Relationship of Retinal Vessel Caliber with Age-Related Macular Degeneration
Sara Toulouie, Sean Chang, Julia Pan, Kiersten Snyder, Glenn Yiu
Abstract
Purpose. Evaluate the relationship between retinal vascular caliber and age-related macular degeneration (AMD) severity or progression. Methods. A retrospective secondary analysis of 1172 fundus photographs and clinical data from the prospective Age-Related Eye Disease Study (AREDS). Central retinal artery equivalent (CRAE), central retinal vein equivalent (CRVE), and arteriole-to-venule ratio (AVR) were measured using the Parr–Hubbard–Knudtson formula. Univariate and multivariate regressions were used to determine the association of CRAE, CRVE, and AVR with age, sex, smoking status, presence of cilioretinal artery, and AMD severity at baseline and 5 years using the 9-step AMD severity score. Results. Only CRAE and CRVE were higher in men ( <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" id="M1"> <a:mi>P</a:mi> <a:mo><</a:mo> <a:mn>0.001</a:mn> </a:math> ), current smokers ( <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" id="M2"> <c:mi>P</c:mi> <c:mo><</c:mo> <c:mn>0.001</c:mn> </c:math> ), and the eyes with a cilioretinal artery ( <e:math xmlns:e="http://www.w3.org/1998/Math/MathML" id="M3"> <e:mi>P</e:mi> <e:mo>=</e:mo> <e:mn>0.009</e:mn> <e:mo>−</e:mo> <e:mn>0.043</e:mn> </e:math> ). AMD severity was greater in older patients ( <g:math xmlns:g="http://www.w3.org/1998/Math/MathML" id="M4"> <g:mi>P</g:mi> <g:mo>=</g:mo> <g:mn>0.001</g:mn> </g:math> ), current smokers ( <i:math xmlns:i="http://www.w3.org/1998/Math/MathML" id="M5"> <i:mi>P</i:mi> <i:mo>=</i:mo> <i:mn>0.012</i:mn> </i:math> ), the eyes without a cilioretinal artery ( <k:math xmlns:k="http://www.w3.org/1998/Math/MathML" id="M6"> <k:mi>P</k:mi> <k:mo>=</k:mo> <k:mn>0.001</k:mn> </k:math> ), and lower AVR ( <m:math xmlns:m="http://www.w3.org/1998/Math/MathML" id="M7"> <m:mi>P</m:mi> <m:mo>=</m:mo> <m:mn>0.034</m:mn> </m:math> ) on multivariate regression but was not influenced by CRAE or CRVE ( <o:math xmlns:o="http://www.w3.org/1998/Math/MathML" id="M8"> <o:mi>P</o:mi> <o:mo>=</o:mo> <o:mn>0.240</o:mn> <o:mo>−</o:mo> <o:mn>0.500</o:mn> </o:math> ). Choroidal neovascularization (CNV) presence was associated with older age ( <q:math xmlns:q="http://www.w3.org/1998/Math/MathML" id="M9"> <q:mi>P</q:mi> <q:mo>=</q:mo> <q:mn>0.003</q:mn> </q:math> ) and absence of a cilioretinal artery ( <s:math xmlns:s="http://www.w3.org/1998/Math/MathML" id="M10"> <s:mi>P</s:mi> <s:mo>=</s:mo> <s:mn>0.009</s:mn> </s:math> ), while central geographic atrophy (CGA) was associated with narrower CRAE ( <u:math xmlns:u="http://www.w3.org/1998/Math/MathML" id="M11"> <u:mi>P</u:mi> <u:mo>=</u:mo> <u:mn>0.002</u:mn> </u:math> ) and possibly AVR ( <w:math xmlns:w="http://www.w3.org/1998/Math/MathML" id="M12"> <w:mi>P</w:mi> <w:mo>=</w:mo> <w:mn>0.046</w:mn> </w:math> ). None of the retinal vessel parameters were predictive of AMD severity score or new onset of CNV or CGA at 5 years. Conclusion. A lower arteriole-to-venule ratio may be associated with AMD severity, with narrower arterioles seen in the eyes with geographic atrophy, suggesting a role of the retinal vasculature in AMD pathophysiology. This trial is registered with ClinicalTrials.gov Identifier: NCT00000145.