The apolipoprotein epsilon4 gene is associated with elevated risk of normal tension glaucoma.
OBJECTIVE
Inheritance of a particular apolipoprotein E gene polymorphism, the epsilon4 allele, has been associated with elevated risk for Alzheimer's disease and a poor outcome following head injury. The neuronal injury associated with Alzheimer's disease and brain injury may have a number of similarities with the nerve cell changes associated with glaucoma. Thus, we have investigated the association of inheritance of apolipoprotein E allelic isoforms (epsilon2, [epsilon]3, and epsilon4) with relative risk for different forms of glaucoma.


METHODS
Apolipoprotein E genotype was examined in a Tasmanian population sample comprised of glaucoma sufferers with elevated or normal intraocular pressure and compared to a control sample of elderly Tasmanians without glaucoma.


RESULTS
Approximately twice as many normal tension (38.0%) and high tension (34.2%) glaucoma cases possessed an epsilon4 allele compared to control cases (18.9%). The odds of epsilon4 carriers having normal tension glaucoma were significantly greater than for epsilon3 homozygotes (odds ratio 2.45, 95% confidence interval [1.02-5.91]) even after adjusting for age and gender (odd ratio 2.87 [1.02-8.05]). The increased odds of high tension glaucoma among [epsilon]4 allele carriers were not significant (adjusted odds ratio 1.53 [0.64-3.68]).


CONCLUSIONS
The data indicate that, in the Tasmanian population, inheritance of the [epsilon]4 allele is associated with elevated risk for glaucomatous changes that are not related to increased intraocular pressure.
Vickers
James C
JC
School of Medicine, University of Tasmania, Hobart, Tasmania, Australia. James.Vickers@utas.edu.au
Craig
Jamie E
JE
Stankovich
Jim
J
McCormack
Graeme H
GH
West
Adrian K
AK
Dickinson
Joanne L
JL
McCartney
Paul J
PJ
Coote
Michael A
MA
Healey
Danielle L
DL
Mackey
David A
DA
D000368:Aged; D000369:Aged, 80 and over; D000483:Alleles; D053327:Apolipoprotein E4; D001057:Apolipoproteins E / Q000235:genetics*; D001315:Australia / Q000453:epidemiology; D004247:DNA / Q000302:isolation & purification; D005838:Genotype; D005902:Glaucoma, Open-Angle / Q000453:epidemiology / Q000235:genetics*; D006801:Humans; D007429:Intraocular Pressure; D016133:Polymerase Chain Reaction; D012307:Risk Factors
D053327:Apolipoprotein E4; D001057:Apolipoproteins E; D004247:DNA