The effect of orbital decompression surgery on refraction and intraocular pressure in patients with thyroid orbitopathy

Abstract

Purpose To investigate the effect of orbital decompression surgery in thyroid orbitopathy (TO) on both refractive status and intraocular pressure (IOP). Patients and methods A prospective, multicentre, consecutive audit of patients undergoing thyroid decompression surgery. Indications for surgery included cosmetically unacceptable proptosis or corneal exposure. Exclusion criteria included the following: previous orbital surgery, glaucoma, corneal disease, steroid use in the preceding 12 months, or an acute optic neuropathy. Automated refraction, keratometry, pachymetry, Hertel exophthalmometry, and IOP were recorded at 1 month pre-and 3 months postoperatively. IOP using the Tono-Pen (mean of three readings) was measured in the primary, upgaze, and downgaze positions. Results Data were collected from 52 orbits of 33 patients (East Grinstead, New York, and Adelaide). There was no significant difference between pre-and postoperative data for sphere, cylinder, or central corneal thickness (CCT). The mean spherical equivalent was À0.43±1.49 D pre-operatively and À0.28±1.52 D postoperatively. The steepest meridian of corneal curvature was 93.1 degrees pre-and 94.2 degrees postoperatively, with no significant difference. Mean IOP significantly decreased when measuring by Goldmann applanation tonometry (GAT) (2.28 mm Hg, *P ¼ 0.001) and Tono-Pen (3.06 mm Hg, *P ¼ o0.0001). IOP measured in upgaze was significantly greater than that in the primary position. Regression analysis between change in IOP and either Hertel exophthalmometry or the number of orbital walls decompressed was non-significant (*Student's t-test). Conclusion Patients with TO undergoing orbital decompression had, on average, with-the-rule astigmatism not affected by orbital decompression surgery. IOP was significantly reduced by decompression surgery although no relationship between IOP and the degree of decompression was observed.

Long‐term follow‐up of patients with thyroid eye disease treated with endoscopic orbital decompression

“…In thyroid eye disease, both decompression [ (Norris et al 2012) and references therein] and recession of the inferior rectus muscle (Gomi et al 2007) may contribute to reduction in IOP. The most likely mechanism is a reduction in retrobulbar and episcleral venous pressure.…”

Intraocular Pressure Lowering Effect of Orbital Decompression is Related to Increased Venous Outflow in Graves Orbitopathy

“…5,13,14,16 Various levels of IOP reduction after orbital decompression were reported probably as a result of different surgical techniques and patient selection criteria. Danesh-Meyer et al 14 found a mean IOP decrease of 4.1 mmHg in 116 eyes, whereas Norris et al 20 reported 2.28 mmHg IOP reduction after orbital decompression performed on 52 orbits of 33 GO patients. In addition to previous studies we also demonstrated that the decrease in IOP was realised together with the increase in SOV-BFV and comparable in most GO cases regardless the presence of DON.…”

Biometric and refractive changes after orbital decompression in Korean patients with thyroid-associated orbitopathy

“…[8][9][10] However, whether or not myopic shift is induced by surgery is uncertain. In our study, the mean spherical refraction was decreased by 0.38 D with the myopic change.…”

“…For patients undergoing successful decompression, we can estimate ophthalmic status prior to the start of proptosis. Although there have been studies reporting the effect of orbital decompression on refraction, [8][9][10] whether or not refractive error is induced or not remains uncertain. In this study, we assessed the biometrics of the eyeball, including axial length (AL), anterior chamber depth (ACD), lens thickness (LT), refraction, keratometry, and aberration, before and after orbital decompression in order to estimate the correlation between proptosis progression and biometric changes.…”