Surgical decompression in endocrine orbitopathy. Visual evoked potential evaluation and effect on the optic nerve

Monitoring of visual-evoked potentials during fat packing in endoscopic resection of a giant pituitary adenoma

Background

Endoscopic transsphenoidal surgery has become a mainstay surgical approach for sellar pathologies and can effectively decompress mass effects on the optic nerves. Visual-evoked potentials (VEPs) have been utilized as an intraoperative adjunct during endoscopic transsphenoidal surgery to monitor the integrity of the optic pathways, but the data surrounding its reliability and efficacy remain heterogeneous.

Case Description

An 80-year-old male underwent endoscopic transsphenoidal resection of a pituitary macroadenoma with preoperative visual deficits related to optic nerve compression. During fat packing of the resection cavity, a decrease in VEPs was noted, which seemingly improved after partial fat removal, although with paradoxically reduced VEP latencies. Despite this, the patient developed a visual field deficit postoperatively, requiring re-operation for further removal of the fat packing.

Conclusion

This was a case of initially poorly formed VEPs that deteriorated and apparently improved following surgical intervention. The finding of shortened latencies of the VEPs was likely from noise contamination, creating the illusion of improved signal amplitudes. We recommend careful assessment of VEP data for baseline reproducibility, particularly in patients with pre-existing visual field deficits. Appropriate anesthetic selection is also important to reduce noise interference from the electroencephalogram.

Comparison of surgical effect in active and inactive Dysthyroid Optic Neuropathy after Endoscopic Transnasal Medial Orbital Decompression

PURPOSE

To evaluate and compare the changes in orbital soft tissue volume and visual function after endoscopic transnasal medial orbital decompression in patients with active and inactive dysthyroid optic neuropathy (DON).

METHODS

This prospective, cohort study recruited 112 patients (112 eyes) with DON who were divided into an active and inactive DON group (56 eyes each) by clinical activity scores. All patients underwent endoscopic transnasal medial orbital decompression. The pre- and post-operative orbital soft tissue volumes were measured with high-resolution computed tomography (CT) using Mimics software. Visual function, including best-corrected visual acuity (BCVA), visual field (VF), and visual evoked potential (VEP), was recorded before and after surgery.

RESULTS

Preoperatively, compared with the inactive DON group, the active DON group had greater extraocular muscle volume (EMV) and EMV/orbital volume (OV) ratio, but worse BCVA, VF, and exophthalmos. Postoperatively, although the EMV slightly increased, with the enlarged medial rectus muscle contributing dramatically, the EMV/OV ratio decreased in patients with DON. Besides, visual function including BCVA, VF, VEP and exophthalmos was also improved in both groups after surgery. There were no significant differences in postoperative OV; EMV; EMV/OV ratio; and the BCVA, VF, and VEP parameters between both groups (all P > 0.05).

CONCLUSION

Patients with DON who did not respond well to steroids, regardless of disease activity, may benefit from orbital decompression via the decrease in the proportion of EMV in OV, especially patients with active DON, who showed more improved visual function than patients with inactive DON.

Visual evoked potential changes following Botox administration in patients with blepharospasm

PURPOSE

To examine visual evoked potential (VEP) changes following botulinum toxin type A (BTA) administration in patients with blepharospasm.

METHODS

Patients diagnosed with blepharospasm receiving BTA administration were included in the study. Three groups, a control group and two study groups (patients examined 14 days after BTA administration-Study Group 1, and patients examined 28 days after BTA administration-Study Group 2) were evaluated. Dilated fundus examinations were performed following detailed ophthalmological examinations and VEP tests. Keypoint (Dantec, Denmark) and ISCEV criteria were adopted for pattern VEP (PVEP) recording. BTA was applied in the form of local injections at a total 15-30 units, at 2.5-5 units per injection.

RESULTS

A mean 19.4 ± 3.2 units of BTA was used for each eye. N70 (ms), P100 (ms), and P100 (uV) values were statistically significantly lower in both study groups following drug administrations compared to the control group (p < 0.001 for all). Significant positive correlation was observed between increased P100 amplitudes and age in the control group (p = 0.008, r = 0.200). Significant negative correlation was observed between the BTA units used and decreased P100 amplitudes in both study groups 1 and 2 following drug administrations (p = 0.017, r = - 0.180 and p = 0.043, r = - 0.153, respectively).

CONCLUSION

VEP may be an important method in the diagnosis and follow-up of blepharospasm and in determining the success of drug administration and additional therapeutic requirements.

Effectiveness of orbital decompression for endocrine orbitopathy and impact on quality of life: A retrospective study

To evaluate the effectiveness of orbital decompression intervention in terms of variation of the exophthalmos and to highlight its association with changes in quality of life before and after surgery. Medical records of patients with moderate-severe GO who underwent orbital decompression surgery were retrospectively reviewed. Clinical parameters, including demographic characteristics, surgical technique, exophthalmos values, and QoL using the GO-QoL questionnaire were studied before and after orbital decompression and analyzed. Thirty patients were included in the study. Surgery was bilateral 26 patients and unilateral in 4 patients (56 operated orbits). Before surgery the average value of exophthalmometry was 24.96 (±2.68) mm. The questionnaires submitted for assessment of the quality of life (GO-QoL) yielded average values of 43.3 for the visual function (VF) and 44.03 for the appearance (AP). 20 patients (64.3%) underwent combined bone and fat decompression surgery, 9 underwent fat decompression, and 1 underwent bone decompression. After surgery, the average values of exophthalmometry were 21.8 (±2.34) mm, with an average reduction of 3.20 (±2.35) mm. (p < 0.0001) GO-QoL questionnaires administered after surgery showed a mean VF score of 76.73 (±26.75), and AP score of 73.71 (±21.89). (p < 0.001, paired t-test) Orbital decompressive surgery is not only effective on GO, but also on a long-term improvement in overall well-being, self-confidence and QoL.

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.

[Orbital decompression : Indications, technique, results]

Orbital decompression is an effective surgical procedure to reduce intraorbital pressure. Causes may diseases leading to rapid pressure increases, e. g., bleedings, and those causing slower, progressive pressure increases, e. g., tumors or Graves' orbitopathy. During fat tissue decompression, peri- and retrobulbar adipose tissue is removed; in bony decompression, one or more bony orbital walls are removed (one-, two-, or three-wall decompression). In many cases the procedures are combined. Recent developments are the transconjunctival approaches for removing parts of bony orbital walls. Complications include double vision, which occurs in up to 30% of cases depending on the approach, hemorrhage, infections, development of chronic sinusitis, and iatrogenic skull base lesions with consecutive meningitis. In the hands of an experienced rhino- and head and neck surgeon, the intervention has low complication rates.

Electrophysiological Studies in Thyroid Associated Orbitopathy: A Systematic Review

Dysthyroid optic neuropathy (DON) is the commonest cause of blindness in thyroid associated orbitopathy (TAO). While diagnosis remains clinical, objective tests for eyes with early or equivocal findings are lacking. Various electrophysiological studies (EPS) have been reported, yet the types and parameters useful for DON remain inconclusive. We performed a systematic literature search in MEDLINE, EMBASE and the Cochrane databases via the OVID platform up to August 20, 2017. 437 records were identified for screening and 16 original studies (1327 eyes, 787 patients) were eligible for review. Pattern visual evoked potential (pVEP) was the most frequently studied EPS. Eyes of TAO patients with DON showed delayed P100 latencies, decreased P100 amplitudes or delayed N75 latencies during pVEP, compared to those without or healthy controls. Due to study heterogeneity, no quantitative analysis was possible. This review highlights the most common type (pVEP) and useful parameters (P100 latency and amplitude) of EPS, and supports further research on them using standardized testing conditions.

Fat-removal orbital decompression for thyroid associated orbitopathy: The right procedure for the right patient

Orbital decompression is an effective and invaluable procedure for addressing some of the chronic manifestations of Graves’ Ophthalmopathy (GO) such as exophthalmos and orbital congestion. Fat–removal orbital decompression (FROD) started to gain popularity after its introduction in the late 20th century. Among the therapeutic armamentarium of techniques and approaches available for orbital decompression, FROD has proven its efficacy and safety in addition to its ability to reduce proptosis in a relatively predictable manner. In addition, postoperative complications occurring after FROD are generally considered to be less frequent and less serious compared to bone-removal orbital decompression (BROD). Nevertheless, despite of FROD’s high benefit-to-risk ratio, proper selection of patients based on meticulous preoperative assessment, including imaging, is of paramount importance to achieve optimal functional and aesthetic results. Although up till now there is still no consensus regarding the procedure of choice in GO patients, FROD is an important option to consider in this subset of patients.

[Transethmoidal decompressive orbitotomy in the patients presenting with endocrine ophthalmopathy at the stage of remission: peculiarities of the surgical intervention and the results of exophthalmos correction]

The objective of the present study was to analyze the original results of the transethmoidal decompressive surgical interventions on the eye orbits of the patients presenting with endocrine ophthalmopathy (EOP) including the evaluation of regress of exophthalmos during the post-operative period. The study included 51 patients with endocrine ophthalmopathy at the stage of remission or pharmacotherapeutic compensation of the underlying process. A total of 80 eye-socket were treated in 29 patients with unilateral exophthalmos and 22 ones having bilateral exophthalmos. All the patients underwent transethmoidal decompression of the orbit (TEDO) with the use of the endonasal approach. The examination before and after surgery included the standard ophthalmological evaluation (such as the external inspection, visiometry, tonometry, computed perimetry, biomicroscopy, and ophthalmoscopy) as well as additional studies including exophthalmometry and orbitometry. The activity of endocrine ophthalmopathy was estimated with use of the clinical activity score scale. The main indication for surgery was cosmetically unacceptable exophthalmos. The results of the analysis of the surgical techniques employed in the present study, anatomical features revealed intra-operatively, methods of post-operative care for the patients, and final outcomes of the treatment taken together have demonstrated the high effectiveness of transethmoidal decompressive surgery. Not a single case of visual acuity deterioration was documented during the follow-up period. Persistent convergent strabismus and post-operative diplopia developed in 18% of the patients. Regress of exophthalmos following transethmoidal decompressive orbitotomy varied from 3.5 to 6.5 mm and averaged 5.1 mm in comparison with the mean initial value of 23.9 mm. In means that transethmoidal decompressive orbitotomy ensured the overall regress of exophthalmos by 18.8 mm (p<0.05). The multispiral CT study revealed the significant reduction of the volume of the eye muscles and the intraorbital adipose tissue. It is worthwhile to emphasize the necessity of the detailed preoperative examination of the patients. Our study included the patients presenting with endocrine ophthalmopathy at the stage of remission or pharmacotherapeutic compensation which gave hope of the favourable outcome of the treatment in terms of the degree of regress of exophthalmos and the improvement of the quality of life. The decision to perform transethmoidal decompressive orbitotomy should be taken based on the results of the multidisciplinary conference including an otorhinolaryngologist, ophthalmologist, and endocrinologist. It is concluded that the results of the present study give evidence of the social significance of transethmoidal decompressive orbitotomy taking into consideration that the patients given such treatment experience dramatic improvement of the quality of life.

[The complications of transethmoidal decompressive orbitotomy associated with endocrine ophthalmopathy]

The objective of the present study was the analysis of the results of transethmoidal decompressive orbitotomy (TEDO) with the resection of the bone matrix of the medial and inferior orbital walls in the patients presenting with endocrine ophthalmopathy (EOP) with the purpose of reduction of the risk of development of this pathological conditions. A total of 51 patient with EOP at the stage of complete remission or pharmacotherapeutic compensation underwent transethmoidal decompressive medial orbitotomy in the ENT Clinic of 1 I.M. Sechenov First Moscow State Medical University during the period from 2006 to 2016. Twenty two of these patients presented with the unilateral process and 29 ones with bilateral exophthalmos. The surgical intervention was performed on the total of 80 eye orbits. The main complaints of the treated patients during the post-operative period included difficulties in nasal breathing (33%), dryness of the nose and crust formation (43%), discharge from the nose and along the posterior pharyngeal wall (15%), nasal bleeding (2%), pain in the forehead and maxillary region (8%), headache (2%). As far as the state of eyes and sight is concerned, 14 (27%) patients reported double vision at the primary gaze position while 6 others (12%) complained of the appearance of diplopia upon a change in the gaze position during the post-operative period. The post-operative endoscopic study revealed synechiae of different localization in the nasal cavity (47%), discharge from the maxillary sinuses (16%) and from the frontal sinus (2%). Eight (16%) patients were found to suffer from maxillary sinusitis, one had acute frontitis, and one sphenoidal sinus mucocelle. These complications were eliminated by pharmacotherapy and additional surgical interventions (2%). Analysis of the results of the study has demonstrated that the above complications were associated with the inadequate post-operative care for the nasal cavity, the excessively large size of the bone window formed during transethmoidal decompressive orbitotomy, resection of the inferior orbital wall, intrusion of the medial rectus muscle of the eye into the wide bone window. We evaluated the possible influence of the orbital soft tissues on the physiological parameters of the functioning of the paranasal sinuses in the post-operative period including blockade of the paranasal drainage pathways by the prolapsed orbital tissues. A few possible approaches to the reduction of the risk of post-operative complications are proposed. The authors emphasize the importance of the further improvement of the surgical treatment of endocrine ophthalmopathy.

Compressive Optic Neuropathy and Repeat Orbital Decompression: A Case Series

PURPOSE

To characterize the presenting characteristics, preoperative clinical activity score (CAS), surgical approach, and visual outcomes in patients with thyroid eye disease undergoing repeat orbital decompression for recurrent or recalcitrant compressive optic neuropathy (CON).

METHODS

The medical records of patients with recurrent or recalcitrant CON undergoing repeat orbital decompressions were retrospectively reviewed. The primary outcome measures included pre- and postoperative Humphrey visual field mean deviation, visual acuity (VA) measured in logarithm of the minimal angle of resolution, color vision measured by Ishihara plates, and presence of relative afferent pupillary defect. Details of the surgical procedure and each patient's CAS at presentation were also recorded.

RESULTS

Six patients, 9 orbits, with a mean preoperative CAS of 3.8 were included in this review. The mean time between initial decompression and presentation to our center for recurrent or persistent CON symptoms was 8.6 years (range, 1 to 15 years). At presentation, the average Humphrey visual field mean deviation was -16.5 (standard deviation: 8.8), improving to -3.8 (2.4) postoperatively with a mean of 9.3 months follow up (mean improvement of 75%). Preoperative VA was 0.34 (0.23) LogMAR, improving to 0.05 (0.10) LogMAR with a mean follow up of 10.4 months. Pre- to postoperative comparisons of clinical measures all showed statistically significant improvement (p < 0.05). Eight eyes presented with decreased VA (any VA < 20/20), 4 with decreased color vision (any color vision < 11), and 1 with a relative afferent pupillary defect, and all these patients demonstrated improvement following repeat orbital decompression.

CONCLUSIONS

In patients with thyroid eye disease, symptoms of recurrent CON occurred up to 15 years following initial orbital decompression underscoring the smoldering, progressive nature of the disease. Repeat decompression that focused on the orbital apex resulted in visual improvement in all 6 patients. Despite clinical evidence of CON, the mean CAS of these patients at presentation was only 3.8, highlighting the importance of close monitoring of patients with thyroid eye disease following decompression regardless of the external manifestations of disease activity.

Surgical care burden in orbito-temporal neurofibromatosis: Multiple procedures and surgical care duration analysis in 47 consecutive adult patients

Patients with orbito-temporal neurofibromatosis (OTNF) bear a heavy burden of surgical care. We studied 47 consecutive patients with OTNF from the French Neurofibromatosis 1 Referral Center cohort (n > 900), over a 15-year period to determine the clinical features most likely to predict repeat surgery and longer duration of surgical care. Forty-seven patients (5.2% of the NF1 patients' cohort) underwent 79 procedures with a 4.8 years average follow-up. Soft-tissue surgery had a high revision rate (19/45 patients), skeletal surgery did not (2/13 patients). Transosseous wire canthopexy and facial aesthetic unit remodeling were associated with stable outcome. Ptosis repair carried an unfavorable outcome, particularly in the presence of sphenoid dysplasia. Stable skeletal remodeling was achieved with polyethylene implants and/or cementoplasty. Multiple procedures were undertaken in 70% of patients and were predicted by the NF volume, canthopexy, skeletal dysplasia, or a Jackson's classification 2 and/or 3; but not by declining visual acuity. A classification based upon predictive risk of repeated procedures is proposed: Group 1: Isolated soft tissue infiltration not requiring levator palpebrae or canthal surgery; Group 2: Soft tissue involvement requiring ptosis repair or canthopexy, or NF great axis over 4.5 cm; Group 3: Presence of sphenoid dysplasia with pulsatile proptosis, regardless of visual acuity.

Myeloid sarcoma: a rare case of an orbital mass mimicking orbital pseudotumor requiring neurosurgical intervention

Objective. A rare case of myeloid sarcoma (MS), previously referred to as granulocytic sarcoma or chloroma, is presented. Representing a unique form of acute myeloid leukemia (AML), MS may rarely occur in adults. Even rarer, MS may occur as the initial presentation of AML. Methods. We report a singular and illustrative case of an orbital pseudotumor mimicking mass in a 65-year-old male as the initial presentation of AML. Results. Neurosurgical intervention was required to establish the definitive diagnosis via right modified orbitofrontozygomatic craniotomy as well as to decompress the optic canal, superior orbital fissure, and orbit. Conclusion. Postoperatively, he reported decreased pain and improvement of his vision. Further examination revealed decreased proptosis and improved extraocular mobility. Pathological findings demonstrated MS. We review the literature and discuss the neurosurgical relevance of MS as the initial presentation of AML.

Clinical and radiological characteristics of Graves' orbitopathy patients showing spontaneous decompression

OBJECTIVE

To investigate clinical implications and radiological characteristics of spontaneous decompression in patients with Graves' orbitopathy (GO).

METHODS

The medical records and images of GO patients showing spontaneous decompression in computed tomography (CT) scans without any other cause, such as orbital surgery or trauma were retrospectively reviewed. Clinical parameters, including clinical activity score (CAS), modified NOSPECS score, exophthalmometry results, extraocular muscle involvement, and the presence of optic nerve compression were evaluated. Paired orbit analyses of maximum recti muscle diameters, area of lamina papyracea, and number of ethmoid air cell septa were determined quantitatively in the unilaterally decompressed group.

RESULTS

77 orbits of 55 patients were found to present spontaneous decompression, which was observed only in the medial orbital wall in all cases. In the paired orbit comparison, maximal diameters of medial (P = 0.009) and lateral recti muscles (P = 0.023) were significantly larger in decompressed orbits than in non-decompressed orbits. However, the incidence of optic neuropathy was not significantly different (P = 0.500). There was no difference in anatomic features of lamina papyracea or ethmoid air cells between decompressed and non-decompressed orbits.

CONCLUSIONS

Spontaneous decompression occurred in the medial wall, associated with enlarged horizontal recti muscles, but not with structures of lamina papyracea or the ethmoidal sinus. Orbital bone remodeling by spontaneous decompression by lowering intraorbital pressure, might have provided a protective effect against the development of optic neuropathy.

Surgical decompression for optic neuropathy from carotid artery ectasia: case report with technical considerations

OBJECTIVE

Symptomatic compression of the optic nerve (ON) through its intracranial course or within the orbit may occur at several locations by abnormalities of adjacent soft tissue, bony, or vascular structures. Compressive optic neuropathy secondary to vascular ectasia is a rare phenomenon.

CASE DESCRIPTION

An adult male patient presented with a several month history of monocular visual loss. Imaging demonstrated compression of the ipsilateral ON by an ectatic carotid artery. Magnetic resonance imaging, ophthalmologic examination, and cerebral angiography did not demonstrate an alternative etiology of his visual loss. Conservative management was recommended; however, the patient's vision deteriorated further and pterional craniotomy was offered. Intraoperative examination demonstrated a distal origin of the ophthalmic artery that was bulging into, and pulsating against, the adjacent ON. Anterior clinoidectomy, falciform ligament transection, and sponge padding of the ON were then performed. The patient's visual loss improved rapidly postoperatively and at 1 month follow-up the patient exhibited normal visual fields on ophthalmologic testing.

CONCLUSIONS

We present a patient with severe monocular visual loss and significant anatomic displacement of the ON by an ectatic internal carotid artery-ophthalmic artery complex with dramatic and rapid visual improvement after surgical decompression. Complete untethering of the nerve and total cessation of transmitted pulsatility may not be necessary for symptomatic improvement. Optic nerve contact or displacement by the ipsilateral carotid artery is common in asymptomatic patients, therefore ruling out other etiologies of monocular visual loss before surgical decompression is paramount.