Hedonic perception of odors in children aged 5-8 years is similar across 18 countries: Preliminary data.

OBJECTIVE: Olfactory preference emerges very early in life, and the sense of smell in children rapidly develops until the second decade of life. It is still unclear whether hedonic perception of odors is shared in children inhabiting different regions of the globe. METHODS: Five-hundred ten healthy children (N = 510; ngirls = 256; nboys = 254) aged from 5 to 8 years from 18 countries rated the pleasantness of 17 odors. RESULTS: The hedonic perception of odors in children aged between 5 and 8 years was rather consistent across 18 countries and mainly driven by the qualities of an odor and the overall ability of children to label odorants. CONCLUSION: Conclusions from this study, being a secondary analysis, are limited to the presented set of odors that were initially selected for the development of U-Sniff test and present null findings for the cross-cultural variability in hedonic perception of odors across 18 countries. These two major issues should be addressed in the future to either contradict or replicate the results presented herewith. This research lays fundament for posing further research questions about the developmental aspects of hedonic perception of odors and opens a new door for investigating cross-cultural differences in chemosensory perception of children.

New onset diabetes after kidney transplantation is associated with increased mortality-A retrospective cohort study.

OBJECTIVE: Clinical outcomes in individuals with new onset diabetes after transplantation (NODAT) and the optimal treatment for this complication are poorly characterized. This study was intended to better define these issues. METHODS: Patients who underwent kidney transplantation and did not have diabetes prior to transplantation were included in the study. Clinical outcomes were compared between those who developed NODAT and those who did not. In those who developed NODAT, oral therapy was compared with insulin based therapy. RESULTS: A total of 266 kidney transplant recipients were included, of which 71 (27%) developed NODAT during the time of the follow-up. Using Cox multivariate analysis adjusted for age and gender, hazard ratio for overall mortality among patients with NODAT versus those without NODAT was 2.69 (95% CI 1.04-7.01). Among patients who developed NODAT, 29 patients (40%) were treated with an insulin-based regimen. At the end of follow-up, no difference was found in mean HbA1c, and therapy regimen was not associated with greater mortality. CONCLUSIONS: New onset diabetes in kidney transplanted patients is associated with increased mortality compared with kidney transplanted patients without NODAT.

Predicting Clostridium difficile infection in diabetic patients and the effect of metformin therapy: a retrospective, case-control study.

Data on risk factors for Clostridium difficile infection (CDI) in diabetic patients are scarce. Recently, it has been shown that metformin increases the Bacteroidetes/Firmicutes ratio; therefore, it may yield a protective effect against CDI. We aimed to assess risk factors for CDI in diabetic patients beyond antibiotic treatment, and to determine the impact of metformin therapy on the development of CDI in these patients. In this retrospective, case-control study, all consecutive CDI diabetic patients, from January 2009 to December 2013, were included and compared to consecutive diabetic patients without CDI, hospitalized during the same period and in the same departments. Of 7,670 patients tested for C. difficile toxins, 486 were diabetics. Of them, 150 (30.8 %) were positive for C. difficile toxins and 336 (69.1 %) were negative. On multivariate analysis, metformin treatment was associated with a significant reduction in CDI [odds ratio (OR) = 0.58; 95 % confidence interval (CI), 0.37-0.93; p = 0.023], while heart failure was associated with significantly higher rates of CDI (OR = 1.654; 95 % CI, 1.007-2.716; p = 0.047), together with poor functional status, previous hospitalization, and abdominal surgery. Our findings suggest that, in diabetic patients, in addition to the well-recognized risk factors, heart failure is an additional risk factor for CDI, while metformin treatment seems to have a protective effect against the development of CDI. The exact mechanisms underlying this protective effect remain to be fully understood.

Characterization of gap junction proteins in the bladder of Cx43 mutant mouse models of oculodentodigital dysplasia.

Oculodentodigital dysplasia (ODDD) is a rare developmental disease resulting from germline mutations in the GJA1 gene that encodes the gap junction protein connexin43 (Cx43). In addition to the classical ODDD symptoms that affect the eyes, teeth, bone and digits, in some cases ODDD patients have reported bladder impairments. Thus, we chose to characterize the bladder in mutant mouse models of ODDD that harbor two distinct Cx43 mutations, G60S and I130T. Histological assessment revealed no difference in bladder detrusor wall thickness in mutant compared to littermate control mice. The overall localization of Cx43 in the lamina propria and detrusor also appeared to be similar in the bladders of mutant mice with the exception that the G60S mice had more instances of intracellular Cx43. However, both mutant mouse lines exhibited a significant reduction in the phosphorylated P1 and P2 isoforms of Cx43, while only the I130T mice exhibited a reduction in total Cx43 levels. Interestingly, Cx26 levels and distribution were not altered in mutant mice as it was localized to intracellular compartments and restricted to the basal cell layers of the urothelium. Our studies suggest that these two distinct genetically modified mouse models of ODDD probably mimic patients who lack bladder defects or other factors, such as aging or co-morbidities, are necessary to reveal a bladder phenotype.

Optical gain in single tensile-strained germanium photonic wire.

We have investigated the optical properties of tensile-strained germanium photonic wires. The photonic wires patterned by electron beam lithography (50 µm long, 1 µm wide and 500 nm thick) are obtained by growing a n-doped germanium film on a GaAs substrate. Tensile strain is transferred in the germanium layer using a Si3N4 stressor. Tensile strain around 0.4% achieved by the technique corresponds to an optical recombination of tensile-strained germanium involving light hole band around 1690 nm at room temperature. We show that the waveguided emission associated with a single tensile-strained germanium wire increases superlinearly as a function of the illuminated length. A 20% decrease of the spectral broadening is observed as the pump intensity is increased. All these features are signatures of optical gain. A 80 cm⁻¹ modal optical gain is derived from the variable strip length method. This value is accounted for by the calculated gain material value using a 30 band k · p formalism. These germanium wires represent potential building blocks for integration of nanoscale optical sources on silicon.

Cystic macular oedema on spectral-domain optical coherence tomography in choroideremia patients without cystic changes on fundus examination.

PURPOSE: To determine the prevalence of cystic macular oedema (CME) in patients with choroideremia (CHM) by using spectral-domain optical coherence tomography (SD-OCT). METHODS: A total 16 patients affected with CHM were enrolled in the study. All patients underwent a complete eye examination. SD-OCT was performed using an OPKO spectral-domain OCT/SLO instrument. RESULTS: The average age of the study patients was 44.0 ± 16.0 years (range, 13-63 years). Out of the 16 patients with CHM, 10 patients (62.5%) showed a degree of CME on SD-OCT testing in at least one eye, and 8 patients (50%) showed CME in both eyes. CONCLUSIONS: Because of its notable prevalence, it would seem prudent to screen CHM patients by SD-OCT for the possible presence of CME and to identify those amenable to future treatment strategies for their macular oedema.

Clinical value, normative retinal sensitivity values, and intrasession repeatability using a combined spectral domain optical coherence tomography/scanning laser ophthalmoscope microperimeter.

PURPOSE: To establish normative values for macular light sensitivity and to determine the intrasession fluctuation of perimetric responses using the OPKO/OTI microperimeter. METHODS: A total of 32 visually normal subjects participated in the study. A standardized grid pattern was used for testing, which consisted of 28 points arranged concentrically in three circles that occupied an area of 11° (in diameter) within the central macula. Each subject participated in at least two tests. Parameters evaluated included: overall mean macular sensitivity for test 1 and 2, overall difference in mean macular sensitivity between tests, and the mean sensitivity for each circle. The relationship between sensitivity and age was also examined. RESULTS: The overall median sensitivity for test 1 was 16.8 decibels (dB) and for test 2 was 16.9 dB. The median sensitivities for test 1 and test 2 were not significantly different (P = 0.72). The mean intrasession sensitivity difference was 0.13 dB. The variability of the sensitivity difference between tests decreased as mean sensitivity increased. The sensitivity values averaged across the two tests for inner, middle, and outer circles ranged from 14.3 to 18.8 dB (median value of 16.9 dB), 13.8-18.3 dB (median value of 17.2 dB), and 11.3-18.3 dB (median value of 16.6 dB), respectively. Linear regression analysis showed a 0.5 dB sensitivity loss for each decade of life. CONCLUSION: We documented a narrow range of intrasession fluctuation using the OPKO/OTI microperimeter. The establishment of normative sensitivity values will facilitate monitoring the loss of macular visual function in patients with retinal disease.

Selective thinning of the perifoveal inner retina as an early sign of hydroxychloroquine retinal toxicity.

PURPOSE: To evaluate macular thickness profiles using spectral-domain optical coherence tomography (SDOCT) and image segmentation in patients with chronic exposure to hydroxychloroquine. METHODS: This study included eight patients with chronic exposure to hydroxychloroquine (group 1) and eight controls (group 2). Group 1 patients had no clinically evident retinal toxicity. All subjects underwent SDOCT imaging of the macula. An image segmentation technique was used to measure thickness of six retinal layers at 200 microm intervals. A mixed-effects model was used for multivariate analysis. RESULTS: By measuring total retinal thickness either at the central macular (2800 microm in diameter), the perifoveal region 1200-microm-width ring surrounding the central macula), or the overall macular area (5200 microm in diameter), there were no significant differences in the thickness between groups 1 and 2. On an image segmentation analysis, selective thinning of the inner plexiform+ganglion cell layers (P=0.021) was observed only in the perifoveal area of the patients in group 1 compared with that of group 2 by using the mixed-effects model analysis. CONCLUSION: Our study results suggest that chronic exposure to hydroxychloroquine is associated with thinning of the perifoveal inner retinal layers, especially in the ganglion cell and inner plexiform layers, even in the absence of functional or structural clinical changes involving the photoreceptor or retinal pigment epithelial cell layers. This may be a contributing factor as the reason most patients who have early detectable signs of drug toxicity present with paracentral or pericentral scotomas.

Effects of chronic exposure to hydroxychloroquine or chloroquine on inner retinal structures.

PURPOSE: To evaluate peripapillary retinal nerve fibre layer (RNFL) thickness and macular inner and outer retinal thickness using spectral domain optical coherence tomography (Sd-OCT) in patients with chronic exposure to hydroxychloroquine or chloroquine. METHODS: Subjects were divided into three groups: Group I, four patients with hydroxychloroquine or chloroquine toxicity with abnormal fundus; Group II, eight patients with chronic exposure without fundus changes; and Group III, eight visually normal controls. Peripapillary RNFL thinning for an individual quadrant was based on measurements of less than the 5th percentile from at least two out of four segments in the quadrant. Macular scans on Groups I and II were carried out to compare the thickness of the inner, outer, and full-thickness retina to that of Group III. RESULTS: The mean ages in Groups I, II, and III were 57.6+/-8.0, 54.9+/-11.0 and 53.7+/-10.5 years, respectively (P=0.83). Median (range) duration of exposure was 7.5 (5-12) years in Group I, and was 10 (6-35) years in Group II. Seven (88%) of eight eyes in Group I showed peripapillary RNFL thinning in at least one quadrant, whereas none of Groups II and III did so. Using macular scans, Group I showed significant thinning of the inner, outer, and full-thickness retina compared to Group III (P<0.001). Group II had significant thinning only of the inner retina compared to Group III (P<0.001). CONCLUSIONS: OCT is useful to detect peripapillary RNFL thinning in clinically evident retinopathy, and selective thinning of the macular inner retina can be detected in the absence of clinically apparent fundus changes.

Predicting the pathogenicity of RPE65 mutations.

To assist in distinguishing disease-causing mutations from nonpathogenic polymorphisms, we developed an objective algorithm to calculate an "estimate of pathogenic probability" (EPP) based on the prevalence of a specific variation, its segregation within families, and its predicted effects on protein structure. Eleven missense variations in the RPE65 gene were evaluated in patients with Leber congenital amaurosis (LCA) using the EPP algorithm. The accuracy of the EPP algorithm was evaluated using a cell-culture assay of RPE65-isomerase activity The variations were engineered into plasmids containing a human RPE65 cDNA and the retinoid isomerase activity of each variant was determined in cultured cells. The EPP algorithm predicted eight substitution mutations to be disease-causing variants. The isomerase catalytic activities of these RPE65 variants were all less than 6% of wild-type. In contrast, the EPP algorithm predicted the other three substitutions to be non-disease-causing, with isomerase activities of 68%, 127%, and 110% of wild-type, respectively. We observed complete concordance between the predicted pathogenicities of missense variations in the RPE65 gene and retinoid isomerase activities measured in a functional assay. These results suggest that the EPP algorithm may be useful to evaluate the pathogenicity of missense variations in other disease genes where functional assays are not available.

Retinal nerve fibre layer thickness analysis in X-linked retinoschisis using Fourier-domain OCT.

PURPOSE: To evaluate the presence of retinal nerve fibre layer (RNFL) defects in patients with X-linked retinoschisis (XLRS) using high-speed, high-resolution, Fourier domain OCT (FD-OCT). METHODS: Twenty-four patients with XLRS seen by the authors were enrolled in the study. All patients underwent a complete eye examination. FD-OCT was performed using Optovue technology. A quadrant of the RNFL was considered to be thinned if at least two of the four segments in the quadrant were reduced in thickness. RESULTS: The average age of the 24 patients in the study was 28.8+/-14.7 years. Thinning of the RNFL in one quadrant was seen in 10 patients (41.7%), and thinning in two or more quadrants was seen in 8 patients (33.3%). Thinning in the inferior quadrant was most commonly seen and was observed in 12 patients (50%), followed by the temporal quadrant in 8 patients (33.3%), nasal quadrant in 4 patients (16.7%), and the superior quadrant in 4 patients (16.7%). CONCLUSIONS: Among our 24 patients with XLRS, 15 patients (62.5%) showed a thinning of the RNFL in one or more quadrants in at least one eye and 9 patients (37.5%) in both eyes. High-speed, high-resolution FD-OCT may be useful to determine the presence of possible changes in RNFL thickness in patients with XLRS. Reductions in RNFL thickness in such patients could be relevant in their selection for future therapeutic trials.

The prevalence of cystoid macular oedema on optical coherence tomography in retinitis pigmentosa patients without cystic changes on fundus examination.

PURPOSE: To determine the prevalence of cystoid macular oedema (CME) by optical coherence tomography (OCT) in retinitis pigmentosa (RP) patients with no evidence of cystic macular lesions on fundus examination. METHODS: We included 63 RP patients with no evidence of cystic-appearing macular changes on fundus examination. All patients underwent a complete ocular examination including best-corrected visual acuity using an ETDRS (Early Treatment Diabetic Retinopathy Study) chart, intraocular pressure measurement, anterior segment examination, and a detailed fundus examination. On 50 of the 63 patients, Fourier-domain OCT was performed using the radial slicer protocol. An additional 13 of the 63 patients were scanned using the macular thickness protocol on a time-domain OCT unit. The diagnosis of CME was defined by the presence of hyporeflective lacunae with well-defined boundaries on at least two of the scans. RESULTS: The mean age of patients included in the study was 36 years (range 9-71 years). Out of the 63 patients examined, 20 showed CME in at least one eye (32%), whereas 11 patients showed CME in both eyes (18%). CONCLUSIONS: Our findings demonstrate that a substantial number of RP patients with CME, as determined by OCT, may not show cystic changes by direct ophthalmoscopy or contact lens biomicroscopy. Knowledge of the high frequency for CME in such patients can serve to identify those who may be amenable to current or future treatment strategies of their macular oedema and can potentially impact on future therapeutic trials where visual acuity is used as an outcome measure.

Prevalence of cystic macular lesions in patients with Usher II syndrome.

PURPOSE: To evaluate the prevalence of cystic macular lesions in patients with Usher II syndrome. METHODS: All Usher type II patients seen in the inherited eye disease clinic at the University of Illinois at Chicago between January 2002 and December 2007 were included (n=76). Each participating patient underwent a detailed clinical examination, including best-corrected visual acuity, slit-lamp biomicroscopy and dilated fundus examination. The presence of cystoid lesions was determined by optical coherence tomography (OCT), fundus fluorescein angiogram (FFA), fundus photographs and/or clinical examination. RESULTS: A cystic-appearing macular change was observed in at least one eye in 19 out of the 76 patients (25%), 13 on the basis of OCT, five using FFA (two solely with the use of FFA and three based on clinical notes and FFA findings) and one based solely on clinical notes. Of the 18 patients with CME, determined by OCT or FFA, five (27.8%) showed either a funduscopically normal-appearing macula (n=4) or an atrophic appearing macular change (n=1). CONCLUSIONS: One-fourth of our total cohort of Usher II patients had cystic macular lesions. Moreover, a funduscopically normal-appearing macula was observed in 22% (n=4) of our 18 patients with cystic-appearing macular lesions on OCT and/or FFA testing. On the basis of the reasonably high prevalence of cystic macular lesions in our cohort, it would seem prudent to evaluate Usher II patients for the presence of cystoid macular oedema.

The prevalence of cystoid macular oedema in retinitis pigmentosa patients determined by optical coherence tomography.

AIMS: To determine the prevalence of cystoid macular oedema (CMO) in retinitis pigmentosa (RP) patients of various genetic subtypes using optical coherence tomography (OCT). METHODS: We performed a complete ocular examination on 124 RP patients including best corrected visual acuity, intraocular pressure measurement, anterior segment and a detailed fundus exam. OCT images were then acquired using two different units. The presence of hypo-reflective lacunae was used to diagnose CMO. RESULTS: Of the 124 patients, 47 showed CMO in at least one eye (38%), while 34 showed CMO in both eyes (27%). The prevalence of CMO in at least one eye for autosomal dominant (AD) patients was 52%, for autosomal recessive (AR) 39%, isolated 39%, Usher II 35% and none in the X linked recessive (XL) group. Using a chi-square analysis, no statistical significant difference was found for the prevalence of "bilateral CMO" (p = 0.60) or "CMO in at least one eye" (p = 0.59) among the AD, AR, isolated and Usher II genetic subtypes. CONCLUSION: Because of its notable prevalence, it would seem prudent to screen RP patients by OCT for the possible presence of CMO, to identify those amenable to treatment and also for future treatment trials when monitoring visual acuity.

Characterization of sinoatrial node in four conduction system marker mice.

The specialized cardiac conduction system (CCS) consists of the sinoatrial node (SAN) and the atrioventricular (AV) conduction system (AVCS), which includes proximal (AV node, bundle of His and bundle branches) and distal (Purkinje fibers) components. In four CCS marker mice [two transgenic (cGATA6|lacZ, CCS|lacZ) and two targeted gene knock-in (minK|lacZ, Hop|lacZ)] the expression of the lacZ gene (beta-gal) has been reported to mark portions of the proximal and distal AVCS; the expression of this marker in the adult SAN is unknown. The primary objective of this study was to analyze the utility of these marker mice in the identification of the SAN. Intercaval and interventricular septal regions, containing all the components of the CCS, were freshly dissected from adult mice based on the anatomical landmarks and sectioned. Immunohistochemical characterization was performed with SAN markers (Cx45, HCN4), compared to the reporter expression (beta-gal) and markers of the working myocardium (Cx40 and Cx43). In all four of the CCS marker mice, we found that beta-gal expression is consistently observed in the proximal and distal AVCS. However, the presence of lacZ gene expression in the working myocardium outside the CCS and/or the absence of this reporter expression in the SAN prevent the effective use of these mice to identify the SAN, leading us to conclude that none of the four CCS marker mice we studied specifically mark the SAN.

Attainment of educational levels in patients with Leber's congenital amaurosis.

PURPOSE: To assess the educational level attained by patients legally blind with Leber's congenital amaurosis (LCA). DESIGN: Cross-sectional assessment. INTERVENTION: None. MAIN OUTCOME MEASURE: Highest educational level attained by 55 patients with LCA. RESULTS: A total of 55 patients with LCA were included in the study. Of the 55, 54 finished high school. In addition, 36 patients (65%) completed a college education and received a bachelor's degree, and 5 additional patients (9%) were recently accepted to college, whereas 3 others (5%) were currently attending college classes. Further, 18 patients were either pursuing (n = 3) or had attained (n = 15) an educational level beyond a bachelor's degree. CONCLUSIONS: Compromised visual function does not preclude the successful attainment of an academic education in patients with LCA who are substantially visually impaired from birth. These data have clinically relevant implications for the parents of children with LCA and for the patients themselves in providing a tone of optimism for their potential of attaining competitive academic achievements.

Spin-induced forbidden evanescent states in III-V semiconductors.

Within the band gap of a semiconductor no electronic propagating states are allowed, but there exist evanescent states which govern charge transport such as tunneling. In this Letter, we address the issue of their spin dependence in III-V semiconductors. Taking into account the spin-orbit interaction, we treat the problem using a k . p 14 x 14 Hamiltonian that we numerically compute for GaAs. Our results show that the removed spin degeneracy in the band gap can lead to giant energy splittings and induces forbidden zones in space where evanescent states are suppressed.

Development of the right ventricular inflow tract and moderator band: a possible morphological and functional explanation for Mahaim tachycardia.

Atriofascicular accessory bundles with AV-node like conduction properties can sustain atrioventricular (AV) re-entrant tachycardia (Mahaim tachycardia). During early embryogenesis, the AV canal is situated above the primitive left ventricle (LV), and a right AV connection has not been achieved yet. We studied the formation of the right ventricular (RV) inflow tract in relation to the developing cardiac conduction system and hypothesized a morphological explanation for functional atriofascicular bypass tracts. Analysis of lacZ-expression during sequential stages of cardiogenesis was performed in CCS-lacZ transgenic mice (E9.5 to 15.5). Embryos were stained for beta-galactosidase activity and the myocardial marker HHF35. At early stages CCS-lacZ expression was observed in a ring surrounding the AV canal, which connected at the inner curvature to the primary fold. The first sign of formation of the (CCS-lacZ negative) RV inlet component was a groove in the CCS-lacZ positive tissue of the primary fold. Outgrowth of the RV inlet tract resulted in division of the primary fold in a septal part, the trabecula septomarginalis and a lateral part, the moderator band, which extended laterally up to the right AV ring. Electrophysiological measurements in embryonic hearts (E15.5) in which the right atrium (RA) and RV were isolated from the left atrium (LA) and LV supported the functionality of this AV-connection via the moderator band, by demonstrating sequential atrial and ventricular activation in both RA/RV and LA/LV preparations. In conclusion, our observations may provide a possible morphological and functional explanation for atriofascicular accessory pathways via the moderator band, underlying Mahaim tachycardia.

Autoantibody panel screening in recurrent miscarriages.

PROBLEM: Antiphospholipid autoantibodies (aPL), antithyroid antibodies and anti-extractable nuclear antigens (anti-ENA) have all been reported to be associated with recurrent miscarriages (RM) and infertility. However, this association remained controversial. MATERIALS AND METHODS: Fifty-eight women with impaired fertility (38 women with RM and 20 women with infertility, but no miscarriages) and 28 control parous women were screened for seven autoantibodies [antithyroglobulin (aTG), antithyroid peroxidase (aTPO), anticardiolipin (aCL), antiphosphatidyl-serine (aPS), antiprothrombin antibodies (aPT), anti-beta 2 glycoprotein 1 (abeta2GP1), and anti-ENA]. There was no evidence for autoimmune diseases in the patients or the control. The analysis was also performed with several panels of autoantibodies, each of which contained two or more autoantibodies. RESULTS: Anti-TPO was the only antibody to be associated with RM (P = 0.01). A significant association was found between RM, and autoantibodies in the 'aTG + aTPO + anti-ENA' or 'aTG + aTPO' panels. The 'aTG + aTPO + anti-ENA' panel was also associated with RM when the analysis was performed only on 17 women who had secondary infertility: 10 from the 38 women with RM, and seven from the 20 women with infertility and no miscarriages. A significant association (P < 0.001) was also apparent between anti-CL and anti-PS and infertility compared with the 28 control women. CONCLUSIONS: RM was associated with autoantibodies to aTPO and the combined panel of aTPO, aTG and anti-ENA, but not with aPL. aPL were associated with infertility.

Interocular amplitude differences of the full field electroretinogram in normal subjects.

AIMS: To determine the interocular amplitude response difference of the electroretinogram (ERG) in normal subjects. METHODS: 79 subjects, without retinal changes of clinical significance, underwent ERG testing. They included 63 men and 16 women, with a mean age of 44 (SD 12) years and range of 18-65 years. Isolated rod, scotopic maximal, dark adapted 30 Hz flicker, photopic single flash, and light adapted 30 Hz flicker responses were recorded in both eyes following the International Society for Clinical Electrophysiology of Vision (ISCEV) standard protocol. The interocular percentage differences of the ERG b-wave amplitudes were calculated and presented as percentiles (25th, 50th, 75th, 95th), means (SD), and medians. RESULTS: The median interocular percentage differences in the b-wave amplitudes for the above ERG stimulus responses were 10%, 8%, 10%, 11%, and 10%, respectively. The mean interocular percentage differences were 11%, 11%, 12%, 13%, and 14%. The 95th percentiles for the interocular percentage differences were 28%, 27%, 36%, 33%, and 35%, respectively. CONCLUSIONS: The interocular percentage differences in the ERG b-wave amplitudes for five different stimulus responses were similar in our cohort of individuals without clinically significant retinal changes and ranged from a median of 8-11% and a 95th percentile of 27-36%. Our findings should be useful for determining sample sizes in future therapeutic trials on retinal diseases with monocular therapeutic strategies and may also have application for the more accurate detection of asymmetric retinal disease.