visual acuity ranged from 20/20 to no light perception and included five eyes with 20/50 or better visual acuity and 11 eyes with less than 5/200 visual acuity. Nine eyes had a final visual acuity of no light perception. Of the 16 eyes infected with a single organism, 71 % (5J7) of eyes infected with coagulasenegative staphylococci retained 20/50 or better final visual acuity compared with no eyes (0/9) infected with other organisms ( P = 0.005). Two eyes infected with both coagulase-negative Staphylococcus and Streptococcus had a final visual acuity of 20/ 400. Three eyes with a total hypopyon later had enucleation or evisceration. Based on the data from four medical centers, the incidence of endophthalmitis after pars plana vitrectomy performed over the last 10 years was 9/12,216 (0.07%). Conclusion: Endophthalmitis after vitrectomy is rare. Postvitrectomy bacterial endophthalmitis caused by organisms other than coagulase-negative staphylococci has a poor visual prognosis.

Interleukin-6 (IL-6) gene expression and secretion by cytokine-stimulated human retinal pigment epithelial cells

Retinal and choroidal inflammatory lesions are important causes of visual loss, but the mechanisms regulating intraocular inflammation remain poorly understood. By virtue of its position at the blood-retina barrier, the retinal pigment epithelium (RPE) cells may be critical to the initiation and propagation of ocular inflammation. Previously we showed that cytokine-stimulated RPE cells produce interleukin-8, a well-defined chemotactic factor for neutrophils and lymphocytes. In this study, we found that human RPE cells stimulated by human recombinant interleukin-1-beta (rIL-1 beta) or tumor necrosis factor-alpha (rTNF-alpha) produce interleukin-6 (IL-6). Using a plasmacytoma proliferation assay, significant levels of IL-6 were found in media of RPE cells stimulated with either rIL-1 beta or rTNF-alpha for 4 hr. Progressive accumulation of IL-6 in media overlying stimulated RPE cells occurred over the subsequent 20 hr. IL-1 beta was a significantly more potent stimulator of RPE IL-6 production than TNF-alpha, RPE IL-6 production in response to each of these cytokines was also dose-dependent over a range of 20 pg to 20 ng ml-1. Specific anti IL-6 antibody, but not control immunoglobulin, neutralized RPE-derived IL-6 activity in the plasmacytoma proliferation assays. RPE IL-6 mRNA levels were detectable 1 hr after cytokine stimulation, plateaued within 8 hr in 24-hr assays, and demonstrated dose-dependent kinetics in 6 hr assays. Lipopolysaccharide failed to induce RPE IL-6 mRNA expression or RPE IL-6 production.(ABSTRACT TRUNCATED AT 250 WORDS)

Toll-like receptor 4 (TLR4) of retinal pigment epithelial cells participates in transmembrane signaling in response to photoreceptor outer segments.

Retinal pigment epithelial (RPE) cells mediate the recognition and clearance of effete photoreceptor outer segments (POS), a process central to the maintenance of normal vision. Given the emerging importance of Toll-like receptors (TLRs) in transmembrane signaling in response to invading pathogens as well as endogenous substances, we hypothesized that TLRs are associated with RPE cell management of POS. TLR4 clusters on human RPE cells in response to human, but not bovine, POS. However, TLR4 clustering could be inhibited by saturating concentrations of an inhibitory anti-TLR4 mAb. Furthermore, human POS binding to human RPE cells elicited transmembrane metabolic and calcium signals within RPE cells, which could be blocked by saturating doses of an inhibitory anti-TLR4 mAb. However, the heterologous combination of bovine POS and human RPE did not trigger these signals. The pattern recognition receptor CD36 collected at the POS–RPE cell interface for both homologous and heterologous samples, but human TLR4 only collected at the human POS–human RPE cell interface. Kinetic experiments of human POS binding to human RPE cells revealed that CD36 arrives at the POS–RPE interface followed by TLR4 accumulation within 2 min. Metabolic and calcium signals immediately follow. Similarly, the production of reactive oxygen metabolites (ROMs) was observed for the homologous human system, but not the heterologous bovine POS–human RPE cell system. As (a) the bovine POS/human RPE combination did not elicit TLR4 accumulation, RPE signaling, or ROM release, (b) TLR4 arrives at the POS–RPE cell interface just before signaling, (c) TLR4 blockade with an inhibitory anti-TLR4 mAb inhibited TLR4 clustering, signaling, and ROM release in the human POS–human RPE system, and (d) TLR4 demonstrates similar clustering and signaling responses to POS in confluent RPE monolayers, we suggest that TLR4 of RPE cells participates in transmembrane signaling events that contribute to the management of human POS.

Retinal pigment epithelium tears after intravitreal injection of bevacizumab (avastin) for neovascular age-related macular degeneration.

Background: Intravitreal bevacizumab (Avastin, Genentech, Inc., South San Francisco, CA) treatment of neovascular age-related macular degeneration (AMD) has become an important part of clinical retinal practice. We describe retinal pigment epithelium (RPE) tears that were noted after intravitreal injection of bevacizumab. Methods: In this multimember, retrospective case series, data on eyes that developed RPE tears after intravitreal bevacizumab injection were collected and analyzed. Previous treatments, type of lesion, time to tear, and preinjection and final visual acuities were all compared. The total numbers of bevacizumab injections were available from all four institutions and compiled to estimate the incidence rate. Results: Four retina centers administered a total of 1,455 intravitreal 1.25-mg bevacizumab injections for neovascular AMD during the 9-month study period. Twelve patients presented with RPE tears within 4 days to 8 weeks of injection (mean ± SD, 24.3 ± 15.2 days from injection to tear). In each case, the RPE tear was preceded by an RPE detachment, and all had a component of serous sub-RPE fluid. On the basis of our collective data, we estimate an incidence rate of ≈0.8%. Conclusions: RPE tears can occur after intravitreal injection of bevacizumab. The low incidence of this adverse event should not preclude anti–vascular endothelial growth factor therapy counseling for patients with neovascular AMD, but eyes with serous RPE detachments appear to be most vulnerable to this adverse event.

Cataract surgery in patients with nanophthalmos: results and complications.

Purpose: To evaluate the results and complications of cataract surgery in patients with nanophthalmos. Setting: University hospital practice. Methods: The records of consecutive patients with nanophthalmos who had cataract surgery from 1978 through 2002 were reviewed for ocular diagnoses, corneal diameter, keratometry, axial length, retinal–choroidal–scleral thickness determined by echography, ocular surgeries, visual acuity, and complications. Results: Eight patients (6 women, 2 men) with a mean age of 59 years were reviewed. Four patients were not previously diagnosed with nanophthalmos; increased retinal–choroidal–scleral thickness (mean 2.41 mm) confirmed the diagnosis. Twelve eyes had cataract extraction with posterior chamber intraocular lens (IOL) implantation, 11 by phacoemulsification and 1 by extracapsular cataract extraction, and 4 eyes had lamellar scleral resections. Additional surgeries included glaucoma laser treatment (8 eyes), cyclocryotherapy (2 eyes), trabeculectomy with scleral resection (1 eye), trabeculectomy combined with phacoemulsification (1 eye), and neodymium:YAG laser capsulotomy (4 eyes). No eye lost vision; however, complications included severe iritis, broken IOL haptic with vitreous loss, posterior capsule opacity, choroidal hemorrhage, phthisis, and aqueous misdirection. Conclusions: Results indicate that echography should be used to assess retinal–choroidal–scleral thickness in eyes that are hyperopic and at risk for narrow‐angle glaucoma. Thickening may confirm the diagnosis of nanophthalmos and allow careful preoperative assessment and appropriate operative procedures in these high‐risk eyes. With advances in cataract, glaucoma, and uveal effusion treatments, surgical results in patients with nanophthalmos are improving.