Orbital Expansion in Cranial Vault After Minimally Invasive Extradural Transorbital Decompression for Thyroid Orbitopathy

Orbital Decompression: Conceptual Approach for Orbital Volume Expansion

PURPOSE

To review the advances in the surgical techniques of orbital decompression.

METHODS

A literature review of orbital decompression surgery and experience-based consideration of bony areas for decompression.

RESULTS

In the 100-year-plus span of orbital decompression literature, multiple incisions and multiple bone and fat removal strategies have been described. In general, bone removal has been conceptualized as consisting of 4 walls of the orbit. However, the orbital bony anatomy is more subtle than a simple box, and considering 6 areas of potential bony removal allows a more nuanced paradigm for clinical decision-making and for understanding various technique descriptions. Historical and current techniques, and surgical planning and decision-making, are described from the perspective of a 6 area paradigm. Potential complications are reviewed.

CONCLUSION

A conceptual framework for orbital decompression focusing on 6 potential areas of bone removal provides a nuanced and flexible paradigm for understanding and describing surgical techniques, and for designing individualized surgery. Orbital decompression surgery should be customized to the patient's anatomy and symptoms.

[Potential of bony regrowth after deep lateral orbital decompression]

The article describes a very rare case of bony regrowth after deep lateral orbital decompression for thyroid eye disease. Bony regrowth was observed in the area of the resected «trigone» of the greater wing of the sphenoid bone and in the area of the exposed dura mater. This case demonstrates that bony regrowth can be a possible cause of exophthalmos (proptosis) recurrence after orbital decompression in thyroid eye disease without clinical or laboratory evidence of reactivation of the disease.

Thyroid Eye Disease: Navigating the New Treatment Landscape

Thyroid eye disease (TED) is a complex inflammatory disease that can have a long clinical course with sight-threatening and debilitating ocular sequelae. Until recently, there were limited therapeutic options available. In the last decade we have gained a deeper understanding of the underlying pathophysiology, which has led to the development of novel effective targeted therapies. This article discusses the challenges encountered in the clinical evaluation and treatment of TED patients, with the goal to empower endocrinologists and ophthalmologists to work together to provide effective multidisciplinary care. We will review recommendations of past clinical guidelines around evaluation and management of TED patients, discuss the randomized controlled trials of new biologic therapies, and explore how to navigate the emerging therapeutic landscape.

Deep Lateral Wall Partial Rim-Sparing Orbital Decompression with Ultrasonic Bone Removal for Treatment of Thyroid-Related Orbitopathy

Purpose

To describe the results of thyroid-related orbitopathy (TRO) treated by ultrasonic deep lateral wall bony decompression with partial rim sparing (DLW-PRS).

Methods

A review was carried out, from January 2015 to September 2017, of all patients treated with ultrasonic DLW-PRS decompression using a SONOPET® (Stryker, Kalamazoo, MI, USA) ultrasonic aspirator, using a lateral, small triangle flap incision for access. The primary outcome was the change in proptosis (measured by the difference in Hertel exophthalmometry measurements). Other secondary outcomes were changes in visual acuity (VA) (using Snellen scale, decimal fraction), presence of lagophthalmos, eyelid retraction (measured by upper eyelid margin distance to the corneal reflex (MRD₁) and lower eyelid margin distance to the corneal reflex (MRD₂), and presence of exposure keratopathy).

Results

A total of 58 orbital decompressions in 35 patients were reviewed, with 23 patients (65.7%) having bilateral decompressions. There was a female preponderance with 26 patients (74.2%), and the mean age ± standard deviation was 52.6 ± 13.9 years. Mean proptosis was 24.51 ± 1.76 mm preoperatively, reduced to 19.61 ± 1.27 mm in final follow-up. The mean reduction was 4.9 ± 1.54 mm. VA improved from 0.8 ± 0.14 to 0.9 ± 0.12, p=0.039. 5 of 13 patients (38.4%) with preoperative diplopia reported improvement or complete resolution after surgery. MRD₁ was reduced from 5.25 ± 0.88 mm to 4.49 ± 0.7 mm. MRD₂ was also reduced from 6.3 ± 0.88 mm to 5.0 ± 0.17 mm. Presence of lagophthalmos was reduced from 35 eyes (60.3%) to five (8.6%); the presence of epiphora was also reduced from 20 patients (57.1%) to 3 (8.5%) following decompression. Complications of the surgery included zygomatic hypoaesthesia in 14 (40%) patients in the early postoperative period and chewing alterations in 10 (28.5%) of the patients. All of these complications were resolved at the 6-month follow-up visit. We noted no surgical complications such as ocular or soft tissue damage, infection, inflammation, or visual loss.

Conclusions

The SONOPET® ultrasonic bone curette can be used safely and effectively for DLW orbital decompression surgery. The main benefits were good visualization and handling of tissues and speed and ease of use of the equipment. This trial is registered with ClinicalTrials.gov identifier: NCT04025034.