Is there any association between primary hyperparathyroidism and ocular changes, such as central corneal thickness, retinal thickness, and intraocular pressure?

Ocular changes are commonly encountered in various endocrine disorders. However, only a few studies have reported ocular changes in patients with primary hyperparathyroidism (PHPT). Here, we examined the central corneal thickness (CCT), retinal thickness (RT), and intraocular pressure (IOP), and their relationships with serum intact parathyroid hormone (iPTH), calcium (Ca), and phosphorus (P) levels in patients with PHPT. Thirty-seven eyes of 37 PHPT patients were compared with 43 eyes of 43 age- and sex-matched normal subjects. A detailed ophthalmologic examination, including CCT, RT, and IOP, was performed. CCT and IOP in PHPT patients were significantly higher than controls (p = 0.024 and p = 0.038, respectively). No statistically significant difference was detected in RT between the two groups (p = 0.730). iPTH levels were positively correlated with CCT and IOP (r = 0.304, p = 0.006 and r = 0.249, p = 0.026, respectively). No significant correlation was found between iPTH levels and RT (p > 0.05), and between serum Ca levels, and RT, CCT, and IOP (all, p > 0.05). While there was a negative correlation between serum P levels and CCT (r = -0.264, p = 0.018), no correlation was observed between serum P levels, and RT and IOP (both, p > 0.05). Using multiple regression analyses, iPTH, serum Ca, and serum P levels were found to have no significant associations with CCT, IOP, and RT (all, p > 0.05). There was no significant association between PHPT, and CCT, RT, and IOP. We postulate that the identification of ocular aspects of PHPT is significant, and further studies related to this condition are required.