Evaluation of ocular findings and their relationship with disease activity in acromegaly cases

Acromegaly, induced by increased growth hormone (GH) secretion, is a clinical syndrome that effects many organs and systems. The clinical features, developed by the increased GH levels that has the effect of triggering growth, are well-known. In the literature the number of studies examining the effect of GH on eyes in cases with acromegaly appears highly few. In this retrospective study it was aimed to evaluate the eye findings of patients diagnosed with acromegaly and to demonstrate whether they are related to the activity of the disease. In this retrospective study the records of 35 patients diagnosed with acromegaly were examined in the Endocrinology and Metabolism Diseases Department of Medical Faculty, Celal Bayar University and whether there was any relationship between patients eye findings (visual field, autorefractometer, corneal hysteresis, corneal resistance factor, intraocular pressure, optical coherence tomography, pachymetry, optical pachymetry and biometri measurements) and activity of disease was evaluated. The findings of acromegaly patients were compared with those of control group. Of the acromegaly patients 21 were women and 14 were males; their mean age was 47.26 ± 12.59 years, age range 20 to 70 years. Six patients were in post-op remission while being followed up without medical therapy, 25 patients were treated with long-acting somatostatin analog post op surgery. Four patients had not received any therapy yet. IGF-1 level at normal limits for gender and age, with random GH level below 2.5 ng/ml and below 1 ng/ml in glucose GH response test were considered at remission. According to remission criteria, 26 were observed out of remission. In statistical analyses NCSS (Number Cruncher Statistical System) 2007&PASS (Power Analysis and Sample Size) 2008 Statistical Software (Utah, USA) were used. Acromegaly patients body mass index, DM frequency, LDL cholesterol and hunger blood glucose levels were found high (p<0.025). Eye findings the autorefrectometry (OR), the corneal hysteresis (CH) and the corneal resistance factor (CRF) measurements were found statistically significantly lower compared to controls (p=0.01). Intraocular pressure (IOP), optic coherence tomography (OCT), pachymetry, optic pachymetry and biometry measurements were found elevated in acromegaly group than in controls (p=0.01). ). Field of vision defects were detected in 12 (34.3 %) of 35 acromegaly patients. In acromegaly patients, although right eye acuity measurements were found statistically significantly reduced in remission patients (p<0.05), the mean visual acuity measurements in left eye and both eyes demonstrated a statistical difference compared to remission status (p=0.05). A positive correlation was established between the average optic pachymetry and the duration of disease (r=0.392, p=0.020). In the results of our study patients with acromegaly is low compared to the controls it increased OR values indicative of the risk of myopia. CH and CRF values were lower in acromegaly cases compared to controls, whereas IOP and cornea thickness were found higher. This situation is parallel with propensity to glaucoma. Even though a relationship is considered between eye findings and activity of disease, this situation could not be shown clearly in our study due to few number of cases. Our study indicates that, besides the visual defect caused by macroadenoma in acromegaly patients, other eye functions may be influenced by the effect of elevated GH and IGF-1 levels and additional eye findings may develop other than field of vision defects. In acromegaly patients are needed investigate the relationship between eye function and disease activity and larger, prospective studies with more patients.