These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Slowed Dark Adaptation in Early AMD: Dual Stimulus Reveals Scotopic and Photopic Abnormalities.
    Author: Tahir HJ, Rodrigo-Diaz E, Parry NRA, Kelly JMF, Carden D, Aslam TM, Murray IJ.
    Journal: Invest Ophthalmol Vis Sci; 2018 Mar 20; 59(4):AMD202-AMD210. PubMed ID: 30398565.
    Abstract:
    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, 3.0° and 5.5°, in the inferior visual field. Post photobleach dark adaptation (DA) curves from 50 early-AMD patients were compared with those from 15 healthy controls of similar age. Curves were characterized in terms of four parameters: ct, cone threshold; α, the transition point from cone to rod function; S2, the slope of the second rod-mediated component; and β, the transition from the second to the third rod-mediated component. RESULTS: There were strong location effects for the healthy group and the AMD group. Cone threshold was higher for the outer compared with the inner stimulus (P = 0.001), S2 was steeper for outer compared with inner (P < 0.001), α was shorter for outer (P = 0.004), and β was shorter for outer than inner (P = 0.002). The high variance in the patient data, particularly for α and β, explained the absence of a group*location interaction in the statistics. CONCLUSIONS: The data provide a novel perspective on abnormal cone- and rod-sensitivity recovery in early dry AMD. The comparison of pairs of DA curves from different locations highlights the involvement of cones in the underlying pathology of AMD. Dynamic measures of visual function are particularly sensitive to early AMD.
    [Abstract] [Full Text] [Related] [New Search]