Corneal and Coronary Calcification in Maintenance Hemodialysis: The Face Is No Index to the Heart

Abstract

Although the eyes are the main site of metastatic calcification in patients with chronic kidney disease (CKD), corneal and conjunctival calcification (CCC) is poorly evaluated in this population. Whether CCC correlates with coronary artery calcification remains unknown since studies so far have relied on methods with low sensitivity. Our objective was to test the relationship between CCC and coronary calcification based on tomography. This was a cross-sectional study that included patients on maintenance dialysis. Clinical, demographic, and biochemical data (calcium, phosphorus, parathormone, alkaline phosphatase, and 25(OH)-vitamin D) were recorded. Hyperparathyroidism was defined as parathyroid hormone (PTH) > 300 pg/mL. CCC was evaluated by anterior segment optical coherence tomography (AS-OCT), and coronary calcium scores (Agatston method) were assessed by computed tomography. We compared no/mild with moderate/severe CCC. Twenty-nine patients were included (49.6 ± 15.0 years, 62.1% female, on hemodialysis for 5.7 [2.7–9.4] years, 17.2% with diabetes mellitus, 75.9% with hyperparathyroidism). CCC was found in 82.7% of patients, with median scores of 9 (3, 14.5), ranging from 0 to 16. CCC was classified as absent/mild, moderate, and severe in 27.6%, 20.7%, and 51.7%, respectively. Coronary calcification was found in 44.8% of patients, with median scores of 11 (0, 464), varying from 0 and 6456. We found no significant correlation between coronary calcium scores and CCC (r = 0.203, p = 0.282). Hyperphosphatemia was more frequent in patients with moderate/severe CCC than in those with absent/mild CCC. We concluded that CCC was frequent in patients with CKD on dialysis and did not correlate with coronary calcium scores. Hyperphosphatemia appears to contribute to CCC. © 2023 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.