Endoplasmic Reticulum Stress Delays Choroid Development in the HCAR1 Knockout Mouse.

The subretina, composed of the choroid and the retinal pigment epithelium (RPE), plays a critical role in proper vision. In addition to phagocytosis of photoreceptor debris, the RPE shuttles oxygen and nutrients to the neuroretina. For their own energy production, RPE cells mainly rely on lactate, a major by-product of glycolysis.

Resting state electroretinography: An innovative approach to intrinsic retinal function monitoring.

The electroretinogram (ERG) represents the biopotential evoked by the retina in response to a light stimulus. The flash evoked ERG (fERG) is the ERG modality most frequently used clinically to diagnose and monitor retinal disorders. We hereby present a new method to record spontaneous retinal activity, without the use of a flash stimulus, that we named the resting-state ERG (rsERG).

Distinguishing Familial from Acquired Traits in the Retinal Blood Vessel Arborization.

Purpose: It has been suggested that retinal blood vessel arborization (RBVA) is unique to each individual. We examined this claim in a pedigree that included two pairs of monozygotic twins.

Methods: Fundus photographs were taken of subjects belonging to this pedigree to compare the pattern of their RBVA.

The effects of bandpass filtering on the oscillatory potentials of the electroretinogram.

Purpose: In order to study the OPs, the ERG signal must be filtered to eliminate the low-frequency waves known as the a- and b-waves. Unfortunately, the ISCEV ERG standard does not give clear guidelines on how to proceed apart from indicating that frequencies below 75 Hz should be filtered out when recording scotopic OPs, while no suggestions are offered for the photopic OPs. The purpose of this study was thus to characterize more extensively the effects of various digital filters on the photopic OP waveforms in order to suggest the most appropriate filtering method to record them.

Recording and Analysis of the Human Clinical Electroretinogram.

The electroretinogram (ERG) represents the biopotential that is produced by the retina in response to a light stimulus. To date, it remains the best diagnostic tool to objectively evaluate the functional integrity of the normal or diseased retina. In the following pages we briefly review the necessary requirements in order to record and analyze the conventional clinical ERG.

The DTL ERG electrode comes in different shapes and sizes: Are they all good?

Purpose: Although the DTL fiber electrode has been in use in the ERG field for more than four decades, its composition was never clearly defined. We compared five different types of conductive (DTL type) yarn (differing in terms of mass, number of filaments, and crimping degree) in order to determine whether we could identify one that would be better suited for the recording of ERGs.

Methods: Photopic flash ERGs were recorded from five subjects using the following DTL electrodes: 27/7, 22/1, 11/1, 11/1*2, and 22/1*2.

Assessing the Contribution of the Oscillatory Potentials to the Genesis of the Photopic ERG with the Discrete Wavelet Transform.

The electroretinogram (ERG) is composed of slow (i.e., a-, b-waves) and fast (i.

Quantifying the ON and OFF Contributions to the Flash ERG with the Discrete Wavelet Transform.

Purpose: Discrete wavelet transform (DWT) analyses suggest that the 20- and 40-Hz components of the short-flash photopic electroretinogram (ERG) are closely related to the ON and OFF pathways, respectively. With the DWT, we examined how the ERG ON and OFF components are modulated by the stimulus intensity and/or duration.

Methods: Discrete wavelet transform descriptors (20, 40 Hz and 40:20-Hz ratio) were extracted from ERGs evoked to 25 combinations of flash durations (150-5 ms) and strengths (0.