The gut microbiota in retinal diseases.

The gut microbiota is a complex ecosystem that inhabits the gastrointestinal tract and consists of archaea, fungi, viruses, and bacteria, with bacteria being dominant. From birth onwards, it coevolves dynamically together with the host. The composition of the gut microbiota is under the influence of a complex interplay between both host and environmental factors. Scientific advances in the past few decades have shown that it is essential in maintaining homeostasis and tipping the balance between health and disease. In addition to its role in food digestion, the gut microbiota is implicated in regulating multiple physiological processes in the host gut mucosa and in distant organs such as the brain. Persistent imbalance between gut microbial communities, termed "dysbiosis," has been associated with several inflammatory and metabolic diseases as well as with central nervous system disorders. In this review, we present the state of the art of current knowledge on an emerging concept, the microbiota-retina axis, and the potential role of its disturbance in the development of retinopathies. We also describe several microbiota-targeting strategies that could constitute preventive and therapeutic tools for retinopathies.

EPIDEMIOLOGY OF VITREOMACULAR INTERFACE ABNORMALITIES USING MACULAR SPECTRAL-DOMAIN OPTICAL COHERENCE TOMOGRAPHY IN AN ELDERLY POPULATION (THE MONTRACHET STUDY).

PURPOSE: The aim of this study was to investigate the prevalence of vitreomacular interface abnormalities (VMIAs) and to identify associated factors in an elderly population in Europe. METHODS: The MONTRACHET (Maculopathy Optic Nerve nuTRition neurovAsCular and HEarT diseases) Study is a population-based study, conducted in subjects older than 75 years. Vitreomacular adhesions, vitreomacular tractions, macular holes, epiretinal membranes, and macular cysts were assessed on spectral-domain optical coherence tomography examinations. The prevalence of VMIAs was estimated. We studied the association of demographic and clinical factors with VMIAs. RESULTS: The mean age of the participants was 82.3 (SD, 3.8) years, and 37.3% were men. The prevalence rates of VMIAs were vitreomacular adhesions (17.7%), vitreomacular tractions (1.4%), lamellar macular holes (1.0%), full-thickness macular holes (0.2%), macular pseudoholes (0.4%), epiretinal membranes (38.9%), and macular cysts (5.8%). In multivariate analysis, vitreomacular adhesions were positively associated with male sex (P < 0.001) and negatively associated with older age (P < 0.001) and cataract extraction (P < 0.001). Epiretinal membranes were positively associated with older age (P < 0.001) and cataract extraction (P < 0.001). CONCLUSION: The prevalence of VMIAs based on spectral-domain optical coherence tomography analysis was high in subjects older than 75 years.

Quality-of-Life Improvement After Scleral Lens Fitting in Patients With Keratoconus.

OBJECTIVES: To assess the quality-of-life improvement after scleral lens fitting in patients with keratoconus. METHODS: We conducted a prospective observational study of all consecutive patients with keratoconus starting scleral lens fitting in 2019, from January 2 to December 27, at the Dijon University Hospital, France. Quality of life was assessed before and after wearing scleral lenses for 3 months through the National Eye Institute Visual Function Questionnaire 25 (NEI-VFQ 25) questionnaire. We investigated factors potentially influencing quality of life: final visual acuity, keratoconus stage, and maximum keratometry reading. RESULTS: In total, 41 eyes of 24 patients were successfully fitted with scleral lenses, 92.9% were 18 mm in diameter and 7.1% were 17 mm. The visual acuity improved by -0.4±0.3 logarithm of the minimum angle of resolution (P<0.001) after scleral lens fitting. Visual gain increased with keratometry and keratoconus severity (P<0.001; P<0.01). The NEI-VFQ 25 score increased by 19.5±19.1 points on average (P<0.001). No association was found between the factors under study and improvement in quality of life. CONCLUSION: Our study confirms the functional improvement in patients with keratoconus fitted with scleral lenses, especially in patients with more advanced disease. Moreover, it suggests a major role of these lenses in improving quality of life, independently of the severity of the disease and the visual gain.

Impact of a high-fat diet on the fatty acid composition of the retina.

Structure and function of the retina mainly rely on its fatty acid (FA) composition. Evidence from epidemiological studies and from animal experiments indicates that FA composition of the retina is influenced by the diet. Mice under chronic high-fat diet (HFD) develop metabolic syndrome, a risk factor for diabetes that is associated with structural and functional alterations of the retina. Here, we studied the impact of chronic exposure of mice to HFD on retinal FA composition. C57BL/6 J male mice were fed either a chow diet or a HFD for 11 weeks. As expected, HFD induced weight gain, adiposity, hyperglycemia and dyslipidemia. The retinal FA composition was determined by gas chromatography coupled to flame ionization detection. No significant change in the relative abundance of total saturated FAs (SFAs), total monounsaturated FAs (MUFAs) or total polyunsaturated FAs (PUFAs) was observed. However, retinas of HFD-fed mice displayed decreased amounts of C24:0 (p = 0.0231), C16:1n-7 (p < 0.0001), C18:1n-7 (p < 0.0001), C20:3n-9 (p = 0.0425) and C20:3n-6 (p = 0.0008), and an increased amount of C20:2n-6 (p < 0.0001). In addition, the ratio of linoleic acid (C18:2n-6) to alpha-linolenic acid (C18:3n-3) was increased in the retinas of HFD-fed mice (15.0 ± 0.8 versus 11.8 ± 0.6 in HFD and CD, respectively, p = 0.0045). No modification in the contents of arachidonic acid (C20:4n-6, AA) and docosahexaenoic acid (C22:6n-3, DHA) were observed. Analysis of dimethylacetals (DMA), which are residues of plasmalogens (Pls), revealed that the amount of Pls containing octadecanal-aldehydes (DMA C18:0) was significantly increased in HFD-fed mice (p = 0.0447). This increase was, at least in part, balanced by a decrease in Pls containing 7-octadecanal-aldehydes (DMA C18:1n-7) (p = 0.0007). In conclusion, HFD had an impact on the relative proportion of essential dietary fatty acids linoleic acid and alpha-linolenic acid that are incorporated in the retina. However, this imbalance in PUFA precursors did not alter the content of the two major retinal long-chain PUFAs, AA and DHA. HFD consumption also led to alterations in the retinal SFAs, MUFAs and Pls profiles.

Increased High-Density Lipoprotein Levels Associated with Age-Related Macular Degeneration: Evidence from the EYE-RISK and European Eye Epidemiology Consortia.

PURPOSE: Genetic and epidemiologic studies have shown that lipid genes and high-density lipoproteins (HDLs) are implicated in age-related macular degeneration (AMD). We studied circulating lipid levels in relationship to AMD in a large European dataset. DESIGN: Pooled analysis of cross-sectional data. PARTICIPANTS: Individuals (N = 30 953) aged 50 years or older participating in the European Eye Epidemiology (E3) consortium and 1530 individuals from the Rotterdam Study with lipid subfraction data. METHODS: AMD features were graded on fundus photographs using the Rotterdam classification. Routine blood lipid measurements, genetics, medication, and potential confounders were extracted from the E3 database. In a subgroup of the Rotterdam Study, lipid subfractions were identified by the Nightingale biomarker platform. Random-intercepts mixed-effects models incorporating confounders and study site as a random effect were used to estimate associations. MAIN OUTCOME MEASURES: AMD features and stage; lipid measurements. RESULTS: HDL was associated with an increased risk of AMD (odds ratio [OR], 1.21 per 1-mmol/l increase; 95% confidence interval [CI], 1.14-1.29), whereas triglycerides were associated with a decreased risk (OR, 0.94 per 1-mmol/l increase; 95% CI, 0.91-0.97). Both were associated with drusen size. Higher HDL raised the odds of larger drusen, whereas higher triglycerides decreases the odds. LDL cholesterol reached statistical significance only in the association with early AMD (P = 0.045). Regarding lipid subfractions, the concentration of extra-large HDL particles showed the most prominent association with AMD (OR, 1.24; 95% CI, 1.10-1.40). The cholesteryl ester transfer protein risk variant (rs17231506) for AMD was in line with increased HDL levels (P = 7.7 × 10-7), but lipase C risk variants (rs2043085, rs2070895) were associated in an opposite way (P = 1.0 × 10-6 and P = 1.6 × 10-4). CONCLUSIONS: Our study suggested that HDL cholesterol is associated with increased risk of AMD and that triglycerides are negatively associated. Both show the strongest association with early AMD and drusen. Extra-large HDL subfractions seem to be drivers in the relationship with AMD, and variants in lipid genes play a more ambiguous role in this association. Whether systemic lipids directly influence AMD or represent lipid metabolism in the retina remains to be answered.

Glaucoma.

Glaucoma is a heterogeneous group of diseases characterised by cupping of the optic nerve head and visual-field damage. It is the most frequent cause of irreversible blindness worldwide. Progression usually stops if the intraocular pressure is lowered by 30-50% from baseline. Its worldwide age-standardised prevalence in the population aged 40 years or older is about 3·5%. Chronic forms of glaucoma are painless and symptomatic visual-field defects occur late. Early detection by ophthalmological examination is mandatory. Risk factors for primary open-angle glaucoma-the most common form of glaucoma-include older age, elevated intraocular pressure, sub-Saharan African ethnic origin, positive family history, and high myopia. Older age, hyperopia, and east Asian ethnic origin are the main risk factors for primary angle-closure glaucoma. Glaucoma is diagnosed using ophthalmoscopy, tonometry, and perimetry. Treatment to lower intraocular pressure is based on topical drugs, laser therapy, and surgical intervention if other therapeutic modalities fail to prevent progression.

Systemic and Ocular Determinants of Peripapillary Retinal Nerve Fiber Layer Thickness Measurements in the European Eye Epidemiology (E3) Population.

PURPOSE: To investigate systemic and ocular determinants of peripapillary retinal nerve fiber layer thickness (pRNFLT) in the European population. DESIGN: Cross-sectional meta-analysis. PARTICIPANTS: A total of 16 084 European adults from 8 cohort studies (mean age range, 56.9±12.3-82.1±4.2 years) of the European Eye Epidemiology (E3) consortium. METHODS: We examined associations with pRNFLT measured by spectral-domain OCT in each study using multivariable linear regression and pooled results using random effects meta-analysis. MAIN OUTCOME MEASURES: Determinants of pRNFLT. RESULTS: Mean pRNFLT ranged from 86.8±21.4 µm in the Rotterdam Study I to 104.7±12.5 µm in the Rotterdam Study III. We found the following factors to be associated with reduced pRNFLT: Older age (ß = -0.38 µm/year; 95% confidence interval [CI], -0.57 to -0.18), higher intraocular pressure (IOP) (ß = -0.36 µm/mmHg; 95% CI, -0.56 to -0.15), visual impairment (ß = -5.50 µm; 95% CI, -9.37 to -1.64), and history of systemic hypertension (ß = -0.54 µm; 95% CI, -1.01 to -0.07) and stroke (ß = -1.94 µm; 95% CI, -3.17 to -0.72). A suggestive, albeit nonsignificant, association was observed for dementia (ß = -3.11 µm; 95% CI, -6.22 to 0.01). Higher pRNFLT was associated with more hyperopic spherical equivalent (ß = 1.39 µm/diopter; 95% CI, 1.19-1.59) and smoking (ß = 1.53 µm; 95% CI, 1.00-2.06 for current smokers compared with never-smokers). CONCLUSIONS: In addition to previously described determinants such as age and refraction, we found that systemic vascular and neurovascular diseases were associated with reduced pRNFLT. These may be of clinical relevance, especially in glaucoma monitoring of patients with newly occurring vascular comorbidities.

Antiplatelet and anticoagulant agents in vitreoretinal surgery: a prospective multicenter study involving 804 patients.

PURPOSE: To assess the rate of hemorrhagic complications after vitreoretinal surgery and the influence of antithrombotic agents. METHODS: Hemorrhagic complications of vitreoretinal procedures performed in seven ophthalmologic centers on patients treated or not treated with antiplatelet (AP) or anticoagulant (AC) agents were prospectively collected. Patients' characteristics, surgical techniques, and complications were recorded during surgery and for 1 month after. RESULTS: Eight hundred four procedures were performed between January 2015 and April 2015. Among them, 18.4% were treated with AP agents (n = 148) and 7.8% with AC agents (n = 63), with 18 of them treated with NOACS (new oral anticoagulants). AP or AC agents were continued in 96.5% and 80.7% of cases, respectively. Fifty-three patients (6.6%) developed one or more hemorrhagic complications in one eye during this period. In univariate analysis, AC agents were not associated with hemorrhagic complications (P = 0.329) in contrast to AP (P = 0.005). However, in multivariate analysis, AP agents were no longer associated with hemorrhagic complications and the intraoperative use of endodiathermy was the only factor associated with hemorrhagic complications (P = 0.001). CONCLUSIONS: This study showed that AP and AC agents were not a factor associated with hemorrhagic complications during vitreoretinal surgery. The continuation of these treatments should be considered without risk of severe hemorrhagic complications.

Screening for Retinopathy of Prematurity: Insight into Optimizing Screening.

PURPOSE: To determine the factors influencing the time from preterm birth and retinopathy of prematurity (ROP) detection to optimize the timing of the initial screening. METHODS: This multicenter retrospective study enrolled preterm infants born before 32 weeks of gestational age (GA) and/or weighing less than 1,500 g between January 1, 2011, and December 31, 2015. ROP screening was performed using fundus photography with a wide-field camera. Population and follow-up characteristics were recorded. RESULTS: Among the 1,266 preterm infants observed, 795 were retained for analysis. One hundred seventy-four (21.6%) cases of ROP were detected with the first examination performed at 32.3 ± 1.6 weeks of postmenstrual age (PMA) and 5.4 ± 1.0 weeks of postnatal age (PNA). The first signs of ROP were detected at 34.0 ± 1.9 weeks of PMA and 7.2 ± 1.8 weeks of PNA, respectively. In the multivariate analysis, an older GA, a longer duration of mechanical ventilation, and a lower birth weight were correlated with a longer time between preterm birth and ROP detection (p < 0.0001, p < 0.0001, and p = 0.0359, respectively). CONCLUSION: The first examination for ROP screening should be individualized to fit the first screening examination as closely as possible to the first signs of ROP in order to avoid unnecessary examinations without missing ROP.

Long-Term Anatomical and Functional Outcomes after Combined Cataract and Idiopathic Epiretinal Membrane Surgery.

PURPOSE: To describe the 2-year functional and anatomical outcomes in patients operated on for combined cataract and idiopathic epiretinal membrane (ERM) and to study the relationship between best-corrected visual acuity (BCVA) and spectral-domain optical coherence tomography (SD-OCT) throughout the follow-up. METHODS: This retrospective observational case series included 72 eyes operated on for combined cataract and idiopathic ERM. They were followed with clinical and SD-OCT examinations preoperatively and 1, 6, 12, and 24 months after surgery. Foveolar thickness (FT), photoreceptor status and morphological parameters were assessed. RESULTS: BCVA and FT substantially improved at 24 months. Postoperatively, no significant improvement was observed beyond 6 months for BCVA and 12 months for FT. Outer limiting membrane and inner and outer segment junction disruption scores were well correlated with BCVA both pre- and postoperatively, and significant visual improvement was demonstrated in each subgroup except in those with the highest scores. FT was correlated with BCVA only from 6 to 24 months postoperatively. CONCLUSION: After combined cataract and idiopathic ERM surgery, BCVA and FT improved rapidly. Most functional and anatomical recovery took place within the first 6 months, but this did not preclude late improvement, in particular in patients with the most disorganized photoreceptor layers. At each time point, the amount of photoreceptor damage seemed closely correlated with visual acuity, but concerning FT, this relationship remains questionable.

French Medical-Administrative Database for Epidemiology and Safety in Ophthalmology (EPISAFE): The EPISAFE Collaboration Program in Cataract Surgery.

Medical-administrative databases are an important source of big data to assess the epidemiology of diseases and interventions, compare drugs, and investigate rare adverse events. We describe the French national health insurance system databases and the Epidemiology and Safety (EPISAFE) collaboration program in ophthalmology and illustrate the paper with recent studies that used the databases to investigate cataract surgery. The Système national d'information inter-régime de l'assurance maladie (SNIIR-AM) is one of the largest databases of medical and administrative data for a general population, covering nearly 65 million people. The SNIIR-AM database links data for all outpatient-reimbursed health expenditures, hospitalization in all 1,546 French private or public healthcare facilities, and date of death. The use of this database provides information at the scale of the entire country, allowing measurement of the impact of changes in practices and new guidelines. Between 2009 and 2012, a total of 2,717,203 eyes in 1,817,865 patients underwent cataract surgery in France, and the incidence of cataract surgery increased from 9.86 to 11.08/1,000 person-years. The 4-year cumulative risk of retinal detachment was 0.99%, and patients <60 years of age were at higher risk of retinal detachment. The incidence of pseudophakic cystoid macular edema was 0.95%. From 2005 to 2014, from data including more than 6 million procedures, the incidence of endophthalmitis after cataract surgery decreased from 0.15 to 0.05%. The EPISAFE collaboration program encompasses the key issues facing ophthalmology, including public health and public policy concerning disease incidence and prevalence, safety and adverse event monitoring, and clinical guidelines.

Incidence of Acute Postoperative Endophthalmitis after Cataract Surgery: A Nationwide Study in France from 2005 to 2014.

PURPOSE: To report the incidence of acute postoperative endophthalmitis (POE) after cataract surgery from 2005 to 2014 in France. DESIGN: Cohort study. PARTICIPANTS: Patients undergoing operation for cataract surgery by phacoemulsification and presenting acute POE. METHODS: We identified acute POE occurring within 6 weeks after phacoemulsification cataract surgery and the use of intracameral antibiotic injection during the surgical procedure by means of billing codes from a national database. MAIN OUTCOME MEASURES: Incidence of acute POE. RESULTS: From January 2005 to December 2014, 6 371 242 eyes in 3 983 525 patients underwent phacoemulsification cataract surgery. The incidence of acute POE after phacoemulsification decreased from 0.145% to 0.053% during this 10-year period; the unadjusted incidence rate ratio (IRR) (95% confidence interval) was 0.37 (0.32-0.42; P < 0.001). In multivariate analysis, intracameral antibiotic injection was associated with a lower risk of acute POE 0.53 (0.50-0.57; P < 0.001), whereas intraoperative posterior capsule rupture, combined surgery, and gender (male) were associated with a higher risk of acute POE: 5.24 (4.11-6.68), 1.77 (1.53-2.05), and 1.48 (1.40-1.56) (P < 0.001), respectively. CONCLUSIONS: Access to a national database allowed us to observe a decrease in acute POE after phacoemulsification cataract surgery from 2005 to 2014. Within the same period, the use of intracameral antibiotics during the surgical procedures increased.

Associations with intraocular pressure across Europe: The European Eye Epidemiology (E3) Consortium.

Raised intraocular pressure (IOP) is the most important risk factor for developing glaucoma, the second commonest cause of blindness globally. Understanding associations with IOP and variations in IOP between countries may teach us about mechanisms underlying glaucoma. We examined cross-sectional associations with IOP in 43,500 European adults from 12 cohort studies belonging to the European Eye Epidemiology (E3) consortium. Each study conducted multivariable linear regression with IOP as the outcome variable and results were pooled using random effects meta-analysis. The association of standardized study IOP with latitude was tested using meta-regression. Higher IOP was observed in men (0.18 mmHg; 95 % CI 0.06, 0.31; P = 0.004) and with higher body mass index (0.21 mmHg per 5 kg/m2; 95 % CI 0.14, 0.28; P < 0.001), shorter height (-0.17 mmHg per 10 cm; 95 % CI -0.25, -0.08; P < 0.001), higher systolic blood pressure (0.17 mmHg per 10 mmHg; 95 % CI 0.12, 0.22; P < 0.001) and more myopic refraction (0.06 mmHg per Dioptre; 95 % CI 0.03, 0.09; P < 0.001). An inverted U-shaped trend was observed between age and IOP, with IOP increasing up to the age of 60 and decreasing in participants older than 70 years. We found no significant association between standardized IOP and study location latitude (P = 0.76). Novel findings of our study include the association of lower IOP in taller people and an inverted-U shaped association of IOP with age. We found no evidence of significant variation in IOP across Europe. Despite the limited range of latitude amongst included studies, this finding is in favour of collaborative pooling of data from studies examining environmental and genetic determinants of IOP in Europeans.

Retinal Vein Occlusions: Therapeutic Switch in Macular Oedema Treatment with a 12-Month Follow-Up.

PURPOSE: To compare the visual and anatomical outcomes of patients with macular oedema secondary to retinal vein occlusion (RVO) after a switch from bevacizumab to intravitreal injection of a dexamethasone implant (IVI-DEX) or conversely. METHODS: 48 patients - 40 in the antivascular endothelial growth factor (VEGF) DEX sequence (AD group), 8 in the DEX anti-VEGF sequence (DA group) - were included in this multicentre retrospective study and evaluated at baseline, 1, 3, 6 and 12 months after the switch. The outcome measurements were visual acuity (VA) and central macular thickness (CMT) evaluated by spectral domain optical coherence tomography. Patients were defined as 'good responders' if CMT was ≤ 300 µm after the switch. RESULTS: VA significantly improved at 1 month in the AD group (p = 0.03) but not in the DA group (p = 0.40). CMT decreased significantly in the AD group at 1, 6 and 12 months (p = 0.002, p = 0.005 and p = 0.002, respectively). In the DA group, VA did not change from baseline at any time point, and CMT decreased at 1 month (p = 0.02) but not later on. CONCLUSIONS: In patients with macula oedema secondary to RVO, the switch from bevacizumab to IVI-DEX seems more beneficial in terms of short-term VA and long-term reduction of CMT than the DEX anti-VEGF agent sequence.

Plasmatic Ganglioside Profile and Age-Related Macular Degeneration: A Case-Control Study.

PURPOSE: Gangliosides are glycosphingolipids that are particularly abundant in the nervous system, including the retina. However, their precise role in this tissue and its pathologies remain poorly understood. The objective of the present study was to characterize the ganglioside profile of human plasma and to determine whether it is affected in age-related macular degeneration (AMD). METHODS: Eighty-three subjects were included: control subjects (n = 25), atrophic AMD patients (n = 27) and exudative AMD patients (n = 31). For each subject, gangliosides were extracted from plasma and analyzed by liquid chromatography coupled to mass spectrometry. RESULTS: GM3 appeared to be by far the major ganglioside of human plasma, associated with GD3. No specific ganglioside class was detected in the plasma of AMD patients. Fourteen molecular species of GM3 and 9 species of GD3, accounting for the variability of the ceramide moiety of the ganglioside molecule, were identified and characterized. Analyses revealed no significant differences in the proportion of these species between control, atrophic and exudative AMD patient groups. Total GM3 levels did not differ either. CONCLUSION: Although gangliosides are considered important for the retina's structure and function, it seems that circulating gangliosides are not associated with the retinal damage occurring during the course of AMD.

Early adaptive response of the retina to a pro-diabetogenic diet: Impairment of cone response and gene expression changes in high-fructose fed rats.

The lack of plasticity of neurons to respond to dietary changes, such as high fat and high fructose diets, by modulating gene and protein expression has been associated with functional and behavioral impairments that can have detrimental consequences. The inhibition of high fat-induced rewiring of hypothalamic neurons induced obesity. Feeding rodents with high fructose is a recognized and widely used model to trigger obesity and metabolic syndrome. However the adaptive response of the retina to short term feeding with high fructose is poorly documented. We therefore aimed to characterize both the functional and gene expression changes in the neurosensory retina of Brown Norway rats fed during 3 and 8 days with a 60%-rich fructose diet (n = 16 per diet and per time point). Glucose, insulin, leptin, triacylglycerols, total cholesterol, HDL-cholesterol, LDL-cholesterol and fructosamine were quantified in plasma (n = 8 in each group). Functionality of the inner retina was studied using scotopic single flash electroretinography (n = 8 in each group) and the individual response of rod and cone photoreceptors was determined using 8.02 Hz Flicker electroretinography (n = 8 in each group). Analysis of gene expression in the neurosensory retina was performed by Affymetrix genechips, and confirmed by RT-qPCR (n = 6 in each group). Elevated glycemia (+13%), insulinemia (+83%), and leptinemia (+172%) was observed after 8 days of fructose feeding. The cone photoreceptor response was altered at day 8 in high fructose fed rats (Δ = 0.5 log unit of light stimulus intensity). Affymetrix analysis of gene expression highlighted significant modulation of the pathways of eIF2 signaling and endoplasmic reticulum stress, regulation of eIF4 and p70S6K signaling, as well as mTOR signaling and mitochondrial dysfunction. RT-qPCR analysis confirmed the down regulation of Crystallins, Npy, Nid1 and Optc genes after 3 days of fructose feeding, and up regulation of End2. Meanwhile, a trend towards an increased expression of αA- and αB-crystallin proteins was observed at day 8. Our results are consistent with early alterations of the functioning and gene expression in the retina in a pro diabetogenic environment.

In vivo consequences of cholesterol-24S-hydroxylase (CYP46A1) inhibition by voriconazole on cholesterol homeostasis and function in the rat retina.

Cholesterol 24S-hydroxylase (CYP46A1) converts cholesterol into 24S-hydroxycholesterol in neurons and participates in cholesterol homeostasis in the central nervous system, including the retina. We aimed to evaluate the consequences of CYP46A1 inhibition by voriconazole on cholesterol homeostasis and function in the retina. Rats received daily intraperitoneal injections of voriconazole (60mg/kg), minocycline (22mg/kg), voriconazole plus minocycline, or vehicle during five consecutive days. The rats were submitted to electroretinography to monitor retinal functionality. Cholesterol and 24S-hydroxycholesterol were measured in plasma, brain and retina by gas chromatography-mass spectrometry. The expression of CYP46A1, and GFAP as a marker for glial activation was analyzed in the retina and brain. Cytokines and chemokines were measured in plasma, vitreous, retina and brain. Voriconazole significantly impaired the functioning of the retina as exemplified by the reduced amplitude and increased latency of the b-wave of the electroretinogram, and altered oscillary potentials. Voriconazole decreased 24S-hydroxycholesterol levels in the retina. Unexpectedly, CYP46A1 and GFAP expression was increased in the retina of voriconazole-treated rats. ICAM-1 and MCP-1 showed significant increases in the retina and vitreous body. Minocycline did not reverse the effects of voriconazole. Our data highlighted the cross talk between retinal ganglion cells and glial cells in the retina, suggesting that reduced 24S-hydroxycholesterol concentration in the retina may be detected by glial cells, which were consequently activated.

Comparison between subjective and objective internal limiting membrane peeling area during epiretinal membrane surgery.

PURPOSE: To determine the reliability of surgeons in estimating internal limiting membrane peeling area during epiretinal membrane surgery and to evaluate their ability to remove a predetermined internal limiting membrane surface. METHODS: One senior surgeon and two junior surgeons were asked to reach a target internal limiting membrane peeling surface (ILMPS) with an eccentricity of 1 optic disk diameter (centered on the fovea) in patients undergoing epiretinal membrane surgery. The ILMPS was measured on video recordings during epiretinal membrane surgery with no dye and then after brilliant blue G staining. RESULTS: Thirty patients were included. Median (interquartile range) ILMPS was 9.3 mm(2) (5.7-16.3 mm(2)) and 7.4 mm(2) (3.7-16.4 mm) before and after brilliant blue G, respectively (P = 0.17). The ILMPS was significantly larger in eyes operated by the senior surgeon than in those operated by the junior surgeons (P = 0.01). The senior surgeon reached the target ILMPS more often than the junior surgeons: 87% versus 47%, respectively (P = 0.02). CONCLUSION: Subjective estimation of the ILMPS with no dye was fair, but this area was larger for the surgeon with greater surgical expertise.