The chemotactic properties of various topical brimonidine tartrate ophthalmic preparations.

BACKGROUND: The study aimed to evaluate and compare the leukocyte chemotactic activities of various brimonidine tartrate (BT) eye drop formulations. METHODS: A 96-well dot-blot platet using a Boyden-style well was used to study the chemotactic effects of BT ophthalmic preparations. A modification was made to create blind wells where the tested agents were placed. Leukocytes were isolated from the peripheral blood of healthy volunteers. As positive controls, we used diluted drugs, benzalkonium chloride solution (BAK), zymosan-activated serum, and formyl-methionine-leucine-phenylalanine peptides. The negative control in our study was a phosphate-buffered saline solution. For each experimental condition, we measured leukocyte migration through a Millipore membrane. The differences in the mean migration distance between groups were compared using the analysis of variance (ANOVA). RESULTS: The measured migration distances (in µm ± SD) were 62.14 ± 3.71 for BT 0.2% with BAK (Alcon Laboratories Inc.); 63.61 ± 3.81 for BT 0.2% with BAK (Allergan Inc); 40.36 ± 3.17 for BT 0.15% without BAK; and 41.02 ± 2.17 for BAK alone. The negative controls showed no chemotactic activity, while the positive controls showed the highest neutrophil migration of all experimental conditions. The differences between BT 0.15% without BAK and the other commercial formulations were statistically significant. CONCLUSION: Commercial ophthalmic preparations of BT 0.2% with BAK 0.005% had higher chemotactic properties than the alternative of a lower concentration of BT and without the preservative BAK. Therefore, the latter should be considered for patients with glaucoma or ocular hypertension in order to minimize iatrogenic ocular inflammation.

The Use of Digital Microscopy to Compare the Thicknesses of Normal Corneas and Ex Vivo Rejected Corneal Grafts with a Focus on the Descemet's Membrane.

OBJECTIVE: To compare the thickness of corneal layers, specifically the Descemet's membrane (DM), in normal corneas and in failed grafts due to rejection (FGRs) using the digital histopathology and to propose a model for the measurement of corneal layers using this method. METHODS: This is a prospective, cross-sectional study performed at the MUHC-McGill University Ocular Pathology & Translational Research Laboratory (McGill University, Montreal, Canada). Histopathological sections of 25 normal human corneas and 40 FGRs were fully digitalized and examined. Inclusion criteria: samples diagnosed as normal corneas or FGRs, from patients older than 18 years of age. Exclusion criteria: histopathological sections without adequate tissue or missing epidemiological information. For each sample, the thicknesses of the epithelium, stroma, and DM were acquired. From a perpendicular plane of reference, two central measurements and two nasal and two temporal peripheral measurements were obtained. RESULTS: There were differences between the normal and FGR groups in the mean central thickness of the epithelium (p < 0.001), the nasal and temporal stromal regions (p < 0.001), and of the DM in the nasal and temporal regions (p < 0.001). Compared with the extremities of the sample (nasal and temporal), the mean thickness of the DM in normal corneas was lower in the central region (p < 0.001), and this difference was not found in the FGR group. CONCLUSIONS: Normal corneas have a thinner epithelium in the central region than the FGR group. In addition, the stroma and DM thicknesses of the nasal and temporal periphery were significantly higher in normal corneas than in those from the FGR group. The digital microscopy protocol applied in this study may be useful for further research studies regarding cornea and other tissues.

Histopathological trabecular meshwork remodeling after cataract surgery detected with an advanced image analyzer.

PURPOSE: To compare the histopathological morphometry of the trabecular meshwork and ciliary processes in pseudophakic eyes and phakic eyes using advanced image analyzer technology. SETTING: McGill University, Montreal, Quebec, Canada. DESIGN: Retrospective case series. METHODS: Thirty-five pseudophakic eyes and 25 phakic eyes were sectioned and converted into digital slides. The total trabecular meshwork area and the ciliary body stroma were demarcated. The area of the trabecular meshwork, cellular and noncellular trabecular meshwork compartments, trabecular space, distance from scleral spur to inner uveal trabecular portion, and degree of fibrosis of the ciliary processes were evaluated. RESULTS: The trabecular meshwork area was larger in the pseudophakic group than the phakic group (P = .03). Furthermore, a trend of larger trabecular space recorded was seen in the pseudophakic group than the phakic group (P = .14). No differences in the proportion of cellular (P = .88) and noncellular trabecular meshwork compartments (P = .4) were seen between groups. The scleral spur to inner uveal trabecular portion distance was longer in the pseudophakic group than the phakic group (P = .008) and correlate with the trabecular meshwork area (P = .0001, r = 0.56). In the ciliary processes, a higher degree of fibrosis was measured in the pseudophakic group than the phakic group (P = .02). CONCLUSIONS: There were significant histopathological changes in the trabecular meshwork and higher fibrosis in the ciliary processes in pseudophakic eyes compared with phakic eyes. These findings support the hypothesis that trabecular meshwork remodeling after cataract surgery is involved in lowering intraocular pressure.

Immunohistochemical analysis of retinoblastoma cell phenotype using neuronal and glial cell markers.

PURPOSE:: The cellular origin of retinoblastoma is uncertain as constituent tumor cells heterogeneously express markers of both immature and mature retinal cells. An immunohistochemical analysis of cellular origin may yield valuable insights into disease progression and treatment options. This study aimed to determine the cellular origin of retinoblastoma in a large case series and correlate these findings with histopathological prognostic factors. METHODS:: Thirty-nine retinoblastoma cases were histopathologically diagnosed and analyzed by immunohistochemistry using monoclonal antibodies against the immature neural cell marker SRY-box containing gene 2 (SOX-2), the mature neuronal cell marker microtubule-associated protein 2 (MAP2), and the mature glial cell marker glial fibrillary acidic protein (GFAP). Histopathological features were also evaluated, including patterns of growth, differentiation, vitreous seeding, and choroidal/scleral, optic nerve, and anterior chamber invasion. Two retinoblastoma cell lines, WERI-1 and Y79, were studied by immunocytochemistry using the same antibodies. RESULTS:: Expression of SOX-2 was strong in 97.4% of retinoblastoma cases, while MAP-2 was expressed in 59% of cases. Immunostaining for GFAP was positive only in reactive stromal astrocytes interspersed amongst tumor cells and in peritumoral tissue. There was no correlation between histopathological prognostic factors and immunohistochemical markers. Retinoblastoma cell lines showed strong positivity for SOX2 (90% of WERI-1 cells and 70% of Y79 cells) and MAP2 (90% of cells in both lines). GFAP was completely negative in both cell lines. CONCLUSION:: The majority of retinoblastomas and both RB cell lines expressed an immature neural and/or a mature neuronal cell marker, but not a glial marker. These results indicate a typical neuroblast or neuronal origin and eliminate astrocyte differentiation from neural stem cells as the source of retinoblastoma.

Corneal stromal dystrophies: a clinical pathologic study.

INTRODUCTION: Corneal dystrophy is defined as bilateral and symmetric primary corneal disease, without previous associated ocular inflammation. Corneal dystrophies are classified according to the involved corneal layer in superficial, stromal, and posterior dystrophy. Incidence of each dystrophy varies according to the geographic region studied. PURPOSE: To evaluate the prevalence of stromal corneal dystrophies among corneal buttons specimens obtained by penetrating keratoplasty (PK) in an ocular pathology laboratory and to correlate the diagnosis with patient age and gender. METHODS: Corneal button cases of penetrating keratoplasty from January-1996 to May-2009 were retrieved from the archives of The Henry C. Witelson Ophthalmic Pathology Laboratory and Registry, Montreal, Canada. The cases with histopathological diagnosis of stromal corneal dystrophies were stained with special stains (Peroxid acid Schiff, Masson trichrome, Congo red analyzed under polarized light, and alcian blue) for classification and correlated with epidemiological information (age at time of PK and gender) from patients' file. RESULTS: 1,300 corneal buttons cases with clinical diagnose of corneal dystrophy were retrieved. Stromal corneal dystrophy was found in 40 (3.1%) cases. Lattice corneal dystrophy was the most prevalent with 26 cases (65%). Nineteen were female (73.07%) and the PK was performed at average age of 59.3 years old. Combined corneal dystrophy was found in 8 (20%) cases, 5 (62.5%) of them were female and the average age of the penetrating keratoplasty was 54.8 years old. Granular corneal dystrophy was represented by 5 (12.5%) cases, and 2 (40%) of them were female. Penetrating keratoplasty was performed at average age of 39.5 years old in granular corneal dystrophy cases. Macular corneal dystrophy was present in only 1 (2.5%) case, in a 36 years old female. CONCLUSION: Systematic histopathological approach and evaluation, including special stains in all stromal corneal dystrophies is critical to establish the correct diagnosis.

Danish type gelsolin-related amyloidosis in a Brazilian family: case reports.

Familial amyloidosis of the Finnish type (FAF) is an autosomal dominant form of systemic amyloidosis showing marked geographic clustering in Finland. The disease is caused by a point mutation, 654G-A, in the gelsolin gene. The Danish-subtype of FAF has been previously described in three families, the patients present clinical findings similar to FAF, and the mutation 654G-T in the gelsolin gene. Three members from two generations of the same family, with familial amyloidosis, were screened for mutations in the GSN gene. Genomic DNA was extracted from peripheral blood lymphocytes and the polymerase chain reaction (PCR) was carried out under standard conditions, using appropriate primers. Sequence analysis showed the presence of a G to T transition at nucleotide 654 of the gelsolin gene. This is the first report of gelsolin-related familial amyloidosis in a Brazilian family, and the result is particularly significant as this pedigree presents an unusual mutation, described previously in three families, with no known Finnish ancestors (Danish type).

Incidence of epithelial lesions of the conjunctiva in a review of 12,102 specimens in Canada (Quebec).

PURPOSE: The purpose of this study was to assess the relative frequency of epithelial lesions of the conjunctiva in Canada. METHODS: A retrospective study of 12,102 consecutive cases received during 16 years (1993-2009) at the Henry C. Witelson Ocular Pathology Laboratory in Montreal, Canada, was performed. Demographic data was retrieved from histopathological request forms and specimens were categorized and analyzed by mean percentage. The relative frequency of epithelial lesions of the conjunctiva from a single center in Canada, representing the province of Quebec was reviewed. RESULTS: Of the 12,102 specimens reviewed, 273 were conjunctival lesions (2.25%), including 86 epithelial tumors (0.71%) of the conjunctiva that comprised the studied sample. The average age of these patients was 59.9 ± 17.6 years, and gender distribution was 66 (69%) males and 30 (31%) females. Fifteen lesions (17.4%) were classified as squamous cell papillomas (mean age, 57.3 ± 16.7 years). Within the ocular surface squamous neoplasia (OSSN) spectrum, there were 10 (11.6%) actinic keratosis (63.8 ± 17.6 years), 27 (31.3%) cases of conjunctival intraepithelial neoplasia (CIN) with variable degrees of atypia (mild to moderate) (63.9 ± 15.3 years), 15 (17.4%) carcinomas in situ (66.7 ± 18.0 years), and 17 (19.7%) squamous cell carcinomas (SCC) (56.2 ± 19.4 years). Two other rare cases of malignant tumors included one basal cell carcinoma and one mucoepidermoid carcinoma. CONCLUSIONS: The distribution of our sample is similar to the one reported by the American Forces Institute of Pathology (AFIP) in 1994. When we compare our sample to others coming from countries with high levels of sunlight exposure, we found a lower incidence of ocular surface squamous neoplasia, including squamous cell carcinomas in Canada.

Fine needle aspiration biopsy to reestablish cell culture in an animal model of uveal melanoma.

PURPOSE: To access the reliability of fine-needle aspiration biopsy in harvesting a sufficient amount of viable melanoma cells to establish a cell culture and maintain a melanoma cell line from an animal model of uveal melanoma. METHODS: For this study, fifteen male New Zealand albino rabbits had their right eye surgically inoculated with uveal melanoma cell line 92.1. The animals were immunosupressed with cyclosporine A using a dose schedule previously published. The animals were followed for 12 weeks. Intraocular tumor growth was monitored weekly by indirect ophthalmoscopy. After the fourth week, one animal was sacrificed per week preceded by fine-needle aspiration biopsy using a sharp 25-gauge, 1-inch long needle. Two separate aspirates were made from different areas of the tumor. Each aspirate was flushed to a separate cell culture media and sent for cell culture. The cells were frozen after two weeks when there were at least 1 million cells, which is enough to maintain a cell line. Cells were defrosted for HMB-45 immuno-stains to confirm the melanoma origin. RESULTS: Cell growth was observed from the samples harvested from 11 out of the 15 animals inoculated with uveal melanoma. All cell cultures, after defrost, immunoassayed positive for HMB-45. CONCLUSION: Fine needle aspiration biopsy seems to be a reliable method to harvest cells from solid intraocular melanomas in an animal model, to establish cell culture and to maintain a melanoma cell line.

The white dot syndromes.

Several entities must be considered when a patient presents with a white dot syndrome. In most cases these can be distinguished from one another based on the appearance or distribution of the lesions, the clinical course, or patient variables such as age, sex, laterality, and functional and image examinations. In this paper we review the distinctive and shared features of the white dot syndromes, highlighting the clinical findings, diagnostic test results, proposed etiologies, treatment, and prognosis.

A case of anterior internal ophthalmomyiasis: case report.

A case of anterior internal ophthalmomyiasis is described. A 27-year-old female from Northern Brazil presenting with anterior uveitis and vitritis had a fly larva surgically removed from the anterior chamber of the left eye. The species was Cochliomyia hominivorax. The larva was covered by macrophages and foreign body giant cells characterizing a foreign body granulomatous reaction.

Prostate-specific membrane antigen is undetectable in choroidal neovascular membrane.

BACKGROUND: Choroidal neovascular membrane (CNVM) is one of the leading causes of severe visual loss and is often associated with age-related macular degeneration (AMD). Various modalities of treatment, including photocoagulation and surgery, are being considered as options, but with limited success. Prostate-specific membrane antigen (PSMA) is a type II membrane glycoprotein expressed in benign and malignant prostatic tissues, in some non-prostatic tissues, and in the endothelium of tumor-associated neovasculature of non-prostatic neoplasm. Some studies have suggested that the expression of PSMA is restricted to endothelium from tumor-associated neovasculature and might be stimulated by some tumor-secreted angiogenic factors. However, no previous study demonstrating PSMA expression in non-related tumor neovasculature, such as CNVM, has been performed to date. Furthermore, demonstration of PSMA expression in CNVM in AMD patients could reveal a novel target for antineovascular therapy. The purpose of this study was to evaluate the immunohistochemical expression of PSMA in CNVM from AMD. METHODS: Immunohistochemical analysis, with a standard avidin-biotin complex technique, was performed using an anti-PSMA mouse monoclonal antibody in 30 specimens of surgically excised CNVM from AMD patients. Antibody to an endothelial cell specific marker, factor VIII, was used to confirm the location of the endothelial cells. RESULTS: The angiogenic microvessels of the 30 cases demonstrated negative staining to PSMA while factor VIII was expressed in all cases. Seventy-five percent of the secretory-acinar epithelium of the prostatic hyperplasia specimen stained positive, confirming that the immunohistochemical technique was correctly performed. CONCLUSION: The absence of PSMA expression in non-tumoral neovasculature supports the theory, previously suggested, that endothelial cell PSMA expression may be stimulated by one or more tumor-secreted angiogenic factors. Angiogenesis is very important in neoplasia and the endothelial expression of PSMA in tumor-associated neovasculature may represent a target for antineovasculature-based therapy. The absence of PSMA expression in CNVM suggests that PSMA may not be a potential target for antineovasculature-based therapy.