Changes in ocular biomechanics after treatment for active Graves' orbitopathy

Effect of Intraorbital Mechanical Compression on Retinal Microvascular Perfusion in Quiescent Thyroid-Associated Ophthalmopathy Based on Ocular Biomechanics Measured by Corvis ST

INTRODUCTION

To analyze the correlation between orbital compliance and retinal vessel density (VD) based on dynamic Scheimpflug analyzer (Corvis ST) and optical coherence tomographic angiography (OCT-A).

METHODS

In this prospective observational study, 65 eyes of 44 patients with thyroid-associated ophthalmopathy (TAO) in quiescent stage were included (15 males and 29 females). The whole eye movement (WEM) was detected by Corvis ST. The superficial capillary plexus VD (SCP-VD) and deep capillary plexus VD (DCP-VD) were obtained by scanning the 3 × 3 mm area around the fovea using OCT-A, while the peripapillary vessel density (ppVD) was obtained by scanning the 4.5 × 4.5 mm area around the optic disk. Covariances including biomechanically corrected intraocular pressure (bIOP), axial length, age and gender were adjusted during data analysis.

RESULTS

The mean WEM of the participants was 0.235 ± 0.066 mm. The mean SCP-VD and DCP-VD in whole image were 46.20% ± 3.77% and 50.51% ± 3.96%; the mean whole pp-VD was 49.75% ± 2.01%. WEM was positively correlated with SCP-VD (r = 0.327, p = 0.01) and the whole pp-VD (r = 0.394, p < 0.01) after adjusting by gender, axial length (AL), age and bIOP, but it was not significantly correlated with DCP-VD (r = 0.072 p = 0.581).

CONCLUSION

Increase in orbital pressure might reduce retinal microvascular perfusion. Our data suggest orbital mechanical compression may be an important cause of retinal VD changes in quiescent patients with TAO.

Refractive Associations With Whole Eye Movement Distance and Time Among Chinese University Students: A Corvis ST Study

Purpose

Eye movement has been frequently studied in clinical conditions, but the association with myopia has been less explored, especially in population-based samples. The purpose of this study was to assess the associations of eye movement measured by the Corvis ST with refractive status in healthy university students.

Methods

A total of 1640 healthy students were included in the study (19.0 ± 0.9 years). Eye movement parameters (whole eye movement [WEM]; whole eye movement time [WEMT]) were measured by the Corvis ST. Spherical equivalent (SE) was measured using an autorefractor without cycloplegia. IOL Master was used to assess axial length (AL).

Results

AL was negatively correlated with WEM and WEMT (rWEM = -0.28, rWEMT = -0.08), and SE was positively correlated with WEM and WEMT (rWEM = 0.21, rWEMT = 0.14). For the risk of high myopia, breakpoint analysis and restricted cubic spline model showed that the knots of the significant steep downward trend of WEM and WEMT were 0.27 mm and 20.4 ms, respectively. The piecewise linear regression model revealed a significant correlation between AL, SE, and WEM when the value of WEM was below 0.27 mm. Additionally, when WEMT exceeded 20.4 ms, a significant decrease in AL and an increase in SE were observed with increasing WEMT.

Conclusions

A larger distance and longer duration of eye movement were correlated with a lower degree of myopia and shorter AL, and there was a threshold effect.

Translational Relevance

The findings might aid in understanding the pathogenesis of myopia and provide a theoretical foundation for clinical diagnosis and prediction.

Evaluation of orbital soft tissue biomechanical parameters in patients with thyroid eye disease using the non-contact Corvis ST

INTRODUCTION

In thyroid eye disease (TED), all ocular components and adnexa such as extraocular muscles, orbital adipose tissues, eyelids, and tear glands could be affected. This study aimed to study the orbital biomechanical parameters in patients with TED, in terms of differences with healthy individuals and correlation with clinical findings, using Corvis ST (CST, Oculus Wetzlar).

MATERIALS AND METHODS

In this study, 26 consecutive patients with TED were recruited. Demographic data were collected, and patients with TED were assessed for exophthalmos, intraocular pressure, and clinical activity score. Biomechanical response parameters of one randomly-chosen eye of each patient, including whole eye movement length (WEMl) and time (WEMt), were evaluated by the CST, and data were compared between patients and age- and gender-matched healthy controls.

RESULTS

The mean age was 39.88 ± 11.61 years old for patients with TED and 34.38 ± 8.57 years old for the healthy subjects. Nine out of 26 patients with TED and nine of 26 healthy individuals were male. The median duration of thyroid disease was 36 (IQR 54) months and the median duration of thyroid ophthalmopathy was 27 (IQR 27) months. Four out of 26 patients (7.7%) had active disease. The mean WEMl was 206.15 ± 61.58 µm in the TED group and 254.23 ± 64.01 μm in the healthy group, the difference of which was statistically significant (p = 0.008). The median of WEMt was 20.90 (1.15) msec in the TED group and 21.45 (0.93) msec in the healthy group (p < 0.001). Also, the mean of WEMl and WEMt were lower in patients with active disease compared to patients with quiescent disease.

CONCLUSION

The CST-derived WEMl was significantly smaller in patients with thyroid eye disease compared to normal subjects. The WEMl and WEMt were relatively shorter in the patients with active TED compared to the patients with quiescent TED, although small numbers of patients with active TED limits took a statistically significant conclusion. WEMl and WEMt might be useful in evaluating the compliance of the orbit in patients with TED.

The Changes in Ocular Biomechanical Response Parameters and Intraocular Pressure After Surgical Treatment for Thyroid Eye Disease

Purpose

To investigate changes in ocular biomechanical response parameters and intraocular pressure (IOP) in patients with thyroid eye disease (TED) undergoing orbital decompression or anterior blepharotomy.

Methods

Eighty-three eyes from 46 patients receiving orbital decompression (the orbital decompression group) and 45 eyes from 28 patients receiving anterior blepharotomy (the anterior blepharotomy group) were retrospectively enrolled from a tertiary center. Corvis ST tonometry was used to assess ocular biomechanical response and biomechanically corrected IOP (bIOP) pre- and postoperatively. Non-contact tonometry (IOP-NCT) was also performed.

Results

In the anterior blepharotomy group, the margin reflex distance decreased (P < 0001). The highest concavity radius (P = 0.026) and whole eye movement (P = 0.003) increased. Neither IOP-NCT nor bIOP had a significant change. In the orbital decompression group, the extent of exophthalmos decreased (P < 0.001). The A2 length (P = 0.009) decreased. The bIOP did not show a significant change (16.4 ± 2.7 vs. 16.7 ± 4.5; P = 0.415), but the IOP-NCT decreased significantly (17.5 ± 3.3 vs. 16.0 ± 3.3; P < 0.001). Higher baseline IOP-NCT (β = -0.40, P < 0.001) and greater reduction in stiffness parameter A1 (SP-A1; β = 0.05, P = 0.002) were associated with more significant IOP-NCT reduction after the orbital decompression.

Conclusions

Ocular biomechanical response parameters may change after TED surgery, potentially affecting IOP measurements, particularly in patients receiving orbital decompression.

Proptosis and Diplopia Response With Teprotumumab and Placebo vs the Recommended Treatment Regimen With Intravenous Methylprednisolone in Moderate to Severe Thyroid Eye Disease: A Meta-analysis and Matching-Adjusted Indirect Comparison

Importance

Thyroid eye disease can be a debilitating autoimmune disorder characterized by progressive proptosis or diplopia. Teprotumumab has been compared with placebo in randomized clinical trials, but not with intravenous methylprednisolone (IVMP), which sometimes is used in clinical practice for this condition.

Objective

To conduct a matching-adjusted indirect comparison of teprotumumab vs IVMP vs placebo.

Data Sources

Deidentified patient-level data from teprotumumab trials and aggregate-level data from literature on the most recommended regimen of IVMP.

Study Selection

PubMed and Embase were searched for randomized/observational studies using key terms and controlled vocabulary. Full texts of eligible articles were reviewed and cataloged.

Data Extraction and Synthesis

Conducted by 1 reviewer (R.A.Q.) and 1 verifier (R.B.), including study characteristics, eligibility criteria, baseline characteristics, and outcomes.

Main Outcomes and Measures

Changes in proptosis by millimeter and diplopia response (percentage with ≥1 grade reduction) from baseline to week 12 in patients receiving IVMP and placebo, and to week 24 in patients receiving teprotumumab.

Results

The search identified 1019 records, and 6 through manual searches, alerts, and secondary references. After excluding duplicates and screening full-text records, 12 IVMP studies were included in the matching-adjusted indirect comparison (11 for proptosis change [n = 419], 4 for diplopia response [n = 125], and 2 teprotumumab [n = 79] and placebo [n = 83] comparator studies). Treatment with IVMP resulted in a proptosis difference of -0.16 mm (95% CI, -1.55 to 1.22 mm) from baseline to week 12 vs placebo. The proptosis treatment difference between IVMP and teprotumumab of -2.31 mm (95% CI, -3.45 to -1.17 mm) favored teprotumumab. Treatment with IVMP (odds ratio, 2.69; 95% CI, 0.94-7.70) was not favored over placebo in odds of diplopia response; however, teprotumumab was favored over IVMP (odds ratio, 2.32; 95% CI, 1.07-5.03).

Conclusions and Relevance

This meta-analysis suggests that use of IVMP is associated with a small, typically not clinically relevant, change from baseline in proptosis vs placebo, with modest changes in diplopia. While this nonrandomized comparison suggests that use of teprotumumab, compared with IVMP, is associated with greater improvements in proptosis and may be twice as likely to have a 1 grade or higher reduction in diplopia, randomized trials comparing these 2 treatments would be warranted to determine if 1 treatment is superior to the other to a clinically relevant degree.