Could Extension Into the Lacrimal Gland and Sac Thwart Topical Chemotherapy for Intraepithelial Sebaceous Carcinoma?

PURPOSE: To identify the frequency of intraepithelial (Pagetoid) spread beyond the ocular surface-namely beyond conjunctiva and cornea-in patients undergoing orbital exenteration for advanced periocular Sebaceous carcinoma (SC). DESIGN: A retrospective, noncomparative observational case series. SUBJECTS: Patients undergoing orbital exenteration for biopsy-proven SC, at Moorfields Eye Hospital between 1997 and 2013. METHODS: Review of clinical records and histological specimens, with particularly reference to involvement of conjunctiva and the extent of Pagetoid infiltration beyond the examinable ocular surface-here termed "hidden" disease. MAIN OUTCOME MEASURES: Histological evidence of intraepithelial SC within the lacrimal sac or lacrimal gland. RESULTS: Twenty-nine patients had clinical data and histological specimens adequate for review. Seventeen (59%) did not have a discrete mass (clinically or histologically) and, on clinical examination, were thought to only have extensive intraepithelial carcinoma; foci of microscopic invasion were, however, detected histologically in 11/17 (65%) of these specimens. Moreover, the in situ carcinoma was found to have invaded far in lacrimal gland ductules in 1/17 patients, in the lacrimal sac (in 2 patients; 12%) or in both the gland and sac (in 2 patients); these 5/17 (29%) cases all showed extensive poorly differentiated intraepithelial SC. Of the 12 other patients who had both Pagetoid spread and a clinically evident nodule, 3 had histological evidence of "hidden" disease. CONCLUSION: Although-due to their being operated in the era prior to the accepted usage of topical therapy for this condition-some of these exenterations might have had particularly advanced in situ SC, over a quarter of patients with periocular SC warranting orbital exenteration show "hidden" intraepithelial tumor within the lacrimal gland and sac. This important finding might significantly reduce the efficacy (particularly in the lacrimal gland) of the various topical therapies used for in situ SC of the ocular surface, and it also emphasizes the importance of excising both the lacrimal gland and sac in all orbital exenterations for this particular tumor.

Form, shape and function: segmented blood flow in the choriocapillaris.

The development of fluid transport systems was a key event in the evolution of animals and plants. While within vertebrates branched geometries predominate, the choriocapillaris, which is the microvascular bed that is responsible for the maintenance of the outer retina, has evolved a planar topology. Here we examine the flow and mass transfer properties associated with this unusual geometry. We show that as a result of the form of the choriocapillaris, the blood flow is decomposed into a tessellation of functional vascular segments of various shapes delineated by separation surfaces across which there is no flow, and in the vicinity of which the transport of passive substances is diffusion-limited. The shape of each functional segment is determined by the distribution of arterioles and venules and their respective relative flow rates. We also show that, remarkably, the mass exchange with the outer retina is a function of the shape of each functional segment. In addition to introducing a novel framework in which the structure and function of the metabolite delivery system to the outer retina may be investigated in health and disease, the present work provides a general characterisation of the flow and transfers in multipole Hele-Shaw configurations.

Recurrent ptosis due to myopathy of the levator palpebrae superioris.

The authors report the 10-year follow-up of a case with a recurrent ptosis affecting both eyelids independently. The histology of the levator palpebrae superioris and Müller's muscle was consistent with a localised myopathic process. A therapeutic response to acetazolamide suggests that ion-channel dysfunction may be the underlying cause for this new myopathy.

Plasma levels of matrix metalloproteinase-2 and -9 (MMP-2 and MMP-9) in age-related macular degeneration.

BACKGROUND: Several studies indicate that age-related macular degeneration (AMD) and atherosclerosis may share common pathogenetic pathways. The aim of this study was to determine the role of systemic matrix metalloproteinases (MMPs) in AMD, given that MMPs are implicated in the pathogenesis of atherosclerosis. METHODS: This study determined the plasma matrix metalloproteinases (MMP-2 and MMP-9) levels in three groups of subjects: group 1 included subjects with age-related maculopathy (ARM), group 2 included subjects with choroidal neovascularization (CNV) owing to AMD and group 3 consisted of age-matched controls. RESULTS: The mean plasma levels of MMP-2 were not significantly different in the three groups. In contrast, the mean plasma MMP-9 levels were significantly higher in ARM and CNV groups compared to that of the control group. However, there was no significant difference in MMP-9 levels between ARM and CNV groups. CONCLUSION: This is the first study that reveals a link between raised plasma MMP-9 levels with AMD. Further studies are required to identify the factors that contribute to this association.

Plasma levels of matrix metalloproteinase-2 and -9 (MMP-2 and MMP-9) in age-related macular degeneration.

BACKGROUND: Several studies indicate that age-related macular degeneration (AMD) and atherosclerosis may share common pathogenetic pathways. The aim of this study was to determine the role of systemic matrix metalloproteinases (MMPs) in AMD, given that MMPs are implicated in the pathogenesis of atherosclerosis. METHODS: This study determined the plasma matrix metalloproteinases (MMP-2 and MMP-9) levels in three groups of subjects: group 1 included subjects with age-related maculopathy (ARM), group 2 included subjects with choroidal neovascularization (CNV) owing to AMD and group 3 consisted of age-matched controls. RESULTS: The mean plasma levels of MMP-2 were not significantly different in the three groups. In contrast, the mean plasma MMP-9 levels were significantly higher in ARM and CNV groups compared to that of the control group. However, there was no significant difference in MMP-9 levels between ARM and CNV groups. CONCLUSION: This is the first study that reveals a link between raised plasma MMP-9 levels with AMD. Further studies are required to identify the factors that contribute to this association.

Legeais BioKpro III keratoprosthesis implantation: long term results in seven patients.

AIMS: The long term results of the Legeais BioKpro III keratoprosthesis are presented for seven patients with severe corneal scarring. METHODS: The study took place at Moorfields Eye Hospital, London. Patients had either end stage ocular surface disease or corneal opacification after multiple failed graft surgery, with the potential for significant visual improvement. After insertion the device was covered with a conjunctival flap or buccal mucous membrane graft, which was later opened to expose the optic. The outcome measures were vision, complications, and retention of the device. RESULTS: The BioKpro III was inserted into seven patients with severe corneal scarring: ocular cicatricial pemphigoid, measles keratitis, thermal injury, Stevens-Johnson syndrome, aniridia, chemical injury, and congenital rubella. The follow up was 18-48 months. The keratoprosthesis failed in six, because of extrusion occurring 2-28 months postoperatively. Retroprosthetic membranes occurred in three patients, and endophthalmitis in one. Vision improved from hand movements to 6/12 in the only patient who retained the KPro; however he was troubled by mucus accumulation on the optic. CONCLUSIONS: The one success has been in a patient with thermal burns. The remaining results have been poor, with the KPro extruding in six of the seven patients.

Effect of steroidal and non-steroidal drugs on the microglia activation pattern and the course of degeneration in the retinal degeneration slow mouse.

BACKGROUND: In hereditary retinal degeneration, microglia cells become activated, migrate through the outer nuclear layer (ONL) and accumulate in the subretinal space. Although this inflammatory process is not likely to be responsible for the onset of photoreceptor apoptosis, cytotoxic substances secreted by activated microglia could potentially accelerate and perpetuate the degenerative process. Anti-inflammatory drugs have been shown to modulate the microglia response in neurodegenerative disorders and potentially ameliorate the disease progression in various animal model systems. In this study we wanted to test the impact of the most commonly used anti-inflammatory drugs (acetylsalicylate and prednisolone) on the microglia activation pattern, the rate of caspase-3-dependent photoreceptor apoptosis and the course of the degeneration in the retinal degeneration slow (rds) mouse retina. METHODS: 169 pigmented rds mice and 30 CBA wild-type mice were used for this study. The treatment groups were injected daily with either acetylsalicylate (200 mg/kg) or prednisolone (2 mg/kg) i.p. from day 0 up to 3 months. Animals were sacrificed at days 10, 14, 16, 18, 20, 30, 40, 60 and 90. Cryoprotected frozen sections were immunostained with F4/80 and cleaved caspase-3 antibodies. The main outcome measures were the total microglia count in the subretinal space, the total cleaved caspase-3-positive cells in the ONL and the averaged number of photoreceptor rows in the midperipheral retina. RESULTS: Neither acetylsalicylate nor prednisolone reduced subretinal microglia accumulation in the rds mouse degeneration model. Moreover, they aggravated migration and accumulation in the early time course. The apoptotic cascade started earlier and was more pronounced in both treatment groups compared to the control group. The pace of retinal degeneration was not reduced in the treatment groups compared to the untreated control. In contrast, acetylsalicylate did significantly accelerate the photoreceptor cell degeneration in comparison to the prednisolone (p < 0.001) and to the control group (p < 0.001). CONCLUSIONS: Acetylsalicylate and prednisolone do not decrease the microglia response in the rds mouse and are not neuroprotective. More research is needed to clarify the molecular mechanisms which lead to photoreceptor cell death and to elucidate the complex role of microglia in inherited retinal degeneration.

Minimising the risk of prion transmission by contact tonometry.

AIMS: The unknown prevalence of variant Creutzfeldt-Jakob disease (vCJD) in the UK population has led to fears of horizontal transmission through routine medical procedures. The potential risk of transmission via contact tonometry was examined. METHODS: The total amount of protein carried over by tonometer tips after applanation of patients was assessed. RESULTS: Tonometer tips had an inherent ability to carry proteinaceous material. There was a large variability in the load carried over between individual patients. Rinsing tonometer tips in water reduced protein carryover. Wiping the tonometer tips also reduced carriage, though less dramatically. CONCLUSION: There is a small theoretical risk of transmission of vCJD by contact tonometry through reuse, but this should be reduced if the prisms are washed and wiped. In the light of these findings a protocol for the management of reusable tonometer prisms is recommended.

Laser photocoagulation alters the pattern of staining for neurotrophin-4, GFAP, and CD68 in human retina.

AIMS: To investigate the staining pattern of neurotrophin-3 (NT3), neurotrophin-4 (NT4), and brain derived neurotrophic factor (BDNF) as well as glial fibrillary acid protein (GFAP) and CD68 in lasered human retina. METHODS: Retinal laser photocoagulation was performed on four patients (two males, two females) with choroidal malignant melanoma 1-6 days before enucleation. Three other enucleated eyes with malignant melanoma and three normal cadaveric donor eyes were used as controls. Immunohistochemistry was performed to investigate the pattern of staining of NT3, NT4, BDNF, GFAP, and CD68 in 7 mm sections of fixed specimens. RESULTS: Expression of NT4 was detected in the inner and outer nuclear layers of all the retinal sections examined but no NT3 and BDNF staining was seen. NT4 staining was found to be less intense in lasered and melanoma controls compared to normal cadaveric donor retinas. There was an upregulation of GFAP expression in both lasered and control eyes with melanoma in comparison with normal controls. CD68 staining was only observed in retinal pigment epithelium and choroid of lasered eyes. CONCLUSION: NT4 is expressed in inner and outer nuclear layers of normal human retina and its expression is downregulated following laser photocoagulation. This occurs in parallel with an increased expression of GFAP suggesting that reactive changes in Muller cells may be responsible for reduced NT4 staining. Expression of CD68 at the site of laser injury is consistent with a wound healing process as a response to local damage.

Modulation of hydrogen peroxide induced injury to corneal endothelium by virus mediated catalase gene transfer.

AIM: To examine the effect of catalase gene transfer on survival of corneal endothelial cells (EC) following challenge with hydrogen peroxide (H(2)O(2)) in an ex vivo model of oxidative stress. METHODS: A recombinant adenovirus vector (AdCL) was used to transfer human catalase cDNA into EC of whole thickness rabbit corneas ex vivo. The resulting catalase protein concentration was measured in corneal lysates by ELISA; catalase functional activity in lysates was determined using a H(2)O(2) activity assay. To examine the morphological effects of catalase gene transfer in modulation of H(2)O(2) induced injury, transduced corneas were maintained in ex vivo culture and challenged with H(2)O(2). Laser scanning confocal microscopy was used to image EC injury. Cell density, cell morphology, and ratios of viable to necrotic cells were determined. RESULTS: Following incubation with AdCL, catalase expression reached maximum at 5-7 days. Corneas transduced with AdCL showed increased EC cell survival following challenge with H(2)O(2) on day 3 when compared to null vector control or mock infected corneas. CONCLUSIONS: Ex vivo catalase gene transfer can protect EC from death mediated by H(2)O(2). This gene based approach to the protection of corneal endothelium from oxidative stress may have application in prevention of EC loss in pathological conditions in which H(2)O(2) is involved and in ex vivo donor corneal storage before transplantation.

Kinetics of transgene expression in mouse retina following sub-retinal injection of recombinant adeno-associated virus.

Using confocal microscopy we have examined in detail the temporal and spatial pattern of green fluorescent protein expression following sub-retinal injection of recombinant adeno-associated virus (rAAV) in the mouse and have determined the effect of viral titre on the number and type of cells transduced. Our results suggest that some transgene expression occurs as early as three days after injection, and that transgene expression occurs beyond the area of retinal detachment. Vector titre appears to have a substantial effect on both transduction efficiency and the speed of onset of photoreceptor cell transduction. Our data suggests that we have not yet reached the limits of photoreceptor transduction efficiency using AAV vectors. An increase in titre could still lead to an improved transduction efficiency and faster onset of photoreceptor transduction. We failed to detect transfected cones even in areas where nearly 100% of the rods were transduced, but we found efficient and sustained RPE transduction.

An integrated hypothesis that considers drusen as biomarkers of immune-mediated processes at the RPE-Bruch's membrane interface in aging and age-related macular degeneration.

Age-related macular degeneration (AMD) is a blinding disease that afflicts millions of adults in the Western world. Although it has been proposed that a threshold event occurs during normal aging which leads to AMD, the sequelae of biochemical, cellular, and/or molecular events leading to the development of AMD are poorly understood. Although available data provide strong evidence that a significant proportion of AMD has a genetic basis, no gene(s) has yet been identified that causes a significant proportion of AMD. Moreover, no major molecular pathways involved in the etiology of this disease have been elucidated.Drusen, pathological deposits that form between the retinal pigmented epithelium (RPE) and Bruch's membrane, are significant risk factors for the development of AMD. In our view, the development of testable new hypotheses of drusen origins has been hindered significantly by the absence of a comprehensive profile of their molecular composition. In this review, we describe an integrated ultrastructural, histochemical, molecular biological, and biochemical approach to identify specific molecular pathways associated with drusen biogenesis. The implicit assumption underlying these recent investigations has been that a thorough understanding of the composition of drusen and source(s) of drusen-associated material is likely to provide fresh insight into the pathobiology underlying AMD. Significantly, these studies have revealed that proteins associated with inflammation and immune-mediated processes are prevalent among drusen-associated constituents. Transcripts that encode a number of these molecules have been detected in retinal, RPE, and choroidal cells. These data have also lead to the observations that dendritic cells, potent antigen-presenting cells, are intimately associated with drusen development and that complement activation is a key pathway that is active both within drusen and along the RPE-choroid interface. We propose herein a unifying hypothesis of drusen biogenesis that attempts to incorporate a large body of new and previously published structural, histochemical, and molecular data pertaining to drusen composition and development. This theory is put forth with the acknowledgment that numerous AMD genotypes may exist. Thus, only some aspects of the proposed hypothesis may be involved in any given AMD genotype. Importantly, this hypothesis invokes, for the first time, the potential for a direct role of cell- and immune-mediated processes in drusen biogenesis. We acknowledge that the proposed hypothesis clearly represents a paradigm shift in our conceptualization pertaining to pathways that participate in the development of drusen and age-related macular degeneration. It is our hope that other investigators will test, validate and/or refute various aspects of this hypothesis, and in so doing, increase our overall understanding of the biological pathways associated with early AMD.

Differential immunoreactivity of melanocytic lesions of the conjunctiva.

AIMS: To evaluate the expression of S100NKI/C3 and HMB45 antigens in melanocytic lesions of the conjunctiva and the ability of HMB45 to aid assessment of neoplasia. METHODS AND RESULTS: Stored formalin-fixed specimens of conjunctival melanomas and primary acquired melanosis were considered as participants and conjunctival naevi and racial melanosis as controls. Ninety-seven conjunctival melanocytic lesions were analysed using formalin-fixed paraffin-embedded material. These included 20 melanomas arising in the context of primary acquired melanosis (PAM), 22 melanomas arising without evidence of pre-existing PAM, seven cases of PAM with atypia, nine cases of PAM with no atypia, 35 conjunctival naevi and four cases of racial melanosis. S100 and NKI/C3 were similarly expressed in all lesions, with at least one of these markers positive in 100% of the lesions examined. HMB45 was expressed in 72.7% of primary melanomas and 85% of melanomas in the context of PAM; 42.8% of PAM with atypia expressed HMB45 while it was expressed in 11.1% of PAM without atypia and 8.5% of naevi. Racial melanosis cases did not express HMB45. S100 and NKI/C3 were expressed to a similar extent in all groups. CONCLUSIONS: S100 and NKI/C3 are useful markers to assess the extent of melanocytic lesions in the conjunctiva. HMB45 immunoreactivity can act as a useful aid to histopathology for the distinction of benign from malignant conjunctival lesions, particularly in the context of primary acquired melanosis.

Tissue distribution of protease resistant prion protein in variant Creutzfeldt-Jakob disease using a highly sensitive immunoblotting assay.

BACKGROUND: Variant Creutzfeldt-Jakob disease (vCJD) has a pathogenesis distinct from other forms of human prion disease: disease-related prion protein (PrP(Sc)) is readily detectable in lymphoreticular tissues. Quantitation of risk of secondary transmission, and targeting of risk reduction strategies, is limited by lack of knowledge about relative prion titres in these and other peripheral tissues, the unknown prevalence of preclinical vCJD, and a transmission barrier which limits the sensitivity of bioassay. We aimed to improve immunoblotting methods for high sensitivity detection of PrP(Sc) to investigate the distribution of PrP(Sc) in a range of vCJD tissues. METHODS: We obtained tissues at necropsy from four patients with neuropathologically confirmed vCJD and from individuals without neurological disease. Tissues were analysed by sodium phosphotungstic acid precipitation of PrP(Sc) and western blotting using high sensitivity enhanced chemiluminescence. FINDINGS: We could reliably detect PrP(Sc) in the equivalent of 50 nL 10% vCJD brain homogenate, with a maximum limit of detection equivalent to 5 nl. PrP(Sc) could be detected in tissue homogenates when present at concentrations 10(4)-10(5) fold lower than those reported in brain. Tonsil, spleen, and lymph node were uniformly positive for PrP(Sc) at concentrations in the range of 0.1-15% of those found in brain: the highest concentrations were consistently seen in tonsil. PrP(Sc) was readily detected in the retina and proximal optic nerve of vCJD eye at levels of 2.5 and 25%, respectively of those found in brain. Other peripheral tissues studied were negative for PrP(Sc) with the exception of low concentrations in rectum, adrenal gland, and thymus from a single patient with vCJD. vCJD appendix and blood (Buffy coat fraction) were negative for PrP(Sc) at this level of assay sensitivity. INTERPRETATION: We have developed a highly sensitive immunoblot method for detection of PrP(Sc) in vCJD tissues that can be used to provide an upper limit on PrP(Sc) concentrations in peripheral tissues, including blood, to inform risk assessment models. Rectal and other gastrointestinal tissues should be further investigated to assess risk of iatrogenic transmission via biopsy instruments. Ophthalmic surgical instruments used in procedures involving optic nerve and the posterior segment of the eye, in particular the retina, might represent a potential risk for iatrogenic transmission of vCJD. Tonsil is the tissue of choice for diagnostic biopsy and for population screening of surgical tissues to assess prevalence of preclinical vCJD infection within the UK and other populations.

Two unusual osteogenic orbital tumors: presumed parosteal osteosarcomas of the orbit.

OBJECTIVE: To report two cases of suspected parosteal osteosarcoma of the orbit, with dedifferentiation into a high-grade liposarcoma occurring in one patient. DESIGN: Two retrospective case reports. METHODS: The clinical, radiologic, and pathologic records of two patients with suspected orbital parosteal osteosarcoma were retrospectively reviewed. MAIN OUTCOME MEASURES: Histologic evaluation and clinical follow-up were measured. RESULTS: The first patient was a 47-year-old male presenting with a 5-month history of painless right lower lid swelling; excision biopsy suggested a well-differentiated parosteal osteosarcoma of the orbital floor, which recurred 3 years later. Six months after excision of the recurrence, the mass demonstrated accelerated growth, and a lid-sparing exenteration was performed; histologic examination showed a high-grade liposarcoma. The patient remains disease-free at 4 years. The second patient, a 40-year-old male, presented with an 8-year history of proptosis and a right superotemporal orbital mass. The mass was excised completely at lateral orbitotomy; histologic examination suggested a well-differentiated parosteal osteosarcoma. The patient remains well 9 months postoperatively. CONCLUSIONS: Parosteal osteosarcoma is an uncommon tumor, usually affecting long bones, that is extremely rare in the orbit. It is a low-grade sarcoma that tends to recur locally after excision but has a favorable prognosis. Dedifferentiation into a high-grade sarcoma occasionally occurs in parosteal osteosarcoma, but transformation into liposarcoma does not seem to have been previously reported. It is important to recognize dedifferentiated parosteal osteosarcoma, because the prognosis is poor, and radical treatment may be required.