An endoscopic overview of the anterior vitreous base in retinal detachment and anterior proliferative vitreoretinopathy

Heads-up 3-Dimensional Visualization to Enhance Video Endoscopy During Vitreoretinal Surgery

Purpose: To describe 2 cases in which video endoscopy was combined with heads-up 3-dimensional (3D) visualization. Methods: The imaging modalities of the heads-up 3D visualization system and video endoscopy were combined by converting the endoscope's S-Video output into a high-definition multimedia interface. The technique was used in 2 cases that included lens dislocation and endophthalmitis. Results: In the 2 cases, the heads-up split-screen view simplified the surgical setup. Simultaneously viewing the endoscopic image and widefield 3D image anecdotally appeared to improve ergonomics, help keep the probe oriented, and assist in guiding surgical movements endoscopically. Conclusions: These cases show the advantages of a heads-up 3D system to simultaneously view endoscopic and widefield images during ophthalmic endoscopy in vitreoretinal surgery.

Endoscopy-assisted pars plana vitrectomy in retinal detachments associated with anterior proliferative vitreoretinopathy and epiciliary membranes

BACKGROUND

Proliferative vitreoretinopathy (PVR) is the leading cause of recurrent retinal detachment. Anterior PVR can contribute to recurrent retinal detachment and is often difficult to remove during conventional pars plana vitrectomy. The purpose of this study is to report surgical outcomes of single endoscopy-assisted pars plana vitrectomy (E-PPV) in patients with tractional retinal detachments associated with anterior proliferative vitreoretinopathy and epiciliary membranes.

METHODS

Retrospective review of E-PPV between 2017 and 2021 at a tertiary referral center. Inclusion criteria involved adult patients who underwent E-PPV for tractional retinal detachment with anterior PVR and epiciliary membranes. Data collection included patients' demographics, ophthalmic exam findings, and surgical outcomes. A series of independent sample tests of proportion were conducted using a p-value of 0.05 as the threshold for statistical significance.

RESULTS

Eighteen out of 55 patients who underwent E-PPV met the inclusion criteria. There were six females (33%) and 12 males (p-value = 0.096). Age ranged between 27 and 82 years old (mean age 52.1 ± 17.3 years). Nine patients (50%) had a history of ipsilateral retinal detachment repair. Single E-PPV success rate was 100% after three months, and 94.4% at the latest follow up visit. Recurrent retinal detachment with posterior PVR occurred in one patient four months after surgery. Cataract progressed in 57% (8/14) of phakic patients, with 63% (5/8) undergoing cataract extraction surgery within the first postoperative year.

CONCLUSION

E-PPV enabled epiciliary membrane and anterior PVR visualization and removal. The single E-PPV success rate remained high at the latest follow up visit. E-PPV enabled the preservation of the phakic lens in all study patients. Larger prospective studies are needed on the role of E-PPV in retina surgeries.

Translational and clinical advancements in management of proliferative vitreoretinopathy

PURPOSE OF REVIEW

Despite advancement in the surgical instrumentation and techniques, proliferative vitreoretinopathy (PVR) remains the most common cause for failure of rhegmatogenous retinal detachment (RRD) repair. This review discusses ongoing translational and clinical advancements in PVR.

RECENT FINDINGS

PVR represents an exaggerated and protracted scarring process that can occur after RRD. The primary cell types involved are retinal pigment epithelium, glial, and inflammatory cells. They interact with growth factors and cytokines derived from the breakdown of the blood-retinal barrier that trigger a cascade of cellular processes, such as epithelial-mesenchymal transition, cell migration, chemotaxis, proliferation, elaboration of basement membrane and collagen and cellular contraction, leading to overt retinal pathology. Although there are currently no medical therapies proven to be effective against PVR in humans, increased understanding of the risks factors and pathophysiology have helped guide investigations for molecular targets of PVR. The leading therapeutic candidates are drugs that mitigate growth factors, inflammation, and proliferation are the leading therapeutic candidates.

SUMMARY

Although multiple molecular targets have been investigated to prevent and treat PVR, none have yet demonstrated substantial evidence of clinical benefit in humans though some show promise. Advancements in our understanding of the pathophysiology of PVR may help develop a multipronged approach for this condition.

Endoscopic vitreoretinal surgery: Review of current applications and future trends

Endoscopy provides unique optical properties to circumvent anterior segment opacities and visualize difficult-to-access anatomical regions, including retroirideal, retrolental, ciliary body, and anterior retinal structures. We summarize the basic principles and utilization of endoscopic vitreoretinal surgery, along with recent technological advances in the field base on a structured literature search in Pubmed, Embase, and Google Scholar database up to February, 2020. Endoscopy has been used in the management of retinal detachment, ischemic retinopathies with neovascular glaucoma, severe ocular trauma, endophthalmitis, lens-related disorders in the posterior segment, pediatric vitreoretinal diseases, and implantation of retinal prostheses. Ongoing development of endoscopic technology aims to provide higher resolution images with endoscopes of smaller diameter. New surgical techniques supported by the adoption of endoscopy are available to manage challenging surgical scenarios. Endoscopy can be a useful adjunct to microscope wide-angle viewing systems in the management of complex vitreoretinal diseases.

Endodiathermy assisted vitreous base and anterior hyaloid visualization during vitrectomy for rhegmatogenous retinal detachment

PURPOSE

To describe a novel technique to visualize vitreous base and the anterior hyaloid during vitrectomy for Rhegmatogenous Retinal Detachment (RRD).

METHODS

Retrospective, single-center study enrolling all patients who underwent vitrectomy for RRD between June 2015 and June 2018. After core vitrectomy and the necessary additional procedures, endodiathermy was activated near the edge of the peripheral vitreous. This created a heat-induced bubble stream and the bubbles were entangled in the vitreous base and anterior hyaloid. As a result, the vitreous base and anterior hyaloid were visualized and removed.

RESULTS

Between June 2015 and June 2018, a total of 210 cases of rhegmatogenous retinal detachment were treated with vitrectomy. Endodiathermy assisted vitreous base shaving and anterior hyaloid removal was used in those cases with a very low incidence of iatrogenic peripheral retinal breaks during vitreous base shaving (2%), and with no case of lens injury related to the technique. We achieved a final anatomical success of 95.2% in the study period after mean number of operations of 1.3 ± 0.2. Endodiathermy near the peripheral vitreous was not associated with any intraoperative or postoperative complications.

CONCLUSION

Endodiathermy assisted vitreous base and anterior hyaloid visualization is a safe adjuvant method that could help in achieving complete and rapid vitreous base shaving and anterior hyaloid removal.

Endoscopic vitreoretinal surgery: principles, applications and new directions

Purpose

To analyze endoscopic vitreoretinal surgery principles, applications, challenges and potential technological advances.

Background

Microendoscopic imaging permits vitreoretinal surgery for tissues that are not visible using operating microscopy ophthalmoscopy. Evolving instrumentation may overcome some limitations of current endoscopic technology.

Analysis

Transfer of the fine detail in endoscopic vitreoretinal images to extraocular video cameras is constrained currently by the caliber limitations of intraocular probes in ophthalmic surgery. Gradient index and Hopkins rod lenses provide high resolution ophthalmoscopy but restrict surgical manipulation. Fiberoptic coherent image guides offer surgical maneuverability but reduce imaging resolution. Coaxial endoscopic illumination can highlight delicate vitreoretinal structures difficult to image in chandelier or endoilluminator diffuse, side-scattered lighting. Microendoscopy’s ultra-high magnification video monitor images can reveal microscopic tissue details blurred partly by ocular media aberrations in contemporary surgical microscope ophthalmoscopy, thereby providing a lower resolution, invasive alternative to confocal fundus imaging. Endoscopic surgery is particularly useful when ocular media opacities or small pupils restrict or prevent transpupillary ophthalmoscopy. It has a growing spectrum of surgical uses that include the management of proliferative vitreoretinopathy and epiretinal membranes as well as the implantation of posterior chamber intraocular lenses and electrode arrays for intraretinal stimulation in retinitis pigmentosa. Microendoscopy’s range of applications will continue to grow with technological developments that include video microchip sensors, stereoscopic visualization, chromovitrectomy, digital image enhancement and operating room heads-up displays.

Conclusion

Microendoscopy is a robust platform for vitreoretinal surgery. Continuing clinical and technological innovation will help integrate it into the modern ophthalmic operating room of interconnected surgical microscopy, microendoscopy, vitrectomy machine and heads-up display instrumentation.

Proliferative Vitreoretinopathy: A Review

Proliferative vitreoretinopathy (PVR) is the most common cause for failure of rhegmatogenous retinal detachment repair and is characterized by the growth and contraction of cellular membranes within the vitreous cavity and on both sides of the retinal surface as well as intraretinal fibrosis. Currently, PVR is thought to be an abnormal wound healing response that is primarily driven by inflammatory, retinal, and RPE cells. At this time, surgery is the only management option for PVR as there is no proven pharmacologic agent for the treatment or prevention of PVR. Laboratory research to better understand PVR pathophysiology and clinical trials of various agents to prevent PVR formation are ongoing.

Endoscopy-assisted vitrectomy in the anterior vitreous

Endoscopy-assisted ocular surgery is a relatively old technique that is increasingly being recognized for its application in cases of vitreoretinal disease. This technique is especially useful when both the vitreous and retina are difficult to access because of media opacity, a small pupil, or a microcornea. In this context, the anterior vitreous is often difficult to dissect because of its complex pathological changes. This article reviews the common anatomical features and pathologies that are observed in the anterior vitreous, as well as the applications and indications of endoscopy-assisted vitrectomy in the anterior vitreous.

Combined pars plana vitrectomy-scleral buckle versus pars plana vitrectomy for proliferative vitreoretinopathy

The purpose of the study is to evaluate the surgical outcomes of combined pars plana vitrectomy-scleral buckle (PPV-SB) versus pars plana vitrectomy (PPV) for rhegmatogenous retinal detachment complicated with proliferative vitreoretinopathy (PVR). One thousand one hundred and seventy four patients with rhegmatogenous retinal detachment surgery between January 2002 and December 2013 were retrospectively reviewed. Patients with grade C PVR treated with either combined PPV-SB or PPV alone were included in the study. Study outcomes included single surgery anatomic success rate and postoperative visual outcome at 12 months postoperatively. Seventy-seven patients with grade C PVR were identified for analysis. At the end of 12-month follow-up, 80.5 % eyes (33/41) in the PPV-SB group and 58.3 % eyes (21/36) in the PPV group achieved single surgery anatomical success. In a multiple logistic regression model, none of the baseline variables (age, gender, macula status, grade of PVR, extent of detachment, presence of vitreous hemorrhage, lens status, status of high myopia) nor types of retinal detachment surgery (use of scleral buckle, barrier endolaser, 360 degree endolaser, cryopexy, retinectomy, tamponade agent, phacoemulsification) had significant effect on single surgery anatomical success. The post-treatment mean logMAR visual acuity of the PPV-SB group was 1.58 ± 0.58 and the PPV group was 1.57 ± 0.61. There was no significant difference in the postoperative visual acuity between the two groups (P = 0.849). For patients with grade C PVR, PPV-SB did not demonstrate a superiority over PPV alone in achieving single surgery anatomical success.

The use of endoscopic cyclophotocoagulation for moderate to advanced glaucoma

Endoscopic Cyclophotocoagulation (ECP) is a glaucoma surgery designed to reduce the intraocular pressure (IOP) by partially ablating the ciliary processes to decrease aqueous humour production and secretion. The aim of this paper is to review the literature regarding the background, indications and results of the surgery. Although there are case reports of visually devastating complications, including persistent hypotony and phthisis, the use of ECP is often reported in eyes with advanced diseases. When compared with both trabeculectomy and aqueous shunt implantation, the visual outcomes were better with ECP while the IOP outcomes were very similar. The evidence supports ECP as a very effective surgical option in recalcitrant glaucoma while some evidence supports its safety for use as a primary procedure.