Corneal biomechanical properties of patients with acromegaly

Growth hormone (GH) and insulin-like growth factor-1 (IGF-1) excess in acromegaly have various effects on many organs. The ophthalmologic effects of GH and IGF-1 excess have not yet been investigated in detail. The aim of the current study is to compare the corneal biomechanical properties of patients with acromegaly and those of healthy subjects.

45 patients with acromegaly (F/M=27/18) and 42 age-matched and gender-matched healthy individuals (F/M=24/18) were enrolled in this cross-sectional study. Central corneal thickness (CCT), corneal resistance factor (CRF), corneal hysteresis (CH), corneal compensated intraocular pressure (IOPcc) and Goldmann correlated IOPG were measured in patients with acromegaly and in healthy individuals using the Ocular Response Analyser (ORA). GH and IGF1 values were also determined in the study group.

The mean CH and CRF values were higher in acromegalic patients (12.1±2.2 and 12.3±2.4, respectively) than in healthy subjects (11.0±1.6 and 10.8±1.5, respectively; for CH, p=0.014; for CRF, p=0.001). Mean IOPG measurement was higher in the acromegaly group than in the control group (p=0.017). There was no statistically significant difference in measured CCT (p=0.117) and IOPcc (p=0.594) values between acromegalic patients and healthy subjects.

These findings indicate that acromegaly has target organ effects on the eye. Consequently, it can change corneal biomechanical properties such as corneal hysteresis and the CRF. Corneal biomechanical properties are known to affect the accuracy of IOP measurements. These findings should be taken into account when measuring IOP values in acromegaly patients, as IOP readings may be overestimated.