Ptosis Surgery in Patients with Myasthenia Gravis: A Useful Adjunct to Medical Therapy

Eyelid Surgery in Thyroid Eye Disease

PURPOSE

To review and summarize a comprehensive synopsis of surgery of the eyelid in thyroid eye disease (TED).

METHODS

A PubMed search for specific eyelid manifestations of TED was performed. Studies reporting surgical management of these were reviewed, along with the author's own experience.

RESULTS

The most common eyelid manifestations of TED include eyelid retraction, blepharoptosis, entropion, and epiblepharon, with most of them requiring surgical intervention. The correction of eyelid retraction has received maximum attention, with several surgical techniques that have stood the test of time. Blepharoptosis in TED that requires surgical intervention is usually aponeurotic. Entropion and Epiblepharon are rare in TED, and may resolve spontaneously, or following orbital decompression.

CONCLUSIONS

Retraction is the commonest eyelid manifestation of TED, with multiple surgical options available for its correction. Blepharoptosis, entropion, and epiblepharon are rare eyelid findings in TED, that may occasionally require surgical correction.

Ocular Myasthenia Gravis: A Current Overview

Ocular myasthenia gravis (OMG) is a neuromuscular disease characterized by autoantibody production against post-synaptic proteins in the neuromuscular junction. The pathophysiological auto-immune mechanisms of myasthenia are diverse, and this is governed primarily by the type of autoantibody production. The diagnosis of OMG relies mainly on clinical assessment, the use of serological antibody assays for acetylcholine receptors (AchR), muscle-specific tyrosine kinase (MusK), and low-density lipoprotein 4 (LPR4). Other autoantibodies against post-synaptic proteins, such as cortactin and agrin, have been detected; however, their diagnostic value and pathogenic effect are not yet clearly defined. Clinical tests such as the ice test and electrophysiologic tests, particularly single-fiber electromyography, have a valuable role in diagnosis. The treatment of OMG is primarily through cholinesterase inhibitors (pyridostigmine), and steroids are frequently required in cases of ophthalmoplegia. Other immunosuppressive therapies include antimetabolites (azathioprine, mycophenolate mofetil, methotrexate) and biological agents such as B-cell depleting agents (Rituximab) and complement inhibitors (eculizumab). Evidence is scarce on the effect of immunosuppressive therapy on altering the natural course of OMG. Clinicians must be vigilant of a myasthenic syndrome in patients using immune-check inhibitors. Reliable and consistent biomarkers are required to assess disease severity and response to therapy to optimize the management of OMG. The purpose of this review is to summarize the current trends and the latest developments in diagnosing and treating OMG.

A review of surgical management of progressive myogenic ptosis

PURPOSE

Surgical correction of myogenic ptosis is a sophisticated endeavor, as the disease is progressive and the post-operative course is prone to significant complications. We sought to review the literature for repair techniques in different types of myogenic ptosis.

METHODS

A PubMed/MEDLINE literature search of publications pertaining to surgical outcomes of progressive myogenic ptosis repair was performed. Studies included were original retrospective studies with a minimum of four patients.

RESULTS

A total of 27 articles were identified and divided by etiology of myogenic ptosis; either chronic progressive external ophthalmoplegia (CPEO), oculopharyngeal muscular dystrophy (OPMD), myasthenia gravis (MG), or mixed. Surgical techniques predominantly involved levator advancement, levator resection, frontalis sling, blepharoplasty, and Fasanella-Servat. Success rates ranged from 60.5% to 100%. Significant postoperative complications included ptosis recurrence, under-correction, over-correction, keratopathy, lagophthalmos, sling exposure, and sling infection.

CONCLUSION

Like surgical repair for other forms of ptosis, correction of progressive myogenic ptosis is guided by levator excursion. However, myogenic ptosis is especially challenging as it is characterized by worsening ptosis and the loss of protective corneal mechanisms. The goals of care with myogenic ptosis involves repairing ptosis just sufficiently to alleviate visual obstruction while avoiding adverse post-operative complications. This intentional under-correction subsequently increases susceptibility for ptosis recurrence. Myogenic ptosis repair therefore requires delicate balancing between function, sustained repair, and corneal protection.

Pediatric Ocular Myasthenia Gravis: A Review

Pediatric ocular myasthenia gravis (OMG) is difficult to diagnose and manage, owing to its rarity and low index of suspicion in the early stage of the disease. Also, many other conditions having similar presentation cause a further delay in diagnosis. In this review, we highlighted various pointers in history and described bedside clinical tests that can aid in its timely diagnosis. The antibody spectrum in myasthenia is ever increasing and includes anti-muscle specific kinase and low-density lipoprotein-receptor related protein 4 antibodies in addition to acetylcholine receptor antibodies besides many others. However, pediatric OMG patients often test negative for all three antibodies, making the diagnosis even more difficult in triple seronegative patients. Edrophonium and electrophysiological tests, which help in confirming myasthenia in adults, have a limited utility in diagnosing pediatric ocular myasthenia cases. Various practical difficulties are encountered like nonavailability of edrophonium, risk of bradycardia associated with neostigmine use and its lower sensitivity, noncooperative children, and limited technical expertise in performing electrophysiological tests in children. In this article, we described a pragmatic approach to diagnose pediatric OMG along with the important aspects of its management.

Physical training and exercise in myasthenia gravis

Myasthenia gravis is characterized by muscle weakness and fatigue. As sustained muscle use increases the weakness, the value of physical training programs has previously been questioned. This is a review to clarify the safety and usefulness of systematic training in myasthenia gravis, based on a systematic search in available databases using the relevant key words. Ten intervention studies including 159 patients with generalized disease have been published regarding the effect of systematic physical training, three of them on respiratory muscles. Muscle strength improved, and in the majority of the studies also daily function and quality of life. The feeling of fatigue not directly related to actual muscle weakness was less influenced by physical training. Continuous training was necessary to maintain the improved function. Physical training and exercise are safe in myasthenia gravis. This can improve both muscle strength and daily function. Type and intensity of systematic training should be adapted in the individual patient. A minimum of 150 min of exercise per week is recommended for myasthenia gravis patients with mild and moderate disease.

Safety and Efficacy of the Under-Corrected Frontalis Sling in Myogenic Ptosis Accompanying Extraocular Muscle Paralysis

OBJECTIVE

The surgical treatment of myogenic ptosis accompanying extraocular muscle paralysis is an intractable problem in the field of oculoplastic surgery due to the severe complications such as exposure keratopathy. It is promising to find an appropriate procedure to treat this kind of patients, which is able to ensure the safety and efficacy.

METHODS

The authors retrospectively reviewed 12 eyes of 6 patients who underwent the under-corrected "double V-Loop" frontalis suspension sling procedure for myogenic ptosis accompanying extraocular muscle paralysis and access the safety and efficacy of this kind of surgery. All the patients underwent corneal fluorescein staining and confocal microscopy before and after the surgery to inspect the corneal condition. The density of central corneal epithelial cells and endothelial cells were observed.

RESULTS

After the surgery, the eyelids contour was natural, and the symmetry was achieved in these cases. The average palpebral fissures height changed from 2.75 ± 1.41 mm to 4.50 ± 0.35 mm (P = 0.0007) and margin reflex distance 1 changed from -1.25 ± 1.22 mm to +0.50 ± 0.35 mm (P = 0.0002). Out of 12 operated eyes, mild postoperative lagophthalmos was present in 4 cases but without exposure keratopathy during the follow-up, the confocal microscopy showed that there were no significant differences in central corneal superficial epithelial cells (P = 0.93) and endothelial cells (P = 0.90) before and after the surgery.

CONCLUSION

The under-corrected "double V-Loop" frontalis suspension sling is a proper surgery in myogenic ptosis accompanying extraocular muscle paralysis, which leads to a low occurrence of exposure keratopathy, maintains the integrity of the cornea, and remains the patients' vision function.

A Practical Approach to Managing Patients With Myasthenia Gravis-Opinions and a Review of the Literature

When the diagnosis of myasthenia gravis (MG) has been secured, the aim of management should be prompt symptom control and the induction of remission or minimal manifestations. Symptom control, with acetylcholinesterase inhibitors such as pyridostigmine, is commonly employed. This may be sufficient in mild disease. There is no single universally accepted treatment regimen. Corticosteroids are the mainstay of immunosuppressive treatment in patients with more than mild MG to induce remission. Immunosuppressive therapies, such as azathioprine are prescribed in addition to but sometimes instead of corticosteroids when background comorbidities preclude or restrict the use of steroids. Rituximab has a role in refractory MG, while plasmapheresis and immunoglobulin therapy are commonly prescribed to treat MG crisis and in some cases of refractory MG. Data from the MGTX trial showed clear evidence that thymectomy is beneficial in patients with acetylcholine receptor (AChR) antibody positive generalized MG, up to the age of 65 years. Minimally invasive thymectomy surgery including robotic-assisted thymectomy surgery has further revolutionized thymectomy and the management of MG. Ocular MG is not life-threatening but can be significantly disabling when diplopia is persistent. There is evidence to support early treatment with corticosteroids when ocular motility is abnormal and fails to respond to symptomatic treatment. Treatment needs to be individualized in the older age-group depending on specific comorbidities. In the younger age-groups, particularly in women, consideration must be given to the potential teratogenicity of certain therapies. Novel therapies are being developed and trialed, including ones that inhibit complement-induced immunological pathways or interfere with antibody-recycling pathways. Fatigue is common in MG and should be duly identified from fatigable weakness and managed with a combination of physical therapy with or without psychological support. MG patients may also develop dysfunctional breathing and the necessary respiratory physiotherapy techniques need to be implemented to alleviate the patient's symptoms of dyspnoea. In this review, we discuss various facets of myasthenia management in adults with ocular and generalized disease, including some practical approaches and our personal opinions based on our experience.