Cauterization-mediated restriction from penetrating orbital trauma.

A healthy 32-year-old woman presented with binocular diplopia immediately after sustaining a penetrating injury to the left periocular adnexa with a hot metal skewer. Examination revealed an incomitant esotropia, with complete limitation of abduction of the left eye with downshoot in left gaze and normal afferent visual function. Computed tomography and magnetic resonance imaging demonstrated no fracture, but there was mild thickening of the medial rectus muscle and associated fat stranding. Lack of orbitomuscular tethering or hematoma led to the presumptive diagnosis of thermal cauterization injury causing left medial rectus restriction. Given the lack of literature on this mechanism of injury, the patient was monitored closely. She exhibited remarkable spontaneous improvement in motility over 6 months, with near orthophoria in primary gaze. However, bothersome residual esotropic diplopia in left gaze prompted a left medial rectus recession, with a good outcome. This case demonstrates that isolated extraocular muscle thermal injuries and consequential strabismus can recover spontaneously; longitudinal observation before surgical intervention may be appropriate in such cases.

Orbital and Eyelid Characteristics, Strabismus, and Intracranial Pressure Control in Apert Children Treated by Endoscopic Strip Craniectomy versus Fronto-Orbital Advancement.

Apert syndrome is characterized by eyelid dysmorphology, V-pattern strabismus, extraocular muscle excyclorotation, and elevated intracranial pressure (ICP). We compare eyelid characteristics, severity of V-pattern strabismus, rectus muscle excyclorotation, and ICP control in Apert syndrome patients initially treated by endoscopic strip craniectomy (ESC) at about 4 months of age versus fronto-orbital advancement (FOA) performed about 1 year of age. Methods: Twenty-five patients treated at Boston Children's Hospital met inclusion criteria for this retrospective cohort study. Primary outcomes were magnitude of palpebral fissure downslanting at 1, 3, and 5 years of age, severity of V-pattern strabismus, rectus muscle excyclorotation, and interventions to control ICP. Results: Before craniofacial repair and through 1 year of age, none of the studied parameters differed for FOA versus ESC treated patients. Palpebral fissure downslanting became statistically greater for those treated by FOA by 3 (P < 0.001) and 5 years of age (P = 0.001). Likewise, severity of palpebral fissure downslanting correlated with severity of V-pattern strabismus at 3 (P = 0.004) and 5 (P = 0.002) years of age. Palpebral fissure downslanting and rectus muscle excyclorotation were typically coexistent (P = 0.053). Secondary interventions to control ICP were required in four of 14 patients treated by ESC (primarily FOA) and in two of 11 patients initially treated by FOA (primarily third ventriculostomy) (P = 0.661). Conclusions: Apert patients initially treated by ESC had less severe palpebral fissure downslanting and V-pattern strabismus, normalizing their appearance. Thirty percent initially treated by ESC required secondary FOA to control ICP.

Severe Eyelid Malformation With Facial Clefting and Amniotic Bands.

Amniotic bands can lead to eyelid colobomas contiguous with facial clefts, resulting in severe and highly variable eyelid malformations. There is no known underlying genetic cause of amniotic band sequence. Here, the authors review the case of an infant born with large, 4-eyelid colobomatous defects in the setting of facial clefts, amniotic bands and an underlying SMOC1 mutation, which has not previously been linked to amniotic band sequence or eyelid colobomas. Reconstructive technique and the postoperative course are described, and underlying etiologic theories of amniotic band sequence are reviewed and expanded upon. Although amblyopia prevention in this patient with poor visual potential was not a consideration, the goals of improving the patient's ocular surface and maintaining eye contact were achieved.

The Impact of Strabismus on Psychosocial Equity.

Strabismus, the condition of misaligned eyes, can result in severe, long-lasting functional and psychosocial sequelae. This review examines existing literature that has described and quantified the psychosocial consequences of strabismus. In particular, the role of strabismus in creating social, psychological, and vocational disparities, and how these intersect with race, ethnicity, and gender, is described. The reviewed data suggest that negative perceptions of strabismus are formed early in life. Overall, exotropia is more easily noticed than esotropia. Esotropia is perceived more negatively than exotropia, and there is significant variation with respect to gender, racial, and ethnic groups. The data demonstrate that the presence of strabismus affects self-esteem, interpersonal relationships, and access to vocational opportunities. Surgical correction of strabismus has been shown to provide significant and long-lasting improvements in psychosocial well-being.

Orbital disease in neuro-ophthalmology.

PURPOSE OF REVIEW: Orbital disease represents a diverse spectrum of pathology and can result in a variety of neuro-ophthalmic manifestations. The aim of this review is to provide updates on recent advances in our understanding of orbital disease secondary to thyroid eye disease, myositis, IgG4-related disease, sarcoidosis, granulomatosis with polyangiitis and various tumours. RECENT FINDINGS: With regards to thyroid eye disease, there have been recent advances in the development of steroid-sparing therapies, new modalities for objectively monitoring disease activity and increased understanding of the role of environmental risk factors. There has been interest in characterizing the clinical course and underlying mechanism of optic nerve disease secondary to orbital disorders, which has led to advances in how we monitor for and prevent permanent vision loss. Increased knowledge of orbital tumour subtype histopathology and the development of novel classification systems has had prognostic value and aided medical decision-making. SUMMARY: Orbital disease occurs secondary to a wide variety of diseases and can lead to neuro-ophthalmic manifestations with significant morbidity. Advances in our understanding of different subtypes of orbital disease have improved our ability to treat these potentially debilitating conditions.

Principles of Protection of the Eye and Vision in Orbital Surgery.

Orbital surgery can result in damage to ocular and orbital structures, leading to a range of structural and visual sequelae, including corneal abrasions, globe malposition, diplopia, and blindness. Vision loss in particular is the most feared and devastating complication, occurs with an overall incidence of 0.84%, and can occur secondary to direct injury, optic nerve compression, or ischemic events. Different types of orbital surgery and surgical approaches carry their own hazards, and it is important to be mindful of these risks in addition to having a thorough understanding of individual risk factors and anatomical variations for each patient. Although universal guidelines for preserving vision in orbital surgery do not yet exist, there are concrete steps that every surgeon can take at the preoperative, intraoperative, and postoperative stages to minimize the risk of injury and maximize the likelihood of preserving the eye and visual function.

Subperiosteal Masqueraders as Compared to Subperiosteal Abscess: Contrasting Clinical Presentation and Radiographic Densities.

PURPOSE: Subperiosteal orbital lesions are most commonly abscesses secondary to sinusitis but, in rare cases, may represent other processes. Here, the authors compare the clinical and radiographic presentation of subperiosteal abscesses and alternate subperiosteal processes ("masqueraders") in an effort to establish distinguishing preoperative diagnostic criteria. METHODS: A retrospective chart review of cases of subperiosteal orbital lesions that underwent surgical intervention over a 3-year period was performed. The medical records of 6 cases of subperiosteal masqueraders and 6 cases of abscesses were reviewed for the clinical course, imaging (including radiographic density of lesions), and pathology. Clinical and radiographic features of the 2 groups were compared. RESULTS: All cases presented with orbital signs on exam. Fever and leukocytosis were absent in the masquerader group and present in 3 patients from the abscess group. Common radiographic findings in both groups included a rim-enhancing convex mass along the orbital wall and adjacent sinus opacification, often with bony dehiscence. Of the masqueraders, the final diagnosis was hematoma in 3 cases, mucocele in 1, and malignancy in 2. The difference between the mean radiodensity of the subperiosteal abscesses, 38 ± 5 Hounsfield units (95% CI, 34-42), as compared with the average radiodensity of the masqueraders, 71 ± 5 Hounsfield units (95% CI, 67-75), was significant (p = 0.042). Comparing radiodensity of the orbital lesion to adjacent sinus lesions and metastatic lesions elsewhere was also informative in establishing the diagnosis. CONCLUSIONS: Radiographic features, particularly radiodensity, may help distinguish subperiosteal abscesses from other lesions and aid in preoperative diagnosis and management.

Punctal agenesis: Embryology, presentation, management modalities and outcomes.

Punctal agenesis is defined as the absence of the punctum occurring secondary to a failure of embryogenesis. This review synthesizes existing data on the embryology, anatomy, clinical presentation, symptomatology, management options and treatment outcomes of punctal agenesis. A foundational knowledge of the underlying embryologic and anatomical abnormalities is fundamental to understanding its clinical presentation and assists in choosing an appropriate management strategy. Existing outcomes data is generally favorable and suggests management with a step-wise approach can alleviate symptoms in patients across a spectrum of disease.

Strong tissue glue with tunable elasticity.

Many bio-adhesive materials adhere weakly to tissue due to their high water content and weak structural integrity. Others provide desirable adhesive strength but suffer from rigid structure and lack of elasticity after administration. We have developed two water-free, liquid four-armed PEG pre-polymers modified with NHS or with NH2 end groups which upon mixing changed from liquids to an elastic solid. The sealant and adhesive properties increased with the amount of the %v/v PEG4-NHS pre-polymer, and achieved adhesive properties comparable to those of cyanoacrylate glues. All mixtures showed minimal cytotoxicity in vitro. Mixtures of 90%v/v PEG4-NHS were retained in the subcutaneous space in vivo for up to 14days with minimal inflammation. This material's combination of desirable mechanical properties and biocompatibility has potential in numerous biomedical applications. STATEMENT OF SIGNIFICANCE: Many bio-adhesive materials adhere weakly to tissue (e.g. hydrogels) due to their high water content and weak structural integrity. Others provide desirable mechanical properties but suffer from poor biocompatibility (e.g. cyanoacrylates). This study proposes a new concept for the formation of super strong and tunable tissue glues. Our bio-materials' enhanced performance is the product of new neat (without water or other solvents) liquid polymers that solidify after administration while allowing interactions with the tissue. Moreover, the elastic modulus of these materials could easily be tuned without compromising biocompatibility. This system could be an attractive alternative to sutures and staples since it can be applied more quickly, causes less pain and may require less equipment while maintaining the desired adhesion strength.

Corneal Anesthesia With Site 1 Sodium Channel Blockers and Dexmedetomidine.

PURPOSE: Amino-amide or amino-ester local anesthetics, which are currently used for topical ocular anesthesia, are short acting and may delay corneal healing with long-term use. In contrast, site 1 sodium channel blockers (S1SCBs) are potent local anesthetics with minimal adverse tissue reaction. In this study, we examined topical local anesthesia with two S1SCBs, tetrodotoxin (TTX) or saxitoxin (STX) individually or in combination with α2-adrenergic receptor agonists (dexmedetomidine or clonidine), and compared them with the amino-ester ocular anesthetic proparacaine. The effect of test solutions on corneal healing was also studied. METHODS: Solutions of TTX ± dexmedetomidine, TTX ± clonidine, STX ± dexmedetomidine, dexmedetomidine, or proparacaine were applied to the rat cornea. Tactile sensitivity was measured by recording the blink response to probing of the cornea with a Cochet-Bonnet esthesiometer. The duration of corneal anesthesia was calculated. Cytotoxicity from anesthetic solutions was measured in vitro. The effect on corneal healing was measured in vivo after corneal debridement followed by repeated drug administration. RESULTS: Addition of dexmedetomidine to TTX or STX significantly prolonged corneal anesthesia beyond that of either drug alone, whereas clonidine did not. Tetrodotoxin or STX coadministered with dexmedetomidine resulted in two to three times longer corneal anesthesia than did proparacaine. S1SCB-dexmedetomidine formulations were not cytotoxic. Corneal healing was not delayed significantly by any of the test solutions. CONCLUSIONS: Coadministration of S1SCBs with dexmedetomidine provided prolonged corneal anesthesia without delaying corneal wound healing. Such formulations may be useful for the management of acute surgical and nonsurgical corneal pain.

A Stiff Injectable Biodegradable Elastomer.

Injectable materials often have shortcomings in mechanical and drug-eluting properties that are attributable to their high water contents. A water-free, liquid four-armed PEG modified with dopamine end groups is described which changed from liquid to elastic solid by reaction with a small volume of Fe3+ solution. The elastic modulus and degradation times increased with increasing Fe3+ concentrations. Both the free base and the water-soluble form of lidocaine could be dissolved in the PEG4-dopamine and released in a sustained manner from the cross-linked matrix. PEG4-dopamine was retained in the subcutaneous space in vivo for up to 3 weeks with minimal inflammation. This material's tailorable mechanical properties, biocompatibility, ability to incorporate hydrophilic and hydrophobic drugs and release them slowly are desirable traits for drug delivery and other biomedical applications.

Prolonged nerve blockade delays the onset of neuropathic pain.

Aberrant neuronal activity in injured peripheral nerves is believed to be an important factor in the development of neuropathic pain. Pharmacological blockade of that activity has been shown to mitigate the onset of associated molecular events in the nervous system. However, results in preventing onset of pain behaviors by providing prolonged nerve blockade have been mixed. Furthermore, the experimental techniques used to date to provide that blockade were limited in clinical potential in that they would require surgical implantation. To address these issues, we have used liposomes (SDLs) containing saxitoxin (STX), a site 1 sodium channel blocker, and the glucocorticoid agonist dexamethasone to provide nerve blocks lasting ~1 wk from a single injection. This formulation is easily injected percutaneously. Animals undergoing spared nerve injury (SNI) developed mechanical allodynia in 1 wk; nerve blockade with a single dose of SDLs (duration of block 6.9 ± 1.2 d) delayed the onset of allodynia by 2 d. Treatment with three sequential SDL injections resulting in a nerve block duration of 18.1 ± 3.4 d delayed the onset of allodynia by 1 mo. This very prolonged blockade decreased activation of astrocytes in the lumbar dorsal horn of the spinal cord due to SNI. Changes in expression of injury-related genes due to SNI in the dorsal root ganglia were not affected by SDLs. These findings suggest that formulations of this kind, which could be easy to apply clinically, can mitigate the development of neuropathic pain.