Clinical Outcomes of Endoscope-Assisted Vitreous Surgery for Giant Retinal Tear Detachment.

INTRODUCTION: With the advent of perfluorocarbon liquid (PFCL), the success rate of refractory giant retinal tear (GRT) detachment has dramatically improved. PFCL is a very effective tool when used properly, but in GRT detachment, it may move under the retina through the tear, so it is necessary to devise ways to prevent PFCL from migrating under the retina. Ophthalmic endoscope-assisted vitrectomy may reduce the risk of subretinal migration of PFCL, facilitate safer use of PFCL, and increase the success rate of GRT detachment. The present study aimed to describe the clinical outcomes of endoscope-assisted vitreous surgery for giant retinal detachment. METHODS: Twenty consecutive eyes from 19 patients who had undergone endoscope-assisted vitreous surgery for treatment of a GRT detachment were enrolled. Subretinal fluid drainage, extension of the rolled GRT, and endophotocoagulation under air were performed with the aid of an endoscope, without the use of PFCL. Where necessary, extension of a fixed retinal fold and internal limiting membrane peeling was performed with PFCL. RESULTS: The initial and final retinal reattachment rates were 90 and 95%, respectively. In 3 eyes, a small amount of PFCL was used, and there were no PFCL remnants. The mean follow-up duration was 18 months (range, 3-69 months). After surgery, the mean best-correlated visual acuity significantly improved from 20/514 to 20/41 (p = 0.0008). DISCUSSION/CONCLUSION: Endoscope-assisted vitreous surgery for giant retinal detachment has favourable clinical outcomes for visual acuity and retinal detachment.

[Clinical Outcomes of Endoscope-Assisted 30-Gauge Single-Needle Technique for Intrascleral Intraocular Lens Fixation].

INTRODUCTION: We have developed an endoscope-assisted single-needle technique, which is an improvement of Yamane's double-needle technique of the intrascleral intraocular lens (IOL) fixation techniques. In this surgical procedure, the IOL is manipulated in the vitreous cavity, and the IOL haptic is externalized from the eye one by one with the aid of an ophthalmic endoscope. The purpose of this study was to report the postoperative visual function and safety of this new technique. METHODS: Overall, 19 consecutive eyes (16 patients; mean age, 75.1 ± 9.6 years; mean follow-up period, 5.7 months) that underwent intrascleral IOL fixation surgery with our new technique were included in the study. Manifest refraction, uncorrected/corrected visual acuity, and corneal endothelial cell density were measured before and after surgery. Tilt and decentration of IOL were analyzed using anterior segment optical coherence tomography. RESULTS: The mean absolute prediction error (spherical equivalent) was 0.82 ± 0.52. The mean postoperative best-corrected visual acuity had significantly improved at the final visits (p = 0.02). No significant differences in the mean corneal endothelial cell density were observed between the first (2,232 ± 751 cells/mm2) and final (2,099 ± 649 cells/mm2) visits (p = 0.35). The mean IOL tilt was 8.1 ± 3.2°. There were no vision-threatening complications, such as retinal detachment, endophthalmitis, or IOL dislocation, during or after surgery. CONCLUSIONS: The endoscope-assisted single-needle technique is a safe and effective method of intrascleral IOL fixation surgery.

Comparison of Clinical Outcomes Between Intracapsular Implantation and Intrascleral Fixation Using the Same Model of Intraocular Lens.

PURPOSE: To compare the clinical outcomes of intrascleral intraocular lens (IOL) fixation surgery with those of intracapsular IOL implantation in conventional cataract surgery. PATIENTS AND METHODS: Twenty-one eyes of 21 consecutive patients who underwent intrascleral IOL fixation (SF group) and 21 eyes of 21 patients who underwent IOL intracapsular implantation during cataract surgery (IN group) were retrospectively enrolled. For both groups, the same model of IOL was used in all cases. For all cases in the SF group, Yamane's double-needle technique was performed. RESULTS: The mean corrected visual acuity (logMAR) after surgery was significantly better in the IN than in the SF group (-0.063 ± 0.12 vs 0.05 ± 0.14; p = 0.0083). The mean anterior chamber depth after surgery was significantly smaller in the IN than in the SF group (4.65 ± 0.23 mm vs 4.98 ± 0.61 mm; p = 0.0231). The amounts of tilt and decentration were also significantly smaller in the IN group (5.21°± 1.47° and 0.22 ± 0.13 mm, respectively, vs 8.8° ± 3.9° and 0.52 ± 0.35 mm, respectively; p = 0.0003 and p = 0.0007). The mean absolute refractive prediction error was significantly smaller in the IN than in the SF group (0.22 ± 0.17 D vs 0.86 ± 0.59 D; p = 0.0002). CONCLUSION: The intrascleral IOL fixation surgery proved to be highly effective. However, its clinical outcomes were slightly inferior to those of IOL intracapsular implantation, and further improvement of this surgical technique may be needed.

NOVEL ENDOSCOPE-ASSISTED VITREOUS SURGERY COMBINED WITH ATMOSPHERIC ENDOSCOPIC TECHNIQUE AND/OR SUBRETINAL ENDOSCOPIC TECHNIQUE FOR RHEGMATOGENOUS RETINAL DETACHMENT WITH GRADE C PROLIFERATIVE VITREORETINOPATHY.

PURPOSE: The purpose of this study was to investigate the clinical outcomes of novel endoscope-assisted vitreous surgery techniques in patients with rhegmatogenous retinal detachment complicated by Grade C proliferative vitreoretinopathy. METHODS: Eight consecutive patients who had undergone endoscope-assisted vitreous surgery for rhegmatogenous retinal detachment complicated by Grade C proliferative vitreoretinopathy were investigated. The peripheral vitreous was cut under air with the aid of endoscopic view (atmospheric endoscopic technique), and the subretinal proliferation was removed under subretinal endoscopic observation (subretinal endoscopic technique). RESULTS: Retinal reattachment was achieved after the primary surgery without a large retinotomy and scleral buckling in each case. The mean follow-up was 16.8 months (range, 8-28 months). Atmospheric endoscopic technique was performed in all cases, and subretinal endoscopic technique was performed in three cases. After surgery, the mean best-corrected visual acuity significantly improved from 20/778 to 20/111 (P = 0.014). Although microretinal breaks occurred during the removal of vitreous using atmospheric endoscopic technique in all cases, there were no severe postoperative complications, such as retinal detachment or proliferative vitreoretinopathy. CONCLUSION: Endoscope-assisted vitreous surgery with atmospheric endoscopic technique and/or subretinal endoscopic technique is safe and effective in the treatment of rhegmatogenous retinal detachment with Grade C proliferative vitreoretinopathy.

Clinical outcomes of endoscope-assisted vitrectomy for treatment of rhegmatogenous retinal detachment.

SUMMARY: We evaluated the clinical outcomes for ophthalmic endoscope-assisted vitrectomy in consecutive patients with uncomplicated rhegmatogenous retinal detachment (RRD). The primary success rate was 98.4% (125/127) without performing a posterior drainage retinotomy or using perfluorocarbon liquids (PFCL) for subretinal fluid drainage. PURPOSE: To investigate the clinical outcomes of endoscope-assisted vitrectomy in patients with uncomplicated RRD. METHODS: We examined 127 eyes from consecutive patients who underwent repair of RRD by 23- or 25-gauge endoscope-assisted vitrectomy, with a minimum follow-up of 3 months. Eyes with the following criteria were excluded: Giant retinal tears, grade C proliferative vitreoretinopathy, dense vitreous hemorrhage, retinal detachment secondary to other ocular diseases, and prior retinal or vitreous surgery. All cases underwent subretinal fluid drainage, endolaser photocoagulation and fundus inspection were performed under ophthalmic endoscopic observation. Success rate, visual acuity, surgery time and complications were evaluated. RESULTS: Primary and final success rate was 98.4% (125/127) and 100% (127/127), respectively, Surgery time was 59.6±26.3 minutes. The best-corrected visual acuity significantly improved from 20/100 to 20/20 (P<0.0001). There were 2 cases (1.6%) of creation of a peripheral drainage retinotomy and 4 cases (3.1%) of using PFCL to suppress movement of the detached retina, but there were no cases of creation of a posterior drainage retinotomy or using PFCL for subretinal fluid drainage. There was 1 case of presumed endophthalmitis after surgery. There were 12 hypotonous cases at postoperative day 1 and one of them needed additional scleral sutures at postoperative day 4 for prolonged hypotony. CONCLUSION: The present study demonstrated the efficacy of endoscope-assisted vitrectomy for patients with uncomplicated RRD. To perform endoscope-assisted vitrectomy safely, sufficient closure of sclerotomies is necessary at the end of surgery.

Transgenic pigs with pancreas-specific expression of green fluorescent protein.

The development and regeneration of the pancreas is of considerable interest because of the role of these processes in pancreatic diseases, such as diabetes. Here, we sought to develop a large animal model in which the pancreatic cell lineage could be tracked. The pancreatic and duodenal homeobox-1 (Pdx1) gene promoter was conjugated to Venus, a green fluorescent protein, and introduced into 370 in vitro-matured porcine oocytes by intracytoplasmic sperm injection-mediated gene transfer. These oocytes were transferred into four recipient gilts, all of which became pregnant. Three gilts were sacrificed at 47-65 days of gestation, and the fourth was allowed to farrow. Seven of 16 fetuses obtained were transgenic (Tg) and exhibited pancreas-specific green fluorescence. The fourth recipient gilt produced a litter of six piglets, two of which were Tg. The founder Tg offspring matured normally and produced healthy first-generation (G1) progeny. A postweaning autopsy of four 27-day-old G1 Tg piglets confirmed the pancreas-specific Venus expression. Immunostaining of the pancreatic tissue indicated the transgene was expressed in ß-cells. Pancreatic islets from Tg pigs were transplanted under the renal capsules of NOD/SCID mice and expressed fluorescence up to one month after transplantation. Tg G1 pigs developed normally and had blood glucose levels within the normal range. Insulin levels before and after sexual maturity were within normal ranges, as were other blood biochemistry parameters, indicating that pancreatic function was normal. We conclude that Pdx1-Venus Tg pigs represent a large animal model suitable for research on pancreatic development/regeneration and diabetes.

Generation of interleukin-2 receptor gamma gene knockout pigs from somatic cells genetically modified by zinc finger nuclease-encoding mRNA.

Zinc finger nuclease (ZFN) is a powerful tool for genome editing. ZFN-encoding plasmid DNA expression systems have been recently employed for the generation of gene knockout (KO) pigs, although one major limitation of this technology is the use of potentially harmful genome-integrating plasmid DNAs. Here we describe a simple, non-integrating strategy for generating KO pigs using ZFN-encoding mRNA. The interleukin-2 receptor gamma (IL2RG) gene was knocked out in porcine fetal fibroblasts using ZFN-encoding mRNAs, and IL2RG KO pigs were subsequently generated using these KO cells through somatic cell nuclear transfer (SCNT). The resulting IL2RG KO pigs completely lacked a thymus and were deficient in T and NK cells, similar to human X-linked SCID patients. Our findings demonstrate that the combination of ZFN-encoding mRNAs and SCNT provides a simple robust method for producing KO pigs without genomic integration.

Generating porcine chimeras using inner cell mass cells and parthenogenetic preimplantation embryos.

BACKGROUND: The development and validation of stem cell therapies using induced pluripotent stem (iPS) cells can be optimized through translational research using pigs as large animal models, because pigs have the closest characteristics to humans among non-primate animals. As the recent investigations have been heading for establishment of the human iPS cells with naïve type characteristics, it is an indispensable challenge to develop naïve type porcine iPS cells. The pluripotency of the porcine iPS cells can be evaluated using their abilities to form chimeras. Here, we describe a simple aggregation method using parthenogenetic host embryos that offers a reliable and effective means of determining the chimera formation ability of pluripotent porcine cells. METHODOLOGY/SIGNIFICANT PRINCIPAL FINDINGS: In this study, we show that a high yield of chimeric blastocysts can be achieved by aggregating the inner cell mass (ICM) from porcine blastocysts with parthenogenetic porcine embryos. ICMs cultured with morulae or 4-8 cell-stage parthenogenetic embryos derived from in vitro-matured (IVM) oocytes can aggregate to form chimeric blastocysts that can develop into chimeric fetuses after transfer. The rate of production of chimeric blastocysts after aggregation with host morulae (20/24, 83.3%) was similar to that after the injection of ICMs into morulae (24/29, 82.8%). We also found that 4-8 cell-stage embryos could be used; chimeric blastocysts were produced with a similar efficiency (17/26, 65.4%). After transfer into recipients, these blastocysts yielded chimeric fetuses at frequencies of 36.0% and 13.6%, respectively. CONCLUSION/SIGNIFICANCE: Our findings indicate that the aggregation method using parthenogenetic morulae or 4-8 cell-stage embryos offers a highly reproducible approach for producing chimeric fetuses from porcine pluripotent cells. This method provides a practical and highly accurate system for evaluating pluripotency of undifferentiated cells, such as iPS cells, based on their ability to form chimeras.

Hollow fiber vitrification provides a novel method for cryopreserving in vitro maturation/fertilization-derived porcine embryos.

In vitro matured (IVM) oocytes have been used to create genetically modified pigs for various biomedical purposes. However, porcine embryos derived from IVM oocytes are very cryosensitive. Developing improved cryopreservation methods would facilitate the production of genetically modified pigs and also accelerate the conservation of genetic resources. We recently developed a novel hollow fiber vitrification (HFV) method; the present study was initiated to determine whether this new method permits the cryopreservation of IVM oocyte-derived porcine embryos. Embryos were created from the in vitro fertilization of IVM oocytes with frozen-thawed sperm derived from a transgenic pig carrying a humanized Kusabira-Orange (huKO) gene. Morula-stage embryos were assigned to vitrification and nonvitrification groups to compare their in vitro and in vivo developmental abilities. Vitrified morulae developed to the blastocyst stage at a rate similar to that of nonvitrified embryos (66/85, 77.6% vs. 67/84, 79.8%). Eighty-eight blastocysts that developed from vitrified morulae were transferred into the uteri of three recipient gilts. All three became pregnant and produced a total of 17 piglets (19.3%). This piglet production was slightly lower, albeit not significantly, than that of the nonvitrification group (27/88, 30.7%). Approximately half of the piglets in the vitrification (10/17, 58.8%) and nonvitrification (15/27, 55.6%) groups were transgenic. There was no significant difference in the growth rates among the piglets in the two groups. These results indicate that the HFV method is an extremely effective method for preserving cryosensitive embryos such as porcine in vitro maturation/fertilization-derived morulae.

Three-dimensional virtual images modify the waveform of pupillary near response.

PURPOSE: To investigate the effects of the continuous viewing of horizontal disparities on the pupillary near response by using three-dimensional (3-D) displays. METHODS: The pupillary diameter and the horizontal eye position of both eyes were measured during the near response in eight healthy young adults. The measurements were made before and after viewing a 3-D movie for 15 or 30 min, or a two-dimensional (2-D) movie for 90 min. The near response was elicited by a real target that moved from the far position (0.5 m) to the near position (0.1 or 0.125 m) in the midsagittal plane at a constant velocity of +/- 0.26 diopters (D)/s. The accommodative demand was 6 or 8 D. RESULTS: A delay in the pupillary dilation in the near response was observed immediately after a 30-min viewing of a 3-D movie with an accommodative demand of 8 D (P < 0.01, one-way analysis of variance, Dunnett's multiple comparison test). The delay in the pupillary dilation was not observed after a 90-min viewing of a 2-D movie. CONCLUSIONS: Continuous viewing of horizontal disparities can induce a delay in the pupillary dilation in the near response. The parameters of the pupillary near response are useful in assessing the effects of 3-D viewing.

Transition from upbeat to downbeat nystagmus observed in a patient with Wernicke's encephalopathy.

BACKGROUND: We report an unusual case of Wernicke's encephalopathy presenting with transient upbeat nystagmus that changed to a persistent downbeat nystagmus. CASE: A 27-year-old man presented with upbeat nystagmus. Three months earlier, he had been diagnosed with Wernicke's encephalopathy after fasting for a month. OBSERVATIONS: This diagnosis was supported by his symptoms (ataxia, a confused state). Clinical recovery followed thiamine therapy. His upbeat nystagmus had linear slow phases with average amplitude and frequency (+/-SD) during fixation straight ahead of 2.8 +/- 0.7 degrees and 4.6 +/- 2.2 Hz, respectively. Two months later, the primary position upbeat nystagmus had diminished and downbeat nystagmus (0.9 +/- 0.5 degrees and 3.2 +/- 0.7 Hz on average) for a 20 degrees downward gaze had developed. Then, 8 months later, he showed only downbeat nystagmus, which obeyed Alexander's law. His primary position downbeat nystagmus was completely suppressed by clonazepam, a gamma-aminobutyric acid (GABA) agonist. CONCLUSIONS: Owing to an underlying central vestibular imbalance, even after the recovery of acute neurological symptoms, Wernicke's encephalopathy can be complicated by persistent downbeat nystagmus, which can be treated by a GABA agonist.