Alteration in choroidal microvasculature determined by optical coherence tomography angiography in patients with acromegaly

Blood Glucose Levels Moderate the Associations Between IGF-1 Levels and Choroidal Metrics in Patients With Diabetes With Acromegaly Without Diabetic Retinopathy

Purpose

To examine the effects of serum growth hormone (GH) and insulin-like growth factor-1 (IGF-1) on choroidal structures with different blood glucose levels in patients with diabetes mellitus (DM) with acromegaly without diabetic retinopathy.

Methods

Eighty-eight eyes of 44 patients with acromegaly were divided into a nondiabetic group (23 patients, 46 eyes) and a diabetic group (21 patients, 42 eyes). Forty-four age- and sex-matched healthy controls and 21 patients with type 2 DM without diabetic retinopathy were also included. Linear regression models with a simple slope analysis were used to identify the correlation and interaction between endocrine parameters and choroidal thickness (ChT), total choroidal area (TCA), luminal area (LA), stromal area (SA), and choroidal vascular index (CVI).

Results

Our study revealed significant increases in the ChT, LA, SA, and TCA in patients with acromegaly compared with healthy controls, with no difference in the CVI. Comparatively, patients with DM with acromegaly had greater ChT than matched patients with type 2 DM, with no significant differences in other choroidal parameters. The enhancement of SA, LA and TCA caused by an acromegalic status disappeared in patients with diabetic status, whereas ChT and CVI were not affected by the interaction. In the diabetic acromegaly, higher IGF-1 (P = 0.006) and GH levels (P = 0.049), longer DM duration (P = 0.007), lower blood glucose (P = 0.001), and the interaction between GH and blood glucose were associated independently with thicker ChT. Higher GH levels (P = 0.016, 0.004 and 0.007), longer DM duration (P = 0.022, 0.013 and 0.013), lower blood glucose (P = 0.034, 0.011 and 0.01), and the interaction of IGF-1 and blood glucose were associated independently with larger SA, LA, and TCA. As blood glucose levels increased, the positive correlation between serum GH level and ChT diminished, and became insignificant when blood glucose was more than 7.35 mM/L. The associations between serum IGF-1 levels and LA, SA, and TCA became increasingly negative, with LA, becoming significantly and negatively associated to the GH levels only when blood glucose levels were more than 8.59 mM/L.

Conclusions

Acromegaly-related choroidal enhancements diminish in the presence of DM. In diabetic acromegaly, blood glucose levels are linked negatively with changes in choroidal metrics and their association with GH and IGF-1.

Translational Relevance

We revealed the potential beneficial impacts of IGF-1 and GH on structural measures of the choroid in patients with DM at relatively well-controlled blood glucose level, which could provide a potential treatment target for diabetic retinopathy.

Corneal Tonometric and Morphological Changes in Patients with Acromegaly

(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.