Jacob Pe’er

Vascular Endothelial Growth Factor Upregulation in Human Central Retinal Vein Occlusion

BACKGROUND AND OBJECTIVE Vascular endothelial growth factor (VEGF), a key mediator of intraocular neovascularization, is triggered by hypoxia and has been shown in the eyes of animal models of central retinal vein occlusion (CRVO). However, there is little information on CRVO in humans, in particular, the identity of VEGF-producing cells. STUDY DESIGN The study design was molecular localization of the site of VEGF production in the eyes of patients with CRVO. PARTICIPANTS Ten formaldehyde solution-fixed and paraffin-embedded eyes removed surgically from patients with CRVO and neovascular glaucoma were studied. Five eyes with uveal melanoma and no neovascularization served as control specimens. METHODS Thin whole-eye sections were hybridized in situ with a VEGF-specific probe to identify cells producing VEGF messenger RNA (mRNA). RESULTS All ten eyes with CRVO showed evidence of intraretinal expression of VEGF mRNA. In all eyes, the inner nuclear layer showed VEGF-upregulated expression. Upregulation of VEGF mRNA was identified in four eyes in the ganglion cell layer and in two eyes with retinal detachment in the outer nuclear layer as well. CONCLUSIONS The population of VEGF-producing retinal cells in each eye is likely to represent cells residing in ischemic regions of the retina. Hypoxia-induced VEGF is, most likely, the linking factor between retinal ischemia and iris and retinal neovascularization in CRVO.

Role of intravitreal methotrexate in the management of primary central nervous system lymphoma with ocular involvement

PURPOSE To evaluate the safety and efficacy of intravitreal methotrexate in the management of primary central nervous system lymphoma (PCNSL) involving the eye. DESIGN Retrospective noncomparative interventional case series. PARTICIPANTS Sixteen human immunodeficiency virus-negative white patients (5 males and 11 females, aged 30-76 years) with intraocular B cell lymphoma treated with intravitreal methotrexate at Oregon Health & Science University or Hadassah University Hospital between August 1995 and September 2000. INTERVENTION Patients were treated with intravitreal methotrexate (400 micro g/0.1 ml) according to a standard induction-consolidation-maintenance regimen and monitored by serial examinations, including measurement of visual acuity, slit-lamp biomicroscopy, and dilated funduscopy. MAIN OUTCOME MEASURES Clinical response to intravitreal chemotherapy, number of injections for clinical remission, visual acuity, complications during study period, length of survival from diagnosis, and cause of death. RESULTS Time of follow-up from commencement of the methotrexate injections was 6 to 35 months (median, 18.5 months). Twenty-six of 26 eyes (100%) were cleared clinically of malignant cells after a maximum of 12 methotrexate injections. A second remission was induced in three patients, who were treated with a further course of intravitreal chemotherapy after their tumor recurred within the eye. Complications that occurred during the period of treatment and follow-up included cataract (73% of 26 eyes), corneal epitheliopathy (58% of 26 eyes), maculopathy (42% of 26 eyes), vitreous hemorrhage (8% of 26 eyes), optic atrophy (4% of 26 eyes), and sterile endophthalmitis (4% of 26 eyes). No patient had irreversible loss of vision that could be definitely attributed to the intravitreal injection of methotrexate. CONCLUSIONS Intravitreal chemotherapy with methotrexate is effective in inducing clinical remission of intraocular tumor in PCNSL with acceptable morbidity. Further study is indicated to determine whether this approach extends life expectancy.

Nerve growth factor is preformed in and activates human peripheral blood eosinophils

BACKGROUND Recent studies have shown that nerve growth factor (NGF) is produced by and can act on several immune-inflammatory cells. OBJECTIVES The objective of this study was to study the effects of NGF on human peripheral blood eosinophils and assess whether these cells produce and store NGF. METHODS Eosinophils were purified by negative immunoselection (magnetic cell sorting systems, purity 98% to 100%) from 13 subjects (9 to 26 years old) with mild blood eosinophilia, mainly of allergic origin. Eosinophils were incubated with NGF (50 to 1000 ng/mL), and supernatants were collected for measurement of eosinophil peroxidase (EPO, 20 minutes, colorimetric enzymatic assay) and IL-6 (12 hours, ELISA). Eosinophil viability was evaluated by Trypan blue test (days 2, 3, and 4). NGF content in freshly isolated eosinophils, after ultrasound disruption, was determined with a 2-site immunoenzymatic assay. The presence of mRNA for NGF was evaluated by reverse transcription PCR. RESULTS NGF caused EPO release (highly significant at 1000 ng/mL NGF). IL-6 release from eosinophils was not higher than IL-6 spontaneously released into culture medium alone. NGF did not significantly affect the number of viable eosinophils. NGF was found in the eosinophil sonicates (1.5 to 17.8 pg/mL per 106 cells). Similarly, mRNA for NGF was detected by reverse transcription PCR in the freshly isolated eosinophils. CONCLUSIONS NGF activates human peripheral blood eosinophils from subjects with mild eosinophilia to selectively release inflammatory mediators. Eosinophils store and produce NGF. Therefore the capability of NGF to induce a secretory response and its production and storage by circulating human eosinophils suggest a possible role for NGF in conditions associated with eosinophilia, including allergic disease.

Mitomycin C treatment for conjunctival-corneal intraepithelial neoplasia: a multicenter experience.

OBJECTIVE The purpose of the study is to evaluate the efficacy and risks of topical mitomycin C (MMC) for conjunctival-corneal intraepithelial neoplasia (CCIN). DESIGN The study design was a clinical case series of CCIN. PARTICIPANTS Seventeen patients, 16 with biopsy-confirmed CCIN and 1 with invasive squamous cell carcinoma (SCC), were included in the study. INTERVENTION Patients received topical drops of MMC 0.02% to 0.04% four times daily from 7 to 28 days. Retreatment was done in cases of lesion recurrence. MAIN OUTCOME MEASURES The size of the CCIN before and after the treatment and ocular complications post-MMC application were evaluated. RESULTS Ten patients remained disease-free after one course of MMC application. In one case, residual CCIN remained very small without regrowth. In the one patient with invasive SCC and in five patients with CCIN, regrowth occurred within 6 months of the first treatment. After retreatment, invasive SCC and CCIN in an additional two patients were eradicated. In two cases, although the size of the lesions decreased after two and three applications of MMC, regrowth occurred, and the CCIN returned to its original size. In the final case, limited recurrence has occurred and no retreatment has been done. The complications of MMC use included mild-to-moderate conjunctival hyperemia and mild allergy, which resolved after discontinuation of the treatment. Severe pain manifested when treatment was longer than 14 days. CONCLUSIONS Application of topical MMC is an efficient treatment for most but not all cases of CCIN.

New techniques for drug delivery to the posterior eye segment.

ABSTRACTOcular drug delivery has become an increasingly important field of research especially when treating posterior segment diseases of the eye, such as age-related macular degeneration, diabetic retinopathy, posterior uveitis and retinitis. These diseases are the leading causes of vision loss in developed countries which require repeated long-term administration of therapeutic agents. New drugs for the medication of the posterior ocular segment have emerged, but most drugs are delivered by repeated intravitreal injections associated with ocular complications. Advances in ocular drug delivery system research are expected to provide new tools for the treatment of the posterior segment diseases, providing improved drug penetration, prolonged action, higher efficacy, improved safety and less invasive administration, resulting in higher patient compliance. This review provides an insight into the recent progress and trends in ocular drug delivery systems for treating posterior eye segment diseases, with an emphasis on transscleral iontophoresis.

Control of Melanoma Morphogenesis, Endothelial Survival, and Perfusion by Extracellular Matrix

The morphogenetic properties of endothelial cells and melanoma cells were tested under varying matrix quantities and distributions and under constant and saturating levels of growth factors. Aggressive melanoma cells self-assembled into cords vasculogenically only when seeded on thin matrices: nonaggressive melanoma cells did not mimic endothelial cell behavior under any matrix thickness. When buried in matrix, however, aggressive melanoma cells generated looping patterns that contained tumor cells and matrix. These patterns were different topologically and compositionally from cord-like structures or blood vessels but were nevertheless capable of conducting dye by microinjection or passive diffusion. When seeded on three-dimensional cultures of nonaggressive nonpattern-forming melanoma cells, prelabeled endothelial cells attached to, penetrated through, and survived for 2 weeks but failed to form vasculogenic cords. In cocultures containing aggressive melanoma cells, endothelial cells survived briefly but formed short cords only in contact with looping patterns formed by the aggressive tumor cells. Time-lapse recording showed that endothelial cells were lysed upon direct contact with aggressive melanoma cells. Looping patterns identified in human tissue samples were composed ultrastructurally of electron-dense material on either side of a layer of tumor cells; scattered red blood cells were seen in this central cellular layer. By immunohistochemistry, patterns labeled with laminin and fibrinogen colocalized to these looping laminin-positive patterns, suggesting the presence of plasma within these patterns from contiguous leaky tumor vessels. These observations are consistent with the perfusion of these patterns in vitro and with repeated demonstrations of the colocalization of intravenous tracers to looping laminin patterns in animal xenograft models by independent groups. Thus, the distribution and localized quantity of extracellular matrix in aggressive melanomas contributes to the regulation of tumor cell morphogenesis, modulates interactions between tumor cells and endothelial cells, and may contribute to an extravascular matrix–directed circulation.

Proliferative activity and p53 expression in primary and recurrent pterygia

PURPOSE To assess p53 expression and proliferative activity in primary and recurrent pterygia from the same eyes. DESIGN Retrospective comparative human tissue study. PARTICIPANTS Tissue from excised primary pterygia that did not recur (group A, n = 10) was compared with tissue from primary pterygia that recurred (group B, n = 10) and to the recurrent pterygia tissue that was excised from subjects in group B (group C, n = 10). Ten normal conjunctivas served as controls (group D). METHODS Sections from each pterygium were immunostained with the MIB-1 and bp53. 12 monoclonal antibodies that react with Ki-67 and p53 antigens, respectively. MAIN OUTCOME MEASURES Proliferative activity was calculated as the mean of the MIB-1 positive cell count per eyepiece grid in high magnification (x40) (positive cell count/grid). Percentage of positive cells of all cells in the grid area was evaluated in the p53-stained sections. RESULTS Proliferative activity was found in the epithelium overlying the pterygia and normal conjunctiva. The mean MIB-1 positive cell count/grid +/- standard error was 2.84 +/- 1.07, 1.74 +/- 0.82, 3.83 +/- 1.35, and 0.86 +/- 0.33 in groups A, B, C, and D, respectively (P = 0.17, Kruskal-Wallis). P53 staining was found in 50% of pterygia in groups A, B, and C; none of the normal conjunctival tissues showed p53 immunoreactivity. Four of five p53-positive tissues in group B were p53-negative in group C. In the p53-positive pterygia, less than 10% of cells were p53 positive. However, p53-positive pterygia had higher mean MIB-1 positive cell count/grid +/- standard error as compared with the p53-negative lesions, 4.56 +/- 0.94 vs 1.39 +/- 0.59 (P = 0.021, Mann-Whitney). CONCLUSIONS p53 immunoreactivity and high proliferative activity in the epithelium overlying the pterygium are not associated with recurrence of pterygium.

Topical mitomycin-c for partially excised conjunctival squamous cell carcinoma

PURPOSE To evaluate the efficacy of topical mitomycin-C (MMC) for treatment of postoperative residual conjunctival squamous cell carcinoma (SCC). DESIGN Retrospective noncomparative case series. PARTICIPANTS Five patients, two males and three females, with conjunctival and histologically proven incompletely excised conjunctival SCC. METHODS Patients were treated with topical MMC. Two to three courses of topical MMC, 0.02% or 0.04%, were applied four times daily for 14 days per course. One month after the final treatment, the scar area with surrounding normal conjunctiva was excised, and histologic evaluation was done. MAIN OUTCOME MEASURES No evidence of malignant cells in excised tissues. RESULTS Histologic evaluation of the five specimens showed no malignant cells. Conjunctival scarring with inflammatory response was observed. No regrowth was reported during the follow-up period of 18 to 37 months. The complications of MMC use included mild to moderate conjunctival hyperemia in three patients. All signs and symptoms were resolved after discontinuation of the treatment. CONCLUSIONS Application of topical MMC is an efficient treatment for residual conjunctival SCC. Longer follow-up is required to confirm these findings.

Glandular Tumors of the Lacrimal Sac: Their Histopathologic Patterns and Possible Origins

PURPOSE To describe and characterize the primary lacrimal sac epithelial tumors of glandular origin, and to describe their possible source from glands in the lacrimal sac and nasolacrimal duct walls. METHODS The authors conducted a clinicopathologic study on 14 patients with epithelial lacrimal sac tumors of possible glandular origin. In addition, they reviewed 35 surgical specimens of the lacrimal sac and nasolacrimal duct region and 13 cadaver specimens of the lacrimal sac region. RESULTS Six of the tumors were benign: four were oncocytomas and two were pleomorphic adenomas. Eight of the tumors were malignant: three were oncocytic adenocarcinomas, three were adenoid cystic carcinomas, and two were adenocarcinomas. All tumors were from adults, ranging in age from 38 to 87 years. Twenty-eight of the 47 specimens of lacrimal sac and nasolacrimal duct region showed mixed glands of serous and mucous elements. CONCLUSIONS Although rare, benign and malignant glandular lacrimal sac tumors should be considered in the differential diagnosis of lacrimal sac obstruction. Their possible origin is from the normal glands that exist under the lacrimal sac and nasolacrimal duct epithelium.

Clinical Review: Treatment of Vitreoretinal Lymphoma

Vitreoretinal lymphoma is the most common type of intraocular lymphoma. It is mostly a high-grade B-cell malignancy with a poor prognosis, and is often associated with primary central nervous system lymphoma. Since intraocular lymphoma was first recognized almost 60 years ago, its treatment has gradually evolved. In the early years enucleation was often performed. Since that time, radiation therapy alone, systemic chemotherapy alone, or a combination of the two have been used extensively Because of the limited intraocular penetration of drugs administered systemically, the systemic and local toxicity of chemotherapy and radiation therapy and the high rate of recurrence, intravitreous chemotherapy, mainly using methotrexate, has become popular in the last decade, with encouraging results. More recently, biological treatment with intravitreal injections of rituximab has been investigated, with good results and minimal side effects. This review summarizes the present knowledge on vitreoretinal lymphoma therapy, with an eye to future molecular approaches.