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

Bei Li,Li Feng,Huamin Tang,Liuzhi Zeng,Wei Lin

doi:10.1186/s12886-021-01911-9

Abstract

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

Highlights

Thyroid-associated ophthalmopathy (TAO), known as Graves’ ophthalmopathy (GO) or thyroid eye disease (TED), is an autoimmune disease that accounts for the highest incidence of orbital diseases in adults
Based on the anatomy of the orbit, most of the orbital fat outside the muscle cone is located in the front of the orbit, and the most direct force that causes exophthalmos comes from the fat in the muscle cone behind the eyeball
Case inclusion criteria: all patients met the criteria for moderate to severe patients in the inactive phase based on the guidelines formulated by European Group on Graves’ Orbitopathy (EUGOGO) [1], and their thyroid function and exophthalmos had been stable for more than half a year

Summary

Introduction

Thyroid-associated ophthalmopathy (TAO), known as Graves’ ophthalmopathy (GO) or thyroid eye disease (TED), is an autoimmune disease that accounts for the highest incidence of orbital diseases in adults. Surgery is an effective treatment for moderate to severe inactive patients, patients with active severe exposed ocular surface inflammation, and active patients with oppressive optic neuropathy [1]. In most of the literature, during orbital fat decompression surgery, the orbital fat inside the muscle cone, and the orbital fat outside the muscle cone is removed [4–7]. Based on the anatomy of the orbit, most of the orbital fat outside the muscle cone is located in the front of the orbit, and the most direct force that causes exophthalmos comes from the fat in the muscle cone behind the eyeball. In our experience, removing the orbital fat outside the muscle cone had no effect on improving the exophthalmos and might affect the position of the eyeball. Some surgeons only removed the fat behind the ball during the surgery without the need to disturb the anterior orbital fat pads, and achieved obvious surgical effect [2]

Methods

Results

Conclusion