Identification of torque teno virus in culture-negative endophthalmitis by representational deep DNA sequencing.

PURPOSE: To test the hypothesis that uncultured organisms may be present in cases of culture-negative endophthalmitis by use of deep DNA sequencing of vitreous biopsies. DESIGN: Single-center, consecutive, prospective, observational study. PARTICIPANTS: Aqueous or vitreous biopsies from 21 consecutive patients presenting with presumed infectious endophthalmitis and 7 vitreous samples from patients undergoing surgery for noninfectious retinal disorders. METHODS: Traditional bacterial and fungal culture, 16S quantitative polymerase chain reaction (qPCR), and a representational deep-sequencing method (biome representational in silico karyotyping [BRiSK]) were applied in parallel to samples to identify DNA sequences corresponding to potential pathogens. MAIN OUTCOME MEASURES: Presence of potential pathogen DNA in ocular samples. RESULTS: Zero of 7 control eyes undergoing routine vitreous surgery yielded positive results for bacteria or virus by culture or 16S polymerase chain reaction (PCR). A total of 14 of the 21 samples (66.7%) from eyes harboring suspected infectious endophthalmitis were culture-positive, the most common being Staphylococcal and Streptococcal species. There was good agreement among culture, 16S bacterial PCR, and BRiSK methodologies for culture-positive cases (Fleiss' kappa of 0.621). 16S PCR did not yield a recognizable pathogen sequence in any culture-negative sample, whereas BRiSK suggested the presence of Streptococcus in 1 culture-negative sample. With the use of BRiSK, 57.1% of culture-positive and 100% of culture-negative samples demonstrated the presence of torque teno virus (TTV) sequences, compared with none in the controls (P=0.0005, Fisher exact test). The presence of TTV viral DNA was confirmed in 7 cases by qPCR. No other known viruses or potential pathogens were identified in these samples. CONCLUSIONS: Culture, 16S qPCR, and BRiSK provide complementary information in presumed infectious endophthalmitis. The majority of culture-negative endophthalmitis samples did not contain significant levels of bacterial DNA. "Culture negativity" does not seem to be due to failure of growth of fastidious bacteria. The small DNA virus TTV was unexpectedly found in all culture-negative samples and some culture-positive samples. This study cannot distinguish whether TTV is a direct intraocular pathogen, an adjuvant for inflammation, a general marker of inflammation, or a commensal virus but provides a testable hypothesis for a pathogenic mechanism in culture-negative endophthalmitis.

Vision loss after intravitreal ocriplasmin: correlation of spectral-domain optical coherence tomography and electroretinography.

IMPORTANCE Clinical trials indicate that visual impairment is significantly greater in patients receiving ocriplasmin than placebo. The mechanism of this symptom has not been explained. We report a patient with persistent darkening of her vision after intravitreal ocriplasmin and describe ancillary testing findings that may yield insights into the effects of ocriplasmin and the cause of this symptom. OBSERVATIONS We describe a 71-year-old woman with symptomatic vitreomacular traction who received intravitreal ocriplasmin and experienced darkening of vision in dim illumination for 4 months, despite improvement in visual acuity and release of symptomatic vitreomacular traction. We demonstrate that disruption of photoreceptor inner segment-outer segment (ellipsoid) layer on SD-OCT and reduced ERG amplitudes correspond to the patient's symptom of darkened vision. The ERG demonstrated a greater reduction in scotopic function compared with photopic function. CONCLUSIONS AND RELEVANCE On the basis of these findings, it is possible that ocriplasmin may have a diffuse enzymatic effect on photoreceptors or the retinal pigment epithelium that is not limited to areas of vitreomacular adhesion. The rod photoreceptors may be more susceptible than cone photoreceptors to the effects of ocriplasmin. Further work is needed to understand mechanisms of visual impairment after ocriplasmin.

Stem cell therapy for retinal disease.

PURPOSE OF REVIEW: Stem cell therapy holds great promise for the treatment of retinal diseases. This review summarizes recent advances in stem cell biology, outlines ongoing clinical trials and details the obstacles that must be overcome for stem cell therapy to be a viable treatment for retinal disease. RECENT FINDINGS: Stem cells can now be directed to specific retinal cell fates with high yields and acceptable purity for clinical trials. New stem cell sources have been discovered including induced pluripotent stem cells that can be derived from adult tissues then differentiated into multiple retinal cell types. The initial results of clinical trials of subretinal transplantation of human embryonic stem cell-derived retinal pigment epithelium cells in patients with Stargardt's macular dystrophy and dry age-related macular degeneration showed preliminary safety and possible visual acuity benefits. A phase I trial of intravitreally injected autologous bone marrow-derived mononuclear cells for hereditary retinal dystrophy demonstrated no evidence of toxicity with possible visual acuity benefits but no structural or functional changes. Ongoing trials are examining the trophic effects of undifferentiated umbilical cells for the treatment of geographic atrophy in age-related macular degeneration. SUMMARY: Stem cell therapy is a promising treatment under active investigation in multiple retinal diseases. Ongoing clinical trials should yield further insights into the potential for stem cell-based retinal therapies.

Hypertensive retinopathy in a child caused by pheochromocytoma: identification after a failed school vision screening.

A 7-year-old girl was referred for ophthalmological examination after the result of a routine school vision screening identified unilateral vision loss. Fundus examination showed bilateral but markedly asymmetric macular exudates and optic disk edema. After the results of two blood pressure measurements were within normal limits, a third markedly elevated measurement revealed malignant hypertension and led to a diagnosis of pheochromocytoma, a rare catecholamine-secreting tumor. The tumor was resected, and 6 months later the patient's blood pressure had normalized; however, although visual acuity had improved to 20/20 in the right eye, it remained 20/200 in the left eye, with decreased disk edema but the persistence of the macular exudates. The identification of an abdominal malignancy through a school vision screening may have saved this child's life. The need for repeated blood pressure measurement is also highlighted.

Treatment of acute retinal necrosis.

OBJECTIVES: To compare outcomes from patients with acute retinal necrosis (ARN) treated in the acyclovir-only era with those treated in the era of newer antiviral therapies, identify variables affecting outcomes in ARN, and evaluate strategies for fellow eye prophylaxis. DESIGN: Multicenter, nonrandomized, retrospective, interventional series. PARTICIPANTS: A cohort of 58 patients diagnosed with ARN by a retina specialist at 1 of 4 referral centers between 1981 and 2008. The cohort was divided into 2 subgroups: patients treated during the acyclovir-only era (n = 36) and patients treated during the current era of newer antiviral medications (n = 22). INTERVENTION: Intravenous, oral, or intravitreal antiviral medications, including acyclovir, valacyclovir, famciclovir, valganciclovir, ganciclovir, and foscarnet; prophylactic laser retinopexy; aspirin; oral steroids. MAIN OUTCOME MEASURES: Visual acuity, retinal detachment, and fellow eye involvement. RESULTS: A wide range and combination of antiviral agents are currently used for initial and long-term treatment of ARN. Outcomes from the newer antivirals era were similar to those achieved during the acyclovir-only era. In both groups, the incidence of 20/200 or worse visual acuity was 24% per person-year (P = 0.91). The prevalence of retinal detachment was approximately 50% in each group (P = 0.59). No variables, including prophylactic laser retinopexy, were associated with risk of retinal detachment. Two patients (3.4%) developed ARN in the initially unaffected eye. CONCLUSIONS: Current treatment trends vary widely, including single agents or combinations of oral, intravenous, and intravitreal agents. Differing strategies did not affect outcomes. The final visual acuity in ARN was generally poor. Retinal detachment was common and could neither be predicted nor prevented. Development of ARN in the unaffected fellow eye occurred rarely. Long-term oral antiviral treatment strategies varied with unclear relative efficacy. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found after the references.

Crystal structure of a FYVE-type zinc finger domain from the caspase regulator CARP2.

The caspase-associated ring proteins (CARP1 and CARP2) are distinguished from other caspase regulators by the presence of a FYVE-type zinc finger domain. FYVE-type domains are divided into two known classes: FYVE domains that specifically bind to phosphatidylinositol 3-phosphate in lipid bilayers and FYVE-related domains of undetermined function. Here, we report the crystal structure of the N-terminal region of CARP2 (44-139) including the FYVE-type domain and its associated helical bundle at 1.7 A resolution. The structure reveals a cramped phosphoinositide binding pocket and a blunted membrane insertion loop. These structural features indicate that the domain is not optimized to bind to phosphoinositides or insert into lipid bilayers. The CARP2 FYVE-like domain thus defines a third subfamily of FYVE-type domains that are functionally and structurally distinct. Structural analyses provide insights into the possible function of this unique subfamily of FYVE-type domains.

The death effector domain protein family: regulators of cellular homeostasis.

The death effector domain (DED) occurs in proteins that regulate programmed cell death. Both pro- and anti-apoptotic proteins containing DEDs have been identified. For Fas and possibly other death receptors, homotypic DED interactions connect the Fas-associated death domain (FADD) protein to caspase-8 and caspase-10 to mediate formation of the death-inducing signal complex. This complex can be inhibited by other DED-containing proteins. Accumulating evidence now suggests that DED-containing proteins have additional roles in controlling pathways of cellular activation and proliferation. Thus, the DED defines a family of proteins that may be pivotal to cellular homeostasis by establishing a 'cell renewal set point' that coregulates proliferation and apoptosis in parallel.