Co-occurring nitrifying symbiont lineages are vertically inherited and widespread in marine sponges

Ammonia-oxidising archaea and nitrite-oxidising bacteria are common members of marine sponge microbiomes. They derive energy for carbon fixation and growth from nitrification - the aerobic oxidation of ammonia to nitrite and further to nitrate - and are proposed to play essential roles in the carbon and nitrogen cycling of sponge holobionts. In this study, we characterise two novel nitrifying symbiont lineages, Candidatus Nitrosokoinonia and Candidatus Nitrosymbion in the marine sponge Coscinoderma matthewsi using a combination of molecular tools, in situ visualisation, and physiological rate measurements. Both represent a new genus in the ammonia-oxidising archaeal class Nitrososphaeria and the nitrite-oxidising bacterial order Nitrospirales, respectively. Furthermore, we show that larvae of this viviparous sponge are densely colonised by representatives of Ca. Nitrosokoinonia and Ca. Nitrosymbion indicating vertical transmission. In adults, the representatives of both symbiont genera are located extracellularly in the mesohyl. Comparative metagenome analyses and physiological data suggest that ammonia-oxidising archaeal symbionts of the genus Ca. Nitrosokoinonia strongly rely on endogenously produced nitrogenous compounds (i.e., ammonium, urea, nitriles/cyanides, and creatinine) rather than on exogenous ammonium sources taken up by the sponge. Additionally, the nitrite-oxidising bacterial symbionts of the genus Ca. Nitrosymbion may reciprocally support the ammonia-oxidisers with ammonia via the utilisation of sponge-derived urea and cyanate. Comparative analyses of published environmental 16S rRNA gene amplicon data revealed that Ca. Nitrosokoinonia and Ca. Nitrosymbion are widely distributed and predominantly associated with marine sponges and corals, suggesting a broad relevance of our findings.

Cultivation and genomic characterization of novel and ubiquitous marine nitrite-oxidizing bacteria from the Nitrospirales

Nitrospirales, including the genus Nitrospira, are environmentally widespread chemolithoautotrophic nitrite-oxidizing bacteria. These mostly uncultured microorganisms gain energy through nitrite oxidation, fix CO2, and thus play vital roles in nitrogen and carbon cycling. Over the last decade, our understanding of their physiology has advanced through several new discoveries, such as alternative energy metabolisms and complete ammonia oxidizers (comammox Nitrospira). These findings mainly resulted from studies of terrestrial species, whereas less attention has been given to marine Nitrospirales. In this study, we cultured three new marine Nitrospirales enrichments and one isolate. Three of these four NOB represent new Nitrospira species while the fourth represents a novel genus. This fourth organism, tentatively named "Ca. Nitronereus thalassa", represents the first cultured member of a Nitrospirales lineage that encompasses both free-living and sponge-associated nitrite oxidizers, is highly abundant in the environment, and shows distinct habitat distribution patterns compared to the marine Nitrospira species. Partially explaining this, "Ca. Nitronereus thalassa" harbors a unique combination of genes involved in carbon fixation and respiration, suggesting differential adaptations to fluctuating oxygen concentrations. Furthermore, "Ca. Nitronereus thalassa" appears to have a more narrow substrate range compared to many other marine nitrite oxidizers, as it lacks the genomic potential to utilize formate, cyanate, and urea. Lastly, we show that the presumed marine Nitrospirales lineages are not restricted to oceanic and saline environments, as previously assumed.

Cable bacteria with electric connection to oxygen attract flocks of diverse bacteria

Cable bacteria are centimeter-long filamentous bacteria that conduct electrons via internal wires, thus coupling sulfide oxidation in deeper, anoxic sediment with oxygen reduction in surface sediment. This activity induces geochemical changes in the sediment, and other bacterial groups appear to benefit from the electrical connection to oxygen. Here, we report that diverse bacteria swim in a tight flock around the anoxic part of oxygen-respiring cable bacteria and disperse immediately when the connection to oxygen is disrupted (by cutting the cable bacteria with a laser). Raman microscopy shows that flocking bacteria are more oxidized when closer to the cable bacteria, but physical contact seems to be rare and brief, which suggests potential transfer of electrons via unidentified soluble intermediates. Metagenomic analysis indicates that most of the flocking bacteria appear to be aerobes, including organotrophs, sulfide oxidizers, and possibly iron oxidizers, which might transfer electrons to cable bacteria for respiration. The association and close interaction with such diverse partners might explain how oxygen via cable bacteria can affect microbial communities and processes far into anoxic environments.

Assessment of meat quality attributes of four commercial broiler strains processed at various market weights

As the demand for poultry meat continues to rise, industry production is constantly challenged with obtaining consumer needs. Integrators have answered this increasing demand by improving the growth rate of broilers allowing for increased production efficiently. The resulting broiler produces higher yields and a larger quantity of fresh poultry to satisfy consumer needs. However, this increase in efficiency has cost integrators as new quality issues continue to manifest through global production. Therefore, the objective of the current experiment was to evaluate the effect of genetic strain (standard and high yielding) and target weight on meat quality attributes such as pH, water holding capacity (WHC), and tenderness, alongside meat quality defects such as breast and tender myopathies. In the current study, 1,800 broilers from 4 commercial strains (2 high breast yielding (HY) and 2 standard yielding (SY) were raised sex separate to evaluate meat quality trends over time at 6 previously defined market weights. Birds were processed at weights ranging from 2,043 to 4,313 g in 454 g increments. HY strains produced higher breast and tender yields than those of SY strains (P < 0.05). There was an increase in breast and tender yield as target weight increased (P < 0.05) for both HY and SY strains. Differences were observed between strains for all fillet dimensions (P < 0.05); however, these measurements increased as target weight increased as expected. Woody breast (WB) had a higher severity (P < 0.05) in HY strains over SY strains, for both males and females. Differences were observed in white striping (WS; P < 0.05) for females in both strains, but no differences were observed in males. A main effect of target was noticed for both WB and WS (P < 0.05), expressing increased severity as target weight increased. Shear values were influenced more by target weight (P < 0.05), but inconsistent differences were observed between HY and SY groups. Meullenet-Owens Razor Shear (MORS) energy values increased slightly as target weights increased (P < 0.05) from 2,951 to 4,313 g in both males and females, but differences were minor and inconsistent with the smaller carcass weights. The MORS peak counts generally increased as target weight increased for both sexes. While strain had minimal effects on meat quality attributes, processing weight had a greater influence on quality, specifically muscle myopathies, WHC, and shear properties.

Differential carbon utilization enables co-existence of recently speciated Campylobacteraceae in the cow rumen epithelial microbiome

The activities of different microbes in the cow rumen have been shown to modulate the host's ability to utilize plant biomass, while the host-rumen interface has received little attention. As datasets collected worldwide have pointed to Campylobacteraceae as particularly abundant members of the rumen epithelial microbiome, we targeted this group in a subset of seven cows with meta- and isolate genome analysis. We show that the dominant Campylobacteraceae lineage has recently speciated into two populations that were structured by genome-wide selective sweeps followed by population-specific gene import and recombination. These processes led to differences in gene expression and enzyme domain composition that correspond to the ability to utilize acetate, the main carbon source for the host, at the cost of inhibition by propionate. This trade-off in competitive ability further manifests itself in differential dynamics of the two populations in vivo. By exploring population-level adaptations that otherwise remain cryptic in culture-independent analyses, our results highlight how recent evolutionary dynamics can shape key functional roles in the rumen microbiome.

Genomic and kinetic analysis of novel Nitrospinae enriched by cell sorting

Chemolithoautotrophic nitrite-oxidizing bacteria (NOB) are key players in global nitrogen and carbon cycling. Members of the phylum Nitrospinae are the most abundant, known NOB in the oceans. To date, only two closely affiliated Nitrospinae species have been isolated, which are only distantly related to the environmentally abundant uncultured Nitrospinae clades. Here, we applied live cell sorting, activity screening, and subcultivation on marine nitrite-oxidizing enrichments to obtain novel marine Nitrospinae. Two binary cultures were obtained, each containing one Nitrospinae strain and one alphaproteobacterial heterotroph. The Nitrospinae strains represent two new genera, and one strain is more closely related to environmentally abundant Nitrospinae than previously cultured NOB. With an apparent half-saturation constant of 8.7 ± 2.5 µM, this strain has the highest affinity for nitrite among characterized marine NOB, while the other strain (16.2 ± 1.6 µM) and Nitrospina gracilis (20.1 ± 2.1 µM) displayed slightly lower nitrite affinities. The new strains and N. gracilis share core metabolic pathways for nitrite oxidation and CO2 fixation but differ remarkably in their genomic repertoires of terminal oxidases, use of organic N sources, alternative energy metabolisms, osmotic stress and phage defense. The new strains, tentatively named "Candidatus Nitrohelix vancouverensis" and "Candidatus Nitronauta litoralis", shed light on the niche differentiation and potential ecological roles of Nitrospinae.

An automated Raman-based platform for the sorting of live cells by functional properties

Stable-isotope probing is widely used to study the function of microbial taxa in their natural environment, but sorting of isotopically labelled microbial cells from complex samples for subsequent genomic analysis or cultivation is still in its early infancy. Here, we introduce an optofluidic platform for automated sorting of stable-isotope-probing-labelled microbial cells, combining microfluidics, optical tweezing and Raman microspectroscopy, which yields live cells suitable for subsequent single-cell genomics, mini-metagenomics or cultivation. We describe the design and optimization of this Raman-activated cell-sorting approach, illustrate its operation with four model bacteria (two intestinal, one soil and one marine) and demonstrate its high sorting accuracy (98.3 ± 1.7%), throughput (200-500 cells h^-1; 3.3-8.3 cells min^-1) and compatibility with cultivation. Application of this sorting approach for the metagenomic characterization of bacteria involved in mucin degradation in the mouse colon revealed a diverse consortium of bacteria, including several members of the underexplored family Muribaculaceae, highlighting both the complexity of this niche and the potential of Raman-activated cell sorting for identifying key players in targeted processes.

Characterization of the First "Candidatus Nitrotoga" Isolate Reveals Metabolic Versatility and Separate Evolution of Widespread Nitrite-Oxidizing Bacteria

Nitrification is a key process of the biogeochemical nitrogen cycle and of biological wastewater treatment. The second step, nitrite oxidation to nitrate, is catalyzed by phylogenetically diverse, chemolithoautotrophic nitrite-oxidizing bacteria (NOB). Uncultured NOB from the genus "Candidatus Nitrotoga" are widespread in natural and engineered ecosystems. Knowledge about their biology is sparse, because no genomic information and no pure "Ca Nitrotoga" culture was available. Here we obtained the first "Ca Nitrotoga" isolate from activated sludge. This organism, "Candidatus Nitrotoga fabula," prefers higher temperatures (>20°C; optimum, 24 to 28°C) than previous "Ca Nitrotoga" enrichments, which were described as cold-adapted NOB. "Ca Nitrotoga fabula" also showed an unusually high tolerance to nitrite (activity at 30 mM NO2-) and nitrate (up to 25 mM NO3-). Nitrite oxidation followed Michaelis-Menten kinetics, with an apparent Km (Km(app)) of ~89 µM nitrite and a Vmax of ~28 µmol of nitrite per mg of protein per h. Key metabolic pathways of "Ca Nitrotoga fabula" were reconstructed from the closed genome. "Ca Nitrotoga fabula" possesses a new type of periplasmic nitrite oxidoreductase belonging to a lineage of mostly uncharacterized proteins. This novel enzyme indicates (i) separate evolution of nitrite oxidation in "Ca Nitrotoga" and other NOB, (ii) the possible existence of phylogenetically diverse, unrecognized NOB, and (iii) together with new metagenomic data, the potential existence of nitrite-oxidizing archaea. For carbon fixation, "Ca Nitrotoga fabula" uses the Calvin-Benson-Bassham cycle. It also carries genes encoding complete pathways for hydrogen and sulfite oxidation, suggesting that alternative energy metabolisms enable "Ca Nitrotoga fabula" to survive nitrite depletion and colonize new niches.IMPORTANCE Nitrite-oxidizing bacteria (NOB) are major players in the biogeochemical nitrogen cycle and critical for wastewater treatment. However, most NOB remain uncultured, and their biology is poorly understood. Here, we obtained the first isolate from the environmentally widespread NOB genus "Candidatus Nitrotoga" and performed a detailed physiological and genomic characterization of this organism ("Candidatus Nitrotoga fabula"). Differences between key phenotypic properties of "Ca Nitrotoga fabula" and those of previously enriched "Ca Nitrotoga" members reveal an unexpectedly broad range of physiological adaptations in this genus. Moreover, genes encoding components of energy metabolisms outside nitrification suggest that "Ca Nitrotoga" are ecologically more flexible than previously anticipated. The identification of a novel nitrite-oxidizing enzyme in "Ca Nitrotoga fabula" expands our picture of the evolutionary history of nitrification and might lead to discoveries of novel nitrite oxidizers. Altogether, this study provides urgently needed insights into the biology of understudied but environmentally and biotechnologically important microorganisms.

A systems biology approach to defining regulatory mechanisms for cartilage and tendon cell phenotypes

Phenotypic plasticity of adult somatic cells has provided emerging avenues for the development of regenerative therapeutics. In musculoskeletal biology the mechanistic regulatory networks of genes governing the phenotypic plasticity of cartilage and tendon cells has not been considered systematically. Additionally, a lack of strategies to effectively reproduce in vitro functional models of cartilage and tendon is retarding progress in this field. De- and redifferentiation represent phenotypic transitions that may contribute to loss of function in ageing musculoskeletal tissues. Applying a systems biology network analysis approach to global gene expression profiles derived from common in vitro culture systems (monolayer and three-dimensional cultures) this study demonstrates common regulatory mechanisms governing de- and redifferentiation transitions in cartilage and tendon cells. Furthermore, evidence of convergence of gene expression profiles during monolayer expansion of cartilage and tendon cells, and the expression of key developmental markers, challenges the physiological relevance of this culture system. The study also suggests that oxidative stress and PI3K signalling pathways are key modulators of in vitro phenotypes for cells of musculoskeletal origin.

Oxidative responses in soybean foliage to herbivory by bean leaf beetle and three-cornered alfalfa hopper

Variation in induced responses in soybean is shown to be dependent, in part, upon herbivore species. Herbivory by the phloem-feeding three-cornered alfalfa hopper caused increases in the activities of several oxidative enzymes including lipoxygenases, peroxidases, ascorbate oxidase, and polyphenol oxidase. Bean leaf beetle defoliation caused increased lipoxygenase activity, but had little effect upon peroxidase, polyphenol oxidase, ascorbate oxidase, or trypsin inhibitor levels in either field or greenhouse studies. In one field experiment, prior herbivory by the bean leaf beetle subsequently reduced the suitability of foliage to the corn earwormHelicoverpa zea. The contribution of these findings to emerging theories of insect-plant interactions is discussed.

Potential role of lipoxygenases in defense against insect herbivory

The potential role of the plant enzyme lipoxygenase in host resistance against the corn earwormHelicoverpa zea was examined. Lipoxygenase is present in most of the common host plants ofH. zea, with highest activity in the leguminous hosts such as soybean and redbean. Treatment of dietary proteins with linoleic acid and lipoxygenase significantly reduced the nutritive quality of soybean protein and soy foliar protein. Larval growth was reduced from 24 to 63% depending upon treatment. Feeding byH. zea on soybean plants caused damage-induced increases in foliar lipoxygenase and lipid peroxidation products. Larvae feeding on previously wounded plant tissue demonstrated decreased growth rates compared to larvae feeding on unwounded tissue. Midgut epithelium from larvae feeding on wounded tissues showed evidence of oxidative damage as indicated by significant increases in lipid peroxidation products and losses in free primary amines. The potential role of oxidative and nutritional stress as a plant defensive response to herbivory is discussed.

Evidence of a breakdown of corticostriatal connections in Parkinson's disease

Dendritic spines are important structures which receive synaptic inputs in many regions of the CNS. The goal of this study was to test the hypothesis that numbers of dendritic spines are significantly reduced on spiny neurones in basal ganglia regions in Parkinson's disease as we had shown them to be in a rat model of the disease [Exp Brain Res 93 (1993) 17]. Postmortem tissue from the caudate and putamen of patients suffering from Parkinson's disease was compared with that from people of a similar age who had no neurological damage. The morphology of Golgi-impregnated projection neurones (medium-sized spiny neurones) was examined quantitatively. The numerical density of dendritic spines on dendrites was reduced by about 27% in both nuclei. The size of the dendritic trees of these neurones was also significantly reduced in the caudate nucleus from the brains of PD cases and their complexity was changed in both the caudate nucleus and the putamen. Dendritic spines receive crucial excitatory input from the cerebral cortex. Reduction in both the density of spines and the total length of the remaining dendrites is likely to have a grave impact on the ability of these neurones to function normally and may partly explain the symptoms of the disorder.

"Melanoma inhibitory activity" (MIA): a promising serological tumour marker in metastatic uveal melanoma

PURPOSE

To assess the role of "melanoma inhibitory activity" (MIA) as a potential serum marker for screening and detection of metastatic uveal melanoma.

DESIGN

Prospective, clinical study.

MATERIAL AND METHODS

Serum samples of 305 patients with uveal melanoma were collected. Serum samples were analysed by a one-step enzyme-linked immunosorbent assay (ELISA) to quantify the MIA serum levels. All patients underwent a standardized echography of the globe to evaluate maximum tumour height and were checked for systemic metastasis of the tumour by liver enzyme tests and ultrasonography of the liver.

RESULTS

Twenty patients (6.6%) had proven metastatic disease; eight of them developed it during follow-up. The mean serum concentration of MIA in the 285 patients without metastasis was 6.72 ng/ml, whereas the mean serum concentration of MIA in the 20 patients with metastasis was 13.03 ng/ml (P<0.001). The eight patients who developed metastatic disease during follow-up showed an MIA of 5.92 ng/ml before detection of metastasis and 12.21 ng/ml afterwards (P<0.001). MIA serum levels did neither correlate with the tumour height or to whether local therapy had been applied.

CONCLUSION

The elevation of MIA serum levels in patients with metastatic disease from melanoma supports its promising role as a serum marker for monitoring patients with uveal melanoma.

[Combined anterior and posterior segment surgery]

AIM

The aim of this study was to review the postoperative findings in the anterior segment after primary vitrectomy performed in combination with cataract surgery.

PATIENTS AND METHOD

In a retrospective analysis covering the period from August 2000 to March 2002, we identified 513 consecutive operations on the retina and vitreous body performed primarily to correct various retinal diseases in the ophthalmology department of the Ludwig Maximilian University in Munich. Concomitant cataracts present in all cases were also treated in the one session. Measurement parameters of postoperative irritation of the anterior chamber included anterior chamber cells, Tyndall effect, fibrin, intraocular pressure, and synechiae formation. Various influencing factors were compared to the measurement parameters in univariate analysis.

RESULTS

Correlations between some influencing factors and various measurement parameters were statistically significant in univariate analysis. This was not, however, the case for any of the factors in multivariate analysis.

CONCLUSION

Performance of the combined operation according to our protocol does not entail any single parameter that indicates a risk for increased postoperative irritation of the anterior chamber.

[Relative contraindication of latanoprost in iris tumors with secondary glaucoma]

INTRODUCTION

Melanocytic iris tumors are often benign and merely require regular follow-up. Evident growth, increasing pigmentation and secondary glaucoma, however, are possible signs of a malignant transformation.

PATIENT

We present a 34-year-old male patient showing a localized, mildly prominent hyperpigmentation of the right iris expanding over 2 h. The lesion had been known since childhood and increasing intraocular pressure (IOP) was treated with timolole, dipivefrin and finally with latanoprost.

PROGRESSION

The patient was seen for the first time at our hospital 4 years previously, presenting an IOP of 28-30 mmHg of the right eye. The tumor had developed marked heterochromia and a nodular prominent surface, the chamber angle was partly closed and completely hyperpigmented. The ciliary body was not affected by the tumor and standard ultrasound revealed a maximum thickness of 1.2 mm. Over the last 4 years, IOP and heterochromia had increased but without growth of the tumor. An excisional biopsy of the prominent portion was refused by the patient.

DISCUSSION

The melanocytic iris tumor described shows malignant characteristics such as progressive heterochromia and secondary glaucoma. However, increasing iris pigmentation can also be caused by topical application of latanoprost. With the evidence of absent tumor growth, there is no reason to suggest malignant degeneration. Generally, in iris naevi or tumors requiring regular follow-up, application of latanoprost should be avoided in order not to conceal the alteration of pigmentation as possible malignant conversion.

[Regression of an uveal metastatic tumor from breast cancer during chemotherapy--a case report]

BACKGROUND

Choroidal metastases generally respond well to radiation treatment. However, a deterioration of visual acuity after radiation must be taken into account in lesions involving the optic nerve. In these cases, alternatives to radiation, which is a palliative treatment in most cases anyway, should be considered.

MATERIAL AND METHODS

We present the clinical and echographic findings of a case of a 39-year-old patient with choroidal metastasis from breast carcinoma.

RESULTS

We observed a regression of the metastasis and an improvement of visual acuity from 0.2 to 1.0 under systemic chemotherapy. Echography showed a decrease of tumor height and increasing reflectivity indicating progressive scarring of the lesion. Up to now, the patient has survived 9 years after initial diagnosis.

CONCLUSIONS

Especially in cases in which a deterioration of visual acuity after radiation must be expected, the follow-up during systemic chemotherapy alone might be considered an alternative option, as it not only might preserve vision, but also allows an "in vivo" monitoring of the success of the chemotherapy applied.

[Stereotactic radiosurgery using the Gamma Knife for large uveal melanomas]

BACKGROUND

We report the results over 3 years with stereotactic radiosurgery using the Gamma Knife for large and unsuitably located uveal melanomas.

PATIENTS AND METHODS

A total of 100 patients (51 male, 49 female) have been treated since 1997 following a standardised treatment protocol (outpatient single-shot treatment, maximum dose 50 Gy, tumour margin dose min.25 Gy, retrobulbar anaesthesia alone for globe fixation). The localisation and/or dimension of the tumours did not allow radiation brachytherapy with Ru106 plaques. Of the tumours 18 were located in the ciliary body, 61 were located at the posterior pole, and 21 were located in the mid-periphery. All patients were followed and tested ophthalmologically and neuroradiologically at regular intervals. The 1-year follow-up data were available for 73 patients, 2-year follow-up data for 33 patients and 3-year follow-up-data for 17 patients.

RESULTS

Before therapy the maximum apical tumour height (MAH) was median 7.8 mm (95% CI 2.9-12.5 mm): 1 year after treatment (73 patients) the MAH was median 5.7 mm (95% KI 2.4-10.2 mm),2 years after treatment (33 patients) the MAH was median 4.3 mm (95% KI 2.2-8.8 mm),and 3 years after treatment (17 patients) the MAH was median 4.6 mm (95% KI 2.4-8.5 mm). All differences to the MAH of the corresponding patients before treatment were statistically significant (paired t-test). Within the first year after treatment seven patients were enucleated due to a painful secondary glaucoma,within the second year after radiation two patients (one tumour recurrence, and one secondary glaucoma) and within the third year one more patient (tumour recurrence) was enucleated.

CONCLUSIONS

Our 3-year results demonstrate that radiosurgery using the Gamma Knife is beneficial in achieving a local tumour control in 98% of eyes with large and unsuitably located uveal melanomas. The risk for a secondary enucleation is highest in the first year after treatment with a favourable overall rate of 10%. Due to the excellent local tumour control rate we decreased the maximum dose to 40 Gy (min.tumour margin dose 20 Gy) in the subsequently treated patients.

Melanoma inhibitory activity: a novel serum marker for uveal melanoma

The aim of this study was to evaluate the tumour-associated antigen melanoma inhibitory activity (MIA) as a potential novel serological tumour marker in primary and metastatic uveal melanoma in both the laboratory and the clinical setting. In the laboratory setting, immunohistochemical staining with MIA antibody was performed in paraffin-embedded tissues from six amelanotic uveal melanomas and eight metastatic lesions of uveal melanomas. In the clinical setting, serum samples of 139 patients with uveal melanoma were examined; eight of these patients had overt metastatic disease. Sixty-one initially metastatic disease-free patients were followed over time (median follow-up 240 days, 95% confidence interval 60-883 days) and MIA levels were assessed repeatedly. A one-step enzyme-linked immunosorbent assay was used to quantify the MIA serum levels. In the laboratory setting, five of the six primary uveal melanomas and seven of the eight metastatic lesions stained immunohistologically positive for MIA. In the clinical setting, the 131 patients without overt metastatic disease demonstrated a median serum concentration of MIA of 6.6 ng/ml. In the eight patients with overt metastatic disease, the median serum concentration of MIA was 26.28 ng/ml. This difference was highly statistically significant (P < 0.001, analysis of variance). During follow-up, three initially metastatic disease-free patients developed overt metastatic disease, and the MIA level increased from a median of 6.6 ng/ml before to 29.2 ng/ml after clinical detection of metastatic disease. In the 58 other patients, the serum level remained stable during the entire follow-up period. In conclusion, MIA is expressed in primary and metastatic lesions of uveal melanomas, and a statistically significant elevation in MIA serum levels in patients who develop metastatic disease due to uveal melanoma indicates its promising role as a serum marker for monitoring uveal melanoma patients for metastasis.

Interobserver and intraobserver variability of measurements of uveal melanomas using standardised echography

AIMS

To report on the intraindividual and interindividual variability of tumour size (height and base diameter) measurements using standardised echography in a masked prospective study.

METHODS

20 consecutive eyes of 20 patients were examined on four different visits by three experienced examiners using standardised echography. As common in standardised echography, tumour height was evaluated with A-scan technique, while transverse and longitudinal base diameter were calculated with B-scan.

RESULTS

Tumour height measurements using A-scan were more accurate than base diameter measurements using B-scan. The standard deviation for tumour height over all visits/measurements was 0.18 mm (A-scan), 0.79 mm for transverse, and 0.69 mm for longitudinal base diameters (B-scan). The interclass correlation coefficient (ICC) was much higher for tumour height measurements with A-scan (0.7735 for three examiners on one visit) than for transverse (0.6563) or longitudinal (0.4522) base diameter measurements with B-scan techniques.

CONCLUSIONS

A-scan techniques for tumour height measurements provide very reproducible results with little intraindividual and interobserver variability. As B-scan techniques for tumour base evaluation are less accurate they should be used for topographic and morphological examinations.

[Correlation between ICG angiography verified networks in uveal melanomas and rate of tumor regression after brachytherapy]

INTRODUCTION

The post-irradiation regression rate of uveal melanomas is a prognostically significant factor for the development of metastases. Other predictive factors for metastases are histological networks which are imagable with confocal ICG angiography. The purpose of this study was to evaluate a possible connection of networks in the ICGA and tumor regression rates.

METHODS

We compared the post-irradiation regression rates (as %) in 20 patients 1 year after brachytherapy with networks identified in pre-treatment indocyanine green angiography (ICGA). The ICG angiography was performed before irradiation, 10 patients were irradiated with Ru-106 and 10 were irradiated with Id-125.

RESULTS

The mean preoperative maximum apical height was 5.2 mm [SD: 1.5 mm; Ru106 group: 5.7 mm (SD: 1.0 mm); Id-125 group: 5.0 mm (SD: 1.9 mm)]. In 11 patients (55%) (Ru-106: 5; Id-125: 6) we found networks in the preoperative ICG. The mean regression rate in tumors with networks was 51.3% (SD: 14.7%) and 28.0% (SD: 16.4%) in the group without networks. The difference between both groups was statistically significant (p = 0.003, Mann-Whitney test). No statistically significant difference in the regression rates was found between the two groups of brachytherapy Ru-106 and Id-125 (p = 0.165, Mann-Whitney test).

DISCUSSION

Highly proliferative tumors are known to be more sensitive to irradiation. This may be one reason why tumors with a rapid post-irradiation regression are the more aggressive ones with regard to later development of metastases. Histopathological networks are also known to be a strong indication of more aggressive, metastasizing tumors. These networks are also imagable in ICG angiography. Our observation emphasizes a connection between networks in ICG angiography and regression rates of uveal melanomas after brachytherapy.

Imaging the microcirculation of untreated and treated human choroidal melanomas

INTRODUCTION

Histologically demonstrable microcirculation patterns (microcirculation pattern) of human choroidal melanomas have prognostic significance for the patient. We report on our experience in imaging these microcirculation pattern in vivo using simultaneous confocal Fluorescein (FA)- and Indocyaninegreen (ICG) angiography before and after brachytherapy.

PATIENTS AND METHODS

The simultaneously procured confocal FA- and ICG angiograms of 50 patients with untreated choroidal melanomas were studied for the visibility of microcirculation pattern. Patients were also followed with simultaneous FA/ICG after brachytherapy.

RESULTS

Confocal FA disclosed signs of tumor vascularization in 12 (24%) of the 50 examined patients but microcirculation pattern only in 3 patients (6%). In contrast, simultaneously obtained confocal ICG disclosed microcirculation pattern in 47 patients (94%). In 10 (77%) of the 13 patients the tumor microcirculation changed considerably after brachytherapy: Distortion, thickening, thinning, as well as complete obliteration of vessels could be observed.

CONCLUSION

Histologically demonstrated microcirculation pattern can be imaged in vivo. This offers the possibility to assess the likely biologic behavior of the individual tumor without the need for obtaining a cytologic or histologic specimen via enucleation or fine-needle biopsy. Confocal ICG angiogiography images microcirculation pattern better than FA which can be explained by the different absorption-, fluorescence- and exudation-characteristics ICG. Follow-up with confocal ICG of choroidal melanomas after brachytherapy shows different features and allows for visualization of the microcirculation reaction to the treatment which might be a useful tool for studying the effects of future anti-angiogenesis based tumor therapies.

[The Munich/San Diego/Iowa City Collaboration (MuSIC). MuSIC Report I: Design , characteristics of the collective and preliminary results]

BACKGROUND

We have previously shown that histologically described microcirculation patterns (MCP) can be visualized with indocyanine green (ICG) angiography. We have designed a prospective study to evaluate the prognostic value of these angiographically imaged MCP in small choroidal melanocytic lesions. In this report we describe the design of the study, characterize the patient collective, and present the first results.

PATIENTS AND METHODS

In this prospective nonrandomized observational study, unilateral choroidal melanocytic lesions with 1.5-5.5 mm maximum apical height are observed until growth is determined according to defined criteria. Variables are demographic parameters, subjective symptoms, subretinal fluid, location and dimension of tumor, hemorrhage, color, orange pigment, and MCP determined by ICG angiography: normal, straight, parallel without crosslinking, parallel with crosslinking, arcs without branching, arcs with branching, loop, and network.

RESULTS

Seventy patients (22 males, 48 females; age: 33-88 years, median: 64 years) have been included up to now: 19 tumors showed growth so far (time to growth: 51-946 days, median: 127 days). The following parameters were statistically significantly correlated with time to tumor growth: flashes (p = 0.082), orange pigment (p = 0.012), subretinal fluid (p < 0.001), maximum basal tumor diameter (p = 0.001), maximum apical tumor height (p < 0.001), parallel with crosslinking (p < 0.001), arcs with branching (p = 0.006), loop (p < 0.001), and network (p < 0.001). Of these, complex MCP (parallel with crosslinking, arcs with branching, loop and/or network) showed the strongest correlation with time to tumor growth in a Cox regression model. Based on our data, the positive predictive value of imaging complex MCP (for growth within 12 months) is 78% and the negative predictive value is 98%.

CONCLUSION

Our patient collective demonstrates comparable prognostic parameters for time to growth as described in the literature. In addition, the ICG angiographic detection of complex MCP is more strongly predictive of the time to growth than other clinically determinable factors. Thus, we recommend this examination for patients with small choroidal melanocytic lesions, if the patient is to be counseled regarding the likely biologic behavior of his tumor.

[Diagnosis and differential diagnosis of the combined hamartoma of the retina and retinal pigment epithelium]

BACKGROUND

The combined hamartoma of the retina and the retinal pigment epithelium (CHR-RPE) is an important differential diagnosis of retinal and choroidal diseases with variable degrees of pigmentation.

PATIENTS

The clinical picture and typical fluorescence angiography findings of two adult patients who were first diagnosed to have a combined hamartoma of the retina and retinal pigment epithelium are presented. The referral diagnosis macular pucker and malignant melanoma of the choroid, respectively, are discussed regarding severe therapeutic interventions such as pars plana vitrectomy with membrane peeling (macular pucker), and radiotherapy, or enucleation (malignant melanoma of the choroid) as well as other important differentials.

RESULTS

The combined hamartoma of the retina and the retinal pigment epithelium is a benign congenital, mostly unilateral retinal lesion. The presenting symptom is a painless, unilateral, often silent loss of vision. Histologically, three cell populations can be identified: glial, vascular, and pigmented cells. Variations in composition of these three cell types are responsible for the heterogeneous clinical picture and thus diagnostic challenges. The greyish retinal tumor located peripapillary in most cases with varying degrees of pigmentation and surrounding vascular tortuosity can result in secondary changes at the vitreoretinal interface with deterioration of vision. Combined fluorescein-/indocyaningreen angiography and ultrasound are crucial for diagnostic evaluation. Documentation and regular clinical follow-up examinations are essential for successful management of this disorder.

CONCLUSION

Recognition of this rare clinical entity is crucial for administering the appropriate therapy.

Macular hole surgery in an eye with an optic pit

PURPOSE

To report an eye with a full-thickness macular hole and an associated optic pit and the noteworthy intraoperative findings.

METHODS

Case report. A 56-year-old woman presented with visual acuity LE: 20/100, a full thickness macular hole, and an optic pit. Optical coherence tomography and ophthalmic examination were performed preoperatively and postoperatively.

RESULTS

Although usually a macular hole associated with an optic pit tends to be a lamellar and characterized by outer layer defects within preexisting macular detachments or schisis-like cavities, this type of macular hole was not presented in this case. Although the macular hole resembled the idiopathic type on clinical examination as well as on optical coherence tomography, it could only be closed in the third surgical attempt after using silicone oil as a long-standing tamponade. Peeling of an epiretinal membrane or the internal limiting membrane was not possible during any of the three surgeries.

CONCLUSION

Our observations suggest that in cases of macular hole in association with optic pit, instillation of silicone oil should be considered in the first surgical procedure, especially if no epiretinal membrane or internal limiting membrane peeling is possible intraoperatively.

Choroidal melanoma microcirculation with confocal indocyanine green angiography before and 1 year after radiation brachytherapy

PURPOSE

The authors previously demonstrated that confocal indocyanine green (ICG) angiography is capable of imaging the microcirculation of choroidal melanomas. The purpose of this study is to report their observations regarding the response of the microcirculation using confocal ICG at 1 year after radiation brachytherapy.

METHODS

Thirteen patients with unilateral choroidal melanoma were examined once before and several times up to 1 year after radiation brachytherapy (Iodine-125 or Ruthenium-106 plaque). At each visit, a complete ophthalmologic examination including standardized echography and fluorescein and ICG angiography was obtained, the latter using a confocal scanning laser ophthalmoscope.

RESULTS

In 10 patients (77%), the tumor microcirculation changed considerably within 1 year after treatment. Distortion, thickening, thinning, and complete obliteration of vessels could be observed. In the other 3 patients (23%), no changes in the microcirculation were noticed within the observation period.

CONCLUSIONS

Follow-up with confocal ICG of choroidal melanomas after treatment with local radiation brachytherapy allows for visualization of the microcirculation reaction following radiation brachytherapy. This provides the clinician with additional information for the posttreatment monitoring of these patients. Confocal ICG might also be a useful tool to monitor the effects of future antiangiogenesis-based tumor therapies in choroidal melanomas.

[3-D ultrasound. Initial experiences in various eye diseases]

BACKGROUND

Studies have confirmed three-dimensional (3-D) ultrasound as a practical diagnostic tool in examining the eye and orbit and suggest its routine clinical use.

MATERIALS AND METHODS

3-D ultrasound was prospectively performed in 46 patients (46 eyes) with various ocular diseases. In six large choroidal melanomas the tumor volume were measured by 3-D ultrasound and compared to that measured by MRI and to that calculated by a theoretical formula. To assess the reproducibility of volumetry by 3-D ultrasound the volumes of such three intraocular tumors were measured ten times using ten different virtual sectioning planes and a section thickness of 0.5 mm and/or 1.0 mm.

RESULTS

3-D ultrasound allows the precise assessment of complex three-dimensional structures. Choroidal melanoma volumes measured by 3-D ultrasound, MRI, and theoretical calculation were in the same range.

CONCLUSION

Intraocular tumor volume can be measured well by 3-D ultrasound,which may be of clinical importance in follow-up examinations.

[Multifactorial analysis of therapeutic outcome of pseudophakic retinal detachment surgery]

BACKGROUND

Pseudophakic retinal detachment is one of the most severe complications after cataract surgery and is a common cause of permanently reduced visual acuity. We evaluated parameters predicting reduced functional outcome by a model of stepwise regression analysis.

PATIENTS AND METHODS

A series of 102 consecutive patients with pseudophakic retinal detachment were analyzed for various parameters regarding cataract surgery, retinal surgery, and retinal detachment features. First, univariate analysis determined the correlations with reduced functional outcome. Secondly, a stepwise regression model analyzed statistically significant variables for their predictive value of a reduced visual outcome.

RESULTS

The overall reattachment rate was 99%. In 69% of the patients there was an improvement of more than two lines at the end of the follow-up period. The most predictive factors for reduced functional outcome were the need for a silicone oil tamponade and the visual acuity prior to retinal detachment surgery. When silicone oil tamponade was not needed, the requirement of more than two retinal surgeries was the most predictive factor for reduced visual outcome.

CONCLUSION

In our series the strongest predictive factors for a reduced functional outcome were the necessity of silicone oil, reduced visual acuity at the time of retinal detachment, and the requirement of more than two retinal surgeries. These findings suggest that first-line procedures should not be necessarily minimally invasive measurements but rather procedures that result in a stably attached retina in the first instance without permanent silicone oil tamponade, even if this first operation consists of an extended pars plana vitrectomy.

[Stereotaxic precision irradiation of large uveal melanomas with the gamma knife]

BACKGROUND

We report our experience with stereotactic radiosurgery using the Gamma-knife in large uveal melanoma unsuitable for brachytherapy (Ru106).

PATIENTS AND METHODS

We treated 35 patients (16 male, 19 female; age: median 59 years (95% Confidence interval (CI): 31-84 years; 18 right eyes, 17 left eyes). 7 tumors were located juxtapapillary, 16 tumors were located in the mid-periphery and 12 tumors were located in the ciliary body, The localization and/or the dimension of the tumors did not allow for radiation brachytherapy (Ru106). All patients underwent regular clinical, echographical and neuroradiological follow-up examinations.

RESULTS

The follow-up time was median 12 months (95% CI: 4-20 months). A local tumor control defined as either continuous tumor regression or stopping of tumor progression was achieved in 34 (97%) of the 35 treated patients within the observation period. The eye of one patient was enucleated due to tumor regrowth. Maximum apical tumor height according to standardized A-scan before treatment was median 9.1 mm (95% CI: 3.2-13.9 mm) and after treatment median 6.4 mm (95% CI: 2.1 bis 11.9 mm). The difference was statistically highly significant (p < 0.001, one-tailed paired t-test).

CONCLUSIONS

Our results in 35 patients indicate that radiosurgery using the Gamma-knife is beneficial in retaining the eyes of patients with large uveal melanomas that are not suitable for brachytherapy (Ru106).

[Minimally invasive therapy for clinically complete central retinal artery occlusion--results and meta-analysis of literature]

BACKGROUND

Goal of our study was the comparison of the efficacy of various minimal invasive therapeutic regimens for clinically complete central retinal artery occlusion (CRAO) and the comparison with the literature.

PATIENTS AND METHODS

In a retrospective study 93 patients treated for CRAO during the period 1994-1998 were identified. 65 of these patients with clinically complete occlusion without a cilioretinal artery were included in the study. Analysis focused on the results of different therapies and the duration of visual impairment till starting treatment.

RESULTS

The following therapies were used: acetazolamide (65%), aspirin (60%), bulbus massage (45%), hemodilution (34%), oral pentoxifylline (28%), topical beta blockers (9%), paracentesis (8%), heparin (6%). In 15% of all cases an improvement of at least 3 visual acuity gradations was achieved. No significant positive influence of any treatment method could be identified. Also, a correlation between duration of visual impairment and final visual acuity could not be shown. In the literature very different criteria for inclusion of patients to the studies and for visual acuity improvement are found. When applying comparable criteria to ours most studies show similar results for the therapies listed above as well as for paracentesis and the use of carbogen (95% O2 and 5% CO2).

CONCLUSION

The minimal invasive treatments given above do only improve natural course of CRAO in occasional cases. Thus a therapy (-combination) should be chosen, which is adapted to the individual risk factors and is exposing the patient to a low risk by therapy itself.

Stereotactic radiosurgery of large uveal melanomas with the gamma-knife

OBJECTIVE

To present our experience with the Gamma-knife in treating large uveal melanomas with stereotactic radiosurgery.

DESIGN

Prospective, noncomparative, interventional case series.

PARTICIPANTS

Fifty-eight patients with unilateral uveal melanomas were treated from 1996 through 1999 with stereotactic radiosurgery using the Gamma-knife. From these we report the results of 35 patients who had a follow-up of more than 1 year after irradiation.

INTERVENTION

Stereotactic radiosurgery with the Gamma-knife.

MAIN OUTCOME MEASURES

Tumor control, maximum apical tumor height, eye retention rate, and visual acuity.

RESULTS

In 34 eyes (97%), local tumor control was achieved. The maximum apical tumor height decreased from a median of 9.1 mm (95% confidence interval [CI], 3.2-13.9 mm) before treatment to 6.2 mm (95% CI, 2.1-11.9 mm) at 1 year after treatment (P<0.001, paired t test). The tumor volume decreased from a median of 0.8 cm(3) before treatment to 0.5 cm(3) 1 year after treatment (P<0.001, paired t test). Two eyes required enucleation (one radiation failure, one secondary glaucoma). The median visual acuity decreased from 20/60 (95% CI, hand movement [HM] to 20/20) before treatment to 20/200 (95% CI, HM to 20/30) at 1 year after treatment (P = 0.001, paired t test).

CONCLUSIONS

Stereotactic radiosurgery using the Gamma-knife is an alternative to enucleation in treating large uveal melanomas. The visual function may be preserved in selected cases.

[Melanoma inhibitory activity (MIA). Evaluation of a new tumor-associated antigen as a serum marker for uveal melanomas]

BACKGROUND

Currently no serological marker for the monitoring of uveal melanoma and its metastases is available. The novel tumor associated antigen Melanoma inhibitory activity (MIA) is expressed in the uveal melanoma and it's metastatic lesions.

METHOD

We report about the serum samples of 38 patients with uveal melanomas. 4 of these patients had overt metastatic disease. A nonradioactive one step ELISA was used to quantify the MIA serum levels.

RESULTS

In the 34 patients without overt metastatic disease the serum concentration of MIA was mean (+/- 1 SD) 3.6 +/- 1.0 ng/ml. In the 4 patients with overt metastatic disease the serum concentration of MIA was mean (+/- 1 SD) 27.7 +/- 3.0 ng/ml. The difference was statistically highly significant (student t test: p = 0.0001).

CONCLUSION

MIA is expressed in primary and metastatic lesions of uveal melanomas. The elevation of MIA serum levels in patients with metastatic disease from melanomas suggests a promising role as a serum marker for monitoring patients with uveal melanoma.

Intravitreal toxicology and duration of efficacy of a novel antiviral lipid prodrug of ganciclovir in liposome formulation

PURPOSE

To evaluate the intraocular safety and antiviral treatment efficacy of the sustained lipid prodrug of ganciclovir, 1-O-hexadecylpropanediol-3-phospho-ganciclovir (HDP-P-GCV), as an intravitreal injectable drug system for viral retinitis.

METHODS

HDP-P-GCV was synthesized by coupling 1-O-hexadecyl-propanediol-3-phosphate to either free hydroxyl of ganciclovir in pyridine with dicyclohexylcarbodiimide as catalyst. The compound was formulated into liposomes. The antiviral activity was assessed by DNA reduction in vitro, and intraocular safety was assessed by ophthalmoscopy, electrophysiology, and histology after intravitreal injections, with resultant intravitreal concentrations of 0.2, 0.632, 1.12, and 2 mM. The treatment efficacy was evaluated by simultaneous intravitreal injection of HDP-P-GCV and herpes simplex virus type 1 (HSV-1) or by intravitreal injection of HDP-P-GCV at various times before HSV-1 intravitreal inoculation. Retinitis was scored with ophthalmoscopy and compared with controls.

RESULTS

In vitro, the IC50 of HDP-P-GCV against HSV-1 and human cytomegalovirus (HCMV) infected cells was 0.02 and 0.6 microM, respectively. In rabbits in vivo, HDP-P-GCV dispersed evenly and maintained a good vitreous clarity at all doses except 2 mM final intravitreal concentration. Although cataracts were observed in some eyes at the higher doses, they were not observed in eyes with 0.2 mM final intravitreal concentration. No other indications of ocular toxicity were observed. Intravitreal injection of HDP-P-GCV with resultant 0.2 mM intravitreal concentration in the HSV-1 retinitis rabbit model demonstrated a complete protection of the retina with the simultaneous treatment strategy and a 4 (P = 0.03) to 6-(P = 0.058) week significant protection of retina with the pretreatment strategies when compared with ganciclovir or blank liposome controls.

CONCLUSIONS

In the rabbit model of HSV-1 retinitis HDP-P-GCV acts as a long-lasting intravitreal injectable anti-CMV or anti-HSV compound. This self-assembling liposome system could be applicable for many compounds available for intraocular diseases.

Removal of silicone oil with vision improvement after rhegmatogenous retinal detachment following CMV retinitis in patients with AIDS

PURPOSE

To report that silicone oil may be safely removed from immuno-recovered patients with acquired immunodeficiency syndrome (AIDS) after instillation for cytomegalovirus (CMV)-related rhegmatogenous retinal detachment.

METHOD

We report two patients with CMV-related retinal detachment who had previously been treated with vitrectomy and silicone oil.

RESULTS

Six months after removal of silicone oil, the retina remained attached in both patients. Without specific anti-CMV therapy, there was no relapse of CMV retinitis while patients were undergoing highly active antiretroviral therapy. Best-corrected visual acuity improved in both patients.

CONCLUSION

It appears to be possible to remove silicone oil safely from patients with AIDS who show immune recovery, thus avoiding side effects of long-standing silicone oil and increasing quality of life. After silicone oil removal, visual acuity was improved.

[Regression of cytomegalovirus retinitis in AIDS patients without systemic maintenance anti-cytomegalovirus therapy treated with highly active antiretroviral therapy]

BACKGROUND

The purpose of this study was to evaluate the course of CMV retinitis after initiation of highly active antiretroviral therapy (HAART) and discontinuation of systemic anti-CMV maintenance therapy.

PATIENTS AND METHODS

Case reports are presented for two AIDS patients (2 eyes, ages 34, 43, male) with CMV retinitis. The CD4 count at the time of CMV retinitis was 20/microliter (patient 1) and 35/microliter (patient 2). Under HAART the CD4 count rose up to 202/microliter (patient 1) and 350/microliter (patient 2); the viral load was under detection limit in both patients. At that time systemic maintenance therapy was discontinued in both patients.

RESULTS

There was no progression of retinitis during the observation period of 21 months (patient 1) and 24 months (patient 2).

CONCLUSIONS

In selected patients with immune recovery under HAART it is possible to discontinue systemic anti-CMV maintenance therapy.

[What is the value of transpupillary thermotherapy in treatment of flat posterior choroid melanomas? A systematic review of the literature?]

BACKGROUND

Transpupillary thermotherapy is a relatively new method for the treatment of choroidal melanomas. We present a systematic survey of the current literature.

METHOD

A temperature rise in the tumor ranging from 45-60 degrees C is achieved by an infrared laser beam delivered through the dilated pupil. With a modified delivery system beam widths between 1 and 3 mm and exposure times of one minute are generated. Thus, tumors of up to 4 mm thickness are treatable. TTT can be used as a single treatment procedure or in combination with brachytherapy.

RESULTS

Several studies presented in the literature show a satisfactory local tumor control. However, there is a significant risk of vision threatening side effects like retinal vascular occlusion or retinal traction in selected cases.

CONCLUSION

The TTT is a minimal invasive procedure for the treatment of flat choroidal melanomas of the posterior pole which is capable of achieving a good local tumor control. Studies with more patients and longer follow-up will demonstrate if TTT is also beneficial in the longterm management of choroidal melanomas.

Treatment of herpes retinitis in an animal model with a sustained delivery antiviral drug, liposomal 1-O-octadecyl-SN-glycerol-3-phosphonoformate

PURPOSE

To evaluate the clinical treatment efficacy of a long-lasting intravitreous injectable anti-cytomegalovirus (CMV) liposomal drug, 1-O-octadecyl-sn-glycerol-3-phosphonoformate (ODG-PFA).

METHODS

Sixty-four pigmented rabbits were used for evaluation of the potency and duration of action of ODG-PFA after intravitreal injection using a herpes simplex virus (HSV)-1 retinitis model. For the potency evaluation, liposomal ODG-PFA was injected into rabbit vitreous at the same time that HSV-1 virus was inoculated onto the retina (simultaneous treatment). For the duration evaluation, ODG-PFA was injected days or weeks before inoculation (pretreatment). Retinitis was clinically graded by indirect ophthalmoscopy, and the retinitis scores were compared across the treatment and control groups.

RESULTS

Simultaneous treatment study revealed that ODG-PFA was much more potent than its parent compound, foscarnet (P = 0.0027). Pretreatment study indicated that ODG-PFA possesses a much longer antiviral effect (at least 2 weeks) than foscarnet after a single intravitreal injection.

CONCLUSION

Liposomal ODG-PFA is a potent long-lasting intravitreal injectable antiviral compound that may be an ideal alternative for treatment of CMV retinitis in patients with acquired immunodeficiency syndrome.

Evaluation of the human choroidal melanoma rabbit model for studying microcirculation patterns with confocal ICG and histology

The aim of this study was to develop consistently focal elevated choroidal masses of human choroidal melanoma in immunosuppressed rabbits and to correlate the visualization of prognostically significant microcirculation patterns from confocal indocyanine green angiography with histologic microcirculation patterns. A human choroidal melanoma cell line (OCM1) was implanted in the choroid of 40 rabbit eyes using three different techniques: transscleral choroidal injection of a cell suspension, injection of a cell suspension in a surgically induced cyclodialysis cleft, and implantation of solid tumor fragments in a surgically induced cyclodialysis cleft. The rabbits were immunosuppressed with daily injections of Cyclosporin A to prevent host versus graft reaction. The eyes were studied weekly with indirect ophthalmoscopy and fundus photography to monitor tumor growth and indocyanine green angiography using a confocal scanning laser ophthalmoscope to identify microcirculation patterns in vivo and correlate these findings with the histologic demonstration of tumor microcirculation patterns. A tumor mass was identified by indirect ophthalmoscopy in 16 of the 40 implanted rabbit eyes (40%). Each of these tumors was confirmed histologically to represent a focal elevated choroidal mass. All 16 elevated choroidal masses grow in eyes in which solid tumor fragments were implanted. In total, a melanoma was identified histologically in 28 of the implanted 40 eyes (70%). In addition to the 16 eyes where the melanoma appeared as a focal elevated choroidal mass, 4 eyes contained a focal elevated mass in the sclera and 8 eyes contained a flat choroidal tumor. Histologically, microcirculation patterns were identified only in the 16 eyes with focal elevated choroidal masses. Confocal indocyanine green angiography imaged microcirculation patterns in 13 of these 16 eyes (81%). The surgical implantation of small solid fragments of human choroidal melanoma in immunosuppressed rabbit eyes provides the best method to consistently obtain focal elevated choroidal masses. These focal elevated choroidal masses resemble booth the localization and the growth pattern of choroidal melanomas in humans. In addition, they also contain microcirculation patterns similar to those seen in humans that are detectable with confocal indocyanine green angiography. The use of indocyanine green angiography with this animal model may be especially useful in designing and evaluating anti-microcirculation treatments directed at uveal melanoma.

Pattern of early visual field loss in HIV-infected patients

OBJECTIVE

To determine the topographic pattern of visual field loss, if any, and its relationship to the stage of disease in human immunodeficiency virus-positive patients without infectious retinopathy.

METHODS

A total of 151 eyes from 81 alert and cooperative patients with human immunodeficiency virus were evaluated with visual field testing. Results were analyzed relative to the associated underlying nerve fiber layer patterns associated with retinal ganglion cell axons as they traverse the retina to the optic nerve. The stage of visual field loss was analyzed relative to the length of survival using Kaplan-Meier survival analysis.

RESULTS

No correlation of CD4 cell count with visual field mean defect (r2 = 0.23) or corrected pattern standard deviation (r2 = 0.00) was found. A pattern of visual field loss, consistent with sparing of the papillomacular bundles and associated with damage primarily to the inferior retina external to the posterior pole, was found. Survival analysis indicated a significant difference in time of survival between individuals with normal visual fields and those with a diffuse visual field loss, with a trend to less survival with increasing field loss severity.

CONCLUSIONS

These results are consistent with disease at the level of the optic nerve. The relationship of stage of visual field loss to survival has important implications for early detection of field loss and appropriate therapeutic intervention to maintain function and quality of life.

Evaluation of microvascularization pattern visibility in human choroidal melanomas: comparison of confocal fluorescein with indocyanine green angiography

BACKGROUND

The presence of specific microvascularization patterns (networks, parallel with and without crosslinking, silent) in histological sections of human choroidal melanomas has prognostic significance for survival. We showed previously in selected patients that the identification of these microvascularization patterns is possible in vivo by using confocal scanning laser indocyanine green angiography and that this technique is superior to fluorescein angiography using a conventional acquisition technique with a fundus camera. We now routinely use simultaneous confocal fluorescein/indocyanine green angiography to study microvascularization patterns in choroidal melanomas. The purpose of this study was to compare the visibility of tumor vessels and microvascularization patterns in fluorescein and indocyanine green angiography in simultaneous confocal series taken with the same instrument in a large prospective series of patients.

PATIENTS AND METHODS

The simultaneously procured confocal fluorescein and indocyanine green angiograms of 50 patients with untreated choroidal melanomas (maximal apical height according to standardized A-scan between 2 and 8 mm) were studied for the visibility of tumor vessels and microvascularization patterns. At least one simultaneous confocal optical series (32 images in sequential depth order) during the early arterial venous phase was obtained per patient.

RESULTS

Confocal forescein angiography disclosed signs of tumor vascularization in 12 (24%) of the 50 patients examined. However, in only 3 patients (6%) could microvascularization patterns be identified using confocal fluorescein angiography, and only in the very early arterial phase, which is often difficult to capture. In contrast, simultaneously obtained confocal indocyanine green angiograms disclosed tumor vessels in 47 (94%) of the examined 50 patients and microvascularization patterns could be identified in all of these cases. In 3 patients (6%) no tumor vessels could be detected within the tumor borders.

CONCLUSION

This study demonstrates that confocal indocyanine green angiography images microvascularization patterns in choroidal melanomas better than fluorescein angiography, even when the images are acquired with the same technique. This can be explained with the different absorption, fluorescence and exudation characteristics of these dyes. In vivo imaging of these microvascularization patterns using confocal indocyanine green angiography offers the possibility of assessing the prognosis of choroidal melanomas without the removal of tissue.

Retinal blood flow measurements in branch retinal vein occlusion using scanning laser Doppler flowmetry

PURPOSE

To determine capillary blood flow measurements in eyes with branch retinal vein occlusion using a scanning laser Doppler flowmeter.

METHODS

Retinal capillary blood flow in branch retinal vein occlusion areas and corresponding ipsilateral nonbranch retinal vein occlusion areas, 11 equivalent areas of the contralateral fellow eye of 12 consecutive untreated branch retinal vein occlusion patients, and 16 eyes of 11 age-matched normal control subjects were measured with scanning laser Doppler flowmetry. A template consisting of eight squares, each with a field of 100 x 100 microm (10 x 10 pixel) with space interval of 500 microm equidistant horizontally and vertically was used to obtain blood flow measurements in all subjects. Mean blood volume, flow, and velocity were obtained by averaging the mean values measured in each field. We avoided measurement over large retinal vessels to prevent the aliasing artifact of blood cells from moving faster than the sampling frequency.

RESULTS

Branch retinal vein occlusion areas have significantly decreased microvascular blood volume (P = .0009), flow (P = .02), and velocity (P = .016) compared with ipsilateral nonbranch retinal vein occlusion areas in the same eye. Branch retinal vein occlusion areas also have decreased blood volume (P = .001), flow (P = .0042), and velocity (P = .0044) compared with areas of contralateral fellow eyes of branch retinal vein occlusion subjects. Branch retinal vein occlusion areas have significantly decreased blood volume (P = .0012), flow (P = .008), and velocity (P = .02) compared with age-matched normal areas.

CONCLUSION

Average retinal blood volume, flow, and velocity in areas of branch retinal vein occlusion are significantly lower than in healthy retinas. The ability to noninvasively measure hemodynamic changes in the retinal capillary bed may be relevant to development of new therapies for retinovascular disease.

Terson's syndrome in subarachnoid hemorrhage and severe brain injury accompanied by acutely raised intracranial pressure

OBJECT

The syndrome of retinal or vitreous hemorrhage in association with subarachnoid hemorrhage (SAH) is known as Terson's syndrome. The authors' purpose was to determine whether intraocular hemorrhage occurs with similar incidence when caused by severe brain injury accompanied by acutely raised intracranial pressure (ICP).

METHODS

Prospective ophthalmological examination was performed in 22 consecutive patients with SAH or severe brain injury and elevated ICP. Thirteen patients were admitted for SAH (World Federation of Neurological Surgeons Grades II-IV) and nine for severe brain injury (Glasgow Coma Scale scores 3-10). Monitoring of ICP was performed at the time of admission via a ventricular catheter. Initial ICP exceeded 20 mm Hg in all patients. Indirect ophthalmoscopy without induced mydriasis was performed within the 1st week after the acute event. Retinal or vitreous hemorrhage was seen in six (46%) of 13 patients with SAH and in four (44%) of nine patients with severe brain injury. Ocular bleeding was found bilaterally in three patients with SAH and in one patient with severe brain injury (18%). Six of the 10 patients with Terson's syndrome died as a result of their acute event.

CONCLUSIONS

The present results indicate that Terson's syndrome may be related to acute elevation of ICP, independent of its causes, and may occur with similar incidence in patients with severe brain injury and those with SAH. Because recognition and treatment of Terson's syndrome may prevent visual impairment and associated secondary damage to the eye, increased awareness of this entity in all patients with acute raised intracranial hypertension is recommended.