The role of dark adaptation in understanding early AMD.

The main aim of the paper is to discuss current knowledge on how Age Related Macular Degeneration (AMD) affects Dark Adaptation (DA). The paper is divided into three parts. Firstly, we outline some of the molecular mechanisms that control DA.

Slowed Dark Adaptation in Early AMD: Dual Stimulus Reveals Scotopic and Photopic Abnormalities.

Purpose: The recovery of visual sensitivity after a photobleach in early AMD is slowed in rods but cones also may be abnormal. The purpose of this article was to test different stimulus locations to investigate cone function and its relation to rod abnormalities.

Methods: Stimuli were presented at two locations, 3.

Slowed dark adaptation in older eyes; effect of location.

Purpose: The rate of rod sensitivity recovery following a photobleach is a basic measure of the integrity of the outer retina. Rods are selectively impaired in aging and many disorders of the retina, notably Age-Related Macular Degeneration (AMD). It is not known for certain whether the age-related deficit is a pan-retinal effect or if there are localised regions of impaired rod function.

Macular pigment in ophthalmic practice; a survey.

Background: Macular pigment (MP) might provide some protection against age-related eye disease, and it is now being measured in ophthalmic practice. The purpose of the survey described here was to determine the distribution of MP in a random population of patients in a typical UK ophthalmic practice.

Methods: Macular pigment optical density (MPOD) was measured in 56 patients aged 11 to 87 years, mean 52 ± 19, over a 3-month period.

Assessment of age changes and repeatability for computer-based rod dark adaptation.

Purpose: To characterize the rate of rod-mediated sensitivity decline with age using a PC-driven cathode ray tube (CRT) monitor. To provide data regarding the repeatability of the technique.

Methods: Dark adaptation was monitored for 30 min following a minimum 30 % pigment bleach, using a white 1° stimulus (modulated at 1 Hz), presented 11° below fixation on a CRT monitor.

Lutein supplementation over a one-year period in early AMD might have a mild beneficial effect on visual acuity: the CLEAR study.

Purpose: We investigated the effect of daily supplementation with lutein (L) capsules on macular pigment optical density (MPOD) and visual acuity (VA) in patients with early age-related macular degeneration (AMD).

Methods: A randomized, double-blind, placebo-controlled, two-center investigation of the effects of L supplementation in early AMD was conducted. The duration of the trial was 12 months.

Correspondence between retinal reflectometry and a flicker-based technique in the measurement of macular pigment spatial profiles.

A comparison of macular pigment optical density (MPOD) spatial profiles determined by an optical and a psychophysical technique is presented. We measured the right eyes of 19 healthy individuals, using fundus reflectometry at 0, 1, 2, 4, 6, and 8 deg eccentricity; and heterochromatic flicker photometry (HFP) at 0, 0.5, 1, 2, 3, 4, 5, 6, and 7 deg, and a reference point at 8 deg eccentricity.

A new desktop instrument for measuring macular pigment optical density based on a novel technique for setting flicker thresholds.

A rapid portable technique for estimating macular pigment optical density (MPOD) in large populations is described. The new instrument utilises a novel method for setting flicker thresholds which is undemanding for naïve and elderly observers and easily operated by a non-technical person. The method has good repeatability (r = 0.

The mode of action of cell wall-degrading enzymes and their interference with Nod factor signalling in Medicago sativa root hairs.

Medicago sativa L. (alfalfa) root hairs respond to Nod factors [NodRm-IV(C16:2,S)] in a host-specific manner with depolarization and rapid ion fluxes. Protoplasts prepared from these cells using the cell wall-digesting enzymes pectolyase and cellulase do not, or to a rather small extent, respond to Nod factors.

Single-cell measurements of the contributions of cytosolic Na(+) and K(+) to salt tolerance.

Ion concentrations in the roots of two barley (Hordeum vulgare) varieties that differed in NaCl tolerance were compared after exposure to NaCl. Triple-barreled H(+)-, K(+)-, and Na(+)-selective microelectrodes were used to measure cytosolic activities of the three ions after 5 and 8 d of NaCl stress. In both varieties of barley, it was only possible to record successfully from root cortical cells because the epidermal cells appeared to be damaged.