Changes in Choroidal Perfusion after Orbital Decompression Surgery for Graves' Ophthalmopathy

Effect of orbital decompression surgery on the choroidal profile in patients with thyroid eye disease

This study aimed to investigate the effect of orbital wall decompression surgery and reduction of proptosis on the choroidal vascularity index (CVI) and subfoveal choroidal thickness (SFCT) in patients with thyroid eye disease (TED). Fifty-one eyes from 38 patients with controlled TED and proptosis were enrolled in this study. The majority of the patients (50.9%) had a clinical activity score (CAS) of zero, and none had a CAS greater than 2. The patients underwent a complete baseline ophthalmologic examination, and their choroidal profile alterations were monitored using enhanced depth imaging optical coherence tomography (EDI-OCT) before and during the three months after surgery. Changes in SFCT, luminance area (LA), total choroidal area (TCA), and the choroidal vascularity index (CVI) were measured as the ratio of LA to TCA in EDI-OCT images. The participants had an average age of 46.47 years, and 22 were female (57.9%). The SFCT of the patients exhibited a significant reduction over the follow-up period, decreasing from 388 ± 103 to 355 ± 95 µm in the first month (p < 0.001) and further decreasing to 342 ± 109 µm by the third month compared to baseline (p < 0.001). The CVI exhibited a drop from 0.685 ± 0.037 at baseline to 0.682 ± 0.035 and 0.675 ± 0.030 at 1 and 3 months post-surgery, respectively. However, these changes were not statistically significant, indicating comparable decreases in both LA and TCA. There was a significant correlation between improved proptosis and reduction in SFCT (p < 0.001) but not with CVI (p = 0.171). In conclusion, during the three months of follow-up following orbital wall decompression, CVI did not change, while SFCT reduced significantly. Additionally, SFCT was significantly correlated with proptosis reduction, whereas CVI was not.

Changes in choroidal thickness and choroidal vascularity index in thyroid eye disease: a systematic review

PURPOSE

To evaluate the evidence for changes in choroidal thickness and choroidal vascularity index (CVI) in people with thyroid eye disease (TED), stratified by severity, as measured by optical coherence tomography (OCT).

METHODS

Systematic review, including quality assessment, of published studies investigating choroidal thickness in TED. Outcomes of interest included CVI, subfoveal choroidal thickness, mean choroidal thickness, and peripheral choroidal thickness in four quadrants (superior, inferior, medial, lateral).

RESULTS

Nineteen studies were included which contained measurements from 1067 eyes in 798 patients with TED. Most studies found an increased CVI and increased choroidal thickness in patients with TED compared to normal controls, especially in the subfoveal region. In addition, several studies reported an increased thickness in patients with active vs. inactive TED, although the results are equivocal. Finally, many studies reported associations between increased choroidal thickness and worsened clinical measurements of disease activity, such as Clinical Activity Score (CAS).

CONCLUSIONS

This systematic review provided evidence for an association between increased CVI/choroidal thickness and TED, suggesting a potential for OCT-measured CVI/choroidal thickness as an objective clinical marker. Given heterogeneity, future studies are needed to assess the role of measuring the choroidal changes in diagnosis and management of TED.

Evaluation of the Effect of Proptosis on Choroidal Thickness in Graves' Ophthalmopathy

Objectives:

To evaluate the effect of proptosis on choroidal thickness in patients with Graves’ ophthalmopathy.

Materials and Methods:

Twenty-five eyes of 25 Graves’ patients with proptosis, 25 eyes of 25 Graves’ patients without proptosis, and 25 eyes of 25 healthy individuals were included in this prospective study. The subfoveal choroidal thickness and choroidal thicknesses at 6 points from the fovea at 500 μm intervals were measured by Cirrus HD-OCT. All measurements were compared among the proptosis, non-proptosis, and control groups and the active, inactive, and control groups.

Results:

The mean subfoveal choroidal thickness in the proptosis group was 289.7±68.5 μm, 322.5±55.8 μm in the non-proptosis group, and 316.1±63.0 μm in the control group. The mean nasal choroidal thickness was 260.5±63.5 μm in the proptosis group, 293.9±57.9 μm in the non-proptosis group, and 279.5±63.1 μm in the control group. The mean temporal choroidal thickness was 261.8±60.9 μm in the proptosis group, 289.0±51.8 μm in the non-proptosis group, and 287.8±56.2 μm in the control group. Mean choroidal thickness was 264.7±58.5 μm in the proptosis group, 296.2±47.5 μm in the non-proptosis group, and 288.3±55.1 μm in the control group. There were no statistically significant differences among the groups with respect to choroidal thickness measurements (p>0.05).

Conclusion:

No significant difference in choroidal thickness was detected between Graves’ patients with and without proptosis and the controls. There was no effect of clinical activation on choroidal thickness.

Effects of Orbital Decompression on Lamina Cribrosa Depth in Patients with Graves' Orbitopathy

Purpose

We sought to investigate the effects of Graves' orbitopathy (GO) and orbital decompression on lamina cribrosa depth (LCD) using spectral-domain optical coherence tomography.

Methods

Forty eyes that underwent orbital decompression to relieve compressive optic neuropathy or correct disfiguring exophthalmos in the context of GO were included. Subjects were imaged with spectral-domain optical coherence tomography before surgery and at 1 and 3 months after surgery, at which the examiner measured the LCD (distance from the anterior surface of the lamina cribrosa to the Bruch membrane opening line) and peripapillary retinal nerve fiber layer thickness. Subjects were divided into two groups—a muscle-dominant group composed of patients who had extraocular muscle enlargement on preoperative orbital computed tomography scan and a fat-dominant group composed of patients who did not show extraocular muscle enlargement on preoperative orbital computed tomography scan—and subgroup analysis was performed. Preoperative and postoperative intraocular pressure, exophthalmos, LCD, and retinal nerve fiber layer thickness were evaluated.

Results

At baseline, LCD was remarkably shallower in the muscle-dominant group than in the fat-dominant group (95% confidence interval, p = 0.007). In the muscle-dominant group, LCD showed no definite change after surgery. However, the fat-dominant group showed temporary posterior displacement of the lamina cribrosa at 1-month postoperation that was reversed to baseline at 3 months postoperation (95% confidence interval, p < 0.01).

Conclusions

The lamina cribrosa was anteriorly displaced preoperatively, and its position was nearly unchanged after the surgery, especially in association with extraocular muscle enlargement. An enlarged extraocular muscle could reduce the pressure-relieving effect of orbital decompression around the scleral canal in patients with GO.