Twelve-month natural history of dark adaptation in patients with AMD.
OBJECTIVE
A sensitive endpoint is required for clinical trials evaluating preventative therapies for early age-related macular degeneration (AMD). Dark adaptation (DA) is a sensitive marker of AMD and has been proposed as a potential endpoint. This study evaluated whether significant changes in DA speed could be detected in participants with early to intermediate AMD at 12 months following baseline DA measurement.


METHODS
Dark adaptation, visual acuity (VA), and fundus photography were obtained at baseline and at 6 and 12 months in 26 subjects with AMD and in 6 subjects with normal retinal health. Disease severity was assessed by the Nine-Step Age-Related Eye Disease Study AMD severity scale.


RESULTS
At 12 months, significant progression of DA impairment occurred in 5 of 26 (19%) participants with AMD. None of the participants with AMD exhibited a significant worsening of fundus grade or decrease of acuity related to disease progression. The normal group exhibited stable DA and VA during the observation period.


CONCLUSIONS
Significant worsening of DA was observed in 19% of subjects with AMD in 12 months of observation, despite stable VA and fundus appearance. This study suggests that DA may be a suitable functional endpoint for early clinical studies evaluating novel treatments for early to intermediate AMD.
*PhD †BS ‡MD, MPH §COA ∥MD Penn State Hershey Eye Center, Penn State College of Medicine, Hershey, Pennsylvania (GRJ, IUS, LEW, DAQ); Department of Ophthalmology, University of Alabama at Birmingham, Birmingham, Alabama (MEC); and Translational Medicine, Novartis Institute for BioMedical Research, Cambridge, Massachusetts (MGB).
Gregory R
GR
Jackson
Mark E
ME
Clark
Ingrid U
IU
Scott
Laura E
LE
Walter
David A
DA
Quillen
Mitchell G
MG
Brigell
D000368:Aged; D000369:Aged, 80 and over; D003623:Dark Adaptation / Q000502:physiology*; D018450:Disease Progression; D023381:Endpoint Determination; D005260:Female; D006801:Humans; D008268:Macular Degeneration / Q000175:diagnosis / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D012160:Retina / Q000503:physiopathology*; D012684:Sensory Thresholds; D014786:Vision Disorders / Q000503:physiopathology*; D014792:Visual Acuity / Q000502:physiology*