Modified endoscopic transnasal orbital apex decompression in dysthyroid optic neuropathy

Yunhai Tu,Mingna Xu,Wencan Wu,Zhaoqi Pan,Andy D Kim,Michael T M Wang

doi:10.1186/s40662-021-00238-2

Abstract

BackgroundTo describe the surgical technique and assess the clinical efficacy and safety of modified endoscopic transnasal orbital apex decompression in the treatment of dysthyroid optic neuropathy.MethodsIn this retrospective research, forty-two subjects (74 orbits) who underwent modified endoscopic transnasal orbital apex decompression for the treatment of dysthyroid optic neuropathy were enrolled. Preoperative and postoperative best-corrected visual acuity (BCVA), visual field mean deviation (MD), Hertel exophthalmometry, and new onset diplopia were assessed before and after the intervention. The Wilcoxon test was used for differential analysis. Linear mixed-models’ analyses were conducted to assess the potential predictors for BCVA change.ResultsPostoperatively, the mean BCVA improved from 0.70 ± 0.62 logMAR to 0.22 ± 0.33 logMAR. BCVA significantly improved in 69 eyes (93%), remained stable in 4 eyes (5%) and deteriorated in 1 eye (1%). MD of visual fields improved from −13.73 ± 9.22 dB to −7.23 ± 7.04 dB. Proptosis decreased from 19.57 ± 3.38 mm to 16.35 ± 3.01 mm. Preoperative BCVA, MD of visual fields and medical rectus diameter were independent factors associated with improvements in BCVA (P < 0.05) by linear mixed-models’ analyses. Eighteen patients (42.9%) developed new diplopia postoperatively.ConclusionModified endoscopic transnasal orbital apex decompression effectively restores vision in dysthyroid optic neuropathy.

Highlights

To describe the surgical technique and assess the clinical efficacy and safety of modified endoscopic transnasal orbital apex decompression in the treatment of dysthyroid optic neuropathy
Patients with thyroid-associated ophthalmopathy (TAO) were deemed eligible if their age was greater than or equal to 18 years and with the presence of at least one of the followings: visual acuity (VA) > 0.1 logMAR; visual field (VF) defect (defined as the mean deviation (MD) of less than −5 dB); optic disc swelling; evidence of orbital apex crowding on a highresolution computed tomography (HRCT) scan
Clinical measures All participants underwent a comprehensive ocular examination including the determination of bestcorrected visual acuity (BCVA), degree of proptosis, intraocular pressure (IOP), and optical coherence tomography retinal nerve fibre layer (RNFL) thickness

Summary

Introduction

To describe the surgical technique and assess the clinical efficacy and safety of modified endoscopic transnasal orbital apex decompression in the treatment of dysthyroid optic neuropathy. Surgical removal of the orbital wall aims to expand the (2021) 8:19 available orbital volume and decompress the optic nerve [5]. This can be performed in conjunction with orbital fat decompression if fat hypertrophy is present [6]. The endoscopic transnasal approach provides good visualization [9, 10], and has been shown to provide superior postoperative visual recovery than the transcaruncular approach [11] For these reasons, endoscopic transnasal medial wall decompression has gained progressive popularity [6, 12, 13]

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