Comparing open and closed techniques of frontalis suspension with silicone rod for the treatment congenital blepharoptosis.

PURPOSE: To compare open and closed methods of the frontalis suspension operation with a silicone rod in the treatment of congenital blepharoptosis. METHODS: Forty-four cases with unilateral or bilateral congenital ptosis with a poor levator function of < 4 mm were divided randomly into two groups. Each group underwent an eyelid crease incision operation (open) or a supralash stab incision (closed). Ptosis was measured by the difference between the upper eyelid margin reflex distance (MRD) of the affected eyelids of the unilateral and bilateral cases. Frequent follow-up examinations were performed up to 12 months post-surgery. RESULTS: Associated ophthalmologic findings showed that amblyopia, strabismus, wound discharge and knot dehiscence problems were present in 36.6%, 27.3%, 8.5% and 8.5% of the patients, respectively. There was no significant difference between the abovementioned associated ophthalmic findings of the two operative methods studied (P = 0.37). The difference in the surgical methods and MRD 3, 6 and 12 months after operation did not reach statistical significance. Similar results for good MRD (3 < MRD < 5) were found in closed (54.5%, 12/22) and open (54.5%, 12/22) methods, while 40.9% (9/22) and 45.5% (10/22) of cases were attributed to the under correction group in the closed and open methods, respectively. In bilaterally operated cases, MRD was more symmetrical than in unilaterally operated eyes. The symmetry of MRD and the eyelid crease was more prevalent in the open technique group. CONCLUSIONS: The frontalis sling operation using a silicone rod exhibited better results, in terms of symmetry, in the open technique in comparison to the closed method.

Magnetic field effects on the crystal structure, morphology, energy gap, and magnetic properties of manganese selenide nanoparticles synthesized by hydrothermal method.

In this study, we synthesized manganese selenide under magnetic fields ranging from 0 to 800 gauss and investigated its optical, electrical, and magnetic properties. In the absence of a magnetic field, we observed the formation of MnSe nanorods. As the field strength increased, impurities arose. In the 250 G range, two rock salt structures emerged, altering the morphology from nanorods to cubes. Beyond 250 G, MnSe2 formed, returning to a nanorod morphology. Also, with the increase of the magnetic field, the energy gap of the synthesized compounds increased. To measure the electrical properties of the samples, the synthesized powders were compressed under the same pressure for a certain period of time, and it was observed that the synthesized samples showed insulating behavior in the presence of a magnetic field. For this reason, we performed current-voltage, resistance-temperature, and current-temperature analyses on the synthesized sample, at a constant voltage of 5 eV in the absence of a magnetic field.

Highly improved supercapacitance properties of MnFe2O4 nanoparticles by MoS2 nanosheets.

Manganese ferrite (MnFe2O4) nanoparticles were synthesized via a hydrothermal method and combined with exfoliated MoS2 nanosheets, and the nanocomposite was studied as a supercapacitor. X-ray diffractometry and Raman spectroscopy confirmed the crystalline structures and structural characteristics of the nanocomposite. Transmission electron microscopy images showed the uniform size distribution of MnFe2O4 nanoparticles (~ 13 nm) on few-layer MoS2 nanosheets. UV-visible absorption photospectrometry indicated a decrease in the bandgap of MnFe2O4 by MoS2, resulting in a higher conductivity that is suitable for capacitance. Electrochemical tests showed that the incorporation of MoS2 nanosheets largely increased the specific capacitance of MnFe2O4 from 600 to 2093 F/g (with the corresponding energy density and power density of 46.51 Wh/kg and 213.64 W/kg, respectively) at 1 A/g, and led to better charge-discharge cycling stability. We also demonstrated a real-world application of the MnFe2O4/MoS2 nanocomposite in a two-cell asymmetric supercapacitor setup. A density functional theory study was also performed on the MnFe2O4/MoS2 interface to analyze how a MoS2 monolayer can enhance the electronic properties of MnFe2O4 towards a higher specific capacitance.

Incremental substitution of Ni with Mn in NiFe2O4 to largely enhance its supercapacitance properties.

By using a facile hydrothermal method, we synthesized Ni1-xMnxFe2O4 nanoparticles as supercapacitor electrode materials and studied how the incremental substitution of Ni with Mn would affect their structural, electronic, and electrochemical properties. X-ray diffractometry confirmed the single-phase spinel structure of the nanoparticles. Raman spectroscopy showed the conversion of the inverse structure of NiFe2O4 to the almost normal structure of MnFe2O4. Field-emission scanning electron microscopy showed the spherical shape of the obtained nanoparticles with a size in the range of 20-30 nm. Optical bandgaps were found to decrease as the content of Mn increased. Electrochemical characterizations of the samples indicated the excellent performance and the desirable cycling stability of the prepared nanoparticles for supercapacitors. In particular, the specific capacitance of the prepared Ni1-xMnxFe2O4 nanoparticles was found to increase as the content of Mn increased, reaching the highest specific capacitance of 1,221 F/g for MnFe2O4 nanoparticles at the current density of 0.5 A/g with the corresponding power density of 473.96 W/kg and the energy density of 88.16 Wh/kg. We also demonstrated the real-world application of the prepared MnFe2O4 nanoparticles. We performed also a DFT study to verify the changes in the geometrical and electronic properties that could affect the electrochemical performance.

Three novel mutations in KIF21A highlight the importance of the third coiled-coil stalk domain in the etiology of CFEOM1.

BACKGROUND: Congenital fibrosis of the extraocular muscles types 1 and 3 (CFEOM1/CFEOM3) are autosomal dominant strabismus disorders that appear to result from maldevelopment of ocular nuclei and nerves. We previously reported that most individuals with CFEOM1 and rare individuals with CFEOM3 harbor heterozygous mutations in KIF21A. KIF21A encodes a kinesin motor involved in anterograde axonal transport, and the familial and de novo mutations reported to date predictably alter one of only a few KIF21A amino acids--three within the third coiled-coil region of the stalk and one in the distal motor domain, suggesting they result in altered KIF21A function. To further define the spectrum of KIF21A mutations in CFEOM we have now identified all CFEOM probands newly enrolled in our study and determined if they harbor mutations in KIF21A. RESULTS: Sixteen CFEOM1 and 29 CFEOM3 probands were studied. Three previously unreported de novo KIF21A mutations were identified in three CFEOM1 probands, all located in the same coiled-coil region of the stalk that contains all but one of the previously reported mutations. Eight additional CFEOM1 probands harbored three of the mutations previously reported in KIF21A; seven had one of the two most common mutations, while one harbored the mutation in the distal motor domain. No mutation was detected in 5 CFEOM1 or any CFEOM3 probands. CONCLUSION: Analysis of sixteen CFEOM1 probands revealed three novel KIF21A mutations and confirmed three reported mutations, bringing the total number of reported KIF21A mutations in CFEOM1 to 11 mutations among 70 mutation positive probands. All three new mutations alter amino acids in heptad repeats within the third coiled-coil region of the KIF21A stalk, further highlighting the importance of alterations in this domain in the etiology of CFEOM1.

A novel PHOX2A/ARIX mutation in an Iranian family with congenital fibrosis of extraocular muscles type 2 (CFEOM2).

PURPOSE: To describe the clinical features of two affected members of an Iranian family with autosomal recessive congenital fibrosis of the extraocular muscles (CFEOM2) and to report their novel mutation in the PHOX2A/ARIX gene. DESIGN: Experimental study. SETTING: Institutional practice. patient population:Six members of an Iranian family with CFEOM underwent complete ocular examinations including assessment of ocular motility, visual acuity, slit-lamp biomicroscopy, tonometry, and ophthalmoscopy. EXPERIMENTAL PROCEDURE: Mutation analysis of the PHOX2A gene was performed using polymerase chain reaction amplification of the coding exons and direct sequencing of polymerase chain reaction products. MAIN OUTCOME MEASURE: Presence or absence of mutation in PHOX2A gene in two siblings with exotropia and recessive CFEOM. Exotropia and ptosis were corrected surgically in one of the two siblings. RESULTS: The two affected siblings had bilateral ptosis and exotropia and severe limitation of all extraocular movements. One patient underwent strabismus surgery and ptosis repair. PHOX2A mutation analysis revealed a novel nonsense mutation in exon 2 (439C-->T). Both parents and the unaffected siblings were heterozygous,and the two affected siblings were homozygous for this mutation. CONCLUSIONS: The 439C-->T mutation in this family changes a glutamine to a stop codon (Q90X) at the beginning of the PHOX2A homeodomain region. This is the fourth CFEOM2 mutation in PHOX2A and the first nonsense mutation to be identified. It confirms PHOX2A as the autosomal recessive CFEOM2 disease gene and provides evidence that the phenotypic differences between PHOX2A mutations in man and mouse do not result from hypomorphic PHOX2A alleles in humans.

Classification and surgical management of patients with familial and sporadic forms of congenital fibrosis of the extraocular muscles.

PURPOSE: To outline the clinical features and surgical treatment of patients with familial and sporadic (simplex) forms of congenital fibrosis of extraocular muscles (CFEOM) from 2 countries, and to classify them according to phenotype and mode of inheritance. DESIGN: Observational and experimental study. METHODS: Twenty-eight affected individuals from 20 families with familial or sporadic CFEOM underwent assessment of ocular motility, visual acuity, slit-lamp biomicroscopy, tonometry, and ophthalmoscopy. Seventeen patients had a variety of eye muscle procedures and ptosis repair. RESULTS: There were 1 Iranian family with autosomal dominant CFEOM, 4 Iranian families with autosomal recessive disease, and 15 simplex cases with various CFEOM phenotypes. Two simplex patients had unilateral disease. All other cases were bilateral. Inferior rectus recession improved hypotropia and Bell's phenomenon in the patients with infraducted eyes and chin elevation. Horizontal muscle recession, sometimes combined with opposite muscle resection, corrected horizontal strabismus satisfactorily in most cases. Ptosis was repaired by frontalis sling and/or levator resection. CONCLUSION: Definite recessive CFEOM was present only in Iranian patients. American patients had the classic phenotype of dominant CFEOM, which was also observed in some of the Iranian patients. The surgical management of patients with CFEOM is challenging. Correction of vertical and horizontal strabismus was addressed using large muscle recessions. Ptosis repair should aim at placing the lid level 1 to 2 mm above the pupil in the primary position to avoid exposure keratopathy.