Corneal Tonometric and Morphological Changes in Patients with Acromegaly

HIGHLIGHTS: This study is the first prospective clinical trial to evaluate the anterior corneal parameters in patients with acromegaly before and after transsphenoidal pituitary adenoma resection on the basis of several months of postoperative follow-up. An increase in CD and a decrease in AVG and CCT(NSM) were observed after pituitary adenoma resection. The mean CCT measured both with an ultrasonic pachymeter and with non-contact specular microscopy was significantly lower as compared to the preoperative values. IOP decreased statistically for the measured IOP air puff values. A downward trend was observed after treatment in the case of IOP GAT and IOPc, but statistical significance was not achieved. Statistically significant reduction in CH and CRF was found after the surgical treatment of acromegaly. ABSTRACT: (1) Purpose: This study aimed to investigate the changes in Reichert Ocular Response Analyzer (ORA) parameters, corneal endothelium parameters, central corneal thickness (CCT), and intraocular pressure (IOP) before and after the transsphenoidal resection of pituitary adenoma in patients with acromegaly. (2) Methods: This was a single-center, prospective, interventional study. Twenty patients with newly diagnosed acromegaly were examined before and 19 ± 9 months after transsphenoidal resection. The participants underwent a comprehensive ophthalmological examination including pneumatic IOP (IOP air puff), Goldmann applanation tonometry (IOP GAT), CCT measured using the iPac pachymeter (CCT(UP)), IOP value corrected for CCT(UP) using the Ehlers formula (IOPc) ORA measurements included corneal hysteresis (CH), corneal resistance factor (CRF), corneal-compensated IOP (IOPcc), and Goldmann-correlated IOP (IOPg). CCT from non-contact specular microscopy (CCT(NSM)), the number of endothelial cells (CD) per mm2, and average cell size (AVG) were determined with non-contact specular microscopy. (3) Results: A statistically significant decrease was observed in CCT(UP) (p = 0.007), and IOP air puff (p = 0.012) after surgery. Moreover, we noted a statistically significant increase in CD (p = 0.001), and a statistically significant decrease in AVG (p = 0.009) and CCT(NSM) (p = 0.004) after surgery. A statistically significant decrease was also observed in IOPg (p = 0.011), CH (p = 0.016), and CRF (p = 0.001) after surgery. The mean value of IOP GAT and IOPc was lower after the surgery. However, the difference was not statistically significant. (4) Conclusions: Our study revealed significant changes in biomechanics, corneal endothelium, CCT and IOP after pituitary adenoma resection in patients with acromegaly. It proves that the eye might be sensitive to long-term overexposure to growth hormone (GH) and insulin-like growth factor-1 (IGF-1). We suggest that disease activity be taken into consideration on ophthalmological examination.