Immersive teaching using virtual reality technology to improve ophthalmic surgical skills for medical postgraduate students

Medical education is primarily based on practical schooling and the accumulation of experience and skills, which is important for the growth and development of young ophthalmic surgeons. However, present learning and refresher methods are constrained by several factors. Nevertheless, virtual reality (VR) technology has considerably contributed to medical training worldwide, providing convenient and practical auxiliary value for the selection of students' sub-majors. Moreover, it offers previously inaccessible surgical step training, scenario simulations, and immersive evaluation exams. This paper outlines the current applications of VR immersive teaching methods for ophthalmic surgery interns.

Outcomes of Primary Vitrectomy for Rhegmatogenous Retinal Detachment With No Postoperative Positioning

Purpose: To evaluate the anatomic and visual outcomes of primary vitrectomy for rhegmatogenous retinal detachment (RRD) repair using no amount of postoperative prone positioning to clarify the role of face-down posturing for RRD reattachment. Methods: This retrospective consecutive interventional case series comprised patients who had primary vitrectomy for RRD repair. The surgical outcomes, single-surgery anatomic success rate, and postoperative best-corrected visual acuity (BCVA) were assessed. The primary objective was to evaluate the anatomic and visual outcomes of vitrectomy RRD reattachment using no postoperative prone positioning. Results: This study comprised 116 eyes of 116 patients. Single-surgery anatomic success was achieved in 112 (96.5%) of 116 eyes. The single-surgery anatomic success rate was 100% in phakic patients (n = 56) and 93% in pseudophakic patients (n = 60), with both groups having an improvement in the mean BCVA. Conclusions: Primary vitrectomy with no postoperative prone positioning is a successful surgical intervention for RRD repair. The anatomic closure rate in this study is one of the highest reported in the literature and involved a large number of macula-off RRDs, with minimal complications and a significant improvement in BCVA, primarily using 14% perfluoropropane for gas tamponade.

Comprehensive exploration of hub genes involved in oxidative stress in rhegmatogenous retinal detachment based on bioinformatics analysis

Rhegmatogenous retinal detachment (RRD) is a type of ophthalmologic emergency, if left untreated, the blindness rate approaches 100 %. The RRD patient postoperative recovery of visual function is unsatisfactory, most notably due to photoreceptor death. We conducted to identify the key genes for oxidative stress (OS) in RRD through bioinformatics analysis and clinical validation, thus providing new ideas for the recovery of visual function in RRD patients after surgery. A gene database for RRD was obtained from the Gene Expression Omnibus (GEO) database (GSE28133). Then we screened differentially expressed OS genes (DEOSGs) from the database and assessed the critical pathways in RRD with Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway. Protein-protein interaction (PPI) networks and hub genes among the common DEOSGs were identified. In addition, we collected general information and vitreous fluid from 42 patients with RRD and 22 controls [11 each of epiretinal membrane (EM) and macular hole (MH)], examined the expression levels of proteins encoded by hub genes in vitreous fluid by enzyme-linked immunosorbent assay (ELISA) to further assess the relationship between the ELISA data and the clinical characteristics of patients with RRD. Ten hub genes (CCL2, ICAM1, STAT3, CD4, ITGAM, PTPRC, CCL5, IL18, TLR2, VCAM1) were finally screened out from the dataset. The ELISA results showed that, compared with the control group, patients with RRD: TLR2 and ICAM-1 were significantly elevated, and CCL2 had a tendency to be elevated, but no statistically significant; RRD patients and MH patients compared with EM patients: STAT3 and VCAM-1 were significantly elevated. We found affected eyes of RRD patients compared with healthy eyes: temporal and nasal retinal nerve fiber layer (RNFL) were significantly thickened. By correlation analysis, we found that: STAT3 was negatively correlated with ocular perfusion pressure (OPP); temporal RNFL was not only significantly positively correlated with CCL2, but also negatively correlated with Scotopic b-wave amplitude. These findings help us to further explore the mechanism of RRD development and provide new ideas for finding postoperative visual function recovery.

Guidelines and treatment patterns for primary rhegmatogenous retinal detachments: Expert consensus and survey in Taiwan Retina Society

Rhegmatogenous retinal detachment (RRD) is a significant cause of vision loss and requires appropriate surgical intervention. There are several approaches available, including observation, laser demarcation, pneumatic retinopexy, scleral buckling, and pars plana vitrectomy, which are chosen based on patient condition, surgeon experience, and national health insurance policies. Despite the various options, there is still no consensus on the optimal intervention. To address this, the Taiwan Retina Society assembled an expert committee with 11 experienced retina specialists to review the current evidence and develop a guideline with seven recommendations for managing RRD patients. Additionally, a survey was conducted with six questions to assess treatment patterns in Taiwan, which included input from the expert committee and an open poll at the 2023 Congress of the Taiwan Retina Society. This report provides a comprehensive summary of the current knowledge and expert consensus on the treatment of RRD, discussing the characteristics of current approaches and providing an overview of current treatment patterns in Taiwan. These findings aim to provide ophthalmologists with the best possible treatment for RRD.

The effect of a new design of patient gowns for prone position patients after vitrectomy: A non-randomized, concurrent, controlled study

BACKGROUND

The existing patient clothing is not suitable for patients that have to maintain a prone position for a long time after vitrectomy.

OBJECTIVE

To investigate the effect of a new design of patient gowns for prone position patients after vitrectomy.

METHOD

This study designed a kind of patient's gown for prone position patients. A non-randomized, concurrent, controlled study was conducted on 212 patients who met the inclusion criteria for the prone position after vitrectomy in Grade III at a Class A hospital department of ophthalmology in Zhejiang Province from April to August 2020. The experimental group (106 patients in prone position) and the control group (106 patients in common position) were managed by the same group of nurses. The study recorded and compared the comfort degree of patients' clothing used in the course of operation rehabilitation between the two groups and the satisfaction degree of doctors with nurses to patients' clothing used in the prone position.

RESULTS

The satisfaction degree and comfort degree of patients and the health care providers in the experiment group were significantly higher than those in the control group (p< 0.001).

CONCLUSION

The process of making patient gowns for prone position patients is simple, which can improve the safety and comfort of patients when they were in the prone position. The new design also facilitated the treatment and nursing procedures of the medical staff and improved satisfaction among patients and medical staff.

Choroidal vascular changes in silicone oil-filled eyes after vitrectomy for rhegmatogenous retinal detachments

INTRODUCTION

The tamponade of silicone oil (SO) can affect both the structure and blood flow of the retina. However, there are few studies on the effect of SO tamponade on choroidal blood flow. Our study aimed to compare the effects of SO tamponade on the choroidal vascular index (CVI) and choroidal thickness (CT) in patients with unilateral rhegmatogenous retinal detachment (RRD) with operated eyes and fellow healthy eyes.

METHODS

We retrospectively collected demographic and clinical data from 36 patients who underwent 23G pars plana vitrectomy and SO tamponade for unilateral complicated RRD. Enhanced depth imaging-optical coherence tomography (EDI-OCT) scans were performed both within 1 week before SO removal and at the last follow-up visit after SO removal. Using ImageJ software, images were binarized to segment the total choroidal area, luminal area, and stromal area, respectively. The CVI was calculated as CVI=(luminal area)/(total choroidal area), and CT was also evaluated.

RESULTS

During SO tamponade, the CVI and luminal area in operated eyes were significantly lower compared to fellow eyes (57.616 ± 0.030 vs. 60.042 ± 0.019, P < 0.0001; 0.909 [0.694; 1.185] vs. 1.091 [0.785; 1.296], P = 0.007). Even after SO removal, the CVI remained lower in operated eyes than in fellow eyes (59.530 ± 0.018 vs. 60.319 ± 0.020, P = 0.031). Both CVI and luminal area were lower in operated eyes before SO removal than after SO removal (57.616 ± 0.030 vs. 59.530 ± 0.018, P = 0.0003; 0.909 [0.694; 1.185] vs. 0.994 [0.712; 1.348], P = 0.028). The duration of SO tamponade was positively correlated with the difference in CVI between fellow eyes and operated eyes during SO tamponade (P = 0.035). Total choroidal area, stromal area, and CT did not differ significantly between fellow eyes and operated eyes or between pre- and post-SO removal.

CONCLUSIONS

SO tamponade reduces CVI and decreases choroidal blood circulation in patients with retinal detachments required vitrectomy combined with SO tamponade. The longer the SO tamponade time, the more CVI reduction. In future work, we will aim to reduce these side effects by shortening the duration of silicone oil filling.

Preoperative estimation of retinal hole location using ultra-wide-field imaging

BACKGROUND/OBJECTIVE

Accurate localization of retinal holes is essential for successful scleral buckling (SB) surgery. We aimed to verify the feasibility of using ultra-wide-field (UWF) imaging for preoperative estimation of retinal hole location.

PATIENTS AND METHODS

We observed 21 eyes from 21 patients with rhegmatogenous retinal detachment (RRD) who underwent successful SB. They were treated at the Department of Ophthalmology of the Second Hospital of Hebei Medical University between November 2020 and November 2021. UWF fundus photography using an Optos device was performed at different steering positions 1 day before, 1 day after, and 1 month after SB. Using the preoperative fundus images, we measured the transverse diameter of the optic disc (D1) and the distance from the centre of the retinal holes to the ora serrata (D2). The accurate transverse diameter of the optic disc (Dd) was measured preoperatively using optical coherence tomography. The same surgeon measured the scleral chord lengths intraoperatively from the limbus to the located retinal hole marked on the sclera using an ophthalmic calliper. Statistical software was used to analyze the consistency of scleral chord length between the retinal hole and the limbus, which was estimated by preoperative UWF imaging and was measured using an ophthalmic calliper intraoperatively.

RESULTS

There was no statistically significant difference in the scleral chord length between the retinal holes and the limbus, which was estimated by preoperative UWF fundus photography and was measured by the calliper during surgery.

CONCLUSION

It is feasible to locate retinal holes using UWF fundus photography before SB, which is helpful for quick localization, thereby reducing the learning curve of SB surgery.

Corneal Astigmatism Alteration after Combined Silicone Oil Removal and Cataract Surgery with Intraocular Lens Implantation

Purpose

To explore short-term changes in corneal astigmatism after combined silicone oil removal and cataract (SORC) surgery.

Methods

We enrolled 89 patients (43 men and 46 women). Zeiss IOLMaster was used to measure corneal astigmatism status and axial length on the day before and after the SORC surgery. Best-corrected visual acuity (BCVA) and intraocular pressure (IOP) were recorded. The results were compared to the outcomes at 3 days, 1 week, and 1 month postoperatively.

Results

Compared to baseline, K1 decreased significantly at 3 days postoperatively (P = 0.016), 1 week (P = 0.009), and 1 month (P = 0.035), while K2 increased significantly at 3 days postoperatively (P = 0.002), 1 week (P < 0.001), and 1 month (P = 0.001), as well as corneal astigmatism (all P < 0.001). Compared to that at the baseline, BCVA significantly improved at 3 days, 1 week, and 1 month postoperatively (all P < 0.001). Meanwhile, IOP decreased significantly at 3 days postoperatively (P < 0.001), 1 week (P = 0.005), and 1 month (P = 0.007). Similarly, axial length decreased at all follow-up time points (all P < 0.001).

Conclusion

Corneal astigmatism increased in the short term after the SORC operation but gradually decreased at 1 month postoperatively. BCVA improved steadily, and SORC was widely used in the clinic.

Air versus fluorinated gas tamponades in pars plana vitrectomy treatment for primary rhegmatogenous retinal detachment

PURPOSE

To compare the treatment success of air with fluorinated gas (20% SF₆ or 14% C₃ F₈ ) tamponade in pars plana vitrectomy for primary rhegmatogenous retinal detachment.

METHODS

A retrospective cohort study comprised of 1023 consecutive primary retinal detachment cases between 2014 and 2020. We employed a univariate multivariable binary logistic regression model.

RESULTS

We used intraocular gas tamponades in 872 cases with PVR grade B or lower: air tamponade was used in 414 eyes and 458 eyes were treated with a type of fluorinated gas tamponade. There was no significant difference in the type of tamponade with regard to the re-detachment rate (95% CI -1.0% and 4.1%). Additionally, also in the subgroup of rhegmatogenous retinal detachments with inferior located retinal defects we found no significant difference between the two types of tamponade (p = 0.54 Fisher's exact). The multivariable model, which included tamponade, PVR grade, a retinal detachment involving the 6 o'clock position and age as covariates, also showed no significant effect of tamponade choice on treatment success (OR 0.5, 95% 0.2-1.0, p = 0.10).

CONCLUSION

We found no difference in treatment success with air tamponade versus fluorinated gas tamponades in the repair of primary retinal detachments, this also includes inferiorly located retinal tears and detachments.

Factors influencing compliance in RRD patients with the face-down position via grounded theory approach

Patients with rhegmatogenous retinal detachment (RRD) require face-down positioning (FDP) for 3-6 months or longer after pars plana vitrectomy (PPV) combined with silicone oil (SO) tamponade. This paper aimed to identify the factors that influenced FDP compliance. This study adopted semi-structured interviews with patients who require FDP after SO tamponade. Constructivist grounded theory was utilized in this study. The qualitative data was analyzed and coded via NVivo 11.0 through open coding, axial coding and selective coding. Twenty-four RRD patients were involved. The interviews yielded five main themes that defined home FDP compliance were identified: posture discomfort, doctor-patient communication, psychological factors, occupational character, and family factors. A theoretical model of the influencing factors of postural compliance of FDP was constructed based on the interview analysis. A variety of factors can affect FDP conformity. We can increase compliance of RRD patients by enhancing comfort, encouraging doctor-patient communication, providing comprehensive care, promoting community-based intervention, and strengthening family education.

Development of an anti-oxidative intraocular irrigating solution based on reactive persulfides

Anti-oxidative intraocular irrigating solutions (IISs) based on reactive persulfides, such as oxidized glutathione disulfide (GSSG), are commonly used worldwide. However, even with GSSG-based IISs, it has been shown that oxidative stress can occur during surgery, posing a risk to intraocular tissues. This study compared two IISs: one containing GSSG and one containing an oxidized glutathione trisulfide (GSSSG). Experimental in vivo irrigation with the IISs in rabbits showed that there was less leakage into the anterior chamber of rabbit serum albumin during perfusion with a 300-μM GSSSG IIS than with a 300-μM GSSG IIS. Experimental in vivo cataract surgery in rabbits showed that aqueous flare was suppressed 3 days after surgery with a 600-μM GSSSG IIS, but not with a 300-μM GSSSG or 300-μM GSSG IIS. Furthermore, an in vitro experiment, without any live tissue, showed that reactive oxygen species were suppressed more strongly with a 600-μM GSSSG IIS than with a 300-μM GSSG IIS. Thus, this study found that novel IISs based on GSSSG had anti-inflammatory and anti-oxidative effects during and after intraocular surgery and may decrease the rate of complications after surgery.

Advances in biomaterials as a retinal patch for the repair of rhegmatogenous retinal detachment

Rhegmatogenous retinal detachment (RRD) is the most common retinological emergency that can cause blindness without surgical treatment. RRD occurs when liquefied vitreous accumulates between the neurosensory retina and the retinal pigment epithelium via retinal breaks, which are caused by the separation of the vitreous from the retina with aging. Currently, the main treatment option is pars plana vitrectomy, which involves surgical removal of the vitreous and laser photocoagulation around retinal breaks to generate firm chorioretinal adhesion, as well as subsequent filling of the vitreous cavity with long-lasting substitutes (expansile gas or silocone oil) to prevent the connection between the subretinal space and the vitreous cavity via the breaks before the chorioretinal adhesion firm enough. However, the postoperative face-down position and the not very satisfactory first retinal reattachment rate place a heavy burden on patients. With the development of technology and materials engineering, researchers have developed biomaterials that can be used as a retinal patch to seal retinal breaks and prevent the connection of subretinal space and vitreous cavity via breaks, thus replacing the long-lasting vitreous substitutes and eliminating the postoperative face-down position. Preclinical studies have demonstrated that biomaterial sealants have enough biocompatibility and efficacy in the in vitro and in vivo experiments. Some sealants have been used in clinical trials on a small scale, and the results indicate promising application prospects of the biomaterial sealants as retinal patches in the repair of RRD. Herein, we review the recent advances in biomaterials as retinal patches for the repair of RRD, focusing on the biomaterial categories, methods, and procedures for sealing retinal breaks, as well as their biocompatibility and efficacy, current limitations, and development perspectives.

Optical Coherence Tomography Findings in Rhegmatogenous Retinal Detachment: A Systematic Review

Rhegmatogenous retinal detachment is a sight-threatening condition that may lead to blindness if left untreated. Surgical treatments may vary and are tailored to a single patient. Anatomical and functional results may vary, due to factors that are currently under study. Optical coherence tomography (OCT) allows a detailed visualization of the retinal structure. Some studies have been performed using OCT on eyes with retinal detachment. We performed a review on the subject. Several data have been obtained using different OCT applications. Some alterations may represent potential biomarkers since they are associated with visual and anatomical prognoses. Increased knowledge on the subject may be helpful to choose among different surgical strategies and endotamponades. More research on the topic is needed.

Evaluation of Foldable Capsular Vitreous Body Implantation Surgery

Background

Foldable capsular vitreous body (FCVB), a novel artificial vitreous substitute product, has been used clinically in recent years. The aim of this study was to evaluate the outcomes and complications of FCVB implantation surgery during the postoperative period.

Methods

We performed a prospective, nonrandomized study from November 2021 to March 2022. Eight patients with severe retinal detachment that could not be easily reattached were included in this study. Before and after surgery, visual acuity (VA), intraocular pressure (IOP), slit-lamp microscopy, optical coherence tomography (OCT), B-scan and CT were performed.

Results

After the operation, the FCVB was well distributed in the vitreous cavity and supported the retina according to the B-scan and CT images. During the follow-up period, no vitreous hemorrhage or retinal detachment was found in any of the patients. On the first postoperative day, the average IOP increased from 9.6 ± 7.7 mmHg preoperatively to 13.8 ± 14.3 mmHg. Although the IOP of two patients fell outside the normal range, IOP was finally held steady after the fifth postoperative day in all cases. In addition, three patients (37.5%) experienced eye ache, and after taking a Saridon tablet, the pain was greatly alleviated. Moreover, no adverse events, such as silicone oil (SO) spillage and emulsification or serious complications, were observed.

Conclusion

The current vitreous substitute FCVB is effective and safe for treating complicated retinal detachments in ophthalmic applications. Further multiple-center clinical designs should focus on indications and complications of FCVB during long-term follow-up periods.

Recognising and managing retinal detachments

Retinal detachments are a potentially sight-threatening ophthalmic emergency that may result in significant, irreversible vision loss. The risk of developing retinal detachment increases with advancing age, myopia and trauma. Pre-existing retinal degenerations can precipitate a pre-detachment symptomatic period of photopsia or floaters, allowing clinicians to intervene early and prevent detachments. Novel imaging techniques, such as spectral-domain optical coherence tomography, and well-established topographic modalities, such as B scan, can help to elucidate the type of detachment and any underlying causes, and help with surgical management. The overarching goal of treatment is to identify and seal all retinal holes, relieve vitreoretinal traction and prevent further recurrence. Prompt prophylactic retinopexy of retinal holes and tears is crucial in preventing retinal detachment, the main treatments of which are pars plana vitrectomy, tamponading agents and silicone scleral buckle.

New Classification for the Reporting of Complications in Retinal Detachment Surgical Trials

IMPORTANCE

Quantifying severity of complications in rhegmatogenous retinal detachment (RRD) surgical trials is needed. A consensus classification system will help surgeons to more effectively compare harms of different surgical techniques.

OBJECTIVE

To develop a new consensus-based classification to quantify severity of complications of RRD surgery.

DESIGN, SETTING, AND PARTICIPANTS

A comprehensive list of complications was developed followed by a Delphi consensus survey of international vitreoretinal surgeons. The survey was conducted in 17 countries in mainland Europe, the United Kingdom, the United States, Asia, South Africa, and Australia. Seventy vitreoretinal surgeons were invited to take part in the Delphi survey; 45 agreed to participate. Participants were selected through boards/members lists of retinal societies. Data were analyzed between April 2019 and August 2019.

MAIN OUTCOMES AND MEASURES

Consensus-derived classification of complications of RRD surgery, according to their severity.

RESULTS

Forty-three of 45 vitreoretinal surgeons who agreed to participate in the Delphi survey completed round 1 (96%); all but 1 (98%) completed round 2. Consensus was reached for 96% of the 84 complications assessed. Examples of complications classified as least severe (graded 1) included subconjunctival hemorrhage and chemosis while those classified as most severe included endophthalmitis and sympathetic ophthalmia (graded 9) and phthisis (graded 10).

CONCLUSIONS AND RELEVANCE

We propose a new classification for quantifying severity of surgical complications based on an international consensus of vitreoretinal surgeons to quantify harm and improve the reporting of complications of RRD surgery.

Needle decompression of the eye! Emergent management of a vision threatening surgical complication

Acute angle-closure glaucoma (AACG) is a medical emergency that can cause permanent visual deficits without prompt recognition. From 2006 to 2011, nearly 12 million visits to emergency departments (ED) in the United States were ophthalmologic in nature, making it crucial for emergency physicians to be familiar with the diagnosis and treatment of ophthalmologic emergencies. AACG can be precipitated by several mechanisms including pupillary block, anticholinergic medications, and sympathomimetic medications. We present a rare case of angle-closure glaucoma status post pneumatic retinopexy with cryotherapy due to migration of an intravitreal gas bubble into the anterior chamber with emphasis on understanding how retinal surgery types lead to significant differences in management.

Primary rhegmatogenous retinal detachment: evaluation of a minimally restricted face-down positioning after pars plana vitrectomy and gas tamponade

AIM

To evaluate the safety and efficacy of a minimally restricted face-down postoperative positioning following pars plana vitrectomy (PPV) with gas tamponade for primary rhegmatogenous retinal detachment (RRD).

METHODS

Patients with primary RRD treated with PPV and gas tamponade and followed up for at least 6mo were selected for the study. All phakic eyes underwent simultaneous cataract surgery. The patients were required to be in a postoperative position that prevented downward flow of retinal tears. Patients with macular detachment were positioned face-down for only a couple of hours. The patients were assessed for preoperative and postoperative best-corrected visual acuity (BCVA), anatomical retinal reattachment rate, and postoperative complications.

RESULTS

In total, 40 eyes of 39 patients with primary RRD were included in the study. A single tear was present in 30 eyes (75.0%), multiple retinal tears were present in nine eyes (22.5%), and oral dialysis was present in one eye (2.5%). The anatomical success rate was 90.0% (36 cases) after the primary surgery, and the final anatomical success rate was 100%. The BCVA improved significantly (P<0.001) from 0.75 logarithm angle of resolution (logMAR) preoperatively to 0.12 logMAR at the final visit. Postoperative complications included intraocular pressure elevation (≥25 mm Hg) in 11 patients (27.5%), fibrin formation in two patients (5.0%), pupillary capture of the intraocular lens in two patients (5.0%), and posterior synechia in one patient (2.5%).

CONCLUSION

A minimally restricted face-down and flexible postoperative positioning after PPV and gas tamponade for primary RRD is effective and safe.

Reporting of Complications in Retinal Detachment Surgical Trials: A Systematic Review Using the CONSORT Extension for Harms

IMPORTANCE

Knowledge on the frequency and severity of complications in surgical trials for rhegmatogenous retinal detachment (RRD) is essential to determine whether surgical procedures are developed and compared adequately, taking into account not only efficacy but also harms.

OBJECTIVE

To review standards of reporting of complications in recent randomized clinical trials of RRD surgery.

EVIDENCE REVIEW

This systematic review included randomized clinical trials on RRD surgery published between January 2008 and January 2021 in Embase, MEDLINE, and Web of Science Core Collection databases. Titles, abstracts, and full-text articles retrieved were reviewed for eligibility by 2 independent authors. Eligible studies were evaluated against checklist items from the Consolidated Standards of Reporting Trials Extension for Harms criteria by 2 independent authors, and discrepancies were resolved by discussion with a third author.

FINDINGS

Fifty studies were included. The median number of checklist items fulfilled was 8 (range, 0-15), of a possible total of 18. Frequently reported items were discussions balanced with regard to efficacy and adverse events (42 studies [84%]) and inclusions of harm-associated timing of data collection (41 studies [82%]). The least frequently reported items were distinctions between expected and unexpected adverse events (1 study [2%]) and mentions of the use of a validated instrument to report adverse event severity (4 studies [8%]). Frequency of complications was commonly reported (29 studies [58%]) in contrast with complication severity (10 studies [20%]).

CONCLUSIONS AND RELEVANCE

This review suggests that severity of complications of RRD surgery has been infrequently quantified and reported in randomized clinical trials and potentially represents an important area of improvement in future RRD surgical trials.

Experimental models and examination methods of retinal detachment

Retinal detachment refers to the separation of the retinal neuroepithelium and pigment epithelium, usually involving the death of photoreceptor cells. Severe detachment may lead to permanent visual impairment if not treated properly and promptly. According to the underlying causes, retinal detachment falls into one of three categories: exudative retinal detachment, traction detachment, and rhegmatogenous retinal detachment. Like many other diseases, it is difficult to study the pathophysiology of retinal detachment directly in humans, because the human retinal tissues are precious, scarce and non-regenerative; thus, establishing experimental models that better mimic the disease is necessary. In this review, we summarize the existing models of the three categories of retinal detachment both in vivo and in vitro, along with an overview of their examination methods and the major strengths and weaknesses of each model.

USP10 Targeted Self-Deliverable siRNA to Prevent Scarring in the Cornea

Ocular scarring after surgery, trauma, or infection leads to vision loss. The transparent cornea is an excellent model system to test anti-scarring therapies. Cholesterol-conjugated fully modified asymmetric small interfering RNAs (siRNAs) (self-deliverable siRNAs [sdRNAs]) are a novel modality for in vivo gene knockdown, transfecting cells and tissues without any additional formulations. Myofibroblasts are a main contributor to scarring and fibrosis. α_v integrins play a central role in myofibroblast pathological adhesion, overcontraction, and transforming growth factor β (TGF-β) activation. Previously, we demonstrated that α_v integrins are protected from intracellular degradation after wounding by upregulation of the deubiquitinase (DUB) ubiquitin-specific protease 10 (USP10), leading to integrin cell surface accumulation. In this study, we tested whether knockdown of USP10 with a USP10-targeting sdRNA (termed US09) will reduce scarring after wounding a rabbit cornea in vivo. The wounded corneal stroma was treated once with US09 or non-targeting control (NTC) sdRNA. At 6 weeks US09 treatment resulted in faster wound closure, limited scarring, and suppression of fibrotic markers and immune response. Specifically, fibronectin-extra domain A (EDA), collagen III, and a-smooth muscle actin (p < 0.05), CD45⁺ cell infiltration (p < 0.01), and apoptosis at 24 (p < 0.01) and 48 h (p < 0.05) were reduced post-wounding. Corneal thickness and cell proliferation were restored to unwounded parameters. Targeting the DUB, USP10 is a novel strategy to reduce scarring. This study indicates that ubiquitin-mediated pathways should be considered in the pathogenesis of fibrotic healing.

Successful surgical outcomes after 23-, 25- and 27-gauge vitrectomy without scleral encircling for giant retinal tear

PURPOSE

Retinal detachment due to giant retinal tears (GRTs), tears larger than 90°, is rare and difficult to treat. Here, we show and compare surgical results of 23-, 25- and 27-gauge (G) micro-incision vitrectomy surgery (MIVS) for GRT.

STUDY DESIGN

Retrospective and interventional case series.

METHODS

Retrospective review of 41 eyes of 38 patients with GRT who underwent MIVS. Surgical outcomes after MIVS, including reattachment rates and postoperative complications, were compared between instrument gauges. All patients were followed for at least 6 months postoperatively.

RESULTS

MIVS with 23G, 25G and 27G instruments was performed in 7, 19 and 15 eyes, respectively. Silicone oil (SO) was used in 34 of 41 eyes (83%) with a mean removal time of 43.8 days after first surgery. Best-corrected visual acuity (BCVA) was recovered or maintained in 39 eyes (95%). Reattachment was attained after initial surgery in 38 of 41 eyes (93%) (23G: 6/7 [86%]; 25G: 17/19 [89%]; 27G: 15/15 [100%]). Final reattachment was eventually achieved in all eyes (two eyes needed support from scleral encircling). Postoperative complications occurred in 16 eyes (39%) (23G: 3/7 [43%]; 25G: 8/19 [42%]; 27G: 5/15 [33%]), including macular pucker, cystoid macular edema, macular hole, subretinal perfluorocarbon liquid, retinal folds, vitreous hemorrhage and redetachment. There were no significant differences between the three groups in rate of high myopia, GRT size, operation time, phacovitrectomy rate, SO usage rate, initial reattachment rate, final reattachment rate, preoperative BCVA, final BCVA or rate of postoperative complications.

CONCLUSION

Despite occasional postoperative complications, primary MIVS, regardless of gauge size, appears to be a safe and feasible option for GRT surgery.