J. Conrath

High prevalence of fastidious bacteria in 1520 cases of uveitis of unknown etiology.

The etiologic evaluation of uveitis is frequently unsuccessful when noninvasive methods are used. We conducted a prospective study to evaluate systematic screening for pathogens of uveitis. All patients with uveitis referred to the participating tertiary ophthalmology departments from January 2001 to September 2007 underwent intraocular and serum specimen collection. The standardized protocol for laboratory investigations included universal polymerase chain reaction (PCR)-based detection of any bacteria and mycoses, specific PCR-based detection of fastidious (difficult-to-grow) bacteria and herpes viruses, and culture of vitreous fluid. Sera were tested for fastidious bacteria. Among the 1321 included patients (1520 specimens), infection was diagnosed in 147 (11.1%) patients: 78 (53%) were caused by fastidious bacteria that included spirochetes, Bartonella species, intracellular bacteria (Chlamydia species, Rickettsia species, Coxiella burnetii), and Tropheryma whipplei; 18 by herpes viruses; and 9 by fungi. Bartonella quintana, Coxiella burnetii, Paracoccus yeei, Aspergillus oryzae, and Cryptococcus albidus were found to be associated with uveitis for the first time, to our knowledge. We recommend applying a 1-step diagnostic procedure that incorporates intraocular, specific microbial PCR with serum analyses in tertiary centers to determine the etiology of uveitis. Abbreviations: ACP = anterior chamber paracentesis, EBV = Epstein-Barr virus, ELISA = enzyme-linked immunosorbent assay, HIV = human immunodeficiency virus, HSV = herpes simplex virus, PCR = polymerase chain reaction, TP-PA = Treponema pallidum particle agglutination test, VDRL = Venereal Disease Research Laboratory test.

Endophthalmitis After Intravitreal Injections: Incidence, Presentation, Management, and Visual Outcome

PURPOSE To report the incidence and characteristics of endophthalmitis after intravitreal injections of anti-vascular endothelial growth factor agents or corticosteroids and to describe the clinical and bacteriologic characteristics, management, and outcome of these eyes with acute endophthalmitis in France. DESIGN Retrospective, nationwide multicenter case series. METHODS From January 2, 2008 to June 30, 2013, a total of 316,576 intravitreal injections from 25 French ophthalmic centers were included. For each center, the number of intravitreal injections was determined using billing codes and the injection protocol was recorded. A registry and hospital records were reviewed to identify patients treated for endophthalmitis after injection during the same time period. The main outcome measures were the incidence of clinical endophthalmitis and visual acuity of endophthalmitis cases. RESULTS During the study period, 65 cases of presumed endophthalmitis were found, giving an overall incidence of 0.021% (2.1 in 10,000 injections) (95% confidence interval [CI], 0.016%-0.026%). The median number of days from injection to presentation was 4 [1-26] days. The most common symptom was vision loss. Bacterial identification was achieved in 43.4%. The most frequent pathogens were gram-positive bacteria (91.3%), including coagulase-negative Staphylococcus in 78.3%. Neither the interval between injection and presentation for endophthalmitis nor the clinical signs differentiated culture-positive from culture-negative cases. In multivariate analysis, the use of a disposable conjunctival mould assist device and the use of prophylaxis with an antibiotic or antiseptic were significantly associated with an increased incidence of endophthalmitis (P = .001). The majority of patients had worse visual acuity after 3 months of follow-up when compared with acuity before endophthalmitis. CONCLUSIONS The incidence of presumed endophthalmitis after intravitreal injections of anti-vascular endothelial growth factors or corticosteroids was low and the prognosis poor. Prevention and management remain challenging. It remains to be determined whether the findings of this study are relevant for other countries using different techniques for intravitreal injections.

Corneal endothelial cell loss after cataract extraction by using ultrasound phacoemulsification versus a fluid-based system.

Purpose: To compare in vivo corneal endothelial cell loss (ECL) after fluid-based versus ultrasound phacoemulsification. Methods: In this prospective randomized study, 2 groups of 21 patients underwent phacoemulsification with ultrasound (group 1) or a fluid-based system (group 2). A “divide and conquer” method with capsular bag lens implantation was performed. Cataracts graded up to nuclear opalescence 4.9 in Lens Opacities Classification System III (LOCS III) only were included. Endothelial cell density (ECD), percent hexagonality, endothelial cell area (ECA), coefficient of variation in cell size, and central corneal pachymetry were measured preoperatively, 7 days, 1 month, and 3 months after surgery. Statistical analysis was performed by using a 2-tailed Student t test. Results: Average nuclear opalescence was identical in both groups (P = 0.908). Mean ECD was 1867 ± 451 and 2031 ± 400 cells/mm2 at 3 months postoperatively. Mean ECL was 498 ± 415 (20.6% ± 17.1%) and 302 ± 302 cells/mm2 (13.3% ± 13.2%) at 7 days, 589 ± 342 (24.3% ± 14%) and 254 ± 214 cells/mm2 (11.2% ± 9.1%) at 1 month, and 555 ± 340 (22.9% ± 14%) and 247 ± 208 cells/mm2 (10.9% ± 9.1%) at 3 months in groups 1 and 2, respectively. ECL was significantly lower for group 1 than for group 2 (P < 0.001) after the first postoperative month. A significant increase in ECA was also observed at the first and third (P = 0.012) postoperative months. Conclusions: Our study showed significantly lower ECL after phacoemulsification for a fluid-based versus an ultrasound system. The fluid-based method was safer than conventional ultrasound in cataract surgery, with a nuclear opalescence graded up to 4.9 in the LOCS III classification.

Wet versus Dry Age-Related Macular Degeneration in Patients with Central Field Loss: Different Effects on Maximum Reading Speed

PURPOSE To describe new, efficient predictors of maximum reading speed (MRS) in age-related macular degeneration (AMD) patients with central field loss. Type of AMD (wet versus dry) was scrutinized, because this factor seems to offer a promising model of differential visual adaptation induced by different temporal courses of disease progression. METHODS Linear mixed-effects (LME) analyses were performed on a dataset initially collected to assess the effect of interline spacing on MRS. MRS was measured with MNread-like French sentences in 89 eyes (64 dry and 25 wet) of 61 patients with AMD. Microperimetry examination was performed on each eye. The eyes were included only if they had a dense macular scotoma including the fovea, to ensure that patients used eccentric viewing. RESULTS Analyses show the unique contributions--after adjustment for the effects of other factors--of three new factors: (1) MRS was higher for wet than for dry AMD eyes; (2) an advantage of similar amplitude was found for phakic eyes compared with pseudophakic eyes; and (3) MRS decreased when distance between fixation preferred retinal locus (PRL) and fovea increased. In addition, the instantaneous slope of the relationship between scotoma area and MRS was much shallower than reported in two other studies. CONCLUSIONS The four effects improve the ability to predict MRS reliably for AMD patients. The wet/dry difference is a major finding that may result from the different time courses of the two types of disease, thus involving different types of visuomotor and attentional adaptation processes.

Small Effect of Interline Spacing on Maximal Reading Speed in Low-Vision Patients with Central Field Loss Irrespective of Scotoma Size

PURPOSE It has been suggested that crowding, the adverse low-level effect due to the proximity of adjacent stimuli, explains slow reading in low-vision patients with absolute macular scotomas. According to this hypothesis, crowding in the vertical dimension should be released by increasing the vertical spacing between lines of text. However, studies with different experimental paradigms and only a few observers have given discrepant results on this question. The purpose of this study was to investigate this issue with a large number of patients whose macular function was carefully assessed. METHODS MP1 microperimetry examination was performed for each low-vision patient. Only eyes with an absolute macular scotoma and no foveal sparing (61 patients with AMD, 90 eyes; four patients with Stargardt disease, eight eyes) were included. Maximal reading speed was assessed for each eye with French sentences designed on the MNREAD test principles. RESULTS The effect of interline spacing on maximal reading speed (MRS) was significant although small; average MRS increased by 7.1 words/min from standard to double interline spacing. The effect was weak irrespective of PRL distance from the fovea and scotoma area and regardless of whether an eccentric island of functional vision was present within the scotoma. CONCLUSIONS Increasing interline spacing is advisable only for very slow readers (<20 words/min) who want to read a few words (spot reading). Vertical crowding does not seem to be a major determinant of maximal reading speed for patients with central scotomas.

Inhibition of corneal neovascularization after alkali burn: comparison of different doses of bevacizumab in monotherapy or associated with dexamethasone.

Background:  To compare the effects of different doses of bevacizumab with both saline and dexamethasone on inflammatory angiogenesis in the rat cornea induced by small chemical lesions.

Detection of the foveal avascular zone on retinal angiograms using Markov random fields

This paper deals with the segmentation of the Foveal Avascular Zone (FAZ) in digital retinal angiograms. Retinal angiography is used for detection and progression in some eye pathologies. The proposed method consists of two-stages: Singular Value Decomposition (SVD) and FAZ segmentation using Markov Random Fields (MRF). The obtained results demonstrate that the method is encouraging as a first approach for location and evolution of FAZ in retinal images.

Kératoplastie lamellaire antérieure assistée par laser femtoseconde

Introduction Les keratoplasties lamellaires anterieures sont de realisation delicate et l’utilisation du laser femtoseconde dans cette indication doit permettre d’en ameliorer les resultats anatomiques et fonctionnels. Nous rapportons le premier cas de keratoplastie lamellaire anterieure assistee par un laser femtoseconde. Observation Il s’agit d’une patiente âgee de 63 ans, presentant une dystrophie corneenne anterieure de Francois, traitee par keratoplastie lamellaire anterieure assistee par laser femtoseconde ( Femtec 20/10 Perfect Vision ® ). Une decoupe corneenne lamellaire par laser femtoseconde a ete realisee a 400 μm de profondeur sur un greffon corneen, positionne sur une chambre anterieure artificielle ( Moria ® , France ), puis sur la cornee receveuse du patient. Resultats Au cours de la periode postoperatoire, le lenticule corneen etait parfaitement adapte au lit receveur avec une interface claire. L’evaluation en OCT III (Carl Zeiss Meditech, Dublin) a permis de constater une pachymetrie centrale de 713 μm avec un lit receveur extremement regulier et une epaisseur centrale de 132 μm. Discussion Les decoupes corneennes assistees par laser femtoseconde doivent en comparaison avec les decoupes mecanisees ameliorer la securite operatoire, la reproductibilite, et la predictibilite des decoupes obtenues. Une meilleure congruence du greffon limite le risque de deplacement secondaire et la meilleure regularite de l’interface doit ameliorer le resultat fonctionnel. Conclusion Les keratoplasties lamellaires anterieures assistees par laser femtoseconde Femtec 20/10 Perfectvision ® presentent de nombreux avantages pour la prise en charge des pathologies corneennes necessitant une keratoplastie lamellaire anterieure. Des etudes comparatives, multicentriques, et randomisees sont necessaires afin d’evaluer les resultats de cette technique.

Semi-automated detection of the foveal avascular zone in fluorescein angiograms in diabetes mellitus.

Background:  The foveal avascular zone (FAZ) is known to enlarge in diabetic retinopathy. In a preliminary study, the authors applied a region growing algorithm to fluorescein angiograms to detect the FAZ in a semi‐automated fashion.

Human graft cornea and laser incisions imaging with micrometer scale resolution full-field optical coherence tomography

Micrometer scale resolution full-field optical coherence tomography (FF-OCT) is developed for imaging human graft corneas. Three-dimensional (3-D) images with ultrahigh resolution (respectively, 1 and 1.5 μm in the axial and transverse directions), comparable to traditional histological sections, are obtained allowing the visualization of the cells and the precise structure of the different layers that compose the tissue. The sensitivity of our device enables imaging the entire thickness of the cornea, even in edematous corneas more than 800 μm thick. Furthermore, we provide tomographic 3-D images of laser incisions inside the tissue at various depths without slicing the studied corneas. The effects of laser ablations can be observed, along various optical sections, directly in the bulk of the sample with high accuracy, providing information on the interface quality and also imaging tiny changes of the tissue structure. FF-OCT appears to be a powerful tool for subcellular imaging of the corneal structure and pathologies on the entire thickness of the tissue as well as interface quality and changes in the collagen structure due to laser incisions on ex vivo human cornea.