Faculty Bibliography

PURPOSE/OBJECTIVE:To critically review the published literature on orbital radiotherapy as a treatment modality for thyroid eye disease (TED). METHODS:A systematic review and analysis of the relevant published literature was performed. RESULTS:Thyroid eye disease is an autoimmune condition that is amenable to treatments that modulate the immune response, including orbital radiotherapy (ORT). Ideal candidates for ORT are patients in the early, active phase of TED with moderate to severe, or rapidly progressive, disease, including patients with significant motility deficits and compressive optic neuropathy. Patients with progressive strabismus may also benefit. Patients with mild or inactive disease will not benefit from ORT when compared with the natural history of the disease. Orbital radiotherapy should generally be used in conjunction with corticosteroid therapy, with response to corticosteroids demonstrating the immunomodulatory therapeutic potential of ORT. When treating TED-compressive optic neuropathy, ORT may help obviate the need for urgent surgical decompression, or postpone it until the stable, inactive phase of the disease. Orbital radiotherapy treatment doses should approach 20 Gy in most cases, but lower doses may be considered in younger patients without significant dysmotility. The safety profile of ORT is well established, and side effects are minimal in appropriately selected patients. CONCLUSIONS:Radiotherapy is a safe and effective treatment for active TED in appropriately selected patients.

PURPOSE/OBJECTIVE:To compare extraocular muscle volumes in thyroid eye disease patients with and without compressive optic neuropathy. METHODS:A retrospective review of 44 orbital CT scans (28 orbits without compressive disease and 16 orbits with compressive optic neuropathy) was conducted. The extraocular muscle volumes, summated soft tissue volumes, and optic nerve volumes were calculated at a section in the posterior 1/3 of the orbit. The visual fields of the orbits with compressive optic neuropathy were analyzed. RESULTS:The mean combined extraocular muscle/summated soft tissue volume ratio and the mean superior rectus-levator complex/summated soft tissue volume ratio were greater in those with compressive optic neuropathy than in those without compressive optic neuropathy (p = 0.02, 0.008, respectively). The ratio of the mean inferior, medial, or lateral rectus/summated soft tissue volume did not differ significantly between patients with or without compressive optic neuropathy (p values of 0.315, 0.615, and 0.254, respectively). Visual field analysis of the compressive optic neuropathy group demonstrated that 58% of the orbits with visual field defects had inferior field defects. CONCLUSIONS:When measured at a section near the orbital apex, the mean combined muscle/summated soft tissue volume ratio and the mean superior rectus-levator complex/summated soft tissue volume ratio are greater in those with compressive disease than those without. This suggests that the specific enlargement of the superior rectus-levator complex makes a significant contribution to thyroid eye disease-compressive optic neuropathy and may explain the inferior visual field deficits classically found in this group of patients.

Thyroid-related orbitopathy (TRO) is a common and recognizable manifestation of Graves' disease, caused by an increase in orbital fat volume, increased extraocular muscle diameter, and fibrosis. Together, within the bony confines of the orbit, these changes might alter the shape and position of the globe, potentially inducing refractive shifts. These refractive changes may then be affected by corrective surgical interventions for TRO such as orbital decompression and strabismus surgery. We studied refractive changes in patients with TRO who underwent strabismus surgery with or without orbital decompression. Manifest refraction was performed preoperatively and postoperatively in 33 patients who met inclusion criteria. Statistically significant postoperative refractive changes were found for cylinder, axis, and spherical equivalent.

PURPOSE/OBJECTIVE:The purpose of this study was to describe the clinical characteristics, management, and outcomes of orbital blow-in fractures involving compression of the globe by bone fragments. METHODS:A retrospective case series and systematic literature review were performed. RESULTS:Three male patients (mean age 29 years) with orbital blow-in fractures causing globe indentation presented with extraocular movement restriction, choroidal folds, and B-scan ultrasonography demonstrating deformation of the globe contour by a hyperechoic bone fragment. All underwent surgical repair within 1 day of presentation resulting in improved visual outcomes. An additional 10 cases were identified in the literature review. The majority of patients were male (80%) with a mean age of 29 years. Fractures originated primarily from the lateral orbital wall (50%) or the orbital roof (40%). Globe compression was evident on CT of the orbit (100%) and ultrasonography (30%). Common presenting signs included decreased visual acuity (70%), restriction of supraduction (40%) or abduction (40%), choroidal folds (30%), brow laceration (40%), periorbital edema (40%), and hypoglobus (40%). Most patients underwent surgical intervention (80%) involving fracture reduction (50%) or fragment removal (38%). Reported postsurgical outcomes were excellent with resolution of diplopia, motility, and visual acuity. CONCLUSION/CONCLUSIONS:Globe indentation from blow-in fractures are rare. Clinicians should be suspicious in cases of high-velocity trauma to the superolateral orbit with hypoglobus, motility limitation, and indentation of the globe upon dilated exam. Prompt diagnosis and early surgical removal of the compressive orbital bone fragments in a multidisciplinary fashion can lead to good visual, functional, and cosmetic outcomes.

PURPOSE/OBJECTIVE:The reliability of 3 volume measurement strategies was investigated using MRI and a simple method for creating phantom orbit tumors. METHODS:Water-based starch was molded into orbital "tumors" of 3 shapes (sphere, ovoid, diffuse); water displacement was used to calculate volume. "Tumors" were placed into 3D-printed orbit phantoms, MRIs were obtained and volume analysis was performed. Observers measured tumor volume using ellipsoid volume (EV), manual segmentation, and semi-automated segmentation strategies. Intraclass correlation coefficients were calculated comparing observer measurements to true volumes. The coefficient of repeatability determined the percentage of tumor volume change required for each method to detect tumor growth. RESULTS:Intraclass correlation coefficients comparing measured volumes to true volumes using EV, manual segmentation, and semi-automated segmentation were 0.61, 0.98, and 0.99 for spherical, 0.64, 0.97, and 0.98 for ovoid, and 0.18, 0.82, and 0.87 for diffuse tumors. Semi-automated segmentation followed by manual segmentation had the highest correlation between measured and true tumor volume for all 3 tumor geometries. EV had low correlation with true volume for all tumor geometries. Diffuse tumors had high variability and low correlation for all 3 measurement techniques. CONCLUSIONS:This study shows the reliability of 3 strategies to measure orbital tumor volume with MRI based on tumor geometry, using a simple phantom model. EV, the most commonly employed strategy in clinical practice, had low correlation and high variability across tumor shapes. Using manual segmentation and semi-automated segmentation, a measured change in volume greater than 25% may be considered true growth, while the EV strategy required a 40%-400% change in volume to reliably measure tumor growth.

PURPOSE/OBJECTIVE:To evaluate the association between risk of obstructive sleep apnea (OSA) and severity of thyroid eye disease (TED) using a validated OSA screening tool. METHODS:A prospective, observational cohort study was performed. New adult TED patients were offered OSA screening with the Snoring Tired Observed Pressure (STOP)-Bang survey during their initial evaluation. Clinical examination and treatment for TED were standard of care and utilized the International Thyroid Eye Disease Society Vision Inflammation Strabismus Appearance system. At the conclusion of the study period, analysis was performed correlating maximum severity of TED signs and symptoms between high- and low-risk OSA groups. Multivariate logistic and linear regression analyses were also performed to analyze the association between the numerical STOP-Bang score and maximum severity of the potentially actionable clinical features of TED (compressive optic neuropathy, vertical prism deviation, horizontal prism deviation, exophthalmos, vertical fissure height). RESULTS:Eighty-five patients met inclusion criteria. Twenty-eight percent were at high risk of OSA (STOP-Bang score of 3 or higher). When comparing the low- and high-risk cohorts, increased risk of OSA was significantly associated with the development of TED compressive optic neuropathy (p = 0.014), conjunctival injection (p = 0.027), chemosis (p = 0.013), upper eyelid edema (p = 0.024), lower eyelid edema (p = 0.003), eyelid erythema (p = 0.037), and vertical strabismus (p = 0.047). In the multivariate regression analyses, higher STOP-Bang scores correlated with increased risk of TED compressive optic neuropathy (p = 0.006), vertical strabismus (p = 0.019), and higher subjective diplopia scores (p = 0.045). CONCLUSIONS:Increased risk of OSA, as determined by the STOP-Bang survey, is associated with increased severity of multiple clinical features of TED, including TED compressive optic neuropathy and strabismus.

PURPOSE/OBJECTIVE:The purpose of this study was to describe the clinical characteristics, management, and outcomes of orbital osteomas in the pediatric age group, and compare these to osteomas managed in the adult population. METHODS:A retrospective review of 3 cases of rapidly progressive orbital osteomas in young patients was performed. In addition, a systematic review of the literature following Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines was conducted to describe the clinical characteristics, management, and outcomes of orbital osteomas in the pediatric age group. The PubMed/MEDLINE database was searched in December 2019 for studies reporting data on patients with orbital osteomas. RESULTS:Fifty-nine patients were included in this pediatric review, 39 male patients (68%), 18 female patients (32%), and 2 cases with unreported genders. Average age was 15.9 years with a range of 4-21 years. Average osteoma size measured 30.7 mm with a range of 9-60 mm. Adult osteoma size for comparison was smaller than 10 mm in majority of cases. The most common location of pediatric osteomas was the ethmoid sinus. The frontal sinus was the most common location in adult patients. Ninety-seven percent of reported pediatric cases required surgical intervention, compared with only 6.5% in adults. CONCLUSIONS:Orbital osteomas in younger patients are larger when identified, grow faster, are more likely to be symptomatic, and more likely to require surgical intervention compared with those identified in older patients. We recommend close monitoring of osteomas identified in young patients as well as counseling regarding the potential need for future resection.

PURPOSE/OBJECTIVE:To report the surgical technique and outcomes for adjustable ptosis correction using a posterior levator advancement with minimal superior tarsectomy. METHODS:A retrospective single-center study was conducted on patients who underwent adjustable ptosis repair via posterior levator advancement with minimal superior tarsectomy by a single surgeon from 2002 to 2018. Patients with greater than 1 mm asymmetry between eyes or contour abnormalities underwent nonsurgical adjustment in the office within 6 days of surgery. RESULTS:A total of 79 patients (146 eyelids) were included in this study. The patients were female (67%), underwent bilateral surgery (87%) with mean age of 63 years (range, 20-92). The mean improvement in marginal reflex distance 1 at postoperative month 1 was 2.56 ± 1.04 mm (p ≤ 0.0001). Postoperative symmetry of 1 mm or less between eyes was achieved in 96.6% of patients. Only 8 eyes (5.4%) underwent in-office adjustment postoperatively. No demographic or clinical differences were noted in eyes that required adjustments. Postoperative complications included dry eyes that resolved by 3 months (13.6%), suture cyst (1.4%), corneal abrasion (1.4%), and persistent eyelid edema (1.4%). Surgical revision was required in 2.8% of eyes. CONCLUSIONS:The adjustable posterior levator advancement with minimal superior tarsectomy is an effective surgical technique for ptosis repair with the added benefit of in-office adjustability to correct minor asymmetries.