Label-free enrichment of human pluripotent stem cell-derived early retinal progenitor cells for cell-based regenerative therapies.

Pluripotent stem cell-based therapy for retinal degenerative diseases is a promising approach to restoring visual function. A clinical study using retinal organoid (RO) sheets was recently conducted in patients with retinitis pigmentosa. However, the graft preparation currently requires advanced skills to identify and excise suitable segments from the transplantable area of the limited number of suitable ROs. This remains a challenge for consistent clinical implementations. Herein, we enabled the enrichment of wild-type (non-reporter) retinal progenitor cells (RPCs) from dissociated ROs using a label-free ghost cytometry (LF-GC)-based sorting system, where a machine-based classifier was trained in advance with another RPC reporter line. The sorted cells reproducibly formed retinal spheroids large enough for transplantation and developed mature photoreceptors in the retinal degeneration rats. This method of enriching early RPCs with no specific surface antigens and without any reporters or chemical labeling is promising for robust preparation of graft tissues during cell-based therapy.

Extending the Limbus-to-Cannula Distance to 6.0 mm During Pars Plana Vitrectomy in Highly Myopic Eyes.

PURPOSE: To evaluate the utility of extending the limbus-to-cannula distance to 6.0 mm during pars plana vitrectomy for highly myopic eyes. METHODS: Four eyes with axial lengths exceeding 31.0 mm, that underwent 25-gauge pars plana vitrectomy were retrospectively evaluated. Assuming that cannulas were inserted 3.5 mm and 6.0 mm from the corneal limbus, the distance from the cannula to the fovea (CF distance) was preoperatively evaluated using anterior segmental optical coherence tomography. Surgical complications were also investigated. RESULTS: The CF distance was shortened by 1.22 ± 0.05 mm and 1.22 ± 0.09 mm on the temporal and nasal sides, respectively, by inserting the cannula at 3.5 mm to 6.0 mm from the corneal limbus. As per the preoperatively measured CF distance, one of the cannulas was inserted 6.0 mm from the corneal limbus in three eyes. Their cannulas were confirmed to be inserted at the pars plana, and no surgical complications associated with this technique were observed. CONCLUSION: Extending the limbus-to-cannula distance to 6.0 mm during pars plana vitrectomy could be one of the options to reach the posterior pole in highly myopic eyes. A preoperatively measured CF distance can be a clinical criterion in determining the cannula position.

Foveal Crack Sign: An OCT Sign Preceding Macular Hole After Vitrectomy for Rhegmatogenous Retinal Detachment.

PURPOSE: To describe an optical coherence tomography (OCT) sign preceding macular hole (MH) formation after pars plana vitrectomy (PPV) for rhegmatogenous retinal detachment (RRD). DESIGN: Retrospective observational case series. METHODS: Patients who underwent PPV for RRD at Osaka Rosai Hospital between January 2014 and December 2017 were examined. First, the medical records of the patients who had secondary MH after RRD repair were examined, and their sequential changes of the OCT images until MH formation were evaluated. Second, the OCT findings and the medical records of all patients who underwent PPV for RRD were evaluated based on the findings of the cases of secondary MH. RESULTS: Ten eyes of 10 patients who had secondary MH after PPV for RRD were enrolled. Before MH formation, all eyes had parafoveal epiretinal membrane (ERM) and a characteristic OCT sign that was termed a foveal crack sign (FCS), a hyperreflective vertical line in the foveola with a deformation of the fovea. FCS was found 255 ± 217 days after PPV for RRD, and MH developed 232 ± 171 days after FCS appearance. Furthermore, among 518 eyes that underwent PPV for RRD, FCS with parafoveal ERM was found in 3 eyes without succeeding MH after RRD repair. FCS of these 3 eyes were found 363 ± 4 days after PPV for RRD. CONCLUSIONS: In all cases of secondary MH formation after PPV for RRD, FCS with parafoveal ERM was found before MH formation. This sign may predict secondary MH formation caused by ERM traction.

Impact of vitrectomy and air tamponade on aspheric intraocular lens tilt and decentration and ocular higher-order aberrations: phacovitrectomy versus cataract surgery.

PURPOSE: To evaluate the impact of vitrectomy and air tamponade on aspheric intraocular lens (IOL) tilt and decentration and postoperative internal higher-order aberrations (HOAs) in combined cataract surgery and vitrectomy (phacovitrectomy). STUDY DESIGN: Prospective comparative observational study. METHODS: Forty-five eyes that underwent phacovitrectomy using aspheric IOLs and 18 eyes that only underwent cataract surgery also using aspheric IOLs were prospectively evaluated. The subjects were divided into three groups: phacovitrectomy without fluid-air exchange (F/Ax) or with F/Ax and cataract surgery alone (Groups A, B, and C, respectively) Surgery-induced changes in lens tilt and decentration and internal HOAs were compared between each pair of groups. Subgroup analysis was conducted for cases with largely tilted (> 7°) or decentered (> 0.40 mm) IOLs 1 month postoperatively. RESULTS: Surgery-induced changes in lens tilt in Group B were significantly more pronounced than those in Group C at 1 week, 1 month, and 3 months postoperatively (P = 0.007, 0.009, and 0.043, respectively), while there was no significant difference in surgery-induced changes in lens decentration among the groups. IOLs in Group B were tilted and decentered toward the inferonasal direction. In contrast, there was no significant difference in internal HOAs among the groups at any postoperative visit. Only Group B included cases with largely decentered IOLs, and the internal total HOAs in these cases were significantly larger than those in the others (P = 0.015). CONCLUSION: Although largely decentered IOLs were occasionally found in Group B, aspheric IOLs could be effectively used in phacovitrectomy.

Risk Factors, Onset, and Progression of Epiretinal Membrane after 25-Gauge Pars Plana Vitrectomy for Rhegmatogenous Retinal Detachment.

PURPOSE: To investigate the risk factors, onset timing, and progression of epiretinal membrane (ERM) after pars plana vitrectomy (PPV) for rhegmatogenous retinal detachment (RRD). DESIGN: Retrospective, comparative case series. PARTICIPANTS: The study included 322 eyes of 322 patients who underwent primary PPV for RRD from January 2014 through December 2016. METHODS: Patients underwent OCT before and 1, 3, 6, and 12 months after surgery. Patients showing hyperreflective lines above the inner retinal surface and deformation of the foveal pit were defined as ERM cases. Those with loss of the foveal pit were defined as advanced ERM cases. A multivariate logistic regression model was used to evaluate the risk factors of postoperative ERM. The onset timing of ERM and progression to advanced ERM after PPV for RRD were also investigated based on the OCT findings. MAIN OUTCOME MEASURES: Risk factors, onset timing, and progression of ERM after PPV for RRD. RESULTS: In the multivariate analysis, the incidence of postoperative ERM was significantly higher in eyes with preoperative vitreous hemorrhage (VH; P = 0.011) and without internal limiting membrane (ILM) peeling (P < 0.001). Among the patients who underwent ILM peeling, none demonstrated postoperative ERM. Postoperative ERM was observed in 39 of the 322 eyes (12.1%) within 1 year after surgery; in 30 of these eyes (76.9%), ERM occurred within 3 months after surgery. Advanced ERM was observed in 12 eyes (12/39 eyes [30.8%]). Among these, 9 eyes (9/12 eyes [75%]) showed progression within 3 months after surgery. CONCLUSIONS: Preoperative VH can increase the occurrence of postoperative ERM. In most patients with ERM, the occurrence and progression were detected relatively early after surgery; therefore, in high-risk patients, careful follow-up is encouraged until 3 months after surgery.

Paracentral Acute Middle Maculopathy following Vitrectomy for Proliferative Diabetic Retinopathy: Incidence, Risk Factors, and Clinical Characteristics.

PURPOSE: To report the incidence of, risk factors for, and characteristics of paracentral acute middle maculopathy (PAMM) after 25-gauge pars plana vitrectomy for proliferative diabetic retinopathy (PDR). DESIGN: Retrospective, consecutive, interventional case series. PARTICIPANTS: Five hundred thirty eyes of 427 patients who underwent primary vitrectomy for PDR from 2013 through 2016. METHODS: The patients underwent measurement of best-corrected visual acuity (BCVA), fundus photography, and OCT before and within 2 weeks after vitrectomy. A generalized linear mixed-effects model was used to evaluate risk factors for development of PAMM. MAIN OUTCOME MEASURES: The incidence, associated risk factors, and clinical characteristics of PAMM following vitrectomy, including the change in BCVA in eyes with PAMM and the distribution of PAMM as determined by en face OCT. RESULTS: Four hundred ninety-six eyes of 395 patients who met the eligibility criteria were evaluated. The incidence of PAMM was 3.8% (15/395) for patients and 3.6% (18/496) for eyes. Multivariate analysis showed the significant risk factors for PAMM development to be younger age (mean age, 49 years in patients and 59 years in control participants; odds ratio [OR] 0.94; 95% confidence interval [CI], 0.89-0.99; P = 0.021) and female gender (66.7% of patients and 31.3% of control participants; OR, 4.48; 95% CI, 1.57-12.6; P = 0.005). The PAMM was distributed on either side of the causative arterioles. In 14 of the 18 eyes (78%), PAMM was located within a 3-mm diameter of the fovea. In 10 eyes (56%), PAMM measured 1 disc diameter or more, and in 5 eyes (28%), PAMM measured one third disc diameter or less. No emboli were found in any eyes; however, multiple segmental arterial constrictions were confirmed during vitrectomy in 1 eye. The BCVA decreased more than 2 lines in 2 eyes (5%). CONCLUSIONS: Paracentral acute middle maculopathy can develop after pars plana vitrectomy for PDR, especially in patients who are younger and female. Impaired blood flow in arterioles, which leads to tissue hypoxia, was associated with development of PAMM.

Factors Limiting the Visual Outcome After Descemet Stripping Automated Endothelial Keratoplasty: Comprehensive Analysis Including the Graft Position and Irregularity.

PURPOSE: To investigate factors affecting best postoperative corrected distance visual acuity (CDVA) in patients who have undergone Descemet stripping automated endothelial keratoplasty (DSAEK). METHODS: Forty-two eyes of 42 patients with predominantly non-Fuchs endothelial corneal dystrophy after DSAEK were retrospectively evaluated. All patients were examined using anterior segment optical coherence tomography when their best postoperative CDVA had been achieved. We analyzed the relationship between best postoperative CDVA and preoperative, intraoperative, and postoperative factors, including corneal higher-order aberrations (HOAs), corneal backward scattering, graft irregularity, and graft decentration. Variables with P < 0.2 in univariate analysis were entered into a multivariate linear regression model to determine the factors affecting best postoperative CDVA. RESULTS: Mean CDVA improved from 1.16 ± 0.46 preoperatively to 0.22 ± 0.19 logarithm of the minimum angle of resolution equivalents postoperatively (P < 0.0001). Best postoperative CDVA was achieved 11.6 ± 7.7 months after DSAEK. Multivariate analysis showed that anterior corneal coma-like HOAs and venting incisions inside the pupil area were significantly correlated with best postoperative CDVA (t = 2.90, P = 0.006; t = 2.62, P = 0.01, respectively). No significant relationship was found between the visual outcome and any other factor, including posterior corneal HOAs, corneal backward scattering, graft decentration, and graft irregularity. CONCLUSIONS: Irregularity of the anterior corneal surface and venting incisions inside the pupil area are important factors that impair best postoperative CDVA in patients who have undergone DSAEK. In contrast, our results indicate that the graft position and irregularity might not have a strong influence on the visual outcome after DSAEK.

Influence of Surgical Procedures and Instruments on the Incidence of Suprachoroidal Hemorrhage during 25-gauge Pars Plana Vitrectomy.

PURPOSE: To evaluate the influence of surgical procedures and instruments that are associated with intraocular pressure (IOP) fluctuations on the incidence of suprachoroidal hemorrhage (SCH) during 25-gauge pars plana vitrectomy (25G-PPV), and to investigate the clinical features of SCH during 25G-PPV. DESIGN: Retrospective, comparative case series. PARTICIPANTS: A total of 3034 cases that underwent initial 25G-PPV at a single surgical center. METHODS: Univariate analysis was performed to evaluate the relationships between the incidence of SCH during 25G-PPV and the surgical procedures and instruments that were associated with IOP fluctuations. The participants were divided into 4 groups that underwent the following procedures: neither fluid-air exchange nor vitreous shaving under scleral depression (group 1, n = 1144); fluid-air exchange alone (group 2, n = 463); vitreous shaving under scleral depression alone (group 3, n = 639); and both procedures (group 4, n = 788). The incidence of SCH in each group was compared. The clinical features and surgical outcomes of SCH during 25G-PPV were also investigated. MAIN OUTCOME MEASURES: The incidence of SCH during 25G-PPV and the clinical features and surgical outcomes of SCH during 25G-PPV. RESULTS: The incidence of SCH was significantly higher in cases that underwent fluid-air exchange (P = 0.0047) or vitreous shaving under scleral depression (P = 0.0157). There were no significant relationships between the incidence of SCH and the use of surgical instruments. The incidence of SCH in group 4 (8/788, 1.02%) was significantly higher than that in groups 1 (1/1144, 0.09%), 2 (0/463, 0%), and 3 (0/639, 0%) (P = 0.01). Almost all SCH cases were localized, and there were no cases of SCH involving the posterior pole. Of all the SCH cases, only one case required reoperation for retinal redetachment. No cases required secondary surgical management for SCH. CONCLUSIONS: There remains a slight risk of SCH during 25G-PPV in cases that require both fluid-air exchange and vitreous shaving under scleral depression. Even if SCH occurs during 25G-PPV, the surgical outcomes after SCH may not be substantially worse.