Mutations in the gene encoding rhodopsin, the visual pigment in rod photoreceptors, lead to retinal degeneration in species from Drosophila to man. The pathogenic sequence from rod cell-specific mutation to degeneration of rods and cones remains unclear. To understand the disease process in man, we studied heterozygotes with 18 different rhodopsin gene mutations by using noninvasive tests of ro...

Fifteen patients with the incomplete form of congenital stationary night blindness (iCSNB) were reviewed to better characterize their electroretinographic (ERG) findings in view of differential diagnosis with other retinal conditions also presenting with negative bright-flash ERG responses. In all 15 patients, in dark-adapted conditions, the bright-flash ERG response had a normal a-wave followe...

*Correspondence: [email protected] 2School of Mathematics and Computer, Gannan Normal University, Ganzhou, 341000, China Full list of author information is available at the end of the article Abstract In this paper we present some new examples in cone b-metric spaces and prove some fixed point theorems of contractive mappings without the assumption of normality in cone b-metric spaces. The res...

PURPOSE To investigate whether or not thicker retinal nerve fiber layer (RNFL) in retinitis pigmentosa (RP) patients relates to functional abnormalities of the photoreceptors. METHODS Optical coherence tomography-based RNFL thickness was measured by Stratus-3™ (Zeiss, Basel, Switzerland) optical coherence tomography and electroretinogram (ERG) recordings made using the RETI-port(®) system (Ro...

PURPOSE Both implicit time and amplitude of the cone-mediated electroretinographic (ERG) b-wave differ significantly between the C57BL/6JOlaHsd and 129S2/SvHsd inbred mouse strains. The purpose of this work was to undertake a quantitative genetics study to localize the gene or genes involved. METHODS Implicit time and amplitude of the a- and b-waves of the single-flash and flicker cone-mediat...

We study the existence and nonexistence of positive (super-) solutions to a singular semilinear elliptic equation −∇ · (|x|∇u)−B|x|u = C|x|u in cone–like domains of R (N ≥ 2), for the full range of parameters A,B, σ, p ∈ R and C > 0. We provide a complete characterization of the set of (p, σ) ∈ R such that the equation has no positive (super-) solutions, depending on the values of A,B and the p...

OBJECTIVES To determine (1) reference values for cone and rod phototransduction variables derived from the a-wave of the electroretinogram, (2) their dependence on age, (3) the progression in cone and rod variables in patients with X-linked retinitis pigmentosa (XLRP), and (4) the test-retest variability in these a-wave measures compared with the variability in cone and rod b-wave measures. P...

The aim of this paper is to obtain extended variants of some common fixed point results in cone metric spaces in the case that the underlying cone is not normal. The first result concerns g-quasicontractions of D. Ilić and V. Rakočević [Common fixed points for maps on cone metric space, J. Math. Anal. Appl. 341 (2008), 876–882], and the second is concerned with HardyRogers-type conditions and e...