Corneal Biomechanical Properties In Patients With Acromegaly

Program: Abstracts - Orals, Featured Poster Presentations, and Posters
Session: SUN 88-129-Acromegaly & Prolactinoma
Sunday, June 16, 2013: 1:45 PM-3:45 PM
Expo Halls ABC (Moscone Center)

Poster Board SUN-116
Ahmet Ozkok, Esra Hatipoglu*, Burcu Balta, Nevbahar Tamcelik, Ahmet Sadi Gundogdu and Pinar Kadioglu
Cerrahpasa Medical School, University of Istanbul, Istanbul, Turkey
Objective: GH and IGF-1 excess in acromegaly have various effects on many organs. Ophthalmologic effects of GH and IGF-1 excess have not been investigated in detail yet. Aim of the current study is to compare the biomechanical properties of corneas in eyes of patients with acromegaly and in eyes of healthy subjects.

Methods: In this cross-sectional, prospective, comparative study, 31 patients with acromegaly (F/M=16/15) and 42 age and gender matched healthy subjects (F/M=24/18) were enrolled. Central corneal thickness (CCT), corneal resistance factor (CRF), corneal hysteresis (CH), corneal compensated intraocular pressure (IOPcc) and Goldmann correlated intraocular pressure (IOPg) were measured in patients with acromegaly and in healthy subjects using the Ocular Response Analyzer (ORA). GH and IGF1 values were also determined in study group. Unpaired-samples t test was used to compare CRF,CH,IOPcc, and IOPg values. Pearson correlation test was used to evaluate correlation between corneal biomechanical parameters and GH, IGF-1, and duration of acromegaly in the study group.

Results: The mean CRF was 12.7 ± 2.5 mmHg and 10.8 ± 1.4 mmHg, mean CH was  12.3 ± 2.3 mmHg and 11.0 ± 1.5 mmHg, IOPcc was 15.9 ± 4.4 mmHg and 15.1 ± 3.3 mmHg, and IOPg was 17.8 ± 4.5 mmHg and 15.1 ± 2.9 mmHg in the acromegaly and control groups, respectively. CRF, CH, and IOPg were significantly higher in patients with acromegaly (p<0,001, p=0.005, and p=0.002, respectively). On the other hand there was no statistically significant difference in IOPcc and CCT between two groups (p=0.37 and p= 0.21, respectively.) The median GH and IGF-1 levels of the patients with acromegaly were 1.3 [IQR:0.52-2.15] and 275.1 [IQR:205.6-393.9],respectively. Corneal hysteresis was well correlated with duration of acromegaly, whereas CRF was not (r = 0.891, p= 0,026 and r=0.735, p= 0.063, respectively)

Conclusions: These findings indicate that acromegaly has target organ effects on eye. Consequently it can change corneal biomechanical properties such as corneal hysteresis and corneal resistance factor. In addition, corneal hysteresis value is positively correlated with duration of acromegaly which means rather than acute increments, long term exposure to GH and/or IGF-1 may have greater impact on corneal biomechanical changes. 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 in patients with acromegaly.

Nothing to Disclose: AO, EH, BB, NT, ASG, PK

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