Development of optimization method for truss structure by quantum annealing.

In this study, we developed a new method of topology optimization for truss structures by quantum annealing. To perform quantum annealing analysis with real variables, representation of real numbers as a sum of random number combinations is employed. The nodal displacement is expressed with binary variables. The Hamiltonian H is formulated on the basis of the elastic strain energy and position energy of a truss structure. It is confirmed that truss deformation analysis is possible by quantum annealing. For the analysis of the optimization method for the truss structure, the cross-sectional area of the truss is expressed with binary variables. The iterative calculation for the changes in displacement and cross-sectional area leads to the optimal structure under the prescribed boundary conditions.

Different patterns in the corneal endothelial cell loss after pars plana and pars limbal insertion of the Baerveldt glaucoma implant.

PURPOSE: To assess corneal endothelial cell (CE) loss after pars plana (PP) and pars limbal (PL) insertion of a Baerveldt glaucoma implant (BGI). DESIGN: Retrospective multicenter interventional comparative study. METHODS: We studied central CE loss for 5 years after BGI surgery in 192 eyes. RESULTS: The prevalence of bullous keratopathy (BK) was greater in the PL cohort than in the PP cohort (P = .003). The CE loss after simultaneous PP vitrectomy and tube insertion into the vitreous cavity was 11.9% in the first year, which was greater than that of 2.9% in eyes where the tube was inserted simply into the vitreous cavity after a prior vitrectomy (P = .046). The annual percentage CE loss after the first year decreased unidirectionally in both of those groups and was 1.3% and 1.0% in the fifth year, respectively (P < .001). For limbal insertion, the CE loss in the simple PL cohort was biphasic, decreasing from 10.5% in the first year to 7.0% in the fifth year. Simultaneous cataract and BGI surgery enhanced the CE loss slightly in the first year in the PP and PL cohorts to 13.0% and 14.0%, respectively. However, these increases were not significant (P = .816 and .358, respectively). Low preoperative CE density (P < .001) and insertion site (P = .020) were significant risk factors for the development of BK. CONCLUSIONS: CE loss in the PL and PP cohorts was biphasic and unidirectional, respectively. The difference in annual CE loss became evident over time. PP tube implantation may be advantageous when the preoperative CE density is low.

Factors associated with achieving intraocular pressure lower than 15 mmHg by Trabectome surgery in primary open-angle glaucoma.

To assess good prognostic factors of Trabectome surgery in primary open-angle glaucoma (POAG), clinical records of patients with POAG who underwent Trabectome surgery with/without cataract surgery as the first additive therapy to eye drops between January 2015 and March 2018 were retrospectively reviewed. Overall, data of 79 eyes (79 patients; 50 men; mean age, 68.0 years) up to postoperative 24 months were analyzed. Their mean intraocular pressure (IOP) was 20.4 ± 6.0 mmHg at baseline. Forty-two eyes (53.2%) achieved an IOP < 15 mmHg and ≥ 20% reduction from baseline without additional treatments. Phakic eyes had a better survival probability than pseudophakic eyes after adjusting for age, sex, baseline IOP, best-corrected visual acuity, and eye drop score (hazard ratio 3.096; 95% confidence interval [95% CI] 1.367-7.013; P = 0.007). Phakic eyes treated with combined Trabectome and cataract surgeries (mean survival time, 22.250 months; 95% CI 17.606-26.894) had a better survival probability than pseudophakic eyes treated with Trabectome surgery only (mean survival time, 12.111 months; 95% CI 8.716-15.506; P = 0.009) after the adjustment. Among the eyes treated with Trabectome surgery only, phakic eyes required significantly less additional treatments than pseudophakic eyes (P = 0.04). Trabectome surgery may be indicated for phakic eyes with POAG in addition to eye-drop therapy.

Operative Complications of Glaucoma Drainage Implant Tube Insertion Through the Sulcus for Pseudophakic Eye.

PRECIS: Malposition of the tube through the ciliary sulcus is more frequently observed with the Ahmed glaucoma valve (AGV) than the Baerveldt drainage implant (BDI) due to the weaker rigidity of the Ahmed tube. PURPOSE: To report intraoperative and early postoperative complications of ciliary sulcus tube insertion of glaucoma drainage implants (GDIs). PATIENTS AND METHODS: We performed retrospective analysis of 104 eyes of 94 patients with GDI tube insertion through the ciliary sulcus were performed. The rigidities of tubes were also examined using a microcompression tester. RESULTS: The mean observation period was 20.0 (range, 6 to 60) months. Thirteen eyes were treated with the BDI and 91 were with the AGV. The mean age of the patients was 69.3 (34 to 90) years. The mean intraocular pressure was 27.9 mm Hg before surgery and 12.9 mm Hg after surgery (P<0.01). Upon tube insertion 42/91 eyes (46%) with the AGV required reinsertion of the tube due to malpositioning, whereas only 1/13 (8%) eyes with BDI did (P<0.01). Transient hyphema (12 eyes) and hypotony (12 eyes) were observed as early postoperative complications with the AGV. Seven eyes with hypotony were treated by proline stenting of the tube. We could not accomplish sulcus insertions in 4 eyes. Microcompression analysis of the tubes showed that the BGI tube was more rigid than that of the AGV. CONCLUSIONS: Ciliary sulcus insertion of the tube is an effective method to control intraocular pressure. The tube of the AGV was more difficult to insert through the sulcus than the BDI due to its weaker rigidity.

Proline-assisted Tube Insertion Through Sulcus in Ahmed Valve.

To prevent corneal endothelial cell loss, ciliary sulcus tube insertion is preferred for the pseudophakic eye. However, we sometimes encounter technical difficulties when inserting the tube through the sulcus. Even in cases in which we are able to insert a 23-G needle through the sulcus into the space between the iris and intraocular lens, the tube of Ahmed valve may stray into the vitreous cavity or under Elschnig pearls. To remedy such conditions, we developed a new tube insertion method using a 4-0 proline stent as a guide to insert the tube in the appropriate position.

Effects of the Numbers and the Shapes of Venting Slits on Intraocular Pressure after Baerveldt Glaucoma Drainage Implant.

Purpose: Venting slits are widely used as an effective method to avoid the high intraocular pressure (IOP) phase immediately after the implantation of non-valved glaucoma drainage devices. However, there have been no detailed reports comparing the types of needles used and the numbers of slits made. In this study we investigated the effects of different needle types and the number of venting slits. Methods: IOP was measured using a Keyence NR-600 transducer connected to the limbus of a pig eye with a 27G needle. A microsyringe pump was also connected to the corneal limbus using a 27 G needle to make a continuous perfusion system at the rate of 200 µl/hr. The silicone tube of a Baerveldt glaucoma drainage implant (BG101-350) was ligated near the plate and then implanted in the anterior chamber of the pig eye. The tube was covered with scleral tissue of another pig eye after 1 or 3 venting slits were created in the middle of the outer diameter using different types of needles (7-0 Vicryl®, 7-0 PDSⅡ®, 5-0 PDSⅡ®, 3-0 PDS Plus®). IOP measurement was started from 50 mmHg and then we monitored the chronological changes of IOP for 15 minutes. Results: The IOPs at 15 minutes after continuous perfusion with the venting slits made using 7-0 Vicryl needles were 29.0 ± 2.5 mmHg (1 slit) and 23.1 ± 8.3 mmHg (3 slits). The IOPs were 23.1 ± 3.1 mmHg and 23.5 ± 4.7 mmHg with 7-0 PDS needles (1 slit and 3 slits, respectively), 21.8 ± 2.2 mmHg and 20.8 ± 4.3 mmHg with 5-0 PDS needles (1 slit and 3 slits, respectively), and with 3-0 PDS needles they were 12.2 ± 3.0 mmHg for one slit and 13.2 ± 3.5 mmHg for 3 slits. Conclusions: Usage of a round (PDS) needles produces more predictable IOP than a spatulated (Vicryl) needle.

Visual outcome after emergency surgery for open globe eye injury in Japan.

BACKGROUND: Most patients with open globe eye injury are brought to hospital as emergency patients and usually require admission for emergency surgery. We analyzed the visual outcome in patients with open globe eye injury at our hospital over a 4-year period. PATIENTS AND METHODS: This study reviewed 40 eyes of 40 patients with open globe eye injury who were presented to Juntendo University Shizuoka Hospital and required emergency surgery during the 4 years from January 2010 to December 2014. Retrospective evaluation of the visual outcome was performed using data from the medical records, including assessment of the influence of sex, side of the eye injury, cause of injury, and site/severity of injury. RESULTS: The mean age (SD) at the time of the injury was 58.9 years (±25.1 years). There were 28 males (70.0%) and 12 females (30.0%). Statistically significant improvement in visual acuity after treatment was noted in the males (P=0.0015, Wilcoxon test), but not in the females. Twenty-five patients had injury to the right eye (62.5%) and 15 had injury to the left eye (37.5%). A significant improvement in visual acuity was achieved after treatment of injury to the right eye (P=0.021), but not the left eye (P=0.109). The most frequent cause of injury was an accident (15 eyes; 37.5%). The second most frequent cause was work-related injury (14 eyes; 35.0%), which only occurred in males, and the third cause was accident due to negligence (eleven eyes; 27.5%). Two patients developed sympathetic ophthalmia and one patient developed postoperative endophthalmitis. CONCLUSION: The majority of patients with open globe eye injury were male workers in Japan. The visual outcome of work-related injury was better than that of injury due to other causes. The visual outcome was also better if the right eye was injured compared with the left eye. Patients with injuries due to negligence were older than the other groups, and this finding might be characteristic of an aging society.

Prevalence of drug resistance and culture-positive rate among microorganisms isolated from patients with ocular infections over a 4-year period.

PURPOSE: To investigate the microbial isolates from patients with ocular infections and the trend in the emergence of levofloxacin-resistant strains over the past four years from 2006 to 2009 retrospectively. PATIENTS AND METHODS: The subjects were 242 patients with ocular infections or traumas treated in our hospital including outpatients, inpatients, and emergency room patients. Most of them needed urgent care presenting with eye complaints, traumas, or decreased vision. Clinical samples were obtained from discharges, corneal, conjunctival tissues or vitreous fluid or aqueous humor, and cultured. Items for assessment included the patient's age, the diagnosis, the prevalence of isolated bacteria, and the results of susceptibility tests for levofloxacin (LVFX) cefamezin (CEZ), gentamicin (GM) and vancomycin. This information was obtained from the patients' medical records. RESULTS: There were 156 male patients and 86 female patients who were aged from 2 months old to 94 years old and mean age was 56.8 ± 24.2 years. Of the 242 patients, 78 (32.2%) had positive cultures. The culture-positive rate was significantly higher in male patients than female in total (P = 0.002) and in patients with corneal perforation (P = 0.005). Corneal perforation was the highest culture-positive rate (60.0%), followed by orbital cellulitis (56.5%), blepharitis (50.0%), dacryoadenitis (45.5%), conjunctivitis (38.2%), infectious corneal ulcer (28.5%) and endophthalmitis (24.7%). LVFX-resistant strains accounted for 40 out of a total of 122 strains (32.8%), and the minimum inhibitory concentration (MIC) was significantly higher in LVFX and GM compared with the other antibiotics. There were no vancomycin-resistant strains. CONCLUSION: Attention should be paid to a possible future increase of strains with resistance to LVFX, as commonly prescribed ocular antibiotics bring emergence of resistant bacteria. Although no vancomycin-resistant strains were isolated this drug should be reserved as the last resort, in order to prevent the emergence of vancomycin resistance.

Preoperative and postoperative optical coherence tomography findings in patients with rhegmatogenous retinal detachment involving the macular region.

Purpose. To evaluate morphologic changes of the macula, we observed eyes with rhegmatogenous retinal detachment (RRD) involving the macular region by optical coherence tomography (OCT). Subjects and Methods. We studied 26 eyes with RRD before and after surgery, assessing visual acuity, the height of retinal detachment at the fovea (HRD), and morphologic changes of the macular region. The interval between the onset and surgery was also determined. We examined the external limiting membrane (ELM) after surgery and the continuity of the inner segment-outer segment junction (IS/OS junction) of the photoreceptor layer. Results. Impairment of visual acuity was observed when HRD was over 1,000 µ m, when there was outer nuclear layer edema before surgery, and when there was IS/OS junction disruption 3 months after surgery. However, 67% of eyes with a continuous ELM and IS/OS junction disruption 3 months after surgery eventually showed restoration of the continuity of IS/OS junction at 6 months. Conclusions. Impairment of visual acuity was observed in eyes with HRD >1,000 µ m, preoperative outer nuclear layer edema, and IS/OS junction disruption 3 months postoperatively. It is suggested that continuity of ELM might affect restoration of IS/OS junction after surgery for retinal detachment.

Effect of long-term treatment with eyedrops for glaucoma on conjunctival bacterial flora.

OBJECTIVE: The effect of eyedrops for glaucoma on conjunctival bacterial flora was investigated by comparing a group of patients treated with such eyedrops for at least 1 year to a control group that did not use eyedrops. METHODS: In both groups, bacterial culture came from scrapings of the conjunctival sac, and the bacterial infection rate and pattern of drug resistance were determined. Findings were analyzed in various subgroups stratified by age, frequency of instillation, and concentration of antiseptic benzalkonium chloride in the eyedrops. RESULTS: The culture-positive rate was significantly lower in the glaucoma eyedrop group (43/119 eyes, 40.3%) than in the control group (19/28 eyes, 67.8%) (P < 0.05). No differences in infection rate were found among the different age groups. The most frequent bacteria in both groups was coagulase-negative staphylococci. Gram-negative bacteria were only detected in the glaucoma eyedrop group. Retrospective evaluation was possible for 86 eyes of patients from the glaucoma eyedrop group, among which 45 eyes (52.3%) showed some corneal epithelium damage. There was no difference in the culture-positive rate of bacteria between patients who used eyedrops containing 0.01% or higher dose of benzalkonium chloride and those containing less than 0.01%. Strains that showed resistance to levofloxacin were significantly less frequent in the glaucoma eyedrop group (six strains, 15.0%) than in the control group (11 strains, 39.3%) (P < 0.05). CONCLUSION: Patients using eyedrops for glaucoma had a lower culture-positive rate of bacteria in the conjunctival sac, probably due to being washed out by the eyedrops. However, Gram-negative bacteria were detected in the eyedrop group. Bacteria isolated from the eyedrop group had lower resistance to levofloxacin, a finding that may have clinical relevance.

Effects of topical application of ibudilast for seasonal allergic conjunctivitis in patients wearing soft contact lenses.

PURPOSE: To assess the influence of topical application of ibudilast for seasonal allergic conjunctivitis in patients wearing soft contact lenses (SCLs). MATERIALS AND METHODS: There were 16 SCL wearers (32 eyes) with allergic conjunctivitis due to cedar pollen, who were studied from February to April 2007. Before enrollment, informed consent to participation in this study was obtained from all subjects. A frequent replacement SCL (2 Week Pure) was worn for 2 weeks, and ibudilast was applied topically four times daily during this period. The severity of allergic symptoms and the severity of SCL-related symptoms were assessed by scoring using two questionnaires, and before and after topical application of ibudilast results were compared. The severity of objective ocular findings was also scored and compared in the same way. After the final examination, the SCLs were collected and immersed in physiologic saline. Then morphologic changes and drug adsorption were investigated. RESULTS: Among the allergic symptoms, itching and a dry sensation improved after topical application of ibudilast ophthalmic solution (both P<0.05). Phlyctenular conjunctivitis was noted in one eye after topical application, but there were no significant differences of SCL-related symptoms and objective ocular findings between before and after application. There were also no morphologic changes of the contact lenses, and the ibudilast concentration in the lenses was below the detection limit. CONCLUSIONS: These results suggest that topical application of ibudilast while using 2 Week Pure lenses can improve subjective symptoms without influencing drug adsorption or lens morphology.