Excess lead in the neural retina in age-related macular degeneration.
OBJECTIVE
To measure lead and cadmium in retinal tissues of human donor eyes with and without age-related macular degeneration (AMD).


METHODS
Laboratory investigation.


METHODS
Lead and cadmium concentrations in retinal tissues (neural retina and retinal pigment epithelium [RPE]-choroid complex) in 25 subjects with AMD (50 donor eyes) and 36 normal subjects (72 donor eyes) were determined by using inductively coupled plasma-mass spectrometry. Severity of AMD was graded by using color fundus photographs and the Minnesota Grading System. Differences in metal concentrations were compared by using Wilcoxon rank-sum tests.


RESULTS
The neural retinas of subjects with AMD had increased lead concentrations (median, 12.0 ng/g; 25% to 75% interquartile range, 8 to 18 ng/g; n = 25) compared with normal subjects (median, 8.0 ng/g; 25% to 75% interquartile range, 0 to 11 ng/g; P = .04; n = 36). There was no difference in lead concentration in the RPE-choroid complex between subjects with AMD (median, 198 ng/g; 25% to 75% interquartile range, 87 to 381 ng/g) and normal subjects (median, 172 ng/g; 25% to 75% interquartile range, 100 to 288 ng/g; P = .25). Cadmium concentration in the neural retina (median, 0.9 microg/g; 25% to 75% interquartile range, 0.7 to 1.8 microg/g) and RPE-choroid complex (median, 2.2 microg/g; 25% to 75% interquartile range, 1.8 to 3.7 microg/g) in subjects with AMD was not different from concentrations in the neural retina (median, 0.9 microg/g; 25% to 75% interquartile range, 0.7 to 1.4 microg/g; P = .32) and RPE-choroid complex (median, 1.5 microg/g; 25% to 75% interquartile range, 0.9 to 2.5 microg/g; P = .12) of normal subjects.


CONCLUSIONS
AMD is associated with excess lead in the neural retina, and this relationship suggests that metal homeostasis in AMD eyes is different from normal.
Erie
Jay C
JC
Department of Ophthalmology, Mayo Clinic, Rochester, Minnesota 55905, USA. erie.jay@mayo.edu
Good
Jonathan A
JA
Butz
John A
JA
D000368:Aged; D002104:Cadmium / Q000378:metabolism; D002829:Choroid / Q000378:metabolism; D005260:Female; D006801:Humans; D007854:Lead / Q000378:metabolism*; D008268:Macular Degeneration / Q000175:diagnosis / Q000378:metabolism*; D008297:Male; D013058:Mass Spectrometry; D010781:Photography; D012160:Retina / Q000378:metabolism* / Q000473:pathology; D055213:Retinal Pigment Epithelium / Q000378:metabolism; D014019:Tissue Donors
D002104:Cadmium; D007854:Lead