Performance, safety and efficiency comparison between 10,000 and 5000 cuts per minute vitrectomy using a 25G cutter: a prospective randomized controlled study.

PURPOSE: This study aims to compare the performance of the 25+® UltraVit® 5000 cuts per minute (cpm) vitrectomy probe versus the 25+ ® Ultravit 10,000 cpm® beveled tip, dual drive vitrectomy probe. METHOD: In this prospective randomised controlled clinical trial, 52 eyes of 52 consecutive patients were randomized into either the 10,000 cpm (25 patients) or 5000 cpm vitrectomy group (27 patients). Patients were evaluated preoperatively, intraoperatively, and postoperatively on the first day, and at 1 week, 1 month and 3 months. The main outcome measures were vitrectomy time, and secondary endpoints were time to induction of posterior vitreous detachment, intraoperative complications, and number of instruments used. RESULTS: The vitrectomy time was shorter in the 10,000 cpm group (413.7 s) compared to the 5000 cpm group (463.4 s), although there was no significant difference (p = 0.5999). One patient had an iatrogenic retinal break in the 10,000 cpm group while two patients had an iatrogenic retinal break in the 5000 cpm group. The time for posterior vitreous detachment (PVD) induction and the number of instruments used were not significantly different between the two groups. CONCLUSION: The difference in vitrectomy times between the 10,000 cpm vitrectomy probe and the 5000 cpm cutter were not statistically significant. This may suggest that other factors affect efficiency rather than the limitations of equipment.

Ranibizumab for myopic choroidal neovascularization.

INTRODUCTION: Myopic choroidal neovascularization (CNV) is one of the most vision-threatening complications in patients with pathologic myopia. Over the last decade, anti-angiogenesis therapy with anti-vascular endothelial growth factor (anti-VEGF) agents has become the standard-of-care treatment for myopic CNV and ranibizumab has been approved for treating myopic CNV. AREAS COVERED: Review of preclinical studies and clinical trials data supporting the use of ranibizumab for myopic CNV. Discussion on the mechanisms, efficacy, safety, regulatory affairs, and future directions of ranibizumab for myopic CNV are highlighted. EXPERT OPINION: Ranibizumab has demonstrated good efficacy and safety profile in multiple clinical trials and long-term studies for treating myopic CNV. Cost-effective analysis has shown that ranibizumab therapy is a cost-effective treatment for myopic CNV. Among the currently available anti-VEGF agents, ranibizumab is the only drug that is approved for the treatment of myopic CNV by the US Food and Drug Administration. In the coming few years, biosimilars of ranibizumab may become available and will have the potential to lower the cost of ranibizumab. Long-term visual gain after ranibizumab treatment for myopic CNV is limited by chorioretinal atrophy associated with pathologic myopia and further research is required to tackle the development of chorioretinal atrophy.

Treatment of large, chronic and persistent macular hole with internal limiting membrane transposition and tuck technique.

BACKGROUND: Large, chronic full thickness macular holes which failed previous treatments are difficult to manage and even left untreated due to poor prognosis. A retrospective review of consecutive cases with chronic (at least 1 year) full thickness macular holes and internal limiting membrane (ILM) free flap transposition with tuck technique, after previously failed vitrectomy. METHODS: This was a retrospective and interventional study conducted in a single centre by a single surgeon. Patients with full thickness macular hole for at least 1 year and at least one previously failed vitrectomy with ILM peeling were recruited. A 25G vitrectomy with ILM free flap transposition was done without assistance of PFCL, viscoelastic or autologous blood. The free flap was manually tucked into the macular hole free space and gas fluid exchange was performed with 20% SF6 as tamponade. The patients were postured prone for 2 weeks postoperatively. Best corrected visual acuity, macular hole duration, previous surgeries, optical coherence tomography (OCT) appearance, hole size and closure rate were recorded. RESULTS: 8 consecutive patients were included from May 2016 to Feb 2018. Transposition surgery was performed an average of 1481 days (SD 1096) after diagnosis of macular hole and average of 1226 days (SD 1242) after first vitrectomy. Macular hole mean size was 821 µm (SD 361.3), preoperative VA was logMAR 1.038 (SD 0.19), postoperative VA was logMAR 0.69 (SD 0.19) at 3 months. There were 1.13 lines gained and a significant improvement of logMAR 0.33 (p = 0.0084) at 6 months. Hole closure was seen in 7 out of 8 eyes (87.5%). The OCT with failed closure showed ILM flap within a flat hole, however no overlying neurosensory layers was seen. The duration from diagnosis to surgery was 2349 days in this case. CONCLUSION: Free flap ILM transposition tuck without the use of additional intraoperative tamponade is an effective technique in treating large chronic macular holes with previously failed primary macular hole surgeries.Trial registration (IRB of the Hong Kong University and Hospital Authority Hong Kong West Cluster, ref UW19-440), June 17, 2019.

EDN1 Lys198Asn is associated with diabetic retinopathy in type 2 diabetes.

PURPOSE: We tested the hypothesis that genetic variants in vasoactive and angiogenic factors regulating the retina vasculature contribute to the development of diabetic retinopathy (DR). METHODS: A case-control study was performed to study the genetic association between DR and polymorphic variants of EDN1 (Lys198Asn), LTA (IVS1-80C>A, IVS1-206G>C, IVS1-252A>G), eNOS (Glu298Asp), and ITGA2 (BgI II) in a Chinese population with type 2 diabetes mellitus. A well defined population with type 2 diabetes, consisting of 127 controls and 216 DR patients, was recruited. RESULTS: A higher frequency of the Asn/Asn genotype of EDN1 was found in individuals with at least 10 years of diabetes and no retinopathy (controls) compared with DR patients with any duration of diabetes (DR: 2.3%; control: 11.0%; p=0.0002). The Asn allele was also more frequent in controls than DR patients (DR: 16.4%; control: 29.5%; p=0.007). Multiple logistic regression analysis showed that the Asn/Asn genotype was the factor most significantly associated with reduced risk of DR (odds ratio=0.19; 95% CI: 0.07-0.53; p=0.002) and with late onset of diabetes (Asn/Asn: 59 years; Lys/Lys + Lys/Asn: 53 years; p=0.02). Moreover, the Lys/Lys genotype was more common among patients with nonproliferative (75.7%) than proliferative DR (56.9%; p=0.008). The distributions of Lys198Asn alleles in hypertension did not differ from normotensive subjects. No associations between DR and polymorphisms of LTA, eNOS, or ITGA2 were detected, and there were no detectable gene-gene or gene-environmental interactions among the polymorphisms. CONCLUSIONS: The Asn/Asn genotype of EDN1 was associated with a reduced risk of DR and with delayed onset of type 2 diabetes.