A Split-Face, Single-Blinded, Randomized Controlled Comparison of 532 nm Picosecond Neodymium-Doped Yttrium Aluminum Garnet Laser versus 532 nm Q-Switched Neodymium-Doped Yttrium Aluminum Garnet Laser in the Treatment of Solar Lentigines.

BACKGROUND: Solar lentigines are the most common form of benign epidermal pigmentation and one of the major cosmetic concerns in Korea. A 532 nm Q-switched neodymium: yttrium-aluminum-garnet (QSND) laser is typically used for the treatment, but the occurrence of post-inflammatory hyperpigmentation (PIH) is not rare. Recently, the use of picosecond (PS) lasers has emerged in pursuit of better outcomes. OBJECTIVE: To objectively compare the efficacy and safety of 532 nm PS and QSND lasers for the treatment of solar lentigines. METHODS: Twenty patients with solar lentigines were enrolled in a prospective, randomized split-face, single-blind study. One side of each face was treated using a 532 nm PS laser, and the other side using a 532 nm QSND laser. After one treatment, all patients were followed up for evaluation after 2, 4, 8, and 12 weeks. The clinical clearance was assessed by three blinded dermatologists using a 5-point quartile improvement scale (QIS). Subjective satisfaction, development of PIH, pain scale during treatment, and adverse problems were also recorded. RESULTS: Clinical clearance measured by QIS showed that the PS laser was more effective than the QSND laser. Subjective satisfaction and pain scale did not significantly differ between the two groups. The incidence of PIH was 5% in sides treated with the PS laser, and 30% with the QSND laser. CONCLUSION: Both 532 nm PS laser and QSND laser were effective for the treatment of solar lentigines, but the PS laser was more effective with less PIH development.

Clinical Outcome of 1064-nm Picosecond Neodymium-Doped Yttrium Aluminium Garnet Laser for the Treatment of Hypertrophic Scars.

BACKGROUND: Currently no study has evaluated the effect of the novel 1064-nm picosecond neodymium-doped:yttrium aluminium garnet laser (ps-Nd:YAG) for reducing Hypertrophic scarring (HS). OBJECTIVE: The aim of this study was to verify the efficacy and safety of a 1064-nm ps-Nd:YAG in the management of HS. MATERIALS AND METHODS: A retrospective chart review and photographic analysis were conducted on patients treated with a low-fluence 1064-nm ps-Nd:YAG for HS improvement. The Vancouver Scar Scale (VSS), 5-point Global Assessment Score (GAS), and patient satisfaction score were used to determine the effect of scar improvement. RESULTS: A total of 24 Korean patients (9 males and 15 females; mean age of 33.25 ± 15.50 years) were retrospectively evaluated. Mean treatment settings were 1064-nm wavelength, 750 ps pulse duration, 7.94 mm spot size, 0.93 J/cm2 fluence, and 9.69 Hz frequency. The average VSS score decreased significantly (from 5.33 to 2.71) after laser treatment (p < 0.001). The average GAS (3.02 ± 0.93) showed fair cosmetic improvement, and patient satisfaction scores (6.88 ± 2.66) indicated moderate satisfaction. CONCLUSION: The novel low-fluence 1064-nm ps-Nd:YAG could be considered as an effective and safe optional modality for the treatment of HS in Asian skin.

Characteristics of Patients Who Are Not Responsive to Alternate Patching for Overcorrected Intermittent Exotropia.

PURPOSE: To compare the characteristics of patients with surgically overcorrected intermittent exotropia treated with alternate patching. METHODS: The medical records of 51 patients who underwent bilateral lateral rectus muscle recession for intermittent exotropia and required alternate patching to correct postoperative overcorrection were retrospectively reviewed. Patients with postoperative esodeviation ≥18 prism diopters (PD) were started on alternate patching on postoperative day 1, whereas those with postoperative esodeviation of 10 to 17 PD were started after 2 weeks. Postoperative esodeviation <10 PD was considered as slight intentional overcorrection after exotropia surgery. Patients not responsive to alternate patching treatment were defined as those with postoperative esodeviation ≥10 PD after 3 months of treatment. Sex, family history, age, refractive error, amblyopia, stereopsis, suppression, type of exotropia, surgical method, preoperative and postoperative angle of deviation, and start time of alternate patching were compared. RESULTS: Among 51 patients, 29 patients responded to alternate patching and 22 patients did not respond. Female sex (p = 0.04), larger preoperative exodeviation at distance (p = 0.04), late onset of postoperative maximal esodeviation (p < 0.01), larger postoperative maximal esodeviation at near (p = 0.02), and late initiation of alternate patching (p = 0.01) were associated with patients in the non-responsive group. Although postoperative angle of deviation was similar for 2 weeks, the angle of postoperative esodeviation was significantly larger in the non-responsive group than in the responsive group, beginning at 1 month postoperatively. CONCLUSIONS: Female sex, large preoperative exodeviation, late initiation of alternate patching, and large esodeviation 1-month postoperative predisposed patients to be resistant to alternate patching for postoperative overcorrection.

Unilateral lateral rectus muscle advancement surgery based on one-fourth of the angle of consecutive esotropia.

BACKGROUND: To evaluate the efficacy of unilateral lateral rectus muscle advancement surgery based on one-fourth of the angle of consecutive esotropia within 25 prism diopters (PD) occurring after bilateral lateral rectus muscle recession for intermittent exotropia. METHODS: Medical records of 11 patients who underwent unilateral lateral rectus muscle advancement for consecutive esotropia from 2011 to 2014 and who were observed for at least 6 months after surgery were retrospectively reviewed. The change in angle of deviation from before to after consecutive esotropia surgery, as well as the success rate and surgical effect, were evaluated. RESULTS: Preoperative esodeviation was -19.6 ± 4.7 PD [median - 20.0 PD, interquartile range (IQR) 9.0] at distance and -16.5 ± 7.4 PD [median - 18.0 PD, IQR 17.0] at near. The mean surgical amount of unilateral lateral rectus muscle advancement surgeries, based on one-fourth of the angle of consecutive esotropia, was 4.8 ± 1.1 mm [median 5.0 mm, IQR 2.0]. Of the 11 patients, 10 (91%) recovered to orthotropia or exodeviation within 8 PD. The surgical effects of unilateral lateral rectus muscle advancement were 3.3 ± 0.7 PD/mm [median 3.6 PD/mm, IQR 1.0] after 1 day, 3.7 ± 0.6 PD/mm [median 3.8 PD/mm, IQR 1.0] after 1 week, and 3.8 ± 0.7 PD/mm [median 3.8 PD/mm, IQR 1.5] after 6 months. CONCLUSIONS: Unilateral lateral rectus muscle advancement surgery based on one-fourth of the angle of consecutive esotropia within 25 PD was successful in all 11 patients. The surgical effect was significantly greater in unilateral lateral rectus muscle advancement than in primary lateral rectus muscle recession. Reduction in the amount of surgery should be considered carefully in unilateral lateral rectus muscle advancement for consecutive esotropia.

Efficacy and safety of a novel picosecond laser using combination of 1 064 and 595 nm on patients with melasma: A prospective, randomized, multicenter, split-face, 2% hydroquinone cream-controlled clinical trial.

BACKGROUND AND OBJECTIVES: Melasma is a common acquired, chronic hypermelanosis and still remains a therapeutic challenge. The low-fluence 1 064 nm Q-switched Nd:YAG laser is the most widely used for the treatment of moderate to severe melasma in Asia. Recently, the picosecond laser has been introduced for various pigmentary disorders such as melasma. We evaluated the efficacy and safety of a picosecond laser with dual-wavelengths (1 064 and 595 nm) and topical 2% hydroquinone (HQ) combination therapy on patients with melasma, and compared results with those obtained with 2% HQ alone. STUDY DESIGN/MATERIALS AND METHODS: This was a prospective, randomized, split-face, controlled trial comparing two treatments with combined 7 week 2% HQ (daily) and 5 week picosecond laser (weekly) versus 7 week 2% HQ. The primary efficacy variable was the change rate of the relative lightness values (RL*I) at week 7 from baseline. RL*I at a follow-up visit, modified melasma severity score (mMASI), and satisfaction were assessed. RESULTS: Picosecond laser and 2% HQ had superior efficacy to 2% HQ alone: 30/39 (76.92%) subjects on combination treatment achieved ≥51% improvement of RL*I versus 1/39 (2.56%) subjects on 2% HQ. The mMASI, RL*I, and satisfaction on the laser-treated side at week 7 supported these results. Aside from RL*I, no difference between the laser-treated versus control side was found after follow-up. No serious adverse events were reported. CONCLUSION: A 750 picosecond laser using 1 064 and 595 nm was effective and safe for the treatment of Korean melasma patients. The picosecond laser with dual-wavelength used in this study can reduce the photothermal effect generated during the removal of pigment and total duration of the procedure, and can be expected to reduce the occurrence of adverse events. Lasers Surg. Med. 49:899-907, 2017. © 2017 Wiley Periodicals, Inc.

Correlation between depth and area of retinal nerve fiber layer defect as measured by spectral domain optical coherence tomography.

BACKGROUND: To evaluate the correlation between the depth and area of retinal nerve fiber layer (RNFL) defect, as measured on an RNFL map of spectral-domain optical coherence tomography (SD-OCT). METHODS: The RNFL of 472 glaucoma subjects and of 217 healthy subjects was imaged by an SD-OCT. RNFL defect depth and area on the RNFL map were expressed as an RNFL defect depth percentage index (RDPI) and an RNFL defect area index (RDAI), respectively, according to the following two formulas: 100×[1-{summation of thicknesses of RNFL defects/summation of thicknesses of upper 95th percentile range of age-matched healthy subjects in areas corresponding to defects}]; 100×[number of superpixels of RNFL defects/(46 × 46-superpixels inside optic disc or ß zone parapapillary atrophy)]. The best-fitting model describing the relationship between the two parameters was derived by fractional polynomial analysis. RESULTS: Logarithmic fit was determined to be the best-fitting model in describing the relationship of the RDPI against the RDAI (y = 53.4 + 3.7 ln(x) and y = 50.9 + 5.9 ln(x) in superior and inferior hemifields, respectively). The expected RDAIs at the point where the RDPI and RDAI rates of change were the same were 3.7 and 5.9 %; the corresponding upper 95 % confidence interval limits of the RDPI 59.0 and 61.8 % in the superior and inferior hemifields, respectively. CONCLUSIONS: The correlation between the RNFL defect depth and area, as derived from the RNFL map, was best described by the logarithmic fit. Changes were more marked in depth than in area, especially for mild localized defects.

Quantitative assessment of retinal nerve fiber layer defect depth using spectral-domain optical coherence tomography.

PURPOSE: To assess quantitatively the depth of retinal nerve fiber layer (RNFL) defects using a Cirrus high-definition (HD) optical coherence tomography (OCT)-derived RNFL thickness deviation map. DESIGN: Prospective, cross-sectional study. PARTICIPANTS: Three-hundred fifteen eyes with localized and diffuse RNFL defects of 315 glaucoma patients and 217 eyes of 217 healthy subjects. METHODS: For the glaucoma subjects, the severity of the RNFL defect was graded on red-free fundus photographs by 2 observers using a standardized protocol with a 3-level grading system. The RNFL defect depth on the RNFL thickness deviation map was expressed as an RNFL defect depth percentage index (RDPI): 100×(1-[summation of thicknesses of RNFL defects {red or yellow superpixels}/summation of RNFL thicknesses of upper 95th percentile range of age-matched healthy subjects in areas corresponding to RNFL defects]). MAIN OUTCOME MEASURES: Retinal nerve fiber layer defect depth percentage index, average and segmental (4 quadrants and 12 clock-hour sectors) circumpapillary RNFL (cpRNFL) thicknesses according to the RNFL defect severity, and the area under the receiver operating characteristic curves (AUROCs) for various OCT parameters. RESULTS: The RDPIs increased with the increasing severity of the RNFL defect in both the superior and inferior hemifields (P <0.05, 1-way analysis of variance test with Bonferroni correction). The AUROCs of the RDPIs (0.969 and 0.975 in the superior and inferior hemifields, respectively) were larger than those of all of the cpRNFL thicknesses in discriminating the mild from the moderate RNFL defects (P <0.05). Meanwhile, in discriminating the moderate from the severe RNFL defects, the AUROCs of the RDPIs (0.961 and 0.891 in the superior and inferior hemifields, respectively) were larger than those of the cpRNFL thicknesses in all areas except the inferior quadrant and the 6-, 7-, and 11-o'clock sectors (P <0.05). CONCLUSIONS: The RDPI, a new parameter using a Cirrus HD OCT-derived RNFL thickness deviation map, can be a useful adjunct tool for objective quantification of RNFL defect depth. This parameter has an advantage over cpRNFL thickness in discriminating between mild and moderate RNFL defects, not in discriminating between moderate and severe defects.

Biomimetic walking trajectory generation of humanoid robot on an inclined surface using Fourier series.

This article describes a novel method to generate a biomimetic walking trajectory for a biped humanoid robot on an inclined surface. We assume that the configuration of the inclined surface is known, and we solve the human-like walking trajectory generation problem by obtaining the solution from the desired zero moment point (ZMP) trajectory to the center of gravity (CoG) trajectory. We present an analytic solution for the walking trajectory generation by using Fourier series. From the given ZMP trajectory biomimetically represented by the Fourier series, we focus on how to find the CoG trajectory in an analytical way. A time-segmentation based approach is adopted for generating the trajectories. The trajectory functions need to be continuous between the segments; thus, the solution is found by calculating the coefficients under these connectivity conditions. We derive a general form of the ZMP equation using a simple inverted pendulum model (SIPM), which includes the ZMP and the CoG trajectories in the horizontal and vertical directions to quantify the walking parameters on the inclined surface. The performance of the proposed approach is verified by conducting walking simulations using a full-body dynamic simulator on three different inclined surfaces and comparing them to the authors' previous approach.

Nanotransfer molding of free-standing nanowire and porous nanomembranes suspended on microtrenches.

Direct transfer printing of functional materials has been employed in the development of sensors, displays, and energy-harvesting devices. The transfer process can be applied advantageously to depositions onto nonplanar and flexible surfaces at low temperatures. In this work, we fabricated free-standing nanowire arrays and nanomembranes on micrometer-scale trenches by nanotransfer molding. We also investigated how deposition pattern types vary with trench dimensions as well as processing pressure and temperature. Finally, a free-standing polymer membrane fabricated by nanotransfer molding was employed as a novel mask in the preparation of three-dimensional nanodot arrays.