Vitreous Wiping, a new technique for removal of vitreous cortex remnants during vitrectomy

Vitreoschisis-induced vitreous cortex remnants in proliferative vitreoretinopathy: A comprehensive review from basic research to clinical practice

Proliferative vitreoretinopathy (PVR) significantly impacts the prognosis of rhegmatogenous retinal detachment (RRD), one of the most critical and increasing causes of vision loss in the Western world. Despite advancements in surgical instruments and techniques, the failure rate due to PVR remains substantial, necessitating additional surgeries and often leading to unsatisfactory visual outcomes. This comprehensive review explores the role of vitreoschisis-induced vitreous cortex remnants (VCR) as a critical, previously under-recognised factor contributing to PVR. Vitreoschisis, a phenomenon where the inner lamellae of the posterior vitreous cortex detach while the outermost layers remain attached to the retina, creates VCR that may contain hyalocytes and serve as scaffolds for fibrocellular proliferation. These remnants are difficult to visualise without triamcinolone acetonide (TA) staining, leading to their frequent lack of recognition in clinical practice. Moreover, removing VCR can be challenging and time-consuming, often requiring meticulous surgical techniques to avoid retinal damage and ensure complete elimination. This review consolidates insights from basic research and clinical practice, emphasising the importance of complete vitreous removal and effective VCR detection and removal to mitigate PVR risks. It highlights the histopathological and clinical evidence supporting the hypothesis that VCR, containing hyalocytes, play a pivotal role in preretinal membrane formation. The review also discusses epidemiological data, surgical management strategies and potential future directions, including improved visualisation techniques and the development of new surgical tools and methods. This review aims to improve surgical outcomes and reduce the frequency and burden of RRD-related complications by addressing VCR as a critical factor in PVR.

Vitreous Cortex Remnants Removal With Beveled Vitrectomy Probe During Vitrectomy For Primary Rhegmatogenous Retinal Detachment

PURPOSE

To introduce a new surgical technique with a beveled vitrectomy probe for the removal of peripheral vitreous cortex remnants (VCR) in primary rhegmatogenous retinal detachment (RRD).

METHODS

This study was a retrospective case series. From September 2019 to June 2022, 54 patients with complete or partial posterior vitreous detachment who underwent vitrectomy for primary RRD by a single surgeon were enrolled.

RESULTS

After staining the vitreous with triamcinolone acetonide, the presence of VCR was assessed in detail. If VCR were present, the macular VCR were removed using surgical forceps, and then, a free flap of peripheral VCR was used as a handle for removing peripheral VCR using the beveled vitrectomy probe. Of the total patients, the presence of VCR was confirmed in 16 patients (29.6%). There were no intraoperative or postoperative complications, except for retinal redetachment caused by proliferative vitreoretinopathy, that occurred in only one eye (1.9%).

CONCLUSION

Using a beveled vitrectomy probe was a practical solution for removing VCR during RRD vitrectomy because additional instruments were not needed and risk of iatrogenic retinal damage was low.

Development of in situ crosslinked hyaluronan as an adjunct to vitrectomy surgery

Ophthalmologists have used hyaluronan (HA) products as adjuncts to ocular surgery since the 1970s. However, HA products are not always functional in surgeries of the posterior eye segment due to their lack of biomechanical strength. In this study, we developed an in situ crosslinked HA (XL-HA) and evaluated its potential as an adjunct to vitrectomy surgery in an in vitro model with a triamcinolone acetonide (TA) layer used as a pseudo residual vitreous cortex (RVC). Within a few minutes at concentrations over 0.9%, XL-HA, generated by the click chemistry of HA-dibenzocyclooctyne and HA-azidoethylamine, formed a hydrogel with the appropriate hardness for tweezers peeling. XL-HA (concentration, 0.76-1.73%) without dispersion successfully entered the TA layer and removed more than 45% of the total TA. Dynamic viscoelasticity helps to explain the rheological behavior of hydrogels, and the assessment results for XL-HA indicated that suitable concentrations were between 0.97% and 1.30%. For example, 1.30% XL-HA hydrogel reached sufficient hardness at 3 min for tweezers peeling, and the TA removal ability exceeded 70%. These results demonstrated that XL-HA was a potential adjunct to successful vitrectomy.

Surgical technique for removing vitreous cortex remnants using a diamond-dusted membrane scraper

PURPOSE

The purpose of this paper is to present a new surgical technique to remove vitreous cortex remnants.

METHODS

Non-consecutive retrospective interventional case series.

RESULTS

When the posterior vitreous is split, its outermost layer may remain attached to the retina, developing vitreoschisis-induced vitreous cortex remnants (VCR). Their role in macular pathology etiopathogenesis has been well documented; however, recently, it has been proposed that VCR also play a crucial role in proliferative vitreoretinopathy and consequent retinal redetachment. The prevalence of VCR is underestimated because triamcinolone acetonide is not routinely used for vitreous staining. Vitreous cortex remnants (VCR) removal is challenging, and several surgical techniques have been proposed. However, they require sclerotomy enlargement, material that may not be readily available, and manual fashioning. Alternatively, a diamond-dusted membrane scraper (DDMS), already widely used in macular pathology treatment, can follow the contour of the retina, as it is a silicone tube, and remove VCR with its abrasive tip. A DDMS may also be introduced in the vitreous cavity through a standard trocar. Finally, the use of a DDMS provides predictable feedback, making the learning curve short. In this case series, 34 eyes affected by primary rhegmatogenous retinal detachment were enrolled. The retinal redetachment rate was 2.9% at six months of follow-up, below the average literature value of 21%. No adverse events were reported.

CONCLUSION

A DDMS can be suitable for use in VCR removal, although further studies are warranted to understand the indications and extent of this surgical technique for improving the management of rhegmatogenous retinal detachment.

Comparison of 3D Digitally Assisted Visualization System with Current Standard Visualization for the Removal of Vitreous in a Preclinical Model

Purpose

Novel 3D digital display systems, such as NGENUITY 3D digitally assisted visualization system (DAVS), can provide enhanced illumination, depth of field, and digital filtering. This study compared vitreous removal using NGENUITY 3D DAVS with a standard surgical microscope.

Methods

This was an in vivo, 2-arm laboratory study in 15 Yorkshire pig eyes. The LuxOR LX3 microscope with NGENUITY 3D DAVS (arm 1) and the LuxOR LX3 microscope alone (arm 2) were used with 5× optical magnification and Oculus BIOM 200 mm optics. Standard core and peripheral vitrectomy without scleral depression was performed using the CONSTELLATION Vision System. Residual vitreous weight was assessed in enucleated eyes by a masked observer. Axial length and vitreous weight of contralateral eyes were compared from an additional 14 Yorkshire pigs to confirm that eyes from a single animal were essentially identical.

Results

After vitrectomy, mean ± SD residual vitreous was significantly smaller with NGENUITY versus standard microscope (0.143 ± 0.146 versus 0.580 ± 0.269 g, respectively; P < 0.0001). Based on a mean initial vitreous weight of 2.5 g, as determined by assessment in contralateral eyes from an additional 14 Yorkshire pigs, the mean percentage vitreous removal was 94% ± 6% versus 77% ± 11%, respectively. Further, vitreous weight and axial length for contralateral eyes from any single animal in these additional 14 animals were essentially identical, as mean differences were 0.046 ± 0.035 g and 0.11 ± 0.08 mm, respectively.

Conclusion

Vitrectomy with NGENUITY 3D DAVS resulted in significantly less residual vitreous in pig eyes compared with standard microscopy. NGENUITY may improve vitreous removal during vitreoretinal surgery by enhancing visualization.

Surgery for Combined Hamartoma of the Retina and Retinal Pigment Epithelium

There is no consensus on whether and when surgical treatment is indicated for combined hamartoma of the retina and retinal pigment epithelium (CHRRPE). We aim to discuss the benefits of surgical intervention and techniques that may improve the outcome. A 24-year-old man experienced progressive visual loss for 6 months in his left eye due to CHRRPE. At presentation, visual acuity was 1.3 LogMAR and fundoscopy revealed extensive tractional pre- and epiretinal membranes, subretinal exudation, and a vasoproliferative tumor in the inferior periphery. A complete vitrectomy was performed, while paying special attention to vitreous shaving at the vitreous base and removal of vitreoschisis-induced vitreous cortex remnants (VCR) from the retinal surface posterior to the vitreous base. Tractional membranes and internal limiting membrane were peeled, and the vasoproliferative tumor was excised. Silicone oil tamponade was removed 11 weeks after surgery. No intra- or postoperative complications occurred. Visual acuity improved to 0.8 LogMAR and remained stable for 48-month follow-up. Vitreoretinal surgery can prevent complications that occur with CHRRPE. In addition, visual function may improve even if the initial visual acuity is low. Timely and complete vitrectomy with extensive membranectomy and detection and removal of VCR is recommended to avoid complications in challenging CHRRPE.

The role of vitreous cortex remnants in proliferative vitreoretinopathy formation demonstrated by histopathology: A case report

Purpose

The pathogenesis of proliferative vitreoretinopathy (PVR), the most important cause of retinal detachment surgery failure, is still not fully understood. We previously hypothesized a causal link between vitreoschisis-induced vitreous cortex remnants (VCR) and PVR formation. The purpose of this case report is to demonstrate this association by showing the clinical occurrence of PVR in the presence of VCR across the retinal surface, illustrated by histopathological analysis.

Observations

A 69-year-old male was referred because of widespread epiretinal membrane formation after treatment of recurrent retinal detachments. During surgery with extensive membrane peeling, a large continuous membrane was peeled from the superior arcade towards the inferior temporal mid-periphery. Histopathological analysis of this membrane revealed areas with different characteristics: paucicellular laminar collagen-rich areas, suggestive for VCR, areas with increased cellularity, and more fibrotic areas with low cellularity.

The immunohistochemical analysis identified cell type variety in these areas: collagen-rich areas showed glial cells and hyalocytes, while in areas with high cellularity fibroblasts, macrophages and retinal pigment epithelial cells were found, which have previously been shown to play an important role in the development of PVR as they can transdifferentiate into myofibroblasts, which were seen in the more fibrotic areas.

Conclusions and importance

These findings support the theory that VCR have a role in PVR development, where VCR can act as a scaffold for fibrocellular proliferation. We suggest that the presence of VCR over the retinal surface should be qualified as a risk factor for PVR formation. Detection and adequate removal of VCR may improve the success rate of retinal detachment surgery.

The Effect of Internal Limiting Membrane Cleaning on Epiretinal Membrane Formation after Vitrectomy for Proliferative Diabetic Retinopathy

PURPOSE

We hypothesised that cleaning the internal limiting membrane (ILM) with a flexible nitinol loop following diabetic vitrectomy without peeling may reduce the common occurrence of postoperative epiretinal membrane (ERM) formation.

METHODS

Consecutive patients undergoing vitrectomy for proliferative diabetic retinopathy by one surgeon from 2015 to 2019 were studied and divided into 2 cohorts: the control group underwent standard surgery, and the ILM clean group underwent additional cleaning of the macular retina using a flexible nitinol loop after vitrectomy. Masked comparison of ERM on optical coherence tomography was performed at 3 months, and visual acuity (VA) was measured until 12 months postoperatively.

RESULTS

Baseline demographics, clinical features, and protein levels were similar between cohorts. The ILM clean group (n = 56) had fewer clinically significant ERM than the control group (n = 50; 4 vs. 20%; p = 0.01), and a significantly lower proportion of the ILM clean group required revision surgery (2 vs. 14%; p = 0.02). VA in the ILM clean group was significantly better than in the control group at 3 months (0.35 vs. 0.50 logMAR; p = 0.02) but not at 12 months (0.34 vs. 0.43 logMAR; p = 0.17).

CONCLUSION

ILM cleaning with a flexible nitinol loop following diabetic vitrectomy resulted in significant reduction in ERM formation and reduced necessity for revision surgery. There was significant improvement in VA at 3 months but not over a longer follow-up.