The association between plasma 25-hydroxyvitamin D and subgroups in age-related macular degeneration: a cross-sectional study.
OBJECTIVE
To evaluate potential differences in plasma 25-hydroxyvitamin in subtypes of age-related macular degeneration (AMD), and in patients in Clinical Age-Related Maculopathy Staging (CARMS) group 5 with or without subretinal fibrosis.


METHODS
This single-center cross-sectional study included 178 participants during a period of 20 months. Ninety-five patients belonged to CARMS 5; twelve belonged to CARMS 4; twenty-two belonged to CARMS 2 or 3; and 49 individuals did not have AMD (CARMS 1). Following a structured interview, a detailed bilateral retinal examination was performed and participants were allocated to their respective subgroups in accordance with the Clinical Age-Related Maculopathy Staging system. Plasma 25-hydroxyvitamin D2 and D3 were analyzed using liquid chromatography-tandem mass spectrometry. Genomic DNA was extracted from leukocytes and genotyped for single nucleotide polymorphisms (SNPs) in the vitamin D metabolism. Differences in plasma 25-hydroxyvitamin D were determined in the subgroups as well as between patients in CARMS 5 with or without subretinal fibrosis.


RESULTS
Plasma 25-hydroxyvitamin D was comparable in patients across CARMS groups 1 to 5 (p = 0.83). In CARMS 5, the presence of subretinal fibrosis was associated with significantly lower concentrations of 25-hydroxyvitamin D as compared to the absence of subretinal fibrosis (47.2 versus 75.6 nmol/L, p<0.001). Patients in CARMS 5 with subretinal fibrosis were more likely to have insufficient levels of 25-hydroxyvitamin D compared to patients without subretinal fibrosis (p = 0.006). No association was found between the SNPs rs10877012, rs2228570, rs4588, or rs7041 and AMD subgroups or plasma 25-hydroxyvitamin levels.


CONCLUSIONS
This study suggests that the presence of subretinal fibrosis in patients belonging to CARMS 5 may be associated with a poor vitamin D status. Our observations warrant further investigation into the role of vitamin D in the development of subretinal fibrosis.
Department of Ophthalmology, Clinical Eye Research Unit, Copenhagen University Hospital, Roskilde, Denmark. asingh@dadlnet.dk
Amardeep
A
Singh
Mads Krüger
MK
Falk
Yousif
Y
Subhi
Torben Lykke
TL
Sørensen
D000368:Aged; D000369:Aged, 80 and over; D003430:Cross-Sectional Studies; D005260:Female; D005355:Fibrosis; D006801:Humans; D008268:Macular Degeneration / Q000097:blood* / Q000175:diagnosis* / Q000235:genetics; D008297:Male; D020641:Polymorphism, Single Nucleotide; D012160:Retina / Q000473:pathology; D012307:Risk Factors; D012621:Seasons; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood
D014807:Vitamin D; C104450:25-hydroxyvitamin D