[Cyclodialysis, a therapeutic challenge: Review of the literature on current practices]

INTRODUCTION

Cyclodialysis is a rare condition that is difficult to manage. We present the case of a woman with a cyclodialysis complicated by chronic hypotony requiring two surgeries to achieve reattachment of the ciliary body. We also report the results of a review of the literature regarding the treatment of this condition.

DESCRIPTION

This is a 46-year-old woman with history of trauma to the right eye. Examination revealed an intra-ocular pressure (IOP) of 7mmHg, a shallow anterior chamber and signs of chronic hypotony on fundus examination (vascular tortuosity, hypotony maculopathy) due to an extensive 360° cyclodialysis, confirmed by ultrasound biomicroscopy. Transcleral cryotherapy as a first-line approach did not achieve reattachment of the ciliary body. Secondary pars plana vitrectomy with gas tamponade (C2F6) reattached the ciliary body and restored the intraocular pressure (12mmHg) and normal fundus appearance. The patient recovered corrected visual acuity of 20/20.

DISCUSSION

To our knowledge, there is no standardized management for cyclodialysis. The study of the literature available on the Medline database showed that direct cyclopexy remains the most common treatment, followed by vitrectomy with internal tamponade. Neither the extent nor the duration of the cyclodialysis can predict the visual recovery, which can be major even after weeks of hypotony.

CONCLUSION

The management of cyclodialysis is not well-defined; it remains a true therapeutic challenge.

[Hereditary color vision deficiency: Physiology, classification, diagnosis and application to aeronautics]

Hereditary color vision deficiency affects 9% of men and 0.5% of women. It is often unrecognized and diagnosed late, which can interfere with the professional careers of these patients. Most color vision deficiencies are related to X chromosome involvement and concern the red-green chromatic axis. They are secondary to dysfunction of an L or M cone (protanomaly or deuteranomaly) or to the absence of an L or M cone (protanopia or deuteranopia). Color vision deficiency screening and assessment can be done by confusion tests or equalization tests, but also by ergonomic tests, professional tests that assess the aptitude for a given profession.

Isotropic-nematic transition of self-propelled rods in three dimensions

Using overdamped Brownian dynamics simulations we investigate the isotropic-nematic (IN) transition of self-propelled rods in three spatial dimensions. For two well-known model systems (Gay-Berne potential and hard spherocylinders) we find that turning on activity moves to higher densities the phase boundary separating an isotropic phase from a (nonpolar) nematic phase. This active IN phase boundary is distinct from the boundary between isotropic and polar-cluster states previously reported in two-dimensional simulation studies and, unlike the latter, is not sensitive to the system size. We thus identify a generic feature of anisotropic active particles in three dimensions.

In silico clinical trials for pediatric orphan diseases

To date poor treatment options are available for patients with congenital pseudarthrosis of the tibia (CPT), a pediatric orphan disease. In this study we have performed an in silico clinical trial on 200 virtual subjects, generated from a previously established model of murine bone regeneration, to tackle the challenges associated with the small, pediatric patient population. Each virtual subject was simulated to receive no treatment and bone morphogenetic protein (BMP) treatment. We have shown that the degree of severity of CPT is significantly reduced with BMP treatment, although the effect is highly subject-specific. Using machine learning techniques we were also able to stratify the virtual subject population in adverse responders, non-responders, responders and asymptomatic. In summary, this study shows the potential of in silico medicine technologies as well as their implications for other orphan diseases.

Failure of systemic oral doxycycline in preventing ocular toxoplasmic retinochoroiditis in French military personnel

This paper describes two cases of toxoplasmic chorioretinitis presenting in two French soldiers who had been receiving oral doxycycline for malaria prophylaxis. This is despite the proven effectiveness of oral doxycycline in treating Toxoplasma gondii, the most common cause of this infection. The lack of effectiveness of oral doxycycline in these two cases most likely reflected that the ocular concentration of 100 mg daily doxycycline is too low to treat or prevent Toxoplasmic retinochoroiditis (TC). Clinicians should therefore be aware that soldiers taking prophylactic oral doxycycline are still at risk of developing ocular TC with potentially sight-threatening consequences if not treated adequately.

Ionic liquids–lignin combination: an innovative way to improve mechanical behaviour and water vapour permeability of eco-designed biodegradable polymer blends

In this work, the potential use of lignin combined with ionic liquids (ILs) has been investigated on the final properties of biodegradable polymer blends.

[Diagnostic use of macular layer analysis by SD-OCT in primary open angle glaucoma]

PURPOSE

The purpose of this study is to evaluate the diagnostic ability of segmentation of the various internal macular layers by spectral domain optical coherence tomography (Cirrus HD-OCT, Carl Zeiss Meditec (CZM), Dublin, CA, USA) and to compare it to that of the peripapillary retinal nerve fiber layer (cpRNFL) in primary open angle glaucoma (POAG).

MATERIALS AND METHODS

This study included 252 eyes diagnosed with primary open angle glaucoma (POAG) (164 early POAG, 44 moderate POAG and 44 advanced POAG) and 223 eyes of control subjects. All patients underwent visual field testing (Humphrey Field Analyser, SITA-Standard 24-2, CZM), and SD-OCT imaging (Cirrus HD-OCT) of the macular and optic nerve head regions (ganglion cell analysis (GCA), macular cube 200×200; optic disc cube 200×200). OCT macular scans were segmented into macular nerve fiber layer (mNFL), ganglion cell layer with inner plexiform layer (GCIPL), outer retinal layers, and ganglion cell complex (GCC) (mNFL+GCIPL). Glaucoma discriminating ability was assessed using the area under the receiver operator characteristic curve (AUC) for all macular parameters and mean circumpapillary retinal nerve fibre layer (cpRNFL).

RESULTS

For the entire POAG population of this study, the minimum GCIPL index provided greater diagnostic ability than the other parameters studied, with a statistically significant difference in their AUC (minimum GCIPL [0.887], mean GCIPL [0.865], GCC [0.863], cpRNFL [0.823], mean mNFL [0.786] and minimum mNFL [0.742]). The results were similar in the early POAG group but without any statistically significant difference with the cpRNFL parameter. In the moderate POAG group, the diagnostic ability was similar for all indices, whereas in the advanced POAG group, minimum GCIPL and GCC gave the largest AUC indices.

DISCUSSION AND CONCLUSION

The minimum macular GCIPL is a new index obtained with the GCA algorithm of the Cirrus HD-OCT. It appears to have an excellent ability to detect glaucoma at every stage and demonstrates performance comparable to that of the cpRNFL parameter, in combination with which it may provide important complementary information for clinical practice.

Rhombic preordering on a square substrate

A competition of incommensurate symmetries occurs whenever a system is forced to conform to an ordering that is different from the intrinsically preferred structure of the system itself. As a model system of such a competition, we study the rivalry between the triangular ordering of hard disks and the square symmetry induced by a periodic square substrate. By using density functional theory as well as Monte Carlo computer simulations, we determine the full phase behavior for the case of one particle per minimum. We observe a rhombic preordering structure preceding the hexagonal solid as a direct consequence of the competing symmetries. Furthermore, the square-rhombic transition is reentrant with increasing substrate interaction. Our predictions can be verified in experiments of colloids in laser fields.

Severe vaginal chronic graft-versus-host disease (GVHD): two cases with late onset and literature review

Female genital graft-versus-host disease (GVHD) occurs after allogenic stem cell transplantation (SCT) in 25% of long-term survivors. To date, 28 severe cases with hematocolpos requiring surgery have been documented. We report two cases of severe gynecological GVHD. Although most of the vaginal GVH disease cases occurred within two years after oncologic treatment, our two cases highlight the possibility of a very long onset. We also confirmed that hormonal replacement therapy does not protect against synechia and that corticoid treatment has a good therapeutic value in recurrence after surgery. In conclusion, women with SCT experience a high risk of vaginal GVHD that could impair quality of life and sexual function. These cases pinpointed the importance of very long-term gynecological follow-up in order to diagnose early symptoms. To date, only early therapy with local corticoid application might reduce symptoms and development of severe genital GVHD. We support systematic use of topical corticoid therapy in severe cases even after surgery because of the high incidence of recurrence.

Low frequency of Helicobacter species in the stomachs of experimental rabbits

The natural occurrence of established Helicobacter species was investigated in the stomachs of 65 laboratory rabbits, by means of polymerase chain reaction (PCR) (65/65) and histological analysis (51/65). The degree of inflammation in the different regions of the rabbits' stomach was evaluated on haematoxylin and eosin (HE)-stained histological slides. Four rabbits were found positive for Helicobacter species by PCR. Based on 16S ribosomal ribonucleic acid (rRNA) sequences, H. canadensis/H. pullorum organisms were identified in three animals. Bacteria were seen on merely one histological slide from one of these animals. H. felis was identified in one rabbit. Histological examination revealed no inflammation in the stomachs of 40 rabbits, while moderate gastric inflammation was seen in 11 animals, mainly in the antrum. In conclusion, the stomach of the laboratory rabbits included in the study was occasionally found positive for Helicobacter species, which were mostly identified as enterohepatic helicobacters, probably reflecting a mere passage of these bacteria through the stomach.

An in vivo study of the influence of the surface roughness of implants on the microbiology of supra- and subgingival plaque

In nine patients with fixed prostheses supported by endosseous titanium implants, 2 titanium abutments (transmucosal part of the implant) were replaced by either an unused standard abutment or a roughened titanium abutment. After 3 months of habitual oral hygiene, plaque samples were taken for differential phase-contrast microscopy, DNA probe analysis, and culturing. Supragingivally, rough abutments harbored significantly fewer coccoid micro-organisms (64 vs. 81%), which is indicative of a more mature plaque. Subgingivally, the observations depended on the sampling procedure. For plaque collected with paper points, only minor qualitative and quantitative differences between both substrata could be registered. However, when the microbiota adhering to the abutment were considered, rough surfaces harbored 25 times more bacteria, with a slightly lower density of coccoid organisms. The presence and density of periodontal pathogens subgingivally were, however, more related to the patient's dental status than to the surface characteristics of the abutments. These results justify the search for optimal surface smoothness for all intra-oral and intra-sulcular hard surfaces for reduction of bacterial colonization and of periodontal pathogens.

Comparative antiplaque activity of sanguinarine and chlorhexidine in man

This clinical investigation examined the effect of a sanguinarine extract on bacterial plaque growth in man. Three different mouthrinses were examined: (i) Veadent containing 0.03% sanguinarine and 0.2% zinc chloride (test rinse); (ii) a vehicle solution containing all the excipients of Veadent except the 0.03% sanguinarine (control rinse); (iii) Hibident a 0.2% chlorhexidine digluconate formulation (positive control rinse). The trial in which 12 dental students participated, was designed as a single-blind, cross-over study. During 3 experimental periods of 18 days, the participants refrained from mechanical oral hygiene and rinsed twice a day with one of the above mentioned solutions. Between experimental phases, a wash-out period of 11 days was instituted. In each subject, 4 teeth were randomly selected for assessment. Clinical evaluations were performed at days 1 (0, 4, 8, 12 hours), 2, 4, 11 and 18. The plaque on the buccal surfaces of the selected teeth was disclosed with neutral red 0.05% and colour slides taken. The % of the tooth surface covered with plaque was calculated planimetrically from these colour slides. The present results show an excellent anti-plaque effect with Hibident, a very small effect with Veadent and a negligible effect with the vehicle solution without the sanguinarine. These findings would suggest that the Veadent mouthrinse would have at most only a limited role as a plaque inhibitor.

The influence of surface free energy and surface roughness on early plaque formation. An in vivo study in man

Previous in vivo studies suggested that a high substratum surface free energy (s.f.e.) and an increased surface roughness facilitate the supragingival plaque accumulation. It is the aim of this clinical trial to explore the "relative" effect of a combination of these surface characteristics on plaque growth. 2 strips, one made of fluorethylenepropylene (FEP) and the other made of cellulose acetate (CA) (polymers with surface free energies of 20 and 58 erg/cm2, respectively) were stuck to the labial surface of the central incisors of 16 volunteers. Half the surface of each strip was smooth (Ra +/- 0.1 microns) and the other half was rough (Ra +/- 2.2 microns). The undisturbed plaque formation on these strips was followed over a period of 6 days. The plaque extension at day 3 and 6 was scored planimetrically from color slides. Finally, of 6 subjects samples were taken from the strips as well as from a neighbouring smooth tooth surface (s.f.e. 88 erg/cm2; Ra +/- 0.14 microns). These samples were analysed with a light microscope to score the proportion of coccoid cells, and small, medium, and large rods or fusiform bacteria. At day 3, a significant difference in plaque accumulation was only obtained when a rough surface was compared with a smooth surface. However, at day 6, significantly less plaque was recorded on FEP smooth (19.4%) when compared with CA smooth (39.5%). Between FEP rough (96.8%) and CA rough (98.2%), no significant difference appeared.(ABSTRACT TRUNCATED AT 250 WORDS)

The influence of surface free-energy on planimetric plaque growth in man

The purpose of this study was to examine the change in plaque area over nine days in vivo on four materials with different surface free-energies (s.f.e.). Twelve healthy dental students participated in a cross-over, split-mouth, double-blind study. Supragingival plaque formation was recorded over a nine-day period, on four different materials: fluorethylenepropylene (Teflon) (FEP), parafilm (PAR), cellulose acetate (CA), and enamel (E) with s.f.e. of 20, 26, 57, and 88 erg/cm2, respectively. Strips made from the first three materials were stuck to the buccal surface of an upper incisor. The remaining incisor was carefully polished and served as an enamel surface. The increase in plaque was evaluated after three, six, and nine days. A planimetrical analysis was used so that the plaque area could be expressed as a percentage of the total buccal tooth surface. This procedure was repeated on each subject, so that at the end, each pair of central or lateral incisors received the four tested materials. The results indicated that the adherence of micro-organisms on pellicle-coated substrata was influenced by the material's s.f.e.; there was an association between the s.f.e. of the substrata and the supragingival plaque extension in vivo. High surface free-energy substrata in the oral cavity attracted more micro-organisms than did low energetic materials. Additionally, the bacterial adhesion seemed very weak on surfaces with a low s.f.e.