Microplasmin (ocriplasmin) in pediatric vitreoretinal surgery: update and review

Combined brachytherapy and vitreoretinal surgery for a large retinal capillary hemangioma with exudative retinal detachment

Introduction:

We report about a large retinal capillary hemangioma (RCH) with exudative retinal detachment and a macular fold, treated with Ruthenium-106 brachytherapy (Ru-106 BT) and scleral buckling surgery, followed by pars plana vitrectomy (PPV), for the removal of macular tractions.

Case description:

A 17-year-old boy was referred to our Ocular Oncology Unit for a large RCH in the left eye. BCVA was hand motion. The RCH measured 4.9 × 6.85 mm in basal diameters and 4.0 mm in thickness and was located in the mid-peripheral temporal retina. It was surrounded by extensive subretinal exudation, forming an exudative retinal detachment, with a retinal fold that extended from the lesion to the optic disc. We performed Ru-106 BT and at the moment of the plaque removal we placed a radial buckle with the aim to unbend the retinal fold. At 3-months follow-up the exudation decreased, we achieved the opening of the peripheral side of the retinal fold, but the macula was still detached. We decided to perform a lens sparing PPV, macular peeling and air tamponade, to remove the vitreoretinal tractions ab interno and to try to complete the opening of the macular fold. After 1-month BCVA was counting fingers, the retina appeared attached, also in the macular area, but the retinal fold remained partially close in the macular side. After 6 months the tumor was inactivated, the macula remained attached, unfortunately, the macular fold remained partially close.

Conclusion:

Ru-106 BT and scleral buckling concurrent approach can be an effective treatment modality in selected cases of large RCHs, followed by PPV to remove eventual vitreo-retinal tractions.

Spontaneous Attachment of Rhegmatogenous Retinal Detachment Following Vitrectomy for Stage 4B Retinopathy of Prematurity and Atypical Retinal Changes Post-Resolution

A prematurely born baby underwent lens-sparing vitrectomy for Stage 4B retinopathy of prematurity (ROP) in the left eye. This child had a stormy neonatal course, referred late, and was treated with intravitreal anti-vascular endothelial growth factor and laser in both eyes in the past. The surgery was uneventful, and the retina was attached until a month after surgery. Later, there was development of a break that led to the occurrence of rhegmatogenous retinal detachment in the operated eye. The retinal detachment increased with time during the course of 6 weeks. Surprisingly, the hole disappeared with spontaneous attachment of retina in the following weeks, with multiple depigmented spots over the posterior pole. [Ophthalmic Surg Lasers Imaging Retina. 2018;49:544-547.].

Congenital X-Linked Retinoschisis: An Updated Clinical Review

We present an updated clinical review of the pathophysiology, progression, and current treatments in pediatric patients with congenital X-linked retinoschisis (CXLRS). CXLRS is an X-linked inherited retinal degeneration characterized by splitting of the superficial layers of the retina. Most recent classification divides CXLRS into 4 distinct clinical phenotypes: type 1, foveal; type 2, foveolamellar; type 3, complex; and type 4, foveoperipheral. The majority of retinoschisis cavities remain stable throughout life and may spontaneously collapse. However, a select number of patients progress to macula-involving peripheral retinoschisis, rhegmatogenous, and combined tractional-rhegmatogenous detachments that require further intervention. Although several advances have been made over the past several decades, medical therapy remains limited to case series‒based carbonic anhydrase therapy and prophylactic laser retinopexy. Recent advances in genetic-based clinical trials with the retinoschisis gene are promising. Vitreoretinal surgical approaches remain complex, case-based, and require careful planning depending on the configuration and location of the retinoschisis cavity.

Plasmin Enzyme-Assisted Vitrectomy in Pediatric Patients with Vitreoretinal Diseases

PURPOSE

To evaluate the efficacy and safety of using plasmin-assisted vitrectomy in pediatric patients with vitreoretinal diseases.

METHODS

We prospectively recruited children aged 16 years or younger who presented with vitreoretinopathies and underwent plasmin-assisted vitrectomy between 2012 and 2013. The main outcome measure was the induction of posterior vitreous detachment (PVD) using a suction power of 200 mm Hg or less during surgery.

RESULTS

Eleven eyes of 11 patients (mean age: 3.7 years; average follow-up duration: 14.1 months) were included. Of these 11 patients, there were 3 (27%) cases of stage 5 retinopathy of prematurity, 2 (18%) cases of persistent fetal vasculature, 2 (18%) cases of rhegmatogenous retinal detachment, 2 (18%) cases of idiopathic epiretinal membrane, 1 (9%) case of traumatic macular pucker, and 1 (9%) case of traumatic vitreous hemorrhage (9%). PVD was achieved in all cases (100%) during surgery using low suction after plasmin treatment (mean: 150 ± 39 mm Hg; range: 100-200). Overall, anatomical success was achieved in 8 eyes (73%). Visual acuity improved in all 5 (100%) patients for whom vision could be measured at 6 months after the operation. Cataracts were found in 4 eyes (36%), and a rise in transient intraocular pressure was observed in 1 eye (9%).

CONCLUSIONS

Plasmin-assisted vitrectomy offers an effective and less traumatic intervention for a variety of pediatric vitreoretinal diseases.

From the analysis of pharmacologic vitreolysis to the comprehension of ocriplasmin safety

INTRODUCTION

Pharmacologic vitreolysis is a strategy used to treat anomalous posterior vitreous detachment, by weakening vitreoretinal adhesion with an intravitreal drug. Pharmacologic vitreolysis facilitates surgery, and abnormalities of the vitreoretinal interface including vitreomacular traction (VMT) and early stage macular hole (MH) could be resolved. Ocriplasmin is a recombinant protease, active against fibronectin and laminin, which are important components of the vitreoretinal interface. Ocriplasmin has been approved for symptomatic treatment of VMT and MH with visible traction, and it functions by dissolving the proteins that link the vitreous to the macula, thereby creating a complete posterior vitreous detachment (PVD).

AREAS COVERED

This paper reviews the current knowledge and status of investigations regarding the use of ocriplasmin for pharmacologic vitreolysis and its safety.

EXPERT OPINION

Ocriplasmin is a non-specific enzyme; therefore, it dissolves vitreal proteins as well as possibly proteins associated with visual function in the retina, choroid, and lens. Ocular adverse events (OAEs) of ocriplasmin include transient visual loss, intraocular inflammation, vitreous floaters, lens opacification, zonular instability of the lens, and intraocular hemorrhage. The prevalence of the OAEs is very low; however, on rare occasions, they can result in widespread retinal dysfunction. Research into the acute and long-term safety of ocriplasmin is required.

Pharmacotherapies for Retinal Detachment

Retinal detachment is an important cause of visual loss. Currently, surgical techniques, including vitrectomy, scleral buckle, and pneumatic retinopexy, are the only means to repair retinal detachment and restore vision. However, surgical failure rates may be as high as 20%, and visual outcomes continue to vary secondary to multiple processes, including postoperative cystoid macular edema, epiretinal membrane formation, macular folds, and, ultimately, photoreceptor death. Therefore, pharmacotherapies are being sought to aid the success rates of modern surgical techniques and reduce or slow the degeneration of photoreceptors during retinal detachment. This review discusses potential therapeutic avenues that aid in retinal reattachment, reduce the rate of retinal redetachment by limiting proliferative vitreoretinopathy, and protect against photoreceptor cell death.

Ocriplasmin: who is the best candidate?

Enzymatic vitreolysis is currently the focus of attention around the world for treating vitreomacular traction and full-thickness macular hole. Induction of posterior vitreous detachment is an active area of developmental clinical and basic research. Despite exerting an incompletely elucidated physiological effect, ocriplasmin (also known as microplasmin) has been recognized to serve as a well-tolerated intravitreal injection for the treatment of vitreomacular traction and full-thickness macular hole. There are several unexplored areas of intervention where enzymatic vitreolysis could potentially be used (ie, diabetic macular edema). Recent promising studies have included combinations of enzymatic approaches and new synthetic molecules that induce complete posterior vitreous detachment as well as antiangiogenesis. Although no guidelines have been proposed for the use of ocriplasmin, this review attempts to aid physicians in answering the most important question, "Who is the best candidate?"

Profile of ocriplasmin and its potential in the treatment of vitreomacular adhesion

The recent approval by the US Food and Drug Administration of ocriplasmin for the treatment of symptomatic vitreomacular adhesion (VMA), often associated with vitreomacular traction (VMT) and macular hole (MH), has brought new attention to the field of pharmacologic vitreolysis. The need for an enzyme to split the vitreomacular interface, which is formed by a strong adhesive interaction between the posterior vitreous cortex and the internal limiting membrane, historically stems from pediatric eye surgery. This review summarizes the different anatomic classifications of posterior vitreous detachment or anomalous posterior vitreous detachment and puts these in the context of clinical pathologies commonly observed in clinical practice of the vitreoretinal specialist, such as MH, VMT, age-related macular degeneration, and diabetic macular edema. We revisit the outcome of the Phase II studies that indicated ocriplasmin was a safe and effective treatment for selected cases of symptomatic VMA and MH. Release of VMA at day 28 was achieved by 26.5% of patients in the ocriplasmin group versus 10.1% in the placebo group (P<0.001). Interestingly, for MHs, the numbers were more remarkable. Predictive factors for successful ocriplasmin treatment were identified for VMT (VMA diameter smaller than 1,500 μm) and MH (smaller than 250 μm). In comparison with the highly predictable outcome after vitrectomy, the general success rate of ocriplasmin not under clinical trial conditions has not fully met expectations and needs to be proven in real-world clinical settings. The ocriplasmin data will be compared in the future with observational data on spontaneous VMA release, will help retina specialists make more accurate predictions, and will improve outcome rates.

Ocriplasmin for symptomatic vitreomacular adhesion: an evidence-based review of its potential

Vitreomacular traction is a multicategory entity that may cause substantial visual loss due to the formation of a macular hole or traction-induced tissue distortion. The advent of optical coherent tomography (OCT) has demonstrated the anatomic features of persistent vitreomacular attachment (VMA) more definitively, including in many asymptomatic or minimally symptomatic patients. The indications for intervention are unclear, since it is not possible to predict which eyes might be likely to develop progressive visual loss. This has been especially important since for many years, the only treatment option involved surgical intervention (vitrectomy) to release the persistent VMA. Recently, a pharmacolytic agent, ocriplasmin, has become available after many years of development and investigation, and may offer a feasible alternative to surgery, or even a risk/benefit ratio sufficiently favorable to offer intervention at an earlier stage of VMA. Several studies, including a large, prospective clinical trial, have established the foundation of its rationale and efficacy, providing the basis of its approval. The role for ocriplasmin in clinical practice is in the process of being determined. This paper summarizes current knowledge and status of investigations regarding ocriplasmin-induced pharmacologic vitreolysis, and offers some evidence-based considerations for its use.