Surgical strategy and outcome in patients with bilateral proliferative diabetic retinopathy.

OBJECTIVES: To investigate the current surgery strategies for bilateral proliferative diabetic retinopathy (PDR), as well as the surgical outcomes of patients with bilateral PDR who underwent pars plana vitrectomy (PPV). MATERIALS: Patients undergoing bilateral vitrectomy for PDR from January 2019 to December 2020 at The Eye Hospital of Wenzhou Medical University were enrolled. Clinical data were collected from the electronic medical records. Factors associated with the time interval between the surgeries on two eyes and postoperative visual outcomes were analyzed. RESULTS: In total, 152 patients with bilateral PDR who underwent bilateral PPV were included in this analysis. Mean age was 53.7 ± 11.4 years. Compared with second-surgery eyes, 60.5% of first-surgery eyes had worse preoperative best-corrected visual acuity (BCVA). The overall PPV time (median, quartile range) between first and second surgeries eye was 1.40 (0.70, 3.15) months. Multivariate analysis showed that the preoperative BCVA of the second-surgery eye had a significant effect on the inter-surgery time interval (P = 0.048). First-surgery eyes had greater vision improvement than second-surgery eyes (Difference of the logarithm of the minimum angle of resolution [LogMAR] BCVA: - 1.00 [- 1.48, - 0.12] versus 0.00 [- 1.30, 0.00], respectively, P < 0.001), especially when eyes with poorer BCVA underwent PPV first (- 1.15 [- 1.87, - 0.54] versus 0.00 [- 0.70, 0.00], respectively, P < 0.001). CONCLUSIONS: Visual acuity is a significant factor that influences surgical strategies, including both surgery order and interval, for patients with bilateral PDR. The eyes operated upon first show more vision improvement due to prompt surgery.

A comparison between topical and retrobulbar anesthesia in 27-gauge vitrectomy for vitreous floaters: a randomized controlled trial.

BACKGROUND: To compare the safety and efficacy of topical anesthesia versus retrobulbar anesthesia in 27-gauge pars plana vitrectomy (PPV) for vitreous floaters. METHODS: 30 patients with vitreous floaters were randomized into Group T (topical anesthesia, proparacaine eye drop) and Group R (retrobulbar anesthesia), and underwent 27-gauge PPV. A 5-point visual analogue pain scale (VAPS) was used to assess patients' pain experience of anesthesia and surgery procedure (during surgery, 2 h and 1 day after surgery). RESULTS: The VAPS of anesthesia procedure was 1.27 ± 0.59 for patients in Group R, while it was all 0 for patients in Group T (p < 0.001). There was no significant difference for VAPS during surgery (Group T: 1.13 ± 0.74, Group R: 0.67 ± 0.62, p = 0.67), 2 h (Group T: 0.80 ± 1.01, Group R: 0.67 ± 0.62, p = 0.67) and 1 day (Group T: 0.20 ± 0.41, Group R: 0.27 ± 0.46, p = 0.68) after surgery between these two groups. Only one patient (6.7%) in Group T required additional topical anesthesia during the surgery. Most of the patients reported the pain experience came from initial trocar insertion in both groups. None of the patients required post operative analgesia in both groups. No intraoperative or postoperative complications were noted in both groups. CONCLUSION: This study suggested that topical anesthesia is a safe and effective anesthetic approach for patients with floaters who underwent 27-gauge PPV. TRIAL REGISTRATION: ClinicalTrials.gov NCT03049163 . Registered 8 February 2017.

Comparison of the silicone oil removal rate between vitrectomy and manual syringe negative pressure approach.

The purpose of this study was to compare the silicone oil removal rate between vitrectomy and manual syringe negative pressure approach. Thirty-five silicone oil-filled eyes were enrolled and allocated for manual (n = 19) and vitrectomy (n = 16) removal approaches. For manual approach, a 10-ml syringe was connected to the 23-gauge cannula through a short section of blood transfusion tube. Removal was started after pulling and fixing the plunger to the end part. The syringe was pulled away immediately once the residual of silicone oil cannot be observed through the cornea. For vitrectomy approach, the only difference was the source of negative pressure, i.e., the blood transfusion tube was connected to the cannula directly to remove the silicone oil. Silicone oil removal rate was defined as the volume of silicone oil divided by the time taken for removal. The mean time taken for silicone oil removal was faster for manual approach than vitrectomy approach (4.13 ± 1.41 vs. 6.14 ± 1.49, p = 0.001). Furthermore, the silicone oil removal rate was larger for manual approach (1.42 ± 0.30 vs. 0.90 ± 0.16 ml/min, p < 0.001). No severe intraoperative or postoperative complications were noted for both approaches. The mean IOP at day 1 after surgery was significantly lower than that at baseline in both groups (manual group 10.2 ± 4.5 vs. 17.6 ± 5.9, p < 0.001, vitrectomy group 15.1 ± 7.5 vs. 8.3 ± 1.9, p < 0.002). All the eyes were recovered at 1 week after surgery. The best-corrected visual acuity (LogMar) at 1 month postoperatively improved compared to that preoperative for both approaches (manual group: 1.10 ± 0.62 vs. 1.47 ± 0.76, p = 0.07; vitrectomy group: 1.10 ± 0.47 vs. 1.11 ± 0.50, p = 0.62). Both approaches are safe for silicone oil removal. The manual approach is more convenient and efficient.

Vitreous metabolomic signatures of pathological myopia with complications.

BACKGROUND: Pathological myopia (PM) is closely associated with blinding ocular morbidities. Identifying biomarkers can provide clues on pathogeneses. This study aimed to identify metabolic biomarkers and underlying mechanisms in the vitreous humour (VH) of PM patients with complications. METHODS: VH samples were collected from 39 PM patients with rhegmatogenous retinal detachment (RRD) (n = 23) or macular hole (MH)/myopic retinoschisis (MRS) (n = 16) and 23 controls (MH with axial length < 26 mm) who underwent surgical treatment. VH metabolomic profiles were investigated using ultra-performance liquid chromatography‒mass spectrometry. The area under the receiver operating characteristic curve (AUC) was computed to identify potential biomarkers for PM diagnosis. RESULTS: Bioinformatics analysis identified nineteen and four metabolites altered in positive and negative modes, respectively, and these metabolites were involved in tryptophan metabolism. Receiver operating characteristic analysis showed that seventeen metabolites (AUC > 0.6) in the positive mode and uric acid in the negative mode represent potential biomarkers for PM with complications (AUC = 0.894). Pairwise and pathway analyses among the RRD-PM, MH/MRS-PM and control groups showed that tryptophan metabolism and uric acid were closely correlated with PM. Altered metabolites and pathways in our study were characterized by increased oxidative stress and altered energy metabolism. These results contribute to a better understanding of myopia progression with or without related complications. CONCLUSIONS: Our study provides metabolomic signatures and related immunopathological features in the VH of PM patients, revealing new insight into the prevention and treatment of PM and related complications.

Incidence of rhegmatogenous retinal detachments is increasing in Wenzhou, China.

AIM: To estimate and compare the incidence and characteristics of rhegmatogenous retinal detachments (RRDs) in the Wenzhou area in 2015 to 2019. METHODS: All newly developed RRD cases among residents of the Wenzhou area, from January 2015 to December 2019, were retrospectively retrieved from hospital records. Annual population data were extracted from the Wenzhou Statistical Yearbook. RESULTS: There were 3629 eligible cases. The average incidence of RRD was 7.79 cases per 100 000 population (95% confidence interval, 7.24-8.34), and the incidences were 7.99 and 7.56 for males and females, respectively. The annual incidence increased gradually from 7.26 cases per 100 000 in 2015 to 10.00 cases per 100 000 in 2019, with an overall increase of 37.74%. The highest rate of increase occurred in the age group from 60 to 69 years. Of 2750 eyes with axial length (AL) data, 1675 (60.91%) had an AL greater than 24 mm. CONCLUSION: A trend to increasing RRD incidence is observed in the Wenzhou area over the past 5-year period.

Inner limiting membrane peeling prevents secondary epiretinal membrane after vitrectomy for proliferative diabetic retinopathy.

AIM: To evaluate the role of internal limiting membrane (ILM) peeling in preventing secondary epiretinal membrane (ERM) formation in pars plana vitrectomy (PPV) for proliferative diabetic retinopathy (PDR). METHODS: This retrospective study analyzed the medical records of patients who underwent PPV for PDR and were followed up for minimum 3mo. ILM peeling was performed based on the intraoperative surgeons' judgments. ERM was assessed by optical coherence tomography photography. The relationship between ILM peeling and postoperative ERM was analyzed. RESULTS: In total, 212 eyes from 197 patients were included in this study. The incidence of secondary ERM in the ILM non-peeling group was significantly higher than that in the ILM peeling group (37.0% vs 14.0%; P<0.001). Multivariate logistical regression revealed that ILM peeling was highly associated with the prevention of secondary ERM development [odds ratio 0.38; 95% confidence interval 0.17-0.86; P<0.05]. CONCLUSION: ILM peeling during PPV for PDRs can effectively reduce the incidence of secondary ERM development and is worth consideration by vitreoretinal surgeons.

Suppressor of Cytokine Signaling 2 Regulates Retinal Pigment Epithelium Metabolism by Enhancing Autophagy.

Retinal pigment epithelium (RPE) serves critical functions in maintaining retinal homeostasis. An important function of RPE is to degrade the photoreceptor outer segment fragments daily to maintain photoreceptor function and longevity throughout life. An impairment of RPE functions such as metabolic regulation leads to the development of age-related macular degeneration (AMD) and inherited retinal degenerative diseases. As substrate recognition subunit of a ubiquitin ligase complex, suppressor of cytokine signaling 2 (SOCS2) specifically binds to the substrates for ubiquitination and negatively regulates growth hormone signaling. Herein, we explore the role of SOCS2 in the metabolic regulation of autophagy in the RPE cells. SOCS2 knockout mice exhibited the irregular morphological deposits between the RPE and Bruch's membrane. Both in vivo and in vitro experiments showed that RPE cells lacking SOCS2 displayed impaired autophagy, which could be recovered by re-expressing SOCS2. SOCS2 recognizes the ubiquitylated proteins and participates in the formation of autolysosome by binding with autophagy receptors and lysosome-associated membrane protein2 (LAMP-2), thereby regulating the phosphorylation of glycogen synthase kinase 3ß (GSK3ß) and mammalian target of rapamycin (mTOR) during the autophagy process. Our results imply that SOCS2 participates in ubiquitin-autophagy-lysosomal pathway and enhances autophagy by regulating GSK3ß and mTOR. This study provides a potential therapeutic target for AMD.

New technique for removal of perfluorocarbon liquid related sticky silicone oil and literature review.

AIM: To investigate the safety and efficacy of sticky silicone oil (SSO) removal using a 22-gauge vein detained needle and inner limiting membrane (ILM) wrap-and-peel technique. METHODS: This retrospective consecutive case series reviewed the records of patients with a history of retinal detachment who had received silicone oil and perfluorocarbon liquid (PFCL) as intraocular tamponades. Patients were included in the analysis if they exhibited SSO remnants during silicone oil removal. The aspiration of most of the SSO remnants was performed by a 22-gauge vein detained needle. The small amounts of droplets adhered to the macula and epi-macular membrane were subsequently removed by the ILM warp-and-peel technique. The anatomical and functional outcomes, and postoperative complications were recorded. In vitro experiments were performed to simulate the formation of SSO remnants in four groups. RESULTS: Of 711 patients who underwent silicone oil removal during the study period, 9 patients exhibited SSO remnants and underwent follow-up for at least 3mo. Seven eyes (78%) underwent the ILM wrap-and-peel technique to completely remove small droplets of SSO that were glued to the macula and epi-macular membrane. No obvious complications occurred. Postoperative optical coherence tomography revealed normal retinal structure in all patients. In vitro analyses showed that balanced salt solution and prolonged vibration (for 1wk) had the strongest effects on silicone oil and PFCL compound opacities. CONCLUSION: SSO remnants could be removed in an intact manner and without complications, using a vein detained needle-assisted and ILM wrap-and-peel technique. The findings suggest that PFCL and infusion fluid should be completely removed before silicone oil injection to prevent SSO formation.

Pars plana vitrectomy relieves the depression in patients with symptomatic vitreous floaters.

AIM: To investigate the depressive state among the patients with symptomatic vitreous floaters (SVF), as well as its change after SVF removal via vitrectomy surgery. METHODS: Twenty-eight eyes of 28 patients who underwent 27-gauge pars plana vitrectomy (PPV) for SVF were included. Thirty-nine eyes of 39 age- and gender-matched healthy volunteers without SVF were also recruited as a healthy control. Center for Epidemiologic Studies Depression (CES-D) was used to assess volunteers and patients' depression (before and 1wk after PPV). RESULTS: The CES-D score was 18.3±8.6 for patients, and was 12.4±6.0 for healthy control (P=0.003). Patients were significantly more likely to be in a depressive state (53.6%, defined as CES-D score ≥16) than the healthy control (20.5%, P=0.005). For patients with SVF, the CES-D score was negatively correlated with their age (r s=-0.42, P=0.025). After PPV, both the CES-D score (11.9±5.4 vs 18.3±8.6, P<0.001) and proportion of depressive state (18.5% vs 53.6%, P=0.005) were significantly decreased. CONCLUSION: This study suggests that symptoms of vitreous floaters have an apparently negative impact on patients' psychological state. The PPV can effectively relieve the depressive state for patients with SVF.

[Relative factors of retinal detachment after phacoemulsification cataract extraction and intraocular lens implantation].

OBJECTIVE: To investigate the incidence and related factors of retinal detachment (RD) after phacoemulsification cataract extraction and intraocular lens (IOL) implantation in an unselected patient group. METHODS: This retrospective review was comprised of 10 076 cataract patients (13 625 eyes) who had phacoemulsification cataract extraction and IOL implantation from December 1, 1998 to September 30, 2008. The patients were of different ages, gender, left or right eye and different type of cataracts. The incidence of postoperative RD was assessed and the relative risk factors were estimated using the Kaplan-Meier method. RESULTS: The average age was 67.22 +/- 15.10 years old with 4439 males and 5637 females. The difference between the numbers of men and women was statistically significant (chi(2) = 142.44, P < 0.01). A total of 6701 left eyes and 6924 right eyes showed no significant difference (chi(2) = 3.65, P = 0.056). And 65.91% of these eyes were age-related cataract. During the post-operation observation period, 32 eyes of RD in 32 patients were observed from 10 days to 74 months post-operation. The ratio was 0.32% with an estimated risk (Kaplan-Meier) of 0.47% at 74 months. These results confirmed that myopia and increased axial length were significantly associated with RD (chi(2) = 14.55, P < 0.001) and recognized risk factors for RD such as high myopia, posterior capsular bag rupture and Nd: YAG capsulotomy. Among these 32 eyes, 31 eyes had one successful retina re-attaching operation (90.32%) and two eyes were given up because of post-operative relapse. CONCLUSION: The incidence of RD increases after phacoemulsification cataract extraction and IOL implantation in an unselected patient group. Hypermyopia, posterior capsular bag rupture and Nd: YAG capsulotomy are possible risk factors of the RD.

Targeting neuronal and glial cell types with synthetic promoter AAVs in mice, non-human primates and humans.

Targeting genes to specific neuronal or glial cell types is valuable for both understanding and repairing brain circuits. Adeno-associated viruses (AAVs) are frequently used for gene delivery, but targeting expression to specific cell types is an unsolved problem. We created a library of 230 AAVs, each with a different synthetic promoter designed using four independent strategies. We show that a number of these AAVs specifically target expression to neuronal and glial cell types in the mouse and non-human primate retina in vivo and in the human retina in vitro. We demonstrate applications for recording and stimulation, as well as the intersectional and combinatorial labeling of cell types. These resources and approaches allow economic, fast and efficient cell-type targeting in a variety of species, both for fundamental science and for gene therapy.

Air tamponade and without heavy liquid usage in pars plana vitrectomy for rhegmatogenous retinal detachment repair.

AIM: To report the results of rhegmatogenous retinal detachment (RRD) repair after pars plana vitrectomy (PPV) without operative use of heavy liquid, and utilizing air tamponade in selected cases. METHODS: RRD patients without severity of proliferative vitreoretinopathy C2 or more underwent PPV without operative use of heavy liquid, and utilizing air tamponade were consecutively enrolled. Alternative postoperative facedown position or lateral position was required for 3-5d. RESULTS: Totally 36 eyes of 36 patients (24 males, 66.7%) aged 53.8±10.9y underwent this modified surgery. The mean number of retinal break was 2.1±1.3. Most of the eyes (29, 80.6%) had retinal detachment involving more than one quadrant. Twenty-two (61.1%) eyes with cataract had combined phacoemulsification and intraocular lens implantation. The mean follow up time was 4.6±1.8mo. Two eyes with retinal redetachment underwent a second retinal repair surgery with silicone oil tamponade, yielding the primary reattachment rate to 94.4% (34/36). Six (16.7%) eyes had intraocular pressure higher than 25 mm Hg. The visual acuity (logMAR) improved from 0.98±0.74 preoperatively to 0.52±0.31 postoperatively (P<0.001). CONCLUSION: The success rate of this modified retinal repair surgery is comparable with traditional surgery. This technique can be considered for certain retinal detachment patients, since its apparent advantages included lower surgical complications, reduced surgery expenditure, shorter time for postoperative facedown position, and avoiding silicone oil removal surgery.

Sutureless Intrascleral Haptic-Hook Lens Implantation Using 25-Gauge Trocars.

PURPOSE: To report a new technique for sutureless intrascleral fixation of three-piece foldable intraocular lenses (IOLs) using 25-gauge trocars. METHODS: We performed this technique on patients with insufficient posterior capsule support. Seventeen eyes from 15 patients with aphakia, dislocated IOL, or subluxated crystalline lens undergoing posterior chamber sutureless implantation of an IOL were studied. The haptics of the IOL were externalized using two 25-gauge forceps. The haptics were bended back (hook-like) into the vitreous cavity through a scleral incision made by using a 25-gauge trocar. And, IOL tilt was determined by using a slit lamp and UBM, and complications were recorded. RESULTS: The IOLs were fixed with exact centration and axial stability. No wound leakage was reported even without the use of sutures. The mean best-corrected visual acuity (BCVA) was 0.82 logarithm of the minimum angle of resolution (logMAR) units preoperatively, and the mean BCVA was 0.44 logMAR units at the 6-month follow-up visit. No postoperative retinal detachment, endophthalmitis, IOL tilt or dislocation, or vitreous hemorrhage was noted. CONCLUSION: Sutureless intrascleral haptic-hook posterior chamber IOL implantation using 25-gauge trocars provides good IOL fixation with reliable wound closure without the use of sutures. This trial is registered with ChiCTR1800017436.

27-Gauge Vitrectomy for Symptomatic Vitreous Floaters with Topical Anesthesia.

PURPOSE: Traditionally acceptable methods of anesthesia for vitrectomy surgery are quite varied. However, each of these methods has its own potential for complications that can range from minor to severe. The surgery procedure of vitrectomy for symptomatic vitreous floaters is much simpler, mainly reflecting in the nonuse of sclera indentation, photocoagulation, and the apparently short surgery duration. The use of 27-gauge cannulae makes the puncture of the sclera minimally invasive. Hence, retrobulbar anesthesia, due to its rare but severe complications, seemed excessive for this kind of surgery. METHOD: Three cases of 27-gauge, sutureless pars plana vitrectomy for symptomatic vitreous floaters with topical anesthesia are reported. RESULTS: The vitrectomy surgeries were successfully performed with topical anesthesia (proparacaine, 0.5%) without operative or postoperative complications. Furthermore, none of the patients experienced apparent pain during or after the surgery. CONCLUSION: Topical anesthesia can be considered for 27-guage vitrectomy in patients with symptomatic vitreous floaters.

The Impact of the Menstrual Cycle on Perioperative Bleeding in Vitreoretinal Surgery.

Purpose. To investigate the effect of menstrual cycle on perioperative bleeding of primary vitreoretinal surgery. Methods. Data on female patients who had vitrectomy surgery was retrospectively collected. Exclusion criteria were history of trauma, vitreous hemorrhage, previous vitreoretinal surgery, diabetic retinopathy, endophthalmitis, acute retinal necrosis, single vitreous opacity, and use of antiplatelet agents. Perioperative bleeding was defined as hemorrhage in the iris, vitreous, choroidal, retina, or subretina during surgery or up to one day postoperatively. 69 patients had surgery during the perimenstrual phase (group M, days 1-7 and days 21-28) and 86 during periovulatory phase (group O, days 8-20) were enrolled. Results. The proportion of operative bleeding in group M (14.5%) and group O (10.5%) was not found to be significantly different (p = 0.45). No postoperative bleeding was recorded in both groups. The univariate odds ratio (OR) and 95% confidence interval (CI) of perimenstrual phase for operative bleeding were 0.69 (0.26-1.81). After adjusting for patients' age, vitreoretinal diseases, and surgeons, the multivariate OR and 95% CI were 0.71 (0.27-1.86). Conclusion. This study suggests that the timing of the menstrual period does not affect perioperative bleeding for primary vitreoretinal surgery. Menstruation appears not to be a contraindication for vitreoretinal surgery.

Mutational screening of SLC39A5, LEPREL1 and LRPAP1 in a cohort of 187 high myopia patients.

High myopia (HM) is a leading cause of mid-way blindness with a high heritability in East Asia. Although only a few disease genes have been reported, a small proportion of patients could be identified with genetic predispositions. In order to expand the mutation spectrum of the causative genes in Chinese adult population, we investigated three genes, SLC39A5, LEPREL1 and LRPAP1, in a cohort of 187 independent Chinese patients with high myopia. Sanger sequencing was used to find possible pathogenic mutations, which were further screened in normal controls. After a pipeline of database and predictive assessments filtering, we, thereby, identified totally seven heterozygous mutations in the three genes. Among them, three novel missense mutations, c.860C > T, p.Pro287Leu and c.956G > C, p.Arg319Thr in SLC39A5, c.1982A > G, p.Lys661Arg in LEPREL1, were identified as potentially causative mutations. Additionally, the two heterozygous mutations (c.1582G > A, p.Ala528Thr; c.1982A > G, p.Lys661Arg) in one patient in LEPREL1 gene were reported in this study. Our findings will not only augment the mutation spectrum of these three genes, but also provide insights of the contribution of these genes to adult high myopia in Chinese. However, further studies are still needed to address the pathogenicity of each of the mutations reported in this study.

Surgical Outcomes of 27-Gauge Pars PLana Vitrectomy for Symptomatic Vitreous Floaters.

PURPOSE: To report the surgical outcomes of 27-gauge pars plana vitrectomy (PPV) for symptomatic vitreous floaters. METHODS: 47 eyes of 47 patients (39 males, 83.0%) with symptomatic vitreous floaters who underwent 27-gauge PPV and followed up for more than 6 months were included. The mean age was 34.7 ± 13.5 years. RESULTS: No operative complication occurred. At first day postoperatively, the intraocular pressure (IOP) was significantly lower than that at other time points (8.6 ± 2.7 mmHg, p < 0.001). 28 (59.6%) eyes had transient hypotony (IOP < 8 mmHg). All were recovered within 1 week postoperatively. The BCVA of 41 eyes (41/47, 87.2%) remained unchanged or improved. Postoperative complications occurred in two eyes: one (2.1%) had endophthalmitis and one (2.1%) had retinal detachment. No clinical significant cataract was observed in the 42 postoperative phakic eyes. 91.5% of the patients were satisfied with the surgery outcome. Besides, 91.3% of the patients felt that the floaters were removed completely or only had an acceptable residual. CONCLUSION: Visual acuity of most patients remained unchanged or improved following 27-gague pars plana vitrectomy for symptomatic vitreous floaters, resulting in high patient satisfaction. However, this treatment should be performed with great caution since severe postoperative complications may still occur. This trial is registered with NCT03049163.

The Safety and Efficacy of Adjustable Postoperative Position after Pars Plana Vitrectomy for Rhegmatogenous Retinal Detachment.

Purpose. To report the safety and efficacy of adjustable postoperative position for rhegmatogenous retinal detachment (RRD). Methods. Retrospective review of 536 consecutive RRD eyes that underwent vitrectomy surgery for retina repair from year 2008 to 2014. The retinal breaks were divided into superior, lateral (nasal, temporal, and macular), and inferior locations, according to the clock of breaks. Patients with superior and lateral break location were allowed to have facedown position or lateral decubitus position postoperatively, while patients with inferior break location were allowed to have facedown position. Results. 403 eyes of 400 patients were included. The mean follow-up interval was 22.7 ± 21.3 months. The overall primary retinal reattachment rate was 93.3%. There were 24 (6.0%), 273 (67.7%), and 106 (26.3%) patients with superior, lateral, and inferior break location, respectively. The primary reattachment rate was 95.8%, 92.3%, and 95.3% accordingly. After further divided the break location into subgroups as a function of duration of symptom, postoperative lens situation, number of retinal breaks, and different vitreous tamponade, the primary reattachment rates were all higher than 82%. Conclusion. Adjustable postoperative positioning is effective and safe for RRD repair with different break locations. Choosing postoperative position appropriately according to retinal break locations could be recommended.

Targeted RP9 ablation and mutagenesis in mouse photoreceptor cells by CRISPR-Cas9.

Precursor messenger RNA (Pre-mRNA) splicing is an essential biological process in eukaryotic cells. Genetic mutations in many spliceosome genes confer human eye diseases. Mutations in the pre-mRNA splicing factor, RP9 (also known as PAP1), predispose autosomal dominant retinitis pigmentosa (adRP) with an early onset and severe vision loss. However, underlying molecular mechanisms of the RP9 mutation causing photoreceptor degeneration remains fully unknown. Here, we utilize the CRISPR/Cas9 system to generate both the Rp9 gene knockout (KO) and point mutation knock in (KI) (Rp9, c.A386T, P.H129L) which is analogous to the reported one in the retinitis pigmentosa patients (RP9, c.A410T, P.H137L) in 661 W retinal photoreceptor cells in vitro. We found that proliferation and migration were significantly decreased in the mutated cells. Gene expression profiling by RNA-Seq demonstrated that RP associated genes, Fscn2 and Bbs2, were down-regulated in the mutated cells. Furthermore, pre-mRNA splicing of the Fscn2 gene was markedly affected. Our findings reveal a functional relationship between the ubiquitously expressing RP9 and the disease-specific gene, thereafter provide a new insight of disease mechanism in RP9-related retinitis pigmentosa.