Effect of orbital decompression on dysthyroid optic neuropathy: A retrospective case series

Dysthyroid optic neuropathy: a case series at a tertiary ophthalmic referral centre

BACKGROUND/OBJECTIVES

To determine risk factors and treatment outcomes in dysthyroid optic neuropathy (DON) at a single tertiary ophthalmic centre.

METHODS

Retrospective audit of DON patients who have received intravenous methylprednisolone (IVMP) therapy at Royal Victorian Eye and Ear Hospital, Melbourne, Australia from July 2015 to October 2021.

RESULTS

Study included 24 patients (58% female) with an average age of 59.8 ± 14.7 years at DON diagnosis. Majority (92%) had Graves' hyperthyroidism and 77% had a smoking history. At diagnosis, average visual acuity (VA) of worse eye was LogMAR 0.46, and 48% had relative afferent pupillary defect. Proptosis (89%) and diplopia (73%) were most commonly present at diagnosis. 78% showed predominantly extra-ocular muscle enlargement, and apical crowding (52%) on radiology. 38% (n = 9/24) responded to IVMP alone, 58% (n = 14/24) progressed to surgical orbital decompression. The average total cumulative dose of IVMP during DON treatment was 6.8 ± 1.9 g. 29% required further treatment after IVMP and surgical decompression, 4 (17%) had additional radiotherapy, and three (13%) required immuno-modulatory therapy. Average final VA was LogMAR 0.207, with all patients having inactive TED at final follow-up (mean 1.7 years). In refractory DON cases, 71% retained VA ≥ 6/9 and 48% had DON reversal.

CONCLUSIONS

DON patients typically present in late 50s, with a smoking history and predominant extra-ocular muscle enlargement. High-dose IVMP fully resolved DON in only 38%. A considerable proportion required urgent orbital decompression. Most patients retained good vision at final follow-up.

Changes in retinal nerve fiber layer, ganglion cell complex, and ganglion cell layer thickness in thyroid eye disease: A systematic review

Thyroid eye disease (TED) is characterized by progressive orbital inflammation. In severe cases, it can lead to dysthyroid optic neuropathy (DON), involving death of retinal ganglion cells and permanent vision loss. Imaging with optical coherence tomography (OCT) has enabled noninvasive examination of the structural impact of the disease, including of the retinal nerve fiber layer (RNFL), the ganglion cell layer (GCL), and the inner plexiform layer (IPL). In this study, we systematically review 20 studies (897 patients, 1430 eyes) to evaluate changes in retinal thickness in patients with TED, stratified by severity. Most studies found a decrease in thickness in peripapillary RNFL (pRNFL), non-pRNFL, combined RNFL/GCL/IPL, or combined GCL/IPL when comparing patients with DON to healthy controls or to patients without DON. However, results were equivocal regarding differences between non-DON TED patients and controls. In addition, several studies reported a postoperative decrease in pRNFL thickness after orbital decompression surgery. Future studies examining OCT changes of retinal thickness along with disease progression are needed to assess the potential of OCT in diagnosis and management of patients with TED.

Retinal nerve fiber layer thickness measured by optical coherence tomography predicts visual recovery after orbital decompression for dysthyroid optic neuropathy

PURPOSE

To determine the prognostic value of optical coherence tomography (OCT) measurement of the peripapillary retinal nerve fiber layer (RNFL) thickness in visual recovery after orbital decompression of patients with dysthyroid optic neuropathy (DON).

METHODS

A total of 52 eyes of 37 patients who underwent orbital decompression for DON between 2013 and 2019 were retrospectively reviewed. We examined peripapillary RNFL thickness, best-corrected visual acuity (BCVA), visual field (VF) for mean deviation (MD) and pattern standard deviation (PSD), and pattern-reversed visual evoked potential (PVEP) for P100 latency and amplitude before and after surgery. Black and white checkerboard square sizes of PVEP were 15 and 60 arcmin (arcminute and minute of angle). Changes in RNFL overall thickness and by quadrant and interocular differences were evaluated and studied regarding changes in BCVA, VF and PVEP.

RESULTS

There was a significant improvement in BCVA, VF, and PVEP, whereas a dramatic reduction in RNFL thickness of all DON patients in global average, temporal, superior, and inferior quadrants (P = 0.005, P = 0.024, P = 0.016, and P = 0.001, respectively) after decompression surgery, except for nasal quadrant (P = 0.057). The preoperative RNFL thickness in each quadrant was negatively correlated with postoperative changes of BCVA and PSD and positively correlated with changes of MD and P100 amplitude at 60 arcmin (all P < 0.05). Except for temporal quadrant (P = 0.125), the preoperative RNFL thickness in other quadrants was positively correlated with postoperative changes of P100 amplitude at 15 arcmin (all P < 0.05). The nasal RNFL thickness was an excellent predictor for improvement in BCVA by 20/25 or better and in MD by 10 dB or more after surgery, whose cutoff value was 73.50 μm, while the inferior and superior RNFL thickness could act as a predictor for improvement in P100 amplitude by 5 μV or more at 60 arcmin and at 15 arcmin, respectively, whose cutoff value was, respectively, 143.00 μm and 130.50 μm (all P < 0.05).

CONCLUSION

RNFL thickness measured by OCT was correlated with visual function recovery after decompression surgery in patients with DON, which could also act as a predictor for better visual prognosis.

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.

The Therapeutic Effect of Combination of Orbital Decompression Surgery and Methylprednisolone Pulse Therapy on Patients with Bilateral Dysthyroid Optic Neuropathy

PURPOSE

To investigate the synergic effect of combination of orbital decompression surgery and methylprednisolone pulse therapy (MPT) and MPT alone on the visual function in patients with bilateral dysthyroid optic neuropathy (DON).

METHODS

For each involved patient with bilateral DON, only one eye was treated with orbital decompression surgery which was conducted by the same doctor, and each of them received MPT after surgery. If the visual function deteriorated despite treatment, patients would switch to the other treatment. All the patients were followed up for 3 months after surgery. Clinical features of patients including best corrected visual acuity (BCVA), intraocular pressure (IOP), proptosis, upper eyelid retraction, and clinical activity score (CAS) before and after surgery were analyzed, respectively. Visual field and visual evoked potential (VEP) tests were also performed. Paired t-test and Wilcoxon matched-pairs signed ranks sum test were used to analyze the data.

RESULT

A prospective cohort of 23 patients with bilateral DON was enrolled in this cohort study. No patients failed to the therapy or switched to another treatment. The quantitative variables were shown as means and standard deviations (SD). After 3 months of combined treatment of orbital decompression surgery and MPT, BCVA (logMAR) improved, proptosis was reduced and the upper eyelid retraction was relieved in both eyes of patients; however, these improvements were more significant in the operated eyes than in the fellow (nonoperated) eyes. IOP decreased significantly in the operated eyes (P=0.002), while having no significant change in the nonoperated eyes (P=0.002), while having no significant change in the nonoperated eyes (P=0.002), while having no significant change in the nonoperated eyes (P=0.002), while having no significant change in the nonoperated eyes (P=0.002), while having no significant change in the nonoperated eyes (P=0.002), while having no significant change in the nonoperated eyes (P=0.002), while having no significant change in the nonoperated eyes (P=0.002), while having no significant change in the nonoperated eyes (P=0.002), while having no significant change in the nonoperated eyes (P=0.002), while having no significant change in the nonoperated eyes (P=0.002), while having no significant change in the nonoperated eyes (P=0.002), while having no significant change in the nonoperated eyes (P=0.002), while having no significant change in the nonoperated eyes (P=0.002), while having no significant change in the nonoperated eyes (.

CONCLUSION

A combination of orbital decompression and MPT can significantly improve visual function in patients with DON, reduce intraocular pressure, and relieve clinical symptoms such as upper eyelid retraction and proptosis, while MPT alone has a limited effect. For DON patients, orbital decompression should be performed promptly to improve the visual function.

Update on the clinical assessment and management of thyroid eye disease

PURPOSE OF REVIEW

To offer an update on advances and controversies in the assessment, investigation and treatment of thyroid eye disease (TED), a disfiguring orbital autoimmune disease, which can manifest with diplopia and threaten not only sight - but also life.

RECENT FINDINGS

Developments in biomarkers and imaging are helping to tailor the management of patients. Emerging therapies target different pathways in the disease and are informed by studies into TED pathogenesis: the last 2 years has, for example, seen the culmination of a two-decade long bench-to-bedside story in which an original focus on the IGF1 receptor has translated into an effective treatment for proptosis in thyroid eye disease. Whether this will result in a real-world reduction in TED-related morbidity will depend on access; commercial pricing decisions may preclude widespread adoption of novel therapies.

SUMMARY

Thyroid eye disease research is enjoying a renaissance with advances in both monitoring and treatment coupled with a renewed emphasis on a holisitic approach, which includes aesthetic care for patients; this is perhaps the most exciting time to be part of the international thyroid eye disease community in decades - for physicians, surgeons and patients. The commercial window for break-through drugs are narrowing with an array of new therapeutic agents in the pipeline over the coming decade.