Fat-removal orbital decompression for thyroid associated orbitopathy: The right procedure for the right patient

The Changes in Optic Nerve after Orbital Decompression Surgery for Thyroid Eye Disease and Case Reports of Ischemic Optic Neuropathy

Purpose

To demonstrate the changes in the retinal nerve fiber layer (RNFL) after orbital decompression for thyroid eye disease (TED).

Methods

We retrospectively enrolled 52 surgical TED patients, 30 nonsurgical TED patients, and 30 control subjects. Five surgical TED eyes with disc edema were excluded. The surgical TED patients were classified into the “dysthyroid optic neuropathy (DON)” group (16 eyes) and the “non-DON” group (83 eyes). Optical coherence tomography (OCT) and visual field (VF) examinations were performed preoperatively and 6 months later. The control subjects and nonsurgical TED patients received two OCT examinations at 6-month intervals. The postoperative changes in the RNFL thickness were compared between groups. Three cases with severe postoperative vision loss were presented additionally.

Results

The changes in the RNFL thickness of the controls (0.5 ± 3.4 μm) and the nonsurgical TED patients (0.3 ± 2.8 μm) were significantly smaller than the surgical TED patients (P < 0.001). The DON group (−9.2 ± 9.2 μm) had greater RNFL thickness reduction than the non-DON group (−3.9 ± 5.4 μm) (P = 0.002). Bone removal decompression was associated with decreased RNFL in the non-DON (P = 0.025; β = −2.49) and DON (P = 0.042; β = −9.43) groups. Three cases who were hard to operate due to extensive fibrosis experienced severe vision loss postoperatively due to anterior ischemic optic neuropathy, posterior ischemic optic neuropathy, and posterior ciliary artery occlusion, respectively.

Conclusions

TED patients experienced subclinical optic nerve injury and significant RNFL loss after the orbital decompression surgery. Aggressive manipulation during decompression surgery may lead to dreadful vision loss. Tailored surgical plans and delicate manipulation are warranted.

Effect of orbital wall resection areas in the treatment of patients with endocrine orbitopathy

In patients treated by orbital wall decompression for endocrine orbitopathy (EO) there is limited evidence on the effect of orbital wall resections. Thus, the aim of this study was to evaluate the effect of one, two, and three-wall resections on orbital parameters to determine if any such correlations exist. Preoperative and postoperative data from all patients at a tertiary care centre who underwent decompression surgery from 2010 - 2020 were digitally analysed. The effect of the number and area of resected walls on orbital area, orbital volume, and Hertel value, and the effect of lateral rim advancement (LARA) were determined. A total of 131 orbital areas showed an increase from a mean (SD) preoperative area of 42.0 (4.6) cm² to 47.3 (6.1) cm² postoperatively (p<0.001). In total, the mean (SD) area of osseous wall removed in all patients was 6.2 (1.7) cm² at the lateral orbit (n = 129), 6.7 (2.3) cm² at the orbital floor (n = 123), and 5.8 (1.8) cm² at the medial orbital wall (n =30). The mean (SD) orbital volume increased by 6.0 (3.0) cm³ after decompression. There was also a significant reduction in exophthalmos of 7.3 (3.2) mm (from 25.2 (3.9) to 17.9 (3.5), p<0.001). LARA was performed in 50 patients. Changes in volume and area, and reduction in exophthalmos were not significantly different with or without LARA. The postoperative effects of orbital wall resection are predictable and exhibit a relation with six units of change. Two-wall resection is the most common intervention.

A new radiological measurement method used to evaluate the modified transconjunctival orbital fat decompression surgery

Purpose

A new radiological method was used to evaluate the plastic effect of modified transconjunctival orbital fat decompression surgery in patients with inactive thyroid-associated ophthalmopathy.

Methods

In this study, 10 inactive patients (14 eyes) with moderate to severe thyroid-associated ophthalmopathy were selected. The patients underwent modified transconjunctival orbital fat decompression surgery. According to the results of a spiral CT scan before and 6 months after the surgery, the INFINITT system workstation was used to measure the eyeball protrusion value. According to the results obtained by the PHLIPS IntelliSpace Portal elliptical area and line segment measurement tools, the standard elliptical vertebral volume formula was used to calculate the muscular cone inner volume. Changes in eyeball protrusion and the inner volume of the muscular cone before and after surgery were examined. Statistical analysis of the correlation between the two parameters was performed.

Results

Radiological measurement results confirmed that removing the orbital fat in the muscle cone during surgery was effective for alleviating eyeball protrusion in patients with thyroid-associated ophthalmopathy (P < 0.05). This surgery caused an obvious change in the muscle cone inner volume (P < 0.05). And there was significant correlation between changes in eyeball protrusion and muscle cone inner volume (r = 0.797, P = 0.0006, P < 0.05).

Conclusion

The radiological assessment method used in this study is simple and easy to implement. For inactive patients with moderate to severe thyroid-associated ophthalmopathy who just want to improve their appearance, the modified orbital fat decompression surgery is worth considering.

Balancing orbital volume reduction and redistribution for a tailored surgical treatment in Graves' ophthalmopathy

Aim

The purpose of this study is to share our experience on the use of different orbital decompression techniques, as well as the principles followed for deciding the most case-appropriate procedure that ensured the most favorable outcomes.

Methods

We reviewed the Graves’ ophthalmopathy cases operated over the course of 14 years, regarding the presenting signs, the imaging evaluation, the degree of exophthalmos, the type of surgical orbital decompression performed, and the postoperative outcomes.

Results

All 42 patients identified presented with proptosis, with 92.8% cases of bilateral proptosis. The main addressing concern was functional in 54.8% cases and aesthetic in 45.2% patients. CT was used for the preoperative evaluation in all cases. In total, 81 orbits were operated. The orbital decompression surgery involved only the orbital fat in 7.4% of orbits and associated fat and bone decompression in the other 92.6% of orbits. The postoperative results were favorable in all cases regarding both appearance and function, with minimal postoperative complications.

Conclusion

The adequate selection of the most suitable procedure based on the characteristics of each case is the prerequisite for a successful surgery. We found that the association of fat and bone decompression of various extents is most permissive in tailoring the degree of decompression to the existing requirements.